2010 |
Stadler, Adrian-Mihail ; Ramirez, Juan ; Lehn, Jean-Marie Control of Relative Direction and Amplitude in Extension/Contraction Motions of Molecular Strands Induced by Ion Binding Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 16 (18), pp. 5369–5378, 2010, ISSN: 0947-6539. @article{stadler_control_2010, title = {Control of Relative Direction and Amplitude in Extension/Contraction Motions of Molecular Strands Induced by Ion Binding}, author = {Stadler, Adrian-Mihail and Ramirez, Juan and Lehn, Jean-Marie}, doi = {10.1002/chem.200902764}, issn = {0947-6539}, year = {2010}, date = {2010-01-01}, journal = {CHEMISTRY-A EUROPEAN JOURNAL}, volume = {16}, number = {18}, pages = {5369--5378}, abstract = {The shape of ligand strands composed of six-membered aza-heterocycles (het) connected at the alpha and alpha' positions by hydrazone (hyz) units is determined in a predictable fashion by the nature of the heterocyclic groups (pyridine, pyrimidine, pyrazine etc.), and covers the range from extended linear to compact helical structures. The binding of metal ions to the coordination subunits, defined by the het-hyz sequences, leads to marked shape changes by inter-converting bent and linear conformations of the subunits, thus inducing relative motions of strand domains either in the same (con-sense, “twirling”) or in opposite (dis-sense, “flapping”) directions. The amplitude of the motion induced by metal-ion binding and release and the relative directions of the formal motions can be controlled by the nature of the heterocyclic units. Thus, motions around a, central 4,6-disubstituted pyrimidine are dis-sense motions, whereas there are con-sense motions around a central 2,5-disubstituted pyrazine unit, as illustrated by model ligands 1 and 2. respectively. The more extended helical 3 and undulating (zigzag shape) 4 ligands undergo larger-amplitude motions combining the relative displacements displayed by 1 and 2. Ligands 3 and 4 form linear tetranuclear Pb-II and Zn-II complexes, thus producing an extension motion. The same holds for [Ru(4)(terpy)(4)](PF6)(8) (terpy = terpyridine). Reversible acid-base-triggered molecular motions have been generated with [Zn-4(4)(OTf)(8)] (TfOH=triflic acid).}, keywords = {}, pubstate = {published}, tppubtype = {article} } The shape of ligand strands composed of six-membered aza-heterocycles (het) connected at the alpha and alpha' positions by hydrazone (hyz) units is determined in a predictable fashion by the nature of the heterocyclic groups (pyridine, pyrimidine, pyrazine etc.), and covers the range from extended linear to compact helical structures. The binding of metal ions to the coordination subunits, defined by the het-hyz sequences, leads to marked shape changes by inter-converting bent and linear conformations of the subunits, thus inducing relative motions of strand domains either in the same (con-sense, “twirling”) or in opposite (dis-sense, “flapping”) directions. The amplitude of the motion induced by metal-ion binding and release and the relative directions of the formal motions can be controlled by the nature of the heterocyclic units. Thus, motions around a, central 4,6-disubstituted pyrimidine are dis-sense motions, whereas there are con-sense motions around a central 2,5-disubstituted pyrazine unit, as illustrated by model ligands 1 and 2. respectively. The more extended helical 3 and undulating (zigzag shape) 4 ligands undergo larger-amplitude motions combining the relative displacements displayed by 1 and 2. Ligands 3 and 4 form linear tetranuclear Pb-II and Zn-II complexes, thus producing an extension motion. The same holds for [Ru(4)(terpy)(4)](PF6)(8) (terpy = terpyridine). Reversible acid-base-triggered molecular motions have been generated with [Zn-4(4)(OTf)(8)] (TfOH=triflic acid). |
Stadler, Adrian-Mihail ; Puntoriero, Fausto ; Nastasi, Francesco ; Campagna, Sebastiano ; Lehn, Jean-Marie Ru-II Multinuclear Metallosupramolecular Rack-Type Architectures of Polytopic Hydrazone-Based Ligands: Synthesis, Structural Features, Absorption Spectra, Redox Behavior, and Near-Infrared Luminescence Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 16 (19), pp. 5645–5660, 2010, ISSN: 0947-6539. @article{stadler_ru-ii_2010, title = {Ru-II Multinuclear Metallosupramolecular Rack-Type Architectures of Polytopic Hydrazone-Based Ligands: Synthesis, Structural Features, Absorption Spectra, Redox Behavior, and Near-Infrared Luminescence}, author = {Stadler, Adrian-Mihail and Puntoriero, Fausto and Nastasi, Francesco and Campagna, Sebastiano and Lehn, Jean-Marie}, doi = {10.1002/chem.200900632}, issn = {0947-6539}, year = {2010}, date = {2010-01-01}, journal = {CHEMISTRY-A EUROPEAN JOURNAL}, volume = {16}, number = {19}, pages = {5645--5660}, abstract = {A novel class of polytopic hydrazone-based ligands was synthesized. They gave heteroleptic Run polynuclear rack-like complexes of formula [Ru(n)terpy(n)(bridging molecular strand)](2n+) (terpy =2,2':6',2 `'-terpyridine). The new rack-like systems can be viewed as being made of two identical or roughly identical peripheral subunits separated by several similar metal-containing spacer subunits. The presence of pyrazine or pyrimidine units within the molecular multitopic strands introduces additional chemical diversity: whereas a pyrimidine unit leads to appended orthogonal subunits that are on the same side with regard to the main molecular strand, a pyrazine unit leads to orthogonal subunits that lie on different sides. Mixing pyrazine and pyrimidine units within the same (bridging) molecular strand also allows peculiar and topographically controlled geometries to be obtained. Redox studies provided evidence that each species undergoes reversible redox processes at mild potentials, which can be assigned to specific subunits of the multicomponent arrays. Non-negligible electronic coupling takes place among the various subunits, and some electron delocalization extending over the overall bridging molecular strand takes place. In particular, oxidation data suggest that the systems can behave as p-type “molecular wires” and reduction data indicate that n-type electron conduction can occur within the multimetallic framework. All the multinuclear racks exhibit (MLCT)-M-3 emission, both at 77 K in rigid matrix and at 298 K in fluid solution, which takes place in the near-infrared region (emission maxima in the 1000-1100 nm region), and is quite structured. Rigidity of the molecular structures and delocalization within the large bridging ligands are proposed to contribute to the occurrence of the rather uncommon MLCT infrared emission, which is potentially interesting for optical communication devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A novel class of polytopic hydrazone-based ligands was synthesized. They gave heteroleptic Run polynuclear rack-like complexes of formula [Ru(n)terpy(n)(bridging molecular strand)](2n+) (terpy =2,2':6',2 `'-terpyridine). The new rack-like systems can be viewed as being made of two identical or roughly identical peripheral subunits separated by several similar metal-containing spacer subunits. The presence of pyrazine or pyrimidine units within the molecular multitopic strands introduces additional chemical diversity: whereas a pyrimidine unit leads to appended orthogonal subunits that are on the same side with regard to the main molecular strand, a pyrazine unit leads to orthogonal subunits that lie on different sides. Mixing pyrazine and pyrimidine units within the same (bridging) molecular strand also allows peculiar and topographically controlled geometries to be obtained. Redox studies provided evidence that each species undergoes reversible redox processes at mild potentials, which can be assigned to specific subunits of the multicomponent arrays. Non-negligible electronic coupling takes place among the various subunits, and some electron delocalization extending over the overall bridging molecular strand takes place. In particular, oxidation data suggest that the systems can behave as p-type “molecular wires” and reduction data indicate that n-type electron conduction can occur within the multimetallic framework. All the multinuclear racks exhibit (MLCT)-M-3 emission, both at 77 K in rigid matrix and at 298 K in fluid solution, which takes place in the near-infrared region (emission maxima in the 1000-1100 nm region), and is quite structured. Rigidity of the molecular structures and delocalization within the large bridging ligands are proposed to contribute to the occurrence of the rather uncommon MLCT infrared emission, which is potentially interesting for optical communication devices. |
Galeazzi, Simone ; Hermans, Thomas M; Paolino, Marco ; Anzini, Maurizio ; Mennuni, Laura ; Giordani, Antonio ; Caselli, Gianfranco ; Makovec, Francesco ; Meijer, E W; Vomero, Salvatore ; Cappelli, Andrea Multivalent Supramolecular Dendrimer-Based Drugs Journal Article In: BIOMACROMOLECULES, 11 (1), pp. 182–186, 2010, ISSN: 1525-7797. @article{galeazzi_multivalent_2010, title = {Multivalent Supramolecular Dendrimer-Based Drugs}, author = {Galeazzi, Simone and Hermans, Thomas M. and Paolino, Marco and Anzini, Maurizio and Mennuni, Laura and Giordani, Antonio and Caselli, Gianfranco and Makovec, Francesco and Meijer, E. W. and Vomero, Salvatore and Cappelli, Andrea}, doi = {10.1021/bm901055a}, issn = {1525-7797}, year = {2010}, date = {2010-01-01}, journal = {BIOMACROMOLECULES}, volume = {11}, number = {1}, pages = {182--186}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Chouikhi, Dalila ; Barluenga, Sofia ; Winssinger, Nicolas Clickable peptide nucleic acids (cPNA) with tunable affinity Journal Article In: CHEMICAL COMMUNICATIONS, 46 (30), pp. 5476–5478, 2010, ISSN: 1359-7345. @article{chouikhi_clickable_2010, title = {Clickable peptide nucleic acids (cPNA) with tunable affinity}, author = {Chouikhi, Dalila and Barluenga, Sofia and Winssinger, Nicolas}, doi = {10.1039/c0cc01081b}, issn = {1359-7345}, year = {2010}, date = {2010-01-01}, journal = {CHEMICAL COMMUNICATIONS}, volume = {46}, number = {30}, pages = {5476--5478}, abstract = {Peptide nucleic acids (PNAs) are functional analogues of natural oligonucleotides. Herein, we report the synthesis of PNAs bearing a triazole in lieu of the amide bond assembled using a “click” cycloaddition, their hybridization properties as well as the DNA-templated coupling of the azide and alkyne PNA fragments.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Peptide nucleic acids (PNAs) are functional analogues of natural oligonucleotides. Herein, we report the synthesis of PNAs bearing a triazole in lieu of the amide bond assembled using a “click” cycloaddition, their hybridization properties as well as the DNA-templated coupling of the azide and alkyne PNA fragments. |
Eckes, Fabrice ; Bulach, Veronique ; Guenet, Aurelie ; Strassert, Cristian A; De Cola, Luisa ; Hosseini, Mir Wais Sensitization of the NIR emission of Nd(III) by the alpha 4 atropoisomer of a meso-tetraphenyl porphyrin bearing four 8-hydroxyquinolinylamide chelates Journal Article In: CHEMICAL COMMUNICATIONS, 46 (4), pp. 619–621, 2010, ISSN: 1359-7345. @article{eckes_sensitization_2010, title = {Sensitization of the NIR emission of Nd(III) by the alpha 4 atropoisomer of a meso-tetraphenyl porphyrin bearing four 8-hydroxyquinolinylamide chelates}, author = {Eckes, Fabrice and Bulach, Veronique and Guenet, Aurelie and Strassert, Cristian A. and De Cola, Luisa and Hosseini, Mir Wais}, doi = {10.1039/b920676k}, issn = {1359-7345}, year = {2010}, date = {2010-01-01}, journal = {CHEMICAL COMMUNICATIONS}, volume = {46}, number = {4}, pages = {619--621}, abstract = {The alpha 4 atropoisomer of the meso tetrakis 8-hydroxyquinolinylamide porphyrin and its Pd complex binds Nd(III) and sensitizes efficiently its near infrared (NIR) emission when excited in the visible domain.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The alpha 4 atropoisomer of the meso tetrakis 8-hydroxyquinolinylamide porphyrin and its Pd complex binds Nd(III) and sensitizes efficiently its near infrared (NIR) emission when excited in the visible domain. |
Gorska, Katarzyna ; Beyrath, Julien ; Fournel, Sylvie ; Guichard, Gilles ; Winssinger, Nicolas Ligand dimerization programmed by hybridization to study multimeric ligand-receptor interactions Journal Article In: CHEMICAL COMMUNICATIONS, 46 (41), pp. 7742–7744, 2010, ISSN: 1359-7345. @article{gorska_ligand_2010, title = {Ligand dimerization programmed by hybridization to study multimeric ligand-receptor interactions}, author = {Gorska, Katarzyna and Beyrath, Julien and Fournel, Sylvie and Guichard, Gilles and Winssinger, Nicolas}, doi = {10.1039/c0cc02852e}, issn = {1359-7345}, year = {2010}, date = {2010-01-01}, journal = {CHEMICAL COMMUNICATIONS}, volume = {46}, number = {41}, pages = {7742--7744}, abstract = {Oligomerization of receptors induced or stabilized by polyvalent ligands is a fundamental mechanism in cellular recognition and signal transduction. Herein we report a general approach to encode complex peptide macrocycles with peptide nucleic acid (PNA) tags and program their oligomerization through hybridization as exemplified with a ligand binding to oligomeric DR5, a receptor of TRAIL cytokine.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Oligomerization of receptors induced or stabilized by polyvalent ligands is a fundamental mechanism in cellular recognition and signal transduction. Herein we report a general approach to encode complex peptide macrocycles with peptide nucleic acid (PNA) tags and program their oligomerization through hybridization as exemplified with a ligand binding to oligomeric DR5, a receptor of TRAIL cytokine. |
Bronner, Catherine ; Baudron, Stephane A; Hosseini, Mir Wais ; Strassert, Cristian A; Guenet, Aurelie ; De Cola, Luisa Dipyrrin based luminescent cyclometallated palladium and platinum complexes Journal Article In: DALTON TRANSACTIONS, 39 (1), pp. 180–184, 2010, ISSN: 1477-9226. @article{bronner_dipyrrin_2010, title = {Dipyrrin based luminescent cyclometallated palladium and platinum complexes}, author = {Bronner, Catherine and Baudron, Stephane A. and Hosseini, Mir Wais and Strassert, Cristian A. and Guenet, Aurelie and De Cola, Luisa}, doi = {10.1039/b908424j}, issn = {1477-9226}, year = {2010}, date = {2010-01-01}, journal = {DALTON TRANSACTIONS}, volume = {39}, number = {1}, pages = {180--184}, abstract = {A series of complexes based on the combination of cyclometallated palladium or platinum moieties with functionalized dipyrrin ligands bearing mesityl- or benzonitrile groups have been prepared and characterized both in the solid state and in solution; these compounds exhibit a characteristic dipyrrin-centered luminescence with an emission intensity modulated by the degree of rotational freedom of the aromatic group attached to the dipyrrin chelate.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A series of complexes based on the combination of cyclometallated palladium or platinum moieties with functionalized dipyrrin ligands bearing mesityl- or benzonitrile groups have been prepared and characterized both in the solid state and in solution; these compounds exhibit a characteristic dipyrrin-centered luminescence with an emission intensity modulated by the degree of rotational freedom of the aromatic group attached to the dipyrrin chelate. |
Garcia, Jose ; Barluenga, Sofia ; Beebe, Kristin ; Neckers, Len ; Winssinger, Nicolas Concise Modular Asymmetric Synthesis of Deguelin, Tephrosin and Investigation into Their Mode of Action Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 16 (32), pp. 9767–9771, 2010, ISSN: 0947-6539. @article{garcia_concise_2010, title = {Concise Modular Asymmetric Synthesis of Deguelin, Tephrosin and Investigation into Their Mode of Action}, author = {Garcia, Jose and Barluenga, Sofia and Beebe, Kristin and Neckers, Len and Winssinger, Nicolas}, doi = {10.1002/chem.201001080}, issn = {0947-6539}, year = {2010}, date = {2010-01-01}, journal = {CHEMISTRY-A EUROPEAN JOURNAL}, volume = {16}, number = {32}, pages = {9767--9771}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Jager, Michael ; Smeigh, Amanda ; Lombeck, Florian ; Gorls, Helmar ; Collin, Jean-Paul ; Sauvage, Jean-Pierre ; Hammarstrom, Leif ; Johansson, Olof Cyclometalated Ru-II Complexes with Improved Octahedral Geometry: Synthesis and Photophysical Properties Journal Article In: INORGANIC CHEMISTRY, 49 (2), pp. 374–376, 2010, ISSN: 0020-1669. @article{jager_cyclometalated_2010, title = {Cyclometalated Ru-II Complexes with Improved Octahedral Geometry: Synthesis and Photophysical Properties}, author = {Jager, Michael and Smeigh, Amanda and Lombeck, Florian and Gorls, Helmar and Collin, Jean-Paul and Sauvage, Jean-Pierre and Hammarstrom, Leif and Johansson, Olof}, doi = {10.1021/ic9020788}, issn = {0020-1669}, year = {2010}, date = {2010-01-01}, journal = {INORGANIC CHEMISTRY}, volume = {49}, number = {2}, pages = {374--376}, abstract = {Cyclometalated bis-tridentate ruthenium(II) complexes incorporating 2,6-diquinolin-8-ylpyridine ligands and exhibiting broad visible absorptions are described. A [Ru(N boolean AND N boolean AND N)(N boolean AND C boolean AND N)](+) complex based only on ligands with expanded bite angles has a metal-to-ligand charge-transfer excited-state lifetime of 16 ns, which is attributed to a strong ligand field and therefore reduced deactivation via metal-centered states.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cyclometalated bis-tridentate ruthenium(II) complexes incorporating 2,6-diquinolin-8-ylpyridine ligands and exhibiting broad visible absorptions are described. A [Ru(N boolean AND N boolean AND N)(N boolean AND C boolean AND N)](+) complex based only on ligands with expanded bite angles has a metal-to-ligand charge-transfer excited-state lifetime of 16 ns, which is attributed to a strong ligand field and therefore reduced deactivation via metal-centered states. |
Broggini-Tenzer, Angela ; Hollenstein, Andreas ; Pianowski, Zbigniew ; Wampfler, Andrea ; Furmanova, Polina ; Winssinger, Nicolas ; Pruschy, Martin Substrate screening identifies a novel target sequence for the proteasomal activity regulated by ionizing radiation Journal Article In: PROTEOMICS, 10 (2), pp. 304–314, 2010, ISSN: 1615-9853. @article{broggini-tenzer_substrate_2010, title = {Substrate screening identifies a novel target sequence for the proteasomal activity regulated by ionizing radiation}, author = {Broggini-Tenzer, Angela and Hollenstein, Andreas and Pianowski, Zbigniew and Wampfler, Andrea and Furmanova, Polina and Winssinger, Nicolas and Pruschy, Martin}, doi = {10.1002/pmic.200900162}, issn = {1615-9853}, year = {2010}, date = {2010-01-01}, journal = {PROTEOMICS}, volume = {10}, number = {2}, pages = {304--314}, abstract = {The screening for treatment-induced enzyme activities offers the opportunity to discover important regulatory mechanisms and the identification of potential targets for anti-cancer therapies. A novel screening technique was applied to screen substrate peptide sequences for proteolytic activities up- or down-regulated by ionizing radiation in tumor cells. One specific substrate sequence was cleaved in control cell extracts but to a smaller extent in irradiated cell extracts and investigated in detail. Based on protease-class-specific inhibitory studies and cleavage site analysis a potent warhead-inhibitor was synthesized and used to identify the proteasome as the protease of interest. The investigated sequence shows high homology to a regulatory site of nucleoporin 50, an element of the nuclear pore complex, and site specific cleavage of nucleoporin 50 was determined in vitro suggesting a novel link between the ionizing radiation-regulated proteasome and nuclear protein shuttling.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The screening for treatment-induced enzyme activities offers the opportunity to discover important regulatory mechanisms and the identification of potential targets for anti-cancer therapies. A novel screening technique was applied to screen substrate peptide sequences for proteolytic activities up- or down-regulated by ionizing radiation in tumor cells. One specific substrate sequence was cleaved in control cell extracts but to a smaller extent in irradiated cell extracts and investigated in detail. Based on protease-class-specific inhibitory studies and cleavage site analysis a potent warhead-inhibitor was synthesized and used to identify the proteasome as the protease of interest. The investigated sequence shows high homology to a regulatory site of nucleoporin 50, an element of the nuclear pore complex, and site specific cleavage of nucleoporin 50 was determined in vitro suggesting a novel link between the ionizing radiation-regulated proteasome and nuclear protein shuttling. |
Collin, Jean-Paul ; Durola, Fabien ; Heitz, Valerie ; Reviriego, Felipe ; Sauvage, Jean-Pierre ; Trolez, Yann A Cyclic [4]rotaxane that Behaves as a Switchable Molecular Receptor: Formation of a Rigid Scaffold from a Collapsed Structure by Complexation with Copper(I) Ions Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 49 (52), pp. 10172–10175, 2010, ISSN: 1433-7851. @article{collin_cyclic_2010, title = {A Cyclic [4]rotaxane that Behaves as a Switchable Molecular Receptor: Formation of a Rigid Scaffold from a Collapsed Structure by Complexation with Copper(I) Ions}, author = {Collin, Jean-Paul and Durola, Fabien and Heitz, Valerie and Reviriego, Felipe and Sauvage, Jean-Pierre and Trolez, Yann}, doi = {10.1002/anie.201004008}, issn = {1433-7851}, year = {2010}, date = {2010-01-01}, journal = {ANGEWANDTE CHEMIE-INTERNATIONAL EDITION}, volume = {49}, number = {52}, pages = {10172--10175}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Ventura, Barbara ; Flamigni, Lucia ; Beyler, Maryline ; Heitz, Valerie ; Sauvage, Jean-Pierre Unusual Photoinduced Electron Transfer from a Zinc Porphyrin to a Tetrapyridyl Free-Base Porphyrin in a Noncovalent Multiporphyrin Array Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 16 (29), pp. 8748–8756, 2010, ISSN: 0947-6539. @article{ventura_unusual_2010, title = {Unusual Photoinduced Electron Transfer from a Zinc Porphyrin to a Tetrapyridyl Free-Base Porphyrin in a Noncovalent Multiporphyrin Array}, author = {Ventura, Barbara and Flamigni, Lucia and Beyler, Maryline and Heitz, Valerie and Sauvage, Jean-Pierre}, doi = {10.1002/chem.201000375}, issn = {0947-6539}, year = {2010}, date = {2010-01-01}, journal = {CHEMISTRY-A EUROPEAN JOURNAL}, volume = {16}, number = {29}, pages = {8748--8756}, abstract = {Excitation of the peripheral Zn porphyrin units in a noncovalent five-porphyrin array, formed by gable-like zinc(II) bisporphyrins and a central free-base meso-tetrakis(4-pyridyl)-porphyrin in a 2:1 ratio, (ZnP(2))(2)center dot(TPyP), does not lead to a quantitative sensitization of the luminescence of the free-base porphyrin acceptor, even though there is an effective energy transfer. Time resolution of the luminescence evidences a quenching of TPyP upon sensitization by the peripheral ZnP(2). The time evolution of the TPyP fluorescence in the complex can be described by a bi-exponential fitting with a major component of 180 Ps and a minor one of 5 ns, compared to an isolated TPyP lifetime of 9.4 ns. The two quenched lifetimes are shown to be correlated to the presence of 2:1 and 1:1 complexes, respectively. No quenching of TPyP fluorescence occurs in (ZnP(2))(2)center dot(TPyP) at 77 K in a rigid solvent for which only an energy-transfer process (tau=150 +/- 10 ps) from peripheral ZnP(2) to the central TPyP is observed. An unusual HOMO-HOMO electron-transfer reaction from ZnP(2) to the excited TPyP units, responsible for the observed phenomena, is detected. The resulting charge-separated state, (ZnP(2))+(2)center dot(TPyP)(-) is found to recombine to the ground state with a lifetime of 11 ns.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Excitation of the peripheral Zn porphyrin units in a noncovalent five-porphyrin array, formed by gable-like zinc(II) bisporphyrins and a central free-base meso-tetrakis(4-pyridyl)-porphyrin in a 2:1 ratio, (ZnP(2))(2)center dot(TPyP), does not lead to a quantitative sensitization of the luminescence of the free-base porphyrin acceptor, even though there is an effective energy transfer. Time resolution of the luminescence evidences a quenching of TPyP upon sensitization by the peripheral ZnP(2). The time evolution of the TPyP fluorescence in the complex can be described by a bi-exponential fitting with a major component of 180 Ps and a minor one of 5 ns, compared to an isolated TPyP lifetime of 9.4 ns. The two quenched lifetimes are shown to be correlated to the presence of 2:1 and 1:1 complexes, respectively. No quenching of TPyP fluorescence occurs in (ZnP(2))(2)center dot(TPyP) at 77 K in a rigid solvent for which only an energy-transfer process (tau=150 +/- 10 ps) from peripheral ZnP(2) to the central TPyP is observed. An unusual HOMO-HOMO electron-transfer reaction from ZnP(2) to the excited TPyP units, responsible for the observed phenomena, is detected. The resulting charge-separated state, (ZnP(2))+(2)center dot(TPyP)(-) is found to recombine to the ground state with a lifetime of 11 ns. |
Durot, Stephanie ; Reviriego, Felipe ; Sauvage, Jean-Pierre Copper-complexed catenanes and rotaxanes in motion: 15 years of molecular machines Journal Article In: DALTON TRANSACTIONS, 39 (44), pp. 10557–10570, 2010, ISSN: 1477-9226. @article{durot_copper-complexed_2010, title = {Copper-complexed catenanes and rotaxanes in motion: 15 years of molecular machines}, author = {Durot, Stephanie and Reviriego, Felipe and Sauvage, Jean-Pierre}, doi = {10.1039/c0dt00457j}, issn = {1477-9226}, year = {2010}, date = {2010-01-01}, journal = {DALTON TRANSACTIONS}, volume = {39}, number = {44}, pages = {10557--10570}, abstract = {In this review, we try to summarise the work performed in our laboratories in the course of the last 15 years, in the field of catenane- and rotaxane-based molecular machines containing copper(I), copper(II) or zinc(II) atoms. We put our work into perspective, showing how the properties of the compounds made have been gradually improved, mostly in terms of motion rate. In parallel, the function of the molecular machines elaborated have been made more and more complex. Instead of discussing all the systems elaborated and studied in our team, we preferred to select a few representative examples and show what were the principles which guided us for improving their performances and how the compounds were experimentally modified to afford new functions and faster-responding molecular machines. Starting from an electrochemically-driven “swinging” [2]catenane, reported in 1994, whose rearrangement was disappointingly slow, we could recently elaborate fast moving pirouetting copper-complexed [2]rotaxanes or molecular shuttles. The rearrangement mechanism of the pirouetting systems, as studied by experimental and computational methods, led us to synthesise interlocking compounds with a very open structure around the copper centre, allowing facile ligand exchange. With such compounds, whose copper centres are highly accessible, the minutes or hours required for the first generation of molecular machines to rearrange were converted to milliseconds or seconds, demonstrating that the rate limiting step in the electrochemically-steered copper catenanes and rotaxanes is probably decoordination of ligands to be replaced by entering ligands leading to the new form of the species. In addition to the electrochemically-piloted systems, we discuss a few compounds, which were not set in motion using an electrochemical signal but rather a chemical stimulus, including porphyrin-containing [2]rotaxanes or a “molecular muscle”, based on a [2]rotaxane dimer of the hermaphroditic type. In these two machines, the stimulus is based on metal complexation, decomplexation or exchange (copper(I) being replaced by zinc(II) and vice versa for the “muscle”). Using non-sterically hindering ligands of the 8,8'-diaryl-3,3'-biisoquinoline, it is likely that the chemically driven motions used for contracting or stretching the “muscle” could be replaced by electrochemical signals, which are certainly more promising in terms of future devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this review, we try to summarise the work performed in our laboratories in the course of the last 15 years, in the field of catenane- and rotaxane-based molecular machines containing copper(I), copper(II) or zinc(II) atoms. We put our work into perspective, showing how the properties of the compounds made have been gradually improved, mostly in terms of motion rate. In parallel, the function of the molecular machines elaborated have been made more and more complex. Instead of discussing all the systems elaborated and studied in our team, we preferred to select a few representative examples and show what were the principles which guided us for improving their performances and how the compounds were experimentally modified to afford new functions and faster-responding molecular machines. Starting from an electrochemically-driven “swinging” [2]catenane, reported in 1994, whose rearrangement was disappointingly slow, we could recently elaborate fast moving pirouetting copper-complexed [2]rotaxanes or molecular shuttles. The rearrangement mechanism of the pirouetting systems, as studied by experimental and computational methods, led us to synthesise interlocking compounds with a very open structure around the copper centre, allowing facile ligand exchange. With such compounds, whose copper centres are highly accessible, the minutes or hours required for the first generation of molecular machines to rearrange were converted to milliseconds or seconds, demonstrating that the rate limiting step in the electrochemically-steered copper catenanes and rotaxanes is probably decoordination of ligands to be replaced by entering ligands leading to the new form of the species. In addition to the electrochemically-piloted systems, we discuss a few compounds, which were not set in motion using an electrochemical signal but rather a chemical stimulus, including porphyrin-containing [2]rotaxanes or a “molecular muscle”, based on a [2]rotaxane dimer of the hermaphroditic type. In these two machines, the stimulus is based on metal complexation, decomplexation or exchange (copper(I) being replaced by zinc(II) and vice versa for the “muscle”). Using non-sterically hindering ligands of the 8,8'-diaryl-3,3'-biisoquinoline, it is likely that the chemically driven motions used for contracting or stretching the “muscle” could be replaced by electrochemical signals, which are certainly more promising in terms of future devices. |
Collin, Jean-Paul ; Durola, Fabien ; Lux, Jacques ; Sauvage, Jean-Pierre A copper-based shuttling [2]rotaxane with two bidentate chelates in the axis: steric control of the motion Journal Article In: NEW JOURNAL OF CHEMISTRY, 34 (1), pp. 34–43, 2010, ISSN: 1144-0546. @article{collin_copper-based_2010, title = {A copper-based shuttling [2]rotaxane with two bidentate chelates in the axis: steric control of the motion}, author = {Collin, Jean-Paul and Durola, Fabien and Lux, Jacques and Sauvage, Jean-Pierre}, doi = {10.1039/b9nj00296k}, issn = {1144-0546}, year = {2010}, date = {2010-01-01}, journal = {NEW JOURNAL OF CHEMISTRY}, volume = {34}, number = {1}, pages = {34--43}, abstract = {Contrary to most of the other molecular machines based on copper-complexed catenanes or rotaxanes made and investigated in Strasbourg, the present report is dealing with a molecular shuttle for which the copper centre is complexed to two bidentate chelates, regardless of the state of the shuttle. In other words, the axis contains a sterically hindering bidentate chelate, namely a 2,9-diphenyl-1,10-phenanthroline (dpp) derivative, and another but less hindering bidentate chelate, 2,2'-bipyridine (bipy). The synthesis of the [2]rotaxane involves 15 individual chemical steps, excluding the preparation of the macrocyclic component of the [2] rotaxane. The threaded macrocycle is a 39-membered ring which incorporates an endocyclic but non sterically hindering chelate of the 8,8'-diphenyl-3,3'-biisoquinoline family (dpbiiq). The electrochemically-induced gliding motion of the copper-complexed ring from the dpp “station” to the bipy “station” and vice versa is fast on the cyclic voltammetry timescale (milliseconds). The copper(I) state is preferably located on the dpp unit whereas, by oxidising the copper(I) centre to its divalent state, the translation motion takes place to afford the thermodynamically most stable state now involving the bipy chelate.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Contrary to most of the other molecular machines based on copper-complexed catenanes or rotaxanes made and investigated in Strasbourg, the present report is dealing with a molecular shuttle for which the copper centre is complexed to two bidentate chelates, regardless of the state of the shuttle. In other words, the axis contains a sterically hindering bidentate chelate, namely a 2,9-diphenyl-1,10-phenanthroline (dpp) derivative, and another but less hindering bidentate chelate, 2,2'-bipyridine (bipy). The synthesis of the [2]rotaxane involves 15 individual chemical steps, excluding the preparation of the macrocyclic component of the [2] rotaxane. The threaded macrocycle is a 39-membered ring which incorporates an endocyclic but non sterically hindering chelate of the 8,8'-diphenyl-3,3'-biisoquinoline family (dpbiiq). The electrochemically-induced gliding motion of the copper-complexed ring from the dpp “station” to the bipy “station” and vice versa is fast on the cyclic voltammetry timescale (milliseconds). The copper(I) state is preferably located on the dpp unit whereas, by oxidising the copper(I) centre to its divalent state, the translation motion takes place to afford the thermodynamically most stable state now involving the bipy chelate. |
Beyler, Maryline ; Heitz, Valerie ; Sauvage, Jean-Pierre The dual role of Cu(I) as a protective group and a template in the synthesis of a tetra-rhodium(III)porphyrin [2]catenane Journal Article In: NEW JOURNAL OF CHEMISTRY, 34 (9), pp. 1825–1829, 2010, ISSN: 1144-0546. @article{beyler_dual_2010, title = {The dual role of Cu(I) as a protective group and a template in the synthesis of a tetra-rhodium(III)porphyrin [2]catenane}, author = {Beyler, Maryline and Heitz, Valerie and Sauvage, Jean-Pierre}, doi = {10.1039/c0nj00414f}, issn = {1144-0546}, year = {2010}, date = {2010-01-01}, journal = {NEW JOURNAL OF CHEMISTRY}, volume = {34}, number = {9}, pages = {1825--1829}, abstract = {A new [2]catenane containing four Rh(III) porphyrins has been prepared following a three-step strategy: (i) Cu(I)-driven entwining of two free base porphyrin-bearing bidentate chelates, followed by (ii) insertion of rhodium in the porphyrin nuclei, and finally (iii) cyclisation via the formation of N-Rh coordination bonds. Direct metalation of porphyrinic compounds with [Rh(CO)(2)Cl](2) was not met with success when the bidentate chelate used as a connector was metal free, thus making the Cu(I) protecting approach very attractive.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new [2]catenane containing four Rh(III) porphyrins has been prepared following a three-step strategy: (i) Cu(I)-driven entwining of two free base porphyrin-bearing bidentate chelates, followed by (ii) insertion of rhodium in the porphyrin nuclei, and finally (iii) cyclisation via the formation of N-Rh coordination bonds. Direct metalation of porphyrinic compounds with [Rh(CO)(2)Cl](2) was not met with success when the bidentate chelate used as a connector was metal free, thus making the Cu(I) protecting approach very attractive. |
Sondergaard, Thomas ; Bozhevolnyi, Sergey I; Beermann, Jonas ; Novikov, Sergey M; Devaux, Eloise ; Ebbesen, Thomas W Resonant Plasmon Nanofocusing by Closed Tapered Gaps Journal Article In: NANO LETTERS, 10 (1), pp. 291–295, 2010, ISSN: 1530-6984. @article{sondergaard_resonant_2010, title = {Resonant Plasmon Nanofocusing by Closed Tapered Gaps}, author = {Sondergaard, Thomas and Bozhevolnyi, Sergey I. and Beermann, Jonas and Novikov, Sergey M. and Devaux, Eloise and Ebbesen, Thomas W.}, doi = {10.1021/nl903563e}, issn = {1530-6984}, year = {2010}, date = {2010-01-01}, journal = {NANO LETTERS}, volume = {10}, number = {1}, pages = {291--295}, abstract = {We study radiation nanofocusing by closed tapered gaps, i.e. metal V-grooves, under normal illumination, and discover that the local field inside a groove can be resonantly enhanced due to interference of counter-propagating gap plasmons. Considering V-grooves milled in gold, we analyze this phenomenon theoretically, deriving an analytic expression for the resonance condition and predicting more than 550-fold intensity enhancements at resonance, and observe it experimentally with two-photon photoluminescence microscopy, demonstrating more than 100-fold intensity enhancements.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We study radiation nanofocusing by closed tapered gaps, i.e. metal V-grooves, under normal illumination, and discover that the local field inside a groove can be resonantly enhanced due to interference of counter-propagating gap plasmons. Considering V-grooves milled in gold, we analyze this phenomenon theoretically, deriving an analytic expression for the resonance condition and predicting more than 550-fold intensity enhancements at resonance, and observe it experimentally with two-photon photoluminescence microscopy, demonstrating more than 100-fold intensity enhancements. |
Wenger, Jerome ; Aouani, Heykel ; Gerard, Davy ; Blair, Steve ; Ebbesen, Thomas W; Rigneault, Herve Enhanced fluorescence from metal nanoapertures: physical characterizations and biophotonic applications Inproceedings In: {VoDinh, T; Lakowicz, JR} (Ed.): PLASMONICS IN BIOLOGY AND MEDICINE VII, SPIE, 2010, ISBN: 978-0-8194-7973-0. @inproceedings{wenger_enhanced_2010, title = {Enhanced fluorescence from metal nanoapertures: physical characterizations and biophotonic applications}, author = {Wenger, Jerome and Aouani, Heykel and Gerard, Davy and Blair, Steve and Ebbesen, Thomas W. and Rigneault, Herve}, editor = {{VoDinh, T and Lakowicz, JR}}, doi = {10.1117/12.840042}, isbn = {978-0-8194-7973-0}, year = {2010}, date = {2010-01-01}, booktitle = {PLASMONICS IN BIOLOGY AND MEDICINE VII}, volume = {7577}, publisher = {SPIE}, series = {Proceedings of SPIE}, abstract = {Nanoapertures milled in opaque metallic films offer a simple and robust photonic tool to significantly enhance the fluorescence of single molecules. We provide a detailed physical characterization of this phenomenon for apertures milled in gold and aluminum, and discuss its application to biophotonics. For the first time, the most general figures are provided to predict the awaited enhancement factors for almost every kind of fluorescent molecule. This knowledge is essential to discuss the ability to detect low-quantum yield species. We also report the first demonstration of single metal nanoapertures to perform DNA hybridization sensing, and measure similar enhancement factors as for experiments on diffusing molecules.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Nanoapertures milled in opaque metallic films offer a simple and robust photonic tool to significantly enhance the fluorescence of single molecules. We provide a detailed physical characterization of this phenomenon for apertures milled in gold and aluminum, and discuss its application to biophotonics. For the first time, the most general figures are provided to predict the awaited enhancement factors for almost every kind of fluorescent molecule. This knowledge is essential to discuss the ability to detect low-quantum yield species. We also report the first demonstration of single metal nanoapertures to perform DNA hybridization sensing, and measure similar enhancement factors as for experiments on diffusing molecules. |
Sondergaard, Thomas ; Bozhevolnyi, Sergey I; Beermann, Jonas ; Novikov, Sergey M; Devaux, Eloise ; Ebbesen, Thomas W; Rafaelsen, Jens Optical resonances and nanofocusing in triangular metal nano-grooves Inproceedings In: {Stockman, MI} (Ed.): PLASMONICS: METALLIC NANOSTRUCTURES AND THEIR OPTICAL PROPERTIES VIII, SPIE, 2010, ISBN: 978-0-8194-8253-2. @inproceedings{sondergaard_optical_2010, title = {Optical resonances and nanofocusing in triangular metal nano-grooves}, author = {Sondergaard, Thomas and Bozhevolnyi, Sergey I. and Beermann, Jonas and Novikov, Sergey M. and Devaux, Eloise and Ebbesen, Thomas W. and Rafaelsen, Jens}, editor = {{Stockman, MI}}, doi = {10.1117/12.859861}, isbn = {978-0-8194-8253-2}, year = {2010}, date = {2010-01-01}, booktitle = {PLASMONICS: METALLIC NANOSTRUCTURES AND THEIR OPTICAL PROPERTIES VIII}, volume = {7757}, publisher = {SPIE}, series = {Proceedings of SPIE}, abstract = {Optical resonances in a single triangular-shaped metal groove and a periodic array of grooves are studied theoretically with the Green's function surface integral equation method. In the case of a single groove we study the geometric resonances for different groove heights, and show that the groove resonances can be explained by standing waves in the gap being reflected at both the closed groove bottom and the open groove top. We also present the reflection that will be obtained for different cases of picking up the reflected light within a small or large angular range. Large resonant fields at the groove bottom are explained as being due to nanofocusing by the groove which can also be thought of as a closed tapered gap. In the case of a periodic array of grooves we find that resonances of individual grooves are still present in near-field enhancement spectra and reflection spectra but there are also e. g. very sharp resonances (Rayleigh anomalies) at wavelengths near the cutoff wavelength of higher grating-reflection orders. Typical resonant enhancements can easily be two times higher compared with the case of a single groove. The resonances can be realized in the wavelength range from the visible to the infrared by varying groove height, angle, and periodicity.}, keywords = {}, pubstate = {published}, tppubtype = {inproceedings} } Optical resonances in a single triangular-shaped metal groove and a periodic array of grooves are studied theoretically with the Green's function surface integral equation method. In the case of a single groove we study the geometric resonances for different groove heights, and show that the groove resonances can be explained by standing waves in the gap being reflected at both the closed groove bottom and the open groove top. We also present the reflection that will be obtained for different cases of picking up the reflected light within a small or large angular range. Large resonant fields at the groove bottom are explained as being due to nanofocusing by the groove which can also be thought of as a closed tapered gap. In the case of a periodic array of grooves we find that resonances of individual grooves are still present in near-field enhancement spectra and reflection spectra but there are also e. g. very sharp resonances (Rayleigh anomalies) at wavelengths near the cutoff wavelength of higher grating-reflection orders. Typical resonant enhancements can easily be two times higher compared with the case of a single groove. The resonances can be realized in the wavelength range from the visible to the infrared by varying groove height, angle, and periodicity. |
2009 |
Nam, Kwangho ; Verdine, Gregory L; Karplus, Martin Analysis of an Anomalous Mutant of MutM DNA Glycosylase Leads to New Insights into the Catalytic Mechanism Journal Article In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131 (51), pp. 18208+, 2009, ISSN: 0002-7863. @article{nam_analysis_2009, title = {Analysis of an Anomalous Mutant of MutM DNA Glycosylase Leads to New Insights into the Catalytic Mechanism}, author = {Nam, Kwangho and Verdine, Gregory L. and Karplus, Martin}, doi = {10.1021/ja907544b}, issn = {0002-7863}, year = {2009}, date = {2009-12-01}, journal = {JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, volume = {131}, number = {51}, pages = {18208+}, abstract = {To determine the factors involved in the specific recognition function of a bacterial. 8-oxoguanine (oxoG) DNA glycosylase MutM, a series of potentials of mean force and thermodynamic integration simulations were performed with the wild type and a single-point E3Q mutant of MutM bound to oxoG and G-containing DNA, respectively. Interestingly, the mutation of the catalytically important Glu3 (E3) residue to Gin (Q) significantly changes the free-energy surface so that oxoG can bind stably in the active site of the enzyme, Free-energy simulations with the protonated and deprotonated E3 residue further showed that the protonation of the catalytically important E3 residue plays a key role in distinguishing oxoG versus G in the active site by lowering the free energy of oxoG preferentially in the active site. The results suggest that MutM utilizes the thermodynamic recognition mechanism for stable binding of the lesion base in the active site of the enzyme in addition to kinetic discrimination at the early stage of the base extrusion for facilitated extrusion of oxoG.}, keywords = {}, pubstate = {published}, tppubtype = {article} } To determine the factors involved in the specific recognition function of a bacterial. 8-oxoguanine (oxoG) DNA glycosylase MutM, a series of potentials of mean force and thermodynamic integration simulations were performed with the wild type and a single-point E3Q mutant of MutM bound to oxoG and G-containing DNA, respectively. Interestingly, the mutation of the catalytically important Glu3 (E3) residue to Gin (Q) significantly changes the free-energy surface so that oxoG can bind stably in the active site of the enzyme, Free-energy simulations with the protonated and deprotonated E3 residue further showed that the protonation of the catalytically important E3 residue plays a key role in distinguishing oxoG versus G in the active site by lowering the free energy of oxoG preferentially in the active site. The results suggest that MutM utilizes the thermodynamic recognition mechanism for stable binding of the lesion base in the active site of the enzyme in addition to kinetic discrimination at the early stage of the base extrusion for facilitated extrusion of oxoG. |
Qi, Yan ; Spong, Marie C; Nam, Kwangho ; Banerjee, Anirban ; Jiralerspong, Sao ; Karplus, Martin ; Verdine, Gregory L Encounter and extrusion of an intrahelical lesion by a DNA repair enzyme Journal Article In: NATURE, 462 (7274), pp. 762–U79, 2009, ISSN: 0028-0836. @article{qi_encounter_2009, title = {Encounter and extrusion of an intrahelical lesion by a DNA repair enzyme}, author = {Qi, Yan and Spong, Marie C. and Nam, Kwangho and Banerjee, Anirban and Jiralerspong, Sao and Karplus, Martin and Verdine, Gregory L.}, doi = {10.1038/nature08561}, issn = {0028-0836}, year = {2009}, date = {2009-12-01}, journal = {NATURE}, volume = {462}, number = {7274}, pages = {762--U79}, abstract = {How living systems detect the presence of genotoxic damage embedded in a million-fold excess of undamaged DNA is an unresolved question in biology. Here we have captured and structurally elucidated a base-excision DNA repair enzyme, MutM, at the stage of initial encounter with a damaged nucleobase, 8-oxoguanine (oxoG), nested within a DNA duplex. Three structures of intrahelical oxoG-encounter complexes are compared with sequence-matched structures containing a normal G base in place of an oxoG lesion. Although the protein-DNA interfaces in the matched complexes differ by only two atoms-those that distinguish oxoG from G-their pronounced structural differences indicate that MutM can detect a lesion in DNA even at the earliest stages of encounter. All-atom computer simulations show the pathway by which encounter of the enzyme with the lesion causes extrusion from the DNA duplex, and they elucidate the critical free energy difference between oxoG and G along the extrusion pathway.}, keywords = {}, pubstate = {published}, tppubtype = {article} } How living systems detect the presence of genotoxic damage embedded in a million-fold excess of undamaged DNA is an unresolved question in biology. Here we have captured and structurally elucidated a base-excision DNA repair enzyme, MutM, at the stage of initial encounter with a damaged nucleobase, 8-oxoguanine (oxoG), nested within a DNA duplex. Three structures of intrahelical oxoG-encounter complexes are compared with sequence-matched structures containing a normal G base in place of an oxoG lesion. Although the protein-DNA interfaces in the matched complexes differ by only two atoms-those that distinguish oxoG from G-their pronounced structural differences indicate that MutM can detect a lesion in DNA even at the earliest stages of encounter. All-atom computer simulations show the pathway by which encounter of the enzyme with the lesion causes extrusion from the DNA duplex, and they elucidate the critical free energy difference between oxoG and G along the extrusion pathway. |
Treossi, Emanuele ; Melucci, Manuela ; Liscio, Andrea ; Gazzano, Massimo ; Samori, Paolo ; Palermo, Vincenzo High-Contrast Visualization of Graphene Oxide on Dye-Sensitized Glass, Quartz, and Silicon by Fluorescence Quenching Journal Article In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131 (43), pp. 15576+, 2009, ISSN: 0002-7863. @article{treossi_high-contrast_2009, title = {High-Contrast Visualization of Graphene Oxide on Dye-Sensitized Glass, Quartz, and Silicon by Fluorescence Quenching}, author = {Treossi, Emanuele and Melucci, Manuela and Liscio, Andrea and Gazzano, Massimo and Samori, Paolo and Palermo, Vincenzo}, doi = {10.1021/ja9055382}, issn = {0002-7863}, year = {2009}, date = {2009-11-01}, journal = {JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, volume = {131}, number = {43}, pages = {15576+}, abstract = {We present a novel approach for detecting and visualizing graphene oxide (GO) with high contrast on different substrates, including glass, quartz, and silicon. Visualization of GO sheets is accomplished through quenching the fluorescence of a thiophene dye, giving high optical contrast without the need to use interference methods. A comparison of fluorescence, AFM, and XRD measurements confirmed that even a single GO sheet can completely quench the fluorescence and thus be quickly visualized.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We present a novel approach for detecting and visualizing graphene oxide (GO) with high contrast on different substrates, including glass, quartz, and silicon. Visualization of GO sheets is accomplished through quenching the fluorescence of a thiophene dye, giving high optical contrast without the need to use interference methods. A comparison of fluorescence, AFM, and XRD measurements confirmed that even a single GO sheet can completely quench the fluorescence and thus be quickly visualized. |
Drahonovsky, Dusan ; Lehn, Jean-Marie Hemiacetals in Dynamic Covalent Chemistry: Formation, Exchange, Selection, and Modulation Processes Journal Article In: JOURNAL OF ORGANIC CHEMISTRY, 74 (21), pp. 8428–8432, 2009, ISSN: 0022-3263. @article{drahonovsky_hemiacetals_2009, title = {Hemiacetals in Dynamic Covalent Chemistry: Formation, Exchange, Selection, and Modulation Processes}, author = {Drahonovsky, Dusan and Lehn, Jean-Marie}, doi = {10.1021/jo9009886}, issn = {0022-3263}, year = {2009}, date = {2009-11-01}, journal = {JOURNAL OF ORGANIC CHEMISTRY}, volume = {74}, number = {21}, pages = {8428--8432}, abstract = {A reversible formation of hemiacetals represents if useful tool in covalent dynamic chemistry. Heterocyclic hemiacetals can be stabilized effectively via either protonation or metal cation coordination. The resulting hemiacetals systems are highly dynamic, show fast response, and display component selection.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A reversible formation of hemiacetals represents if useful tool in covalent dynamic chemistry. Heterocyclic hemiacetals can be stabilized effectively via either protonation or metal cation coordination. The resulting hemiacetals systems are highly dynamic, show fast response, and display component selection. |
Lehn, Jean-Marie Pierre Preface Journal Article In: RESEARCH ON CHEMICAL INTERMEDIATES, 35 (8-9), pp. 839–840, 2009, ISSN: 0922-6168. @article{lehn_preface_2009, title = {Preface}, author = {Lehn, Jean-Marie Pierre}, doi = {10.1007/s11164-009-0077-x}, issn = {0922-6168}, year = {2009}, date = {2009-11-01}, journal = {RESEARCH ON CHEMICAL INTERMEDIATES}, volume = {35}, number = {8-9}, pages = {839--840}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Hermans, Thomas M; Broeren, Maarten A C; Gomopoulos, Nikos ; van der Schoot, Paul ; van Genderen, Marcel H P; Sommerdijk, Nico A J M; Fytas, George ; Meijer, E W Self-assembly of soft nanoparticles with tunable patchiness Journal Article In: NATURE NANOTECHNOLOGY, 4 (11), pp. 721–726, 2009, ISSN: 1748-3387. @article{hermans_self-assembly_2009, title = {Self-assembly of soft nanoparticles with tunable patchiness}, author = {Hermans, Thomas M. and Broeren, Maarten A. C. and Gomopoulos, Nikos and van der Schoot, Paul and van Genderen, Marcel H. P. and Sommerdijk, Nico A. J. M. and Fytas, George and Meijer, E. W.}, doi = {10.1038/NNANO.2009.232}, issn = {1748-3387}, year = {2009}, date = {2009-11-01}, journal = {NATURE NANOTECHNOLOGY}, volume = {4}, number = {11}, pages = {721--726}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Bonnefond, Amelie ; Vaxillaire, Martine ; Labrune, Yann ; Lecoeur, Cecile ; Chevre, Jean-Claude ; Bouatia-Naji, Nabila ; Cauchi, Stephane ; Balkau, Beverley ; Marre, Michel ; Tichet, Jean ; Riveline, Jean-Pierre ; Hadjadj, Samy ; Gallois, Yves ; Czernichow, Sebastien ; Hercberg, Serge ; Kaakinen, Marika ; Wiesner, Susanne ; Charpentier, Guillaume ; Levy-Marchal, Claire ; Elliott, Paul ; Jarvelin, Marjo-Riitta ; Horber, Fritz ; Dina, Christian ; Pedersen, Oluf ; Sladek, Robert ; Meyre, David ; Froguel, Philippe Genetic Variant m HK1 Is Associated With a Proanemic State and A1C but Not Other Glycemic Control-Related Traits Journal Article In: DIABETES, 58 (11), pp. 2687–2697, 2009, ISSN: 0012-1797. @article{bonnefond_genetic_2009, title = {Genetic Variant m HK1 Is Associated With a Proanemic State and A1C but Not Other Glycemic Control-Related Traits}, author = {Bonnefond, Amelie and Vaxillaire, Martine and Labrune, Yann and Lecoeur, Cecile and Chevre, Jean-Claude and Bouatia-Naji, Nabila and Cauchi, Stephane and Balkau, Beverley and Marre, Michel and Tichet, Jean and Riveline, Jean-Pierre and Hadjadj, Samy and Gallois, Yves and Czernichow, Sebastien and Hercberg, Serge and Kaakinen, Marika and Wiesner, Susanne and Charpentier, Guillaume and Levy-Marchal, Claire and Elliott, Paul and Jarvelin, Marjo-Riitta and Horber, Fritz and Dina, Christian and Pedersen, Oluf and Sladek, Robert and Meyre, David and Froguel, Philippe}, doi = {10.2337/009-0652}, issn = {0012-1797}, year = {2009}, date = {2009-11-01}, journal = {DIABETES}, volume = {58}, number = {11}, pages = {2687--2697}, abstract = {OBJECTIVE-A1C is widely considered the gold standard for monitoring effective blood glucose levels. Recently, a genome-wide association study reported an association between A1C and rs7072268 within HK1 (encoding hexokinase 1), which catalyzes the first step of glycolysis. HK1. deficiency in erythrocytes (red blood cells [RBCs]) causes severe nonspherocytic hemolytic anemia in both humans and mice. RESEARCH DESIGN AND METHODS-The contribution of rs7072268 to A1C and the RBC-related traits was assessed in 6,953 nondiabetic European participants. We additionally analyzed the association with hematologic traits in 5,229 nondiabetic European individuals (in whom A1C was not measured) and 1,924 diabetic patients. Glucose control-related markers other than A1C were analyzed in 18,694 nondiabetic European individuals. A type 2 diabetes case-control study included 7,447 French diabetic patients. RESULTS-Our study confirms a strong association between the rs7072268-T allele and increased A1C (P = 0.029%; P = 2.22 X 10(-7)). Surprisingly, despite adequate study power, rs7072268 showed no association with any other markers of glucose control (fasting- and 2-h post-OGTT-related parameters}, keywords = {}, pubstate = {published}, tppubtype = {article} } OBJECTIVE-A1C is widely considered the gold standard for monitoring effective blood glucose levels. Recently, a genome-wide association study reported an association between A1C and rs7072268 within HK1 (encoding hexokinase 1), which catalyzes the first step of glycolysis. HK1. deficiency in erythrocytes (red blood cells [RBCs]) causes severe nonspherocytic hemolytic anemia in both humans and mice. RESEARCH DESIGN AND METHODS-The contribution of rs7072268 to A1C and the RBC-related traits was assessed in 6,953 nondiabetic European participants. We additionally analyzed the association with hematologic traits in 5,229 nondiabetic European individuals (in whom A1C was not measured) and 1,924 diabetic patients. Glucose control-related markers other than A1C were analyzed in 18,694 nondiabetic European individuals. A type 2 diabetes case-control study included 7,447 French diabetic patients. RESULTS-Our study confirms a strong association between the rs7072268-T allele and increased A1C (P = 0.029%; P = 2.22 X 10(-7)). Surprisingly, despite adequate study power, rs7072268 showed no association with any other markers of glucose control (fasting- and 2-h post-OGTT-related parameters |
Barluenga, Sofia ; Fontaine, Jean-Gonzague ; Wang, Cuihua ; Aouadi, Kais ; Chen, Ruihong ; Beebe, Kristin ; Neckers, Len ; Winssinger, Nicolas Inhibition of HSP90 with Pochoximes: SAR and Structure-Based Insights Journal Article In: CHEMBIOCHEM, 10 (17), pp. 2753–2759, 2009, ISSN: 1439-4227. @article{barluenga_inhibition_2009, title = {Inhibition of HSP90 with Pochoximes: SAR and Structure-Based Insights}, author = {Barluenga, Sofia and Fontaine, Jean-Gonzague and Wang, Cuihua and Aouadi, Kais and Chen, Ruihong and Beebe, Kristin and Neckers, Len and Winssinger, Nicolas}, doi = {10.1002/cbic.200900494}, issn = {1439-4227}, year = {2009}, date = {2009-11-01}, journal = {CHEMBIOCHEM}, volume = {10}, number = {17}, pages = {2753--2759}, abstract = {The pochoximes, based on the radicicol pharmacophore, are potent inhibitors of heat shock protein 90 (HSP90) that retain their activity in vivo. Herein we report an extended library that broadly explores the structure-activity relationship (SAR) of the pochoximes with four points of diversity. Several modifications were identified that afford improved cellular efficacy, new opportunities for conjugation, and further diversifications. Cocrystal structures of pochoximes A and B with HSP90 show that pochoximes bind to a different conformation of HSP90 than radicicol and provide a rationale for the enhanced affinity of the pochoximes relative to radicicol and the pochonins.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The pochoximes, based on the radicicol pharmacophore, are potent inhibitors of heat shock protein 90 (HSP90) that retain their activity in vivo. Herein we report an extended library that broadly explores the structure-activity relationship (SAR) of the pochoximes with four points of diversity. Several modifications were identified that afford improved cellular efficacy, new opportunities for conjugation, and further diversifications. Cocrystal structures of pochoximes A and B with HSP90 show that pochoximes bind to a different conformation of HSP90 than radicicol and provide a rationale for the enhanced affinity of the pochoximes relative to radicicol and the pochonins. |
Winssinger, Nicolas ; Fontaine, Jean-Gonzague ; Barluenga, Sofia Hsp90 Inhibition with Resorcylic Acid Lactones (RALs) Journal Article In: CURRENT TOPICS IN MEDICINAL CHEMISTRY, 9 (15), pp. 1419–1435, 2009, ISSN: 1568-0266. @article{winssinger_hsp90_2009, title = {Hsp90 Inhibition with Resorcylic Acid Lactones (RALs)}, author = {Winssinger, Nicolas and Fontaine, Jean-Gonzague and Barluenga, Sofia}, doi = {10.2174/156802609789895665}, issn = {1568-0266}, year = {2009}, date = {2009-11-01}, journal = {CURRENT TOPICS IN MEDICINAL CHEMISTRY}, volume = {9}, number = {15}, pages = {1419--1435}, abstract = {Heat shock protein 90 (Hsp90) is an ATP-dependent chaperone which is involved in the post-translational maturation and stabilization of over one hundred proteins (”its clients”). In the absence of Hsp90's chaperoning, its clients are misfolded and degraded via ubiquitin-proteasome pathway. HSP90 has become the focus of intense drug discovery efforts as its activity has been implicated in diverse pathologies ranging from oncology to neurodegenerative and infectious diseases. The most promising inhibitors reported to date inhibit the ATPase activity by binding to the N-terminal ATP pocket. Radicicol, a member of the resorcylic acid lactones (RALs), represents an important pharmacophore to this end. Efforts towards the development of this pharmacophore and its SAR are reviewed herein.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Heat shock protein 90 (Hsp90) is an ATP-dependent chaperone which is involved in the post-translational maturation and stabilization of over one hundred proteins (”its clients”). In the absence of Hsp90's chaperoning, its clients are misfolded and degraded via ubiquitin-proteasome pathway. HSP90 has become the focus of intense drug discovery efforts as its activity has been implicated in diverse pathologies ranging from oncology to neurodegenerative and infectious diseases. The most promising inhibitors reported to date inhibit the ATPase activity by binding to the N-terminal ATP pocket. Radicicol, a member of the resorcylic acid lactones (RALs), represents an important pharmacophore to this end. Efforts towards the development of this pharmacophore and its SAR are reviewed herein. |
Volkov, V S; Gosciniak, J; Bozhevolnyi, S I; Rodrigo, S G; Martin-Moreno, L; Garcia-Vidal, F J; Devaux, E; Ebbesen, T W Plasmonic candle: towards efficient nanofocusing with channel plasmon polaritons Journal Article In: NEW JOURNAL OF PHYSICS, 11 , 2009, ISSN: 1367-2630. @article{volkov_plasmonic_2009, title = {Plasmonic candle: towards efficient nanofocusing with channel plasmon polaritons}, author = {Volkov, V. S. and Gosciniak, J. and Bozhevolnyi, S. I. and Rodrigo, S. G. and Martin-Moreno, L. and Garcia-Vidal, F. J. and Devaux, E. and Ebbesen, T. W.}, doi = {10.1088/1367-2630/11/11/113043}, issn = {1367-2630}, year = {2009}, date = {2009-11-01}, journal = {NEW JOURNAL OF PHYSICS}, volume = {11}, abstract = {Channel plasmon polaritons (CPPs) propagating along the bottom of V-grooves cut into a metal were recently shown to exhibit strong confinement combined with low propagation loss, a feature that makes this guiding configuration very promising for the realization of ultracompact photonic components. Here, we present a comprehensive study of radiation nanofocusing with CCPs propagating along subwavelength metal grooves that are terminated with various types of tapers of different lengths. Tapered V-grooves are fabricated in a gold film using a focused ion beam milling technique, with the tapering being realized by gradually decreasing the groove width and/or depth (in different way for different structures), and characterized at telecom wavelengths with a collection scanning near-field optical microscope. Efficient CPP nanofocusing is directly demonstrated featuring a field intensity enhancement of up to similar to 130 for optimal taper configurations. Experimental observations are found to be concurrent with three-dimensional finite-difference time-domain electromagnetic simulations, predicting the possibility of reaching an intensity enhancement of similar to 1200 and opening thereby exciting perspectives for practical applications of CPP nanofocusing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Channel plasmon polaritons (CPPs) propagating along the bottom of V-grooves cut into a metal were recently shown to exhibit strong confinement combined with low propagation loss, a feature that makes this guiding configuration very promising for the realization of ultracompact photonic components. Here, we present a comprehensive study of radiation nanofocusing with CCPs propagating along subwavelength metal grooves that are terminated with various types of tapers of different lengths. Tapered V-grooves are fabricated in a gold film using a focused ion beam milling technique, with the tapering being realized by gradually decreasing the groove width and/or depth (in different way for different structures), and characterized at telecom wavelengths with a collection scanning near-field optical microscope. Efficient CPP nanofocusing is directly demonstrated featuring a field intensity enhancement of up to similar to 130 for optimal taper configurations. Experimental observations are found to be concurrent with three-dimensional finite-difference time-domain electromagnetic simulations, predicting the possibility of reaching an intensity enhancement of similar to 1200 and opening thereby exciting perspectives for practical applications of CPP nanofocusing. |
Petukhov, K; Alam, M S; Rupp, H; Stroemsdoerfer, S; Mueller, P; Scheurer, A; Saalfrank, R W; Kortus, J; Postnikov, A; Ruben, M; Thompson, L K; Lehn, J-M STM spectroscopy of magnetic molecules Journal Article In: COORDINATION CHEMISTRY REVIEWS, 253 (19-20, SI), pp. 2387–2398, 2009, ISSN: 0010-8545. @article{petukhov_stm_2009, title = {STM spectroscopy of magnetic molecules}, author = {Petukhov, K. and Alam, M. S. and Rupp, H. and Stroemsdoerfer, S. and Mueller, P. and Scheurer, A. and Saalfrank, R. W. and Kortus, J. and Postnikov, A. and Ruben, M. and Thompson, L. K. and Lehn, J-M.}, doi = {10.1016/j.ccr.2009.01.024}, issn = {0010-8545}, year = {2009}, date = {2009-10-01}, journal = {COORDINATION CHEMISTRY REVIEWS}, volume = {253}, number = {19-20, SI}, pages = {2387--2398}, abstract = {We have investigated a series of magnetic supramolecular complexes involving coordinated metal ions. Using the current-imaging tunneling spectroscopy mode of a STM, we mapped isolated single molecules. By comparing with DFT calculations, we confirmed that the weakest bonds, i.e. the supramolecular coordination interactions, dominate the molecular orbitals near the Fermi-level of the molecule. Thus, STM spectroscopy can address directly the metal centers in a rather complex molecular entity. Our method allows a selective mapping of the functional units within the supramolecular architecture, even if these units are embedded into a complex set of organic ligands. We observed this behavior in all of our investigated molecules. (C) 2009 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We have investigated a series of magnetic supramolecular complexes involving coordinated metal ions. Using the current-imaging tunneling spectroscopy mode of a STM, we mapped isolated single molecules. By comparing with DFT calculations, we confirmed that the weakest bonds, i.e. the supramolecular coordination interactions, dominate the molecular orbitals near the Fermi-level of the molecule. Thus, STM spectroscopy can address directly the metal centers in a rather complex molecular entity. Our method allows a selective mapping of the functional units within the supramolecular architecture, even if these units are embedded into a complex set of organic ligands. We observed this behavior in all of our investigated molecules. (C) 2009 Elsevier B.V. All rights reserved. |
Lei, Ming ; Velos, Janice ; Gardino, Alexandra ; Kivenson, Alexsandr ; Karplus, Martin ; Kern, Dorothee Segmented Transition Pathway of the Signaling Protein Nitrogen Regulatory Protein C Journal Article In: JOURNAL OF MOLECULAR BIOLOGY, 392 (3), pp. 823–836, 2009, ISSN: 0022-2836. @article{lei_segmented_2009, title = {Segmented Transition Pathway of the Signaling Protein Nitrogen Regulatory Protein C}, author = {Lei, Ming and Velos, Janice and Gardino, Alexandra and Kivenson, Alexsandr and Karplus, Martin and Kern, Dorothee}, doi = {10.1016/j.jmb.2009.06.065}, issn = {0022-2836}, year = {2009}, date = {2009-09-01}, journal = {JOURNAL OF MOLECULAR BIOLOGY}, volume = {392}, number = {3}, pages = {823--836}, abstract = {Recent advances in experimental methods provide increasing evidence that proteins sample the conformational substates that are important for function in the absence of their ligands. An example is the receiver domain of nitrogen regulatory protein C, a member of the phosphorylation-mediated signaling family of “two-component systems.” The receiver domain of nitrogen regulatory protein C samples both inactive conformation and the active conformation before phosphorylation. Here we determine a possible pathway of interconversion between the active state and the inactive state by targeted molecular dynamics simulations and quasi-harmonic analysis; these methods are used because the experimental conversion rate is in the high microsecond range, longer than those that are easily accessible to atomistic molecular dynamics simulations. The calculated pathway is found to be composed of four consecutive stages described by different progress variables. The lowest quasi-harmonic principal components from unbiased molecular dynamics simulations on the active state correspond to the first stage, but not to the subsequent stages of the transition. The targeted molecular dynamics pathway suggests that several transient nonnative hydrogen bonds may facilitate the transition. (C) 2009 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Recent advances in experimental methods provide increasing evidence that proteins sample the conformational substates that are important for function in the absence of their ligands. An example is the receiver domain of nitrogen regulatory protein C, a member of the phosphorylation-mediated signaling family of “two-component systems.” The receiver domain of nitrogen regulatory protein C samples both inactive conformation and the active conformation before phosphorylation. Here we determine a possible pathway of interconversion between the active state and the inactive state by targeted molecular dynamics simulations and quasi-harmonic analysis; these methods are used because the experimental conversion rate is in the high microsecond range, longer than those that are easily accessible to atomistic molecular dynamics simulations. The calculated pathway is found to be composed of four consecutive stages described by different progress variables. The lowest quasi-harmonic principal components from unbiased molecular dynamics simulations on the active state correspond to the first stage, but not to the subsequent stages of the transition. The targeted molecular dynamics pathway suggests that several transient nonnative hydrogen bonds may facilitate the transition. (C) 2009 Elsevier Ltd. All rights reserved. |
Kalgin, Igor V; Karplus, Martin ; Chekmarev, Sergei F Folding of a SH3 Domain: Standard and “Hydrodynamic” Analyses Journal Article In: JOURNAL OF PHYSICAL CHEMISTRY B, 113 (38), pp. 12759–12772, 2009, ISSN: 1520-6106. @article{kalgin_folding_2009, title = {Folding of a SH3 Domain: Standard and “Hydrodynamic” Analyses}, author = {Kalgin, Igor V. and Karplus, Martin and Chekmarev, Sergei F.}, doi = {10.1021/jp903325z}, issn = {1520-6106}, year = {2009}, date = {2009-09-01}, journal = {JOURNAL OF PHYSICAL CHEMISTRY B}, volume = {113}, number = {38}, pages = {12759--12772}, abstract = {Discrete molecular dynamics has been used to Study the folding of a SH3 domain with a C-alpha-based G (o) over bar -model at a temperature within the native state stability region. A standard analysis of the folding process, based on consideration of the mean-force (free energy) surfaces, contact maps and folding time distributions, is complemented by a “hydrodynamic” description of folding flows (Chekmarev et al., PRL, 2008, 018107) using two and three collective variables. Two types of folding trajectories (fast and slow) follow essentially different routes in the final stage of folding. The hydrodynamic description makes possible the calculation of folding flows corresponding to these routes. The results show that the probability flows do not correspond to the free energy surface and that vortex formation is involved in the slow trajectories. Comparison of the simulation results with the experimental data suggests that the two-state kinetics observed for Fyn and Src SH3 domain folding are associated with the slow trajectories, in which a partly formed N- and C-terminal beta sheet hinders the RT-loop from attaching to the protein core; the fast trajectories are not observed because they are in the dead time (1 ms) of the experiments.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Discrete molecular dynamics has been used to Study the folding of a SH3 domain with a C-alpha-based G (o) over bar -model at a temperature within the native state stability region. A standard analysis of the folding process, based on consideration of the mean-force (free energy) surfaces, contact maps and folding time distributions, is complemented by a “hydrodynamic” description of folding flows (Chekmarev et al., PRL, 2008, 018107) using two and three collective variables. Two types of folding trajectories (fast and slow) follow essentially different routes in the final stage of folding. The hydrodynamic description makes possible the calculation of folding flows corresponding to these routes. The results show that the probability flows do not correspond to the free energy surface and that vortex formation is involved in the slow trajectories. Comparison of the simulation results with the experimental data suggests that the two-state kinetics observed for Fyn and Src SH3 domain folding are associated with the slow trajectories, in which a partly formed N- and C-terminal beta sheet hinders the RT-loop from attaching to the protein core; the fast trajectories are not observed because they are in the dead time (1 ms) of the experiments. |
Palma, Carlos-Andres ; Bjork, Jonas ; Bonini, Massimo ; Dyer, Matthew S; Llanes-Pallas, Anna ; Bonifazi, Davide ; Persson, Mats ; Samori, Paolo Tailoring Bicomponent Supramolecular Nanoporous Networks: Phase Segregation, Polymorphism, and Glasses at the Solid-Liquid Interface Journal Article In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131 (36), pp. 13062–13071, 2009, ISSN: 0002-7863. @article{palma_tailoring_2009, title = {Tailoring Bicomponent Supramolecular Nanoporous Networks: Phase Segregation, Polymorphism, and Glasses at the Solid-Liquid Interface}, author = {Palma, Carlos-Andres and Bjork, Jonas and Bonini, Massimo and Dyer, Matthew S. and Llanes-Pallas, Anna and Bonifazi, Davide and Persson, Mats and Samori, Paolo}, doi = {10.1021/ja9032428}, issn = {0002-7863}, year = {2009}, date = {2009-09-01}, journal = {JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, volume = {131}, number = {36}, pages = {13062--13071}, abstract = {We study the formation of four supramolecular bicomponent networks based on four linear modules (linkers) bridging melamine via triple hydrogen-bonds. We explore at the nanoscale level the phenomena of polymorphism and phase segregation which rule the generation of highly crystalline nanoporous patterns self-assembled at the solid-liquid interface. The investigated linkers include two systems exposing diuracil groups in the alpha and omega position, naphthalene tetracarboxylic diimide and pyromellitic diimide. In situ scanning tunneling microscopy (STM) investigations revealed that, when blended with melamine, out of the four systems, three are able to form two-dimensional (2D) porous architectures, two of which exhibit highly ordered hexagonal structures, while pyromellitic diimide assembles only into one-dimensional (1D) supramolecular arrays. These bicomponent self-assembled monolayers are used as a test bed to gain detailed insight into phase segregation and polymorphism in 2D supramolecular systems by exploring the contribution of hydrogen-bond energy and periodicity, molecular flexibility, concentration and ratio of the components in solution as well as the effect of annealing via time-dependent and temperature-modulated experiments. These comparative studies, obtained through a joint experimental and computational analysis, offer new insights into strategies toward the bottom-up fabrication of highly ordered tunable nanopatterning at interfaces mediated by hydrogen bonds.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We study the formation of four supramolecular bicomponent networks based on four linear modules (linkers) bridging melamine via triple hydrogen-bonds. We explore at the nanoscale level the phenomena of polymorphism and phase segregation which rule the generation of highly crystalline nanoporous patterns self-assembled at the solid-liquid interface. The investigated linkers include two systems exposing diuracil groups in the alpha and omega position, naphthalene tetracarboxylic diimide and pyromellitic diimide. In situ scanning tunneling microscopy (STM) investigations revealed that, when blended with melamine, out of the four systems, three are able to form two-dimensional (2D) porous architectures, two of which exhibit highly ordered hexagonal structures, while pyromellitic diimide assembles only into one-dimensional (1D) supramolecular arrays. These bicomponent self-assembled monolayers are used as a test bed to gain detailed insight into phase segregation and polymorphism in 2D supramolecular systems by exploring the contribution of hydrogen-bond energy and periodicity, molecular flexibility, concentration and ratio of the components in solution as well as the effect of annealing via time-dependent and temperature-modulated experiments. These comparative studies, obtained through a joint experimental and computational analysis, offer new insights into strategies toward the bottom-up fabrication of highly ordered tunable nanopatterning at interfaces mediated by hydrogen bonds. |
Mativetsky, Jeffrey M; Samori, Paolo Single-Molecule Wires Get a Lift Journal Article In: SMALL, 5 (17), pp. 1927–1930, 2009, ISSN: 1613-6810. @article{mativetsky_single-molecule_2009, title = {Single-Molecule Wires Get a Lift}, author = {Mativetsky, Jeffrey M. and Samori, Paolo}, doi = {10.1002/smll.200900650}, issn = {1613-6810}, year = {2009}, date = {2009-09-01}, journal = {SMALL}, volume = {5}, number = {17}, pages = {1927--1930}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Bonnefond, A; Vaxillaire, M; Bouatia-Naji, N; Balkau, B; Marre, M; Tichet, J; Jarvelin, M -R; Levy-Marchal, C; Horber, F; Hadjadj, S; Riveline, J -P; Charpentier, G; Sladek, R; Meyre, D; Froguel, P The genetic association between HK1 and increased HbA(1c) but not other glycaemic control related traits reveals the link between anaemia and HbA(1c) Journal Article In: DIABETOLOGIA, 52 (1), pp. S146, 2009, ISSN: 0012-186X. @article{bonnefond_genetic_2009-1, title = {The genetic association between HK1 and increased HbA(1c) but not other glycaemic control related traits reveals the link between anaemia and HbA(1c)}, author = {Bonnefond, A. and Vaxillaire, M. and Bouatia-Naji, N. and Balkau, B. and Marre, M. and Tichet, J. and Jarvelin, M. -R. and Levy-Marchal, C. and Horber, F. and Hadjadj, S. and Riveline, J. -P. and Charpentier, G. and Sladek, R. and Meyre, D. and Froguel, P.}, issn = {0012-186X}, year = {2009}, date = {2009-09-01}, journal = {DIABETOLOGIA}, volume = {52}, number = {1}, pages = {S146}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Beyler, Maryline ; Heitz, Valerie ; Sauvage, Jean-Pierre ; Ventura, Barbara ; Flamigni, Lucia ; Rissanen, Kari Three-Component Noncovalent Assembly Consisting of a Central Tetrakis-4-pyridyl Porphyrin and Two Lateral Gable-Like Bis-Zn Porphyrins Journal Article In: INORGANIC CHEMISTRY, 48 (17), pp. 8263–8270, 2009, ISSN: 0020-1669. @article{beyler_three-component_2009, title = {Three-Component Noncovalent Assembly Consisting of a Central Tetrakis-4-pyridyl Porphyrin and Two Lateral Gable-Like Bis-Zn Porphyrins}, author = {Beyler, Maryline and Heitz, Valerie and Sauvage, Jean-Pierre and Ventura, Barbara and Flamigni, Lucia and Rissanen, Kari}, doi = {10.1021/ic900887q}, issn = {0020-1669}, year = {2009}, date = {2009-09-01}, journal = {INORGANIC CHEMISTRY}, volume = {48}, number = {17}, pages = {8263--8270}, abstract = {A pentaporphyrinic assembly was formed in one step, quantitatively, from a gable like zinc(II) bis-porphyrin and a free-base meso-tetrakis(4-pyridyl)porphyrin, because of the formation of four zinc-nitrogen coordination bonds. The X-ray crystal structure obtained shows a symmetrical structure, the free-base porphyrin being located at the center of a square formed by the four zinc atoms of the two zinc(II) bis-porphyrins. The two phenanthrolines connecting the zinc porphyrins are respectively above and below the plane of the central free-base porphyrin because of favorable CH-pi interactions between several porphyrinic assemblies within the crystal. Spectrophotometric and spectrofluorimetric titrations and studies reveal a high association constant for the porphyrinic assembly in the order of 10(14) M(-2). As expected, energy transfer from the zinc porphyrin component to the central free-base porphyrin quenches the fluorescence of the zinc porphyrin components whereas no sensitization of the emission of the free-base porphyrin was observed. Hypotheses on this unusual behavior are discussed.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A pentaporphyrinic assembly was formed in one step, quantitatively, from a gable like zinc(II) bis-porphyrin and a free-base meso-tetrakis(4-pyridyl)porphyrin, because of the formation of four zinc-nitrogen coordination bonds. The X-ray crystal structure obtained shows a symmetrical structure, the free-base porphyrin being located at the center of a square formed by the four zinc atoms of the two zinc(II) bis-porphyrins. The two phenanthrolines connecting the zinc porphyrins are respectively above and below the plane of the central free-base porphyrin because of favorable CH-pi interactions between several porphyrinic assemblies within the crystal. Spectrophotometric and spectrofluorimetric titrations and studies reveal a high association constant for the porphyrinic assembly in the order of 10(14) M(-2). As expected, energy transfer from the zinc porphyrin component to the central free-base porphyrin quenches the fluorescence of the zinc porphyrin components whereas no sensitization of the emission of the free-base porphyrin was observed. Hypotheses on this unusual behavior are discussed. |
Spichty, Martin ; Taly, Antoine ; Hagn, Franz ; Kessler, Horst ; Barluenga, Sofia ; Winssinger, Nicolas ; Karplus, Martin The HSP90 binding mode of a radicicol-like E-oxime determined by docking, binding free energy estimations, and NMR N-15 chemical shifts Journal Article In: BIOPHYSICAL CHEMISTRY, 143 (3), pp. 111–123, 2009, ISSN: 0301-4622. @article{spichty_hsp90_2009, title = {The HSP90 binding mode of a radicicol-like E-oxime determined by docking, binding free energy estimations, and NMR N-15 chemical shifts}, author = {Spichty, Martin and Taly, Antoine and Hagn, Franz and Kessler, Horst and Barluenga, Sofia and Winssinger, Nicolas and Karplus, Martin}, doi = {10.1016/j.bpc.2009.04.003}, issn = {0301-4622}, year = {2009}, date = {2009-08-01}, journal = {BIOPHYSICAL CHEMISTRY}, volume = {143}, number = {3}, pages = {111--123}, abstract = {We determine the binding mode of a macrocyclic radicicol-like oxime to yeast HSP90 by combining computer simulations and experimental measurements. We sample the macrocyclic scaffold of the unbound ligand by parallel tempering simulations and dock the most populated conformations to yeast HSP90. Docking poses are then evaluated by the use of binding free energy estimations with the linear interaction energy method. Comparison of QM/MM-calculated NMR chemical shifts with experimental shift data for a selective subset of backbone N-15 provides an additional evaluation criteria. As a final test we check the binding modes against available structure-activity-relationships. We find that the most likely binding mode of the oxime to yeast HSP90 is very similar to the known structure of the radicicol-HSP90 complex. (C) 2009 Elsevier B.V. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We determine the binding mode of a macrocyclic radicicol-like oxime to yeast HSP90 by combining computer simulations and experimental measurements. We sample the macrocyclic scaffold of the unbound ligand by parallel tempering simulations and dock the most populated conformations to yeast HSP90. Docking poses are then evaluated by the use of binding free energy estimations with the linear interaction energy method. Comparison of QM/MM-calculated NMR chemical shifts with experimental shift data for a selective subset of backbone N-15 provides an additional evaluation criteria. As a final test we check the binding modes against available structure-activity-relationships. We find that the most likely binding mode of the oxime to yeast HSP90 is very similar to the known structure of the radicicol-HSP90 complex. (C) 2009 Elsevier B.V. All rights reserved. |
Mativetsky, Jeffrey M; Kastler, Marcel ; Savage, Rebecca C; Gentilini, Desiree ; Palma, Matteo ; Pisula, Wojciech ; Muellen, Klaus ; Samori, Paolo Self-Assembly of a Donor-Acceptor Dyad Across Multiple Length Scales: Functional Architectures for Organic Electronics Journal Article In: ADVANCED FUNCTIONAL MATERIALS, 19 (15), pp. 2486–2494, 2009, ISSN: 1616-301X. @article{mativetsky_self-assembly_2009, title = {Self-Assembly of a Donor-Acceptor Dyad Across Multiple Length Scales: Functional Architectures for Organic Electronics}, author = {Mativetsky, Jeffrey M. and Kastler, Marcel and Savage, Rebecca C. and Gentilini, Desiree and Palma, Matteo and Pisula, Wojciech and Muellen, Klaus and Samori, Paolo}, doi = {10.1002/adfm.200900366}, issn = {1616-301X}, year = {2009}, date = {2009-08-01}, journal = {ADVANCED FUNCTIONAL MATERIALS}, volume = {19}, number = {15}, pages = {2486--2494}, abstract = {Molecular dyads based on polycyclic electron donar (D) and electron acceptor (A) units represents suitable building blocks for forming highly ordered, solution-processable, nanosegregated D-A domains for potential use in (opto)electronic applications. A new dyad, based on alkyl substituted hexa-peri-hexabenzocoronene (HBC) and perylene monoimide (PMI) separated by an ethinylene linker, is shown to have a high tendency to self-assemble into ordered supramolecular arrangements at multiple length scales: macroscopic extruded filaments display long-range crystalline order, nanofiber networks are produced by simple spin-coating, and monolayers with a lamellar packing are formed by physisorption at the solution-HOPG interface. Moreover, highly uniform mesoscopic ribbons bearing atomically flat facets and steps with single-molecule heights self-assemble upon solvent-vapor annealing. Electrical measurements of HBC-PMI films and mesoscopic ribbons in a transistor configuration exhibit ambipolar transport with well balanced p- and n-type mobilities. Owing to the increased level of order at the supramolecular level, devices based on ribbons show mobility increases of more than one order of magnitude.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Molecular dyads based on polycyclic electron donar (D) and electron acceptor (A) units represents suitable building blocks for forming highly ordered, solution-processable, nanosegregated D-A domains for potential use in (opto)electronic applications. A new dyad, based on alkyl substituted hexa-peri-hexabenzocoronene (HBC) and perylene monoimide (PMI) separated by an ethinylene linker, is shown to have a high tendency to self-assemble into ordered supramolecular arrangements at multiple length scales: macroscopic extruded filaments display long-range crystalline order, nanofiber networks are produced by simple spin-coating, and monolayers with a lamellar packing are formed by physisorption at the solution-HOPG interface. Moreover, highly uniform mesoscopic ribbons bearing atomically flat facets and steps with single-molecule heights self-assemble upon solvent-vapor annealing. Electrical measurements of HBC-PMI films and mesoscopic ribbons in a transistor configuration exhibit ambipolar transport with well balanced p- and n-type mobilities. Owing to the increased level of order at the supramolecular level, devices based on ribbons show mobility increases of more than one order of magnitude. |
Drezet, A; Przybilla, F; Laux, E; Mahboub, O; Genet, C; Ebbesen, T W; Bouillard, J S; Zayats, A V; Spevak, I S; Kats, A V; Nikitin, Yu A; Martin-Moreno, L Opening the light extraction cone of high index substrates with plasmonic gratings: Light emitting diode applications (vol 95, 021101, 2009) Journal Article In: APPLIED PHYSICS LETTERS, 95 (6), 2009, ISSN: 0003-6951. @article{drezet_opening_2009, title = {Opening the light extraction cone of high index substrates with plasmonic gratings: Light emitting diode applications (vol 95, 021101, 2009)}, author = {Drezet, A. and Przybilla, F. and Laux, E. and Mahboub, O. and Genet, C. and Ebbesen, T. W. and Bouillard, J. S. and Zayats, A. V. and Spevak, I. S. and Kats, A. V. and Nikitin, A. Yu and Martin-Moreno, L.}, doi = {10.1063/1.3202553}, issn = {0003-6951}, year = {2009}, date = {2009-08-01}, journal = {APPLIED PHYSICS LETTERS}, volume = {95}, number = {6}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Aouani, Heykel ; Wenger, Jerome ; Gerard, Davy ; Rigneault, Herve ; Devaux, Eloise ; Ebbesen, Thomas W; Mahdavi, Farhad ; Xu, Tingjun ; Blair, Steve Crucial Role of the Adhesion Layer on the Plasmonic Fluorescence Enhancement Journal Article In: ACS NANO, 3 (7), pp. 2043–2048, 2009, ISSN: 1936-0851. @article{aouani_crucial_2009, title = {Crucial Role of the Adhesion Layer on the Plasmonic Fluorescence Enhancement}, author = {Aouani, Heykel and Wenger, Jerome and Gerard, Davy and Rigneault, Herve and Devaux, Eloise and Ebbesen, Thomas W. and Mahdavi, Farhad and Xu, Tingjun and Blair, Steve}, doi = {10.1021/nn900460t}, issn = {1936-0851}, year = {2009}, date = {2009-07-01}, journal = {ACS NANO}, volume = {3}, number = {7}, pages = {2043--2048}, abstract = {A nanoscale layer of chromium or titanium is commonly used in plasmonic nanoantennas to firmly adhere a gold film to a glass substrate, yet the influence of this layer on the antenna performance is often ignored. As a result, the need for the use of potentially better materials is not widely recognized. Using a single aperture milled in a gold film with 120 nm diameter as a nanobench for these investigations, we present the first experimental report of the strong dependence of the plasmonic enhancement of single-molecule fluorescence on the nature of the adhesion layer. By combining fluorescence correlation spectroscopy and fluorescence lifetime measurements, we show that this structure is very sensitive to the properties of the adhesion layer, and we detail the respective contributions of excitation and emission gains to the observed enhanced fluorescence. Any increase in the absorption losses due to the adhesion layer permittivity or thickness is shown to lower the gains in both excitation and emission, which we relate to a damping of the energy coupling at the nanoaperture. With this nanobench, we demonstrate the largest enhancement factor reported to date (25 X) by using a TiO2 adhesion layer. The experimental data are supported by numerical simulations and argue for a careful consideration of the adhesion layer while designing nanoantennas for high-efficiency single-molecule analysis.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A nanoscale layer of chromium or titanium is commonly used in plasmonic nanoantennas to firmly adhere a gold film to a glass substrate, yet the influence of this layer on the antenna performance is often ignored. As a result, the need for the use of potentially better materials is not widely recognized. Using a single aperture milled in a gold film with 120 nm diameter as a nanobench for these investigations, we present the first experimental report of the strong dependence of the plasmonic enhancement of single-molecule fluorescence on the nature of the adhesion layer. By combining fluorescence correlation spectroscopy and fluorescence lifetime measurements, we show that this structure is very sensitive to the properties of the adhesion layer, and we detail the respective contributions of excitation and emission gains to the observed enhanced fluorescence. Any increase in the absorption losses due to the adhesion layer permittivity or thickness is shown to lower the gains in both excitation and emission, which we relate to a damping of the energy coupling at the nanoaperture. With this nanobench, we demonstrate the largest enhancement factor reported to date (25 X) by using a TiO2 adhesion layer. The experimental data are supported by numerical simulations and argue for a careful consideration of the adhesion layer while designing nanoantennas for high-efficiency single-molecule analysis. |
Brooks, B R; Brooks III, C L; Mackerell Jr., A D; Nilsson, L; Petrella, R J; Roux, B; Won, Y; Archontis, G; Bartels, C; Boresch, S; Caflisch, A; Caves, L; Cui, Q; Dinner, A R; Feig, M; Fischer, S; Gao, J; Hodoscek, M; Im, W; Kuczera, K; Lazaridis, T; Ma, J; Ovchinnikov, V; Paci, E; Pastor, R W; Post, C B; Pu, J Z; Schaefer, M; Tidor, B; Venable, R M; Woodcock, H L; Wu, X; Yang, W; York, D M; Karplus, M CHARMM: The Biomolecular Simulation Program Journal Article In: JOURNAL OF COMPUTATIONAL CHEMISTRY, 30 (10, SI), pp. 1545–1614, 2009, ISSN: 0192-8651. @article{brooks_charmm:_2009, title = {CHARMM: The Biomolecular Simulation Program}, author = {Brooks, B. R. and Brooks, III, C. L. and Mackerell, Jr., A. D. and Nilsson, L. and Petrella, R. J. and Roux, B. and Won, Y. and Archontis, G. and Bartels, C. and Boresch, S. and Caflisch, A. and Caves, L. and Cui, Q. and Dinner, A. R. and Feig, M. and Fischer, S. and Gao, J. and Hodoscek, M. and Im, W. and Kuczera, K. and Lazaridis, T. and Ma, J. and Ovchinnikov, V. and Paci, E. and Pastor, R. W. and Post, C. B. and Pu, J. Z. and Schaefer, M. and Tidor, B. and Venable, R. M. and Woodcock, H. L. and Wu, X. and Yang, W. and York, D. M. and Karplus, M.}, doi = {10.1002/jcc.21287}, issn = {0192-8651}, year = {2009}, date = {2009-07-01}, journal = {JOURNAL OF COMPUTATIONAL CHEMISTRY}, volume = {30}, number = {10, SI}, pages = {1545--1614}, abstract = {CHARMM (Chemistry at HARvard Molecular Mechanics) is a highly versatile and widely used molecular simulation program. It has been developed over the last three decades with a primary focus on molecules of biological interest, including proteins, peptides, lipids, nucleic acids, carbohydrates, and small molecule ligands, as they occur in solution, crystals, and membrane environments. For the study of such systems. the program provides a large suite of computational tools that include numerous conformational and path sampling methods, free energy estimators, molecular minimization, dynamics, and analysis techniques, and model-building capabilities. The CHARMM program is applicable to problems involving a much broader class of many-particle systems. Calculations with CHARMM can be performed using a number of different energy functions and models, from mixed quantum mechanical-molecular mechanical force fields, to all-atom classical potential energy functions with explicit solvent and various boundary conditions, to implicit solvent and membrane models. The program has been ported to numerous platforms in both serial and parallel architectures. This article provides an overview of the program as it exists today with an emphasis on developments since the publication of the original CHARMM article in 1983. (C) 2009 Wiley Periodicals, Inc. J Comput Chem 30: 1545-1614, 2009}, keywords = {}, pubstate = {published}, tppubtype = {article} } CHARMM (Chemistry at HARvard Molecular Mechanics) is a highly versatile and widely used molecular simulation program. It has been developed over the last three decades with a primary focus on molecules of biological interest, including proteins, peptides, lipids, nucleic acids, carbohydrates, and small molecule ligands, as they occur in solution, crystals, and membrane environments. For the study of such systems. the program provides a large suite of computational tools that include numerous conformational and path sampling methods, free energy estimators, molecular minimization, dynamics, and analysis techniques, and model-building capabilities. The CHARMM program is applicable to problems involving a much broader class of many-particle systems. Calculations with CHARMM can be performed using a number of different energy functions and models, from mixed quantum mechanical-molecular mechanical force fields, to all-atom classical potential energy functions with explicit solvent and various boundary conditions, to implicit solvent and membrane models. The program has been ported to numerous platforms in both serial and parallel architectures. This article provides an overview of the program as it exists today with an emphasis on developments since the publication of the original CHARMM article in 1983. (C) 2009 Wiley Periodicals, Inc. J Comput Chem 30: 1545-1614, 2009 |
Cecchini, M; Krivov, S V; Spichty, M; Karplus, M Calculation of Free-Energy Differences by Confinement Simulations. Application to Peptide Conformers Journal Article In: JOURNAL OF PHYSICAL CHEMISTRY B, 113 (29), pp. 9728–9740, 2009, ISSN: 1520-6106. @article{cecchini_calculation_2009, title = {Calculation of Free-Energy Differences by Confinement Simulations. Application to Peptide Conformers}, author = {Cecchini, M. and Krivov, S. V. and Spichty, M. and Karplus, M.}, doi = {10.1021/jp9020646}, issn = {1520-6106}, year = {2009}, date = {2009-07-01}, journal = {JOURNAL OF PHYSICAL CHEMISTRY B}, volume = {113}, number = {29}, pages = {9728--9740}, abstract = {Conformational free-energy differences are key quantities for understanding important phenomena in molecular biology that involve large structural changes of macromolecules. In this paper, all improved version of the confinement approach, which is based oil earlier developments, is used to determine the free energy of individual molecular states by progressively restraining the corresponding molecular structures to pure harmonic basins, whose absolute free energy can be computed by normal-mode analysis. The method is used to calculate the free-energy difference between two conformational states of the alanine dipeptide in vacuo, and of the P-hairpin from protein G with an implicit solvation model. In all cases, the confinement results are in excellent agreement with the ones obtained from converged equilibrium molecular dynamics simulations, which have a much larger computational cost. The systematic and statistical errors of the results are evaluated and the origin of the errors is identified. The sensitivity of the calculated free-energy differences to structure-based definitions of the molecular states is discussed. A variant of the method, which closes the thermodynamic cycle by a quasi-harmonic rather than harmonic analysis, is introduced. The latter is proposed for possible use with explicit solvent simulations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Conformational free-energy differences are key quantities for understanding important phenomena in molecular biology that involve large structural changes of macromolecules. In this paper, all improved version of the confinement approach, which is based oil earlier developments, is used to determine the free energy of individual molecular states by progressively restraining the corresponding molecular structures to pure harmonic basins, whose absolute free energy can be computed by normal-mode analysis. The method is used to calculate the free-energy difference between two conformational states of the alanine dipeptide in vacuo, and of the P-hairpin from protein G with an implicit solvation model. In all cases, the confinement results are in excellent agreement with the ones obtained from converged equilibrium molecular dynamics simulations, which have a much larger computational cost. The systematic and statistical errors of the results are evaluated and the origin of the errors is identified. The sensitivity of the calculated free-energy differences to structure-based definitions of the molecular states is discussed. A variant of the method, which closes the thermodynamic cycle by a quasi-harmonic rather than harmonic analysis, is introduced. The latter is proposed for possible use with explicit solvent simulations. |
Bonini, Massimo ; Zalewski, Leszek ; Breiner, Thomas ; Doetz, Florian ; Kastler, Marcel ; Schaedler, Volker ; Surin, Mathieu ; Lazzaroni, Roberto ; Samori, Paolo Competitive Physisorption Among Alkyl-Substituted pi-Conjugated Oligomers at the Solid-Liquid Interface: Towards Prediction of Self-Assembly at Surfaces from a Multicomponent Solution Journal Article In: SMALL, 5 (13), pp. 1521–1526, 2009, ISSN: 1613-6810. @article{bonini_competitive_2009, title = {Competitive Physisorption Among Alkyl-Substituted pi-Conjugated Oligomers at the Solid-Liquid Interface: Towards Prediction of Self-Assembly at Surfaces from a Multicomponent Solution}, author = {Bonini, Massimo and Zalewski, Leszek and Breiner, Thomas and Doetz, Florian and Kastler, Marcel and Schaedler, Volker and Surin, Mathieu and Lazzaroni, Roberto and Samori, Paolo}, doi = {10.1002/smll.200801901}, issn = {1613-6810}, year = {2009}, date = {2009-07-01}, journal = {SMALL}, volume = {5}, number = {13}, pages = {1521--1526}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Riveline, Daniel ; Nurse, Paul `Injecting' yeast Journal Article In: NATURE METHODS, 6 (7), pp. 513–U64, 2009, ISSN: 1548-7091. @article{riveline_`injecting_2009, title = {`Injecting' yeast}, author = {Riveline, Daniel and Nurse, Paul}, doi = {10.1038/nmeth.1335}, issn = {1548-7091}, year = {2009}, date = {2009-07-01}, journal = {NATURE METHODS}, volume = {6}, number = {7}, pages = {513--U64}, abstract = {Yeast is a powerful genetic model system, but its rigid cell wall has prohibited microinjection. Using microfabricated channels to constrain the fission yeast Schizosaccharomyces pombe, we sheared local regions of individual cells with a piezoelectric unit. The cells remained viable, we detected actin patches in the cell after introduction of fluorescent phalloidin into the medium, and the cytokinetic ring was disrupted after injection of the myosin II inhibitor blebbistatin.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Yeast is a powerful genetic model system, but its rigid cell wall has prohibited microinjection. Using microfabricated channels to constrain the fission yeast Schizosaccharomyces pombe, we sheared local regions of individual cells with a piezoelectric unit. The cells remained viable, we detected actin patches in the cell after introduction of fluorescent phalloidin into the medium, and the cytokinetic ring was disrupted after injection of the myosin II inhibitor blebbistatin. |
Wang, Cuihua ; Barluenga, Sofia ; Koripelly, Girish K; Fontaine, Jean-Gonzague ; Chen, Ruihong ; Yu, Jin-Chen ; Shen, Xiaodong ; Chabala, John C; Heck, James V; Rubenstein, Allan ; Winssinger, Nicolas Synthesis of pochoxime prodrugs as potent HSP90 inhibitors Journal Article In: BIOORGANIC & MEDICINAL CHEMISTRY LETTERS, 19 (14), pp. 3836–3840, 2009, ISSN: 0960-894X. @article{wang_synthesis_2009, title = {Synthesis of pochoxime prodrugs as potent HSP90 inhibitors}, author = {Wang, Cuihua and Barluenga, Sofia and Koripelly, Girish K. and Fontaine, Jean-Gonzague and Chen, Ruihong and Yu, Jin-Chen and Shen, Xiaodong and Chabala, John C. and Heck, James V. and Rubenstein, Allan and Winssinger, Nicolas}, doi = {10.1016/j.bmcl.2009.04.030}, issn = {0960-894X}, year = {2009}, date = {2009-07-01}, journal = {BIOORGANIC & MEDICINAL CHEMISTRY LETTERS}, volume = {19}, number = {14}, pages = {3836--3840}, abstract = {Pochoximes are potent inhibitors of heat shock protein 90 (HSP90) based on the radicicol pharmacophores. Herein we present a pharmacokinetics and pharmacodynamics evaluation of this compound series as well as a phosphate prodrug strategy to facilitate formulation and improve oral bioavailability. (C) 2009 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Pochoximes are potent inhibitors of heat shock protein 90 (HSP90) based on the radicicol pharmacophores. Herein we present a pharmacokinetics and pharmacodynamics evaluation of this compound series as well as a phosphate prodrug strategy to facilitate formulation and improve oral bioavailability. (C) 2009 Elsevier Ltd. All rights reserved. |
Drezet, A; Przybilla, F; Laux, E; Mahboub, O; Genet, C; Ebbesen, T W; Bouillard, J S; Zayats, A; Spevak, I S; Zayats, A V; Nikitin, Yu A; Martin-Moreno, L Opening the light extraction cone of high index substrates with plasmonic gratings: Light emitting diode applications Journal Article In: APPLIED PHYSICS LETTERS, 95 (2), 2009, ISSN: 0003-6951. @article{drezet_opening_2009-1, title = {Opening the light extraction cone of high index substrates with plasmonic gratings: Light emitting diode applications}, author = {Drezet, A. and Przybilla, F. and Laux, E. and Mahboub, O. and Genet, C. and Ebbesen, T. W. and Bouillard, J. S. and Zayats, A. and Spevak, I. S. and Zayats, A. V. and Nikitin, A. Yu and Martin-Moreno, L.}, doi = {10.1063/1.3176435}, issn = {0003-6951}, year = {2009}, date = {2009-07-01}, journal = {APPLIED PHYSICS LETTERS}, volume = {95}, number = {2}, abstract = {The opening of the light extraction cone of a high index substrate (GaP) is demonstrated using plasmonic gratings. We show that the excitation of surface plasmons on the metal grating leads to the extraction of light otherwise undergoing total internal reflection in the substrate with high efficiency. This effect has an immediate application in the context of light emitting diodes, where resonant metal gratings are promising for the design of dual purpose electric contact/extraction structures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The opening of the light extraction cone of a high index substrate (GaP) is demonstrated using plasmonic gratings. We show that the excitation of surface plasmons on the metal grating leads to the extraction of light otherwise undergoing total internal reflection in the substrate with high efficiency. This effect has an immediate application in the context of light emitting diodes, where resonant metal gratings are promising for the design of dual purpose electric contact/extraction structures. |
Castano, Sabine ; Delord, Brigitte ; Fevrier, Annie ; Lehn, Jean-Marie ; Lehn, Pierre ; Desbat, Bernard Asymmetric lipid bilayer formation stabilized by DNA at the air/water interface Journal Article In: BIOCHIMIE, 91 (6), pp. 765–773, 2009, ISSN: 0300-9084. @article{castano_asymmetric_2009, title = {Asymmetric lipid bilayer formation stabilized by DNA at the air/water interface}, author = {Castano, Sabine and Delord, Brigitte and Fevrier, Annie and Lehn, Jean-Marie and Lehn, Pierre and Desbat, Bernard}, doi = {10.1016/j.biochi.2009.01.005}, issn = {0300-9084}, year = {2009}, date = {2009-06-01}, journal = {BIOCHIMIE}, volume = {91}, number = {6}, pages = {765--773}, abstract = {The lipid bis(guanidinium)-tren-cholesterol (BGTC) is a cationic cholesterol derivative bearing guanidinium polar headgroups used for gene transfection either alone or formulated as liposomes with the zwitterionic lipid 1,2-di-[cis-9-octadecenoyl]-sn-glycero-3-phosphoethanolamine (DOPE). Previous investigations have shown its ability to strongly interact with DNA and form asymmetric lipid bilayers at the air/water interface when mixed with DOPE. Here, with a view to further investigate its physicochemical behavior, we studied the interactions of mixtures of BGTC with another zwitterionic lipid, 1,2-Dimyristoyl-sn-Glycero-3-Phosphocholine, (DMPC), with DNA at the air/water interface by using the Langmuir monolayer technique coupled with Brewster Angle Microscopy (BAM) and Polarization Modulation Infra Red Reflexion Absorption (PMIRRAS) spectroscopy and we investigate DNA-BGTC/DMPC interactions. We demonstrate that when DNA is injected into the subphase in excess compared to the positive charges of BGTC, it adsorbs to BGTC/DMPC monolayers at 20 mN/m whatever the lipid monolayer composition (1/5, 2/3 or 3/2 BGTC/DMPC molar ratio) and forms an incomplete monolayer of either isotropic or anisotropic double strands depending on the BGTC content in the monolayer. Compression beyond the collapse of some mixed DNA-BGTC/DMPC (2/3 and 3/2 molar ratio) systems leads to the formation of DNA monolayers underneath asymmetric lipid bilayers characterized by a bottom layer of BGTC in contact with DNA and a top layer mainly constituted of DMPC. (c) 2009 Elsevier Masson SAS. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The lipid bis(guanidinium)-tren-cholesterol (BGTC) is a cationic cholesterol derivative bearing guanidinium polar headgroups used for gene transfection either alone or formulated as liposomes with the zwitterionic lipid 1,2-di-[cis-9-octadecenoyl]-sn-glycero-3-phosphoethanolamine (DOPE). Previous investigations have shown its ability to strongly interact with DNA and form asymmetric lipid bilayers at the air/water interface when mixed with DOPE. Here, with a view to further investigate its physicochemical behavior, we studied the interactions of mixtures of BGTC with another zwitterionic lipid, 1,2-Dimyristoyl-sn-Glycero-3-Phosphocholine, (DMPC), with DNA at the air/water interface by using the Langmuir monolayer technique coupled with Brewster Angle Microscopy (BAM) and Polarization Modulation Infra Red Reflexion Absorption (PMIRRAS) spectroscopy and we investigate DNA-BGTC/DMPC interactions. We demonstrate that when DNA is injected into the subphase in excess compared to the positive charges of BGTC, it adsorbs to BGTC/DMPC monolayers at 20 mN/m whatever the lipid monolayer composition (1/5, 2/3 or 3/2 BGTC/DMPC molar ratio) and forms an incomplete monolayer of either isotropic or anisotropic double strands depending on the BGTC content in the monolayer. Compression beyond the collapse of some mixed DNA-BGTC/DMPC (2/3 and 3/2 molar ratio) systems leads to the formation of DNA monolayers underneath asymmetric lipid bilayers characterized by a bottom layer of BGTC in contact with DNA and a top layer mainly constituted of DMPC. (c) 2009 Elsevier Masson SAS. All rights reserved. |
Barboiu, Mihail ; Legrand, Yves-Marie ; Prodi, Luca ; Montalti, Marco ; Zaccheroni, Nelsi ; Vaughan, Gavin ; van der Lee, Arie ; Petit, Eddy ; Lehn, Jean-Marie Modulation of Photochemical Properties in Ion-Controlled Multicomponent Dynamic Devices Journal Article In: EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, (18), pp. 2621–2628, 2009, ISSN: 1434-1948. @article{barboiu_modulation_2009, title = {Modulation of Photochemical Properties in Ion-Controlled Multicomponent Dynamic Devices}, author = {Barboiu, Mihail and Legrand, Yves-Marie and Prodi, Luca and Montalti, Marco and Zaccheroni, Nelsi and Vaughan, Gavin and van der Lee, Arie and Petit, Eddy and Lehn, Jean-Marie}, doi = {10.1002/ejic.200900089}, issn = {1434-1948}, year = {2009}, date = {2009-06-01}, journal = {EUROPEAN JOURNAL OF INORGANIC CHEMISTRY}, number = {18}, pages = {2621--2628}, abstract = {A bis-pyrenyl-terpyridine ligand 1 has been synthesised and used to prepare zinc homo- and heterocomplexes and their photophysical properties have been studied. Fluorescence titrations displayed modulation of absorption and emission, depending on the molarities of the ionic species (Zn2+, H+). Two single-crystal structures give insights into the formation of multicomponent supramolecular networks, also present in solution as shown by NMR and ESI-MS spectroscopy. NMR spectroscopy revealed fast exchanges of the ligands complexed around the metal ion, which could be reduced at lower temperature. Conformational (from W to U shape) and photophysical changes of the flexible ligand were demonstrated in the solid and liquid phases, Addition of zinc ions to the solution of ligands changes the absorption and fluorescence spectra noticeably. The zinc complexes do not form exciplexes; the fluorescence is mainly due to charge-transfer transitions. The present work illustrates the potential use of ion-triggered switches to generate mechanical motions that can be followed photophysically. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)}, keywords = {}, pubstate = {published}, tppubtype = {article} } A bis-pyrenyl-terpyridine ligand 1 has been synthesised and used to prepare zinc homo- and heterocomplexes and their photophysical properties have been studied. Fluorescence titrations displayed modulation of absorption and emission, depending on the molarities of the ionic species (Zn2+, H+). Two single-crystal structures give insights into the formation of multicomponent supramolecular networks, also present in solution as shown by NMR and ESI-MS spectroscopy. NMR spectroscopy revealed fast exchanges of the ligands complexed around the metal ion, which could be reduced at lower temperature. Conformational (from W to U shape) and photophysical changes of the flexible ligand were demonstrated in the solid and liquid phases, Addition of zinc ions to the solution of ligands changes the absorption and fluorescence spectra noticeably. The zinc complexes do not form exciplexes; the fluorescence is mainly due to charge-transfer transitions. The present work illustrates the potential use of ion-triggered switches to generate mechanical motions that can be followed photophysically. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) |
Roche, Cecile ; Sour, Angelique ; Niess, Frederic ; Heitz, Valerie ; Sauvage, Jean-Pierre A Zinc Porphyrin Bearing Two Lateral dpp-Containing Rings and Its [3]Pseudorotaxane (dpp: 2,9-diphenyl-1,10-phenanthroline) Journal Article In: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, (17), pp. 2795–2800, 2009, ISSN: 1434-193X. @article{roche_zinc_2009, title = {A Zinc Porphyrin Bearing Two Lateral dpp-Containing Rings and Its [3]Pseudorotaxane (dpp: 2,9-diphenyl-1,10-phenanthroline)}, author = {Roche, Cecile and Sour, Angelique and Niess, Frederic and Heitz, Valerie and Sauvage, Jean-Pierre}, doi = {10.1002/ejoc.200900136}, issn = {1434-193X}, year = {2009}, date = {2009-06-01}, journal = {EUROPEAN JOURNAL OF ORGANIC CHEMISTRY}, number = {17}, pages = {2795--2800}, abstract = {A zinc porphyrin attached to two dpp-containing rings was prepared from a 31-membered ring with an attached pendent aldehyde function and 5-mesityldipyrromethane by using the synthetic method introduced long ago by Lindsey and his group. The obtained porphyrin is of the ABAB type, with two mesityl groups on the 5- and 15-positions and two macrocycles on the 10- and 20-positions. From this compound, a [3]pseudorotaxane was obtained in good yield from the reaction of the porphyrin with two equivalents of a copper(I) salt followed by the addition of two equivalents of 2,9-dianisyl-1,10-phenanthroline. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)}, keywords = {}, pubstate = {published}, tppubtype = {article} } A zinc porphyrin attached to two dpp-containing rings was prepared from a 31-membered ring with an attached pendent aldehyde function and 5-mesityldipyrromethane by using the synthetic method introduced long ago by Lindsey and his group. The obtained porphyrin is of the ABAB type, with two mesityl groups on the 5- and 15-positions and two macrocycles on the 10- and 20-positions. From this compound, a [3]pseudorotaxane was obtained in good yield from the reaction of the porphyrin with two equivalents of a copper(I) salt followed by the addition of two equivalents of 2,9-dianisyl-1,10-phenanthroline. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) |
Beyler, Maryline ; Beemelmanns, Christine ; Heitz, Valerie ; Sauvage, Jean-Pierre Various Synthetic Routes to a Gable-Like Bis(porphyrin) Constructed on a 1,10-Phenanthroline Chelate Journal Article In: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, (17), pp. 2801–2805, 2009, ISSN: 1434-193X. @article{beyler_various_2009, title = {Various Synthetic Routes to a Gable-Like Bis(porphyrin) Constructed on a 1,10-Phenanthroline Chelate}, author = {Beyler, Maryline and Beemelmanns, Christine and Heitz, Valerie and Sauvage, Jean-Pierre}, doi = {10.1002/ejoc.200900149}, issn = {1434-193X}, year = {2009}, date = {2009-06-01}, journal = {EUROPEAN JOURNAL OF ORGANIC CHEMISTRY}, number = {17}, pages = {2801--2805}, abstract = {Three different synthetic routes to obtain a gable-like bis(porphyrin) are described. The two porphyrins are covalently linked to a 2,9-diphenyl-1,10-phenanthroline chelate. One way to gain access to the bis(porphyrin) relies on the simultaneous construction of two porphyrins on a 2,9-bis(para-formylphenyl)-1,10-phenanthroline, whereas the other two are based on Suzuki cross-coupling reactions between a presynthesised porphyrin and an appropriate phenanthroline derivative. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)}, keywords = {}, pubstate = {published}, tppubtype = {article} } Three different synthetic routes to obtain a gable-like bis(porphyrin) are described. The two porphyrins are covalently linked to a 2,9-diphenyl-1,10-phenanthroline chelate. One way to gain access to the bis(porphyrin) relies on the simultaneous construction of two porphyrins on a 2,9-bis(para-formylphenyl)-1,10-phenanthroline, whereas the other two are based on Suzuki cross-coupling reactions between a presynthesised porphyrin and an appropriate phenanthroline derivative. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) |
Dabirian, Reza ; Palermo, Vincenzo ; Liscio, Andrea ; Schwartz, Erik ; Otten, Matthijs B J; Finlayson, Chris E; Treossi, Emanuele ; Friend, Richard H; Calestani, Gianluca ; Muellen, Klaus ; Nolte, Roeland J M; Rowan, Alan E; Samori, Paolo The Relationship between Nanoscale Architecture and Charge Transport in Conjugated Nanocrystals Bridged by Multichromophoric Polymers Journal Article In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131 (20), pp. 7055–7063, 2009, ISSN: 0002-7863. @article{dabirian_relationship_2009, title = {The Relationship between Nanoscale Architecture and Charge Transport in Conjugated Nanocrystals Bridged by Multichromophoric Polymers}, author = {Dabirian, Reza and Palermo, Vincenzo and Liscio, Andrea and Schwartz, Erik and Otten, Matthijs B. J. and Finlayson, Chris E. and Treossi, Emanuele and Friend, Richard H. and Calestani, Gianluca and Muellen, Klaus and Nolte, Roeland J. M. and Rowan, Alan E. and Samori, Paolo}, doi = {10.1021/ja809731e}, issn = {0002-7863}, year = {2009}, date = {2009-05-01}, journal = {JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, volume = {131}, number = {20}, pages = {7055--7063}, abstract = {We report on the self-assembly and the electrical characterization of bicomponent films consisting of an organic semiconducting small molecule blended with a rigid polymeric scaffold functionalized in the side chains with monomeric units of the same molecule. The molecule and polymer are a perylene-bis(dicarboximide) monomer (M-PDI) and a perylene-bis(dicarboximide)-functionalized poly(isocyanopeptide) (P-PDI), which have been codeposited on SiOx and mica substrates from solution. These bicomponent films have been characterized by atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM), revealing the relationship between architecture and function for various supramolecular nanocrystalline arrangements at a nanometer spatial resolution. Monomer-polymer interactions can be controlled by varying solvent and/or substrate polarity, so that either the monomer packing dictates the polymer morphology or vice versa, leading to a morphology exhibiting M-PDI nanocrystals connected with each other by P-PDI polymer wires. Compared to pure M-PDI or P-PDI films, those bicomponent films that possess polymer interconnections between crystallites of the monomer display a significant improvement in electrical connectivity and a 2 orders of magnitude increase in charge carrier mobility within the film, as measured in thin film transistor (TFT) devices. Of a more fundamental interest, our technique allows the bridging of semiconducting crystals, without the formation of injection barriers at the connection points.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We report on the self-assembly and the electrical characterization of bicomponent films consisting of an organic semiconducting small molecule blended with a rigid polymeric scaffold functionalized in the side chains with monomeric units of the same molecule. The molecule and polymer are a perylene-bis(dicarboximide) monomer (M-PDI) and a perylene-bis(dicarboximide)-functionalized poly(isocyanopeptide) (P-PDI), which have been codeposited on SiOx and mica substrates from solution. These bicomponent films have been characterized by atomic force microscopy (AFM) and Kelvin probe force microscopy (KPFM), revealing the relationship between architecture and function for various supramolecular nanocrystalline arrangements at a nanometer spatial resolution. Monomer-polymer interactions can be controlled by varying solvent and/or substrate polarity, so that either the monomer packing dictates the polymer morphology or vice versa, leading to a morphology exhibiting M-PDI nanocrystals connected with each other by P-PDI polymer wires. Compared to pure M-PDI or P-PDI films, those bicomponent films that possess polymer interconnections between crystallites of the monomer display a significant improvement in electrical connectivity and a 2 orders of magnitude increase in charge carrier mobility within the film, as measured in thin film transistor (TFT) devices. Of a more fundamental interest, our technique allows the bridging of semiconducting crystals, without the formation of injection barriers at the connection points. |
Publications
2010 |
Control of Relative Direction and Amplitude in Extension/Contraction Motions of Molecular Strands Induced by Ion Binding Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 16 (18), pp. 5369–5378, 2010, ISSN: 0947-6539. |
Ru-II Multinuclear Metallosupramolecular Rack-Type Architectures of Polytopic Hydrazone-Based Ligands: Synthesis, Structural Features, Absorption Spectra, Redox Behavior, and Near-Infrared Luminescence Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 16 (19), pp. 5645–5660, 2010, ISSN: 0947-6539. |
Multivalent Supramolecular Dendrimer-Based Drugs Journal Article In: BIOMACROMOLECULES, 11 (1), pp. 182–186, 2010, ISSN: 1525-7797. |
Clickable peptide nucleic acids (cPNA) with tunable affinity Journal Article In: CHEMICAL COMMUNICATIONS, 46 (30), pp. 5476–5478, 2010, ISSN: 1359-7345. |
Sensitization of the NIR emission of Nd(III) by the alpha 4 atropoisomer of a meso-tetraphenyl porphyrin bearing four 8-hydroxyquinolinylamide chelates Journal Article In: CHEMICAL COMMUNICATIONS, 46 (4), pp. 619–621, 2010, ISSN: 1359-7345. |
Ligand dimerization programmed by hybridization to study multimeric ligand-receptor interactions Journal Article In: CHEMICAL COMMUNICATIONS, 46 (41), pp. 7742–7744, 2010, ISSN: 1359-7345. |
Dipyrrin based luminescent cyclometallated palladium and platinum complexes Journal Article In: DALTON TRANSACTIONS, 39 (1), pp. 180–184, 2010, ISSN: 1477-9226. |
Concise Modular Asymmetric Synthesis of Deguelin, Tephrosin and Investigation into Their Mode of Action Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 16 (32), pp. 9767–9771, 2010, ISSN: 0947-6539. |
Cyclometalated Ru-II Complexes with Improved Octahedral Geometry: Synthesis and Photophysical Properties Journal Article In: INORGANIC CHEMISTRY, 49 (2), pp. 374–376, 2010, ISSN: 0020-1669. |
Substrate screening identifies a novel target sequence for the proteasomal activity regulated by ionizing radiation Journal Article In: PROTEOMICS, 10 (2), pp. 304–314, 2010, ISSN: 1615-9853. |
A Cyclic [4]rotaxane that Behaves as a Switchable Molecular Receptor: Formation of a Rigid Scaffold from a Collapsed Structure by Complexation with Copper(I) Ions Journal Article In: ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 49 (52), pp. 10172–10175, 2010, ISSN: 1433-7851. |
Unusual Photoinduced Electron Transfer from a Zinc Porphyrin to a Tetrapyridyl Free-Base Porphyrin in a Noncovalent Multiporphyrin Array Journal Article In: CHEMISTRY-A EUROPEAN JOURNAL, 16 (29), pp. 8748–8756, 2010, ISSN: 0947-6539. |
Copper-complexed catenanes and rotaxanes in motion: 15 years of molecular machines Journal Article In: DALTON TRANSACTIONS, 39 (44), pp. 10557–10570, 2010, ISSN: 1477-9226. |
A copper-based shuttling [2]rotaxane with two bidentate chelates in the axis: steric control of the motion Journal Article In: NEW JOURNAL OF CHEMISTRY, 34 (1), pp. 34–43, 2010, ISSN: 1144-0546. |
The dual role of Cu(I) as a protective group and a template in the synthesis of a tetra-rhodium(III)porphyrin [2]catenane Journal Article In: NEW JOURNAL OF CHEMISTRY, 34 (9), pp. 1825–1829, 2010, ISSN: 1144-0546. |
Resonant Plasmon Nanofocusing by Closed Tapered Gaps Journal Article In: NANO LETTERS, 10 (1), pp. 291–295, 2010, ISSN: 1530-6984. |
Enhanced fluorescence from metal nanoapertures: physical characterizations and biophotonic applications Inproceedings In: {VoDinh, T; Lakowicz, JR} (Ed.): PLASMONICS IN BIOLOGY AND MEDICINE VII, SPIE, 2010, ISBN: 978-0-8194-7973-0. |
Optical resonances and nanofocusing in triangular metal nano-grooves Inproceedings In: {Stockman, MI} (Ed.): PLASMONICS: METALLIC NANOSTRUCTURES AND THEIR OPTICAL PROPERTIES VIII, SPIE, 2010, ISBN: 978-0-8194-8253-2. |
2009 |
Analysis of an Anomalous Mutant of MutM DNA Glycosylase Leads to New Insights into the Catalytic Mechanism Journal Article In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131 (51), pp. 18208+, 2009, ISSN: 0002-7863. |
Encounter and extrusion of an intrahelical lesion by a DNA repair enzyme Journal Article In: NATURE, 462 (7274), pp. 762–U79, 2009, ISSN: 0028-0836. |
High-Contrast Visualization of Graphene Oxide on Dye-Sensitized Glass, Quartz, and Silicon by Fluorescence Quenching Journal Article In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131 (43), pp. 15576+, 2009, ISSN: 0002-7863. |
Hemiacetals in Dynamic Covalent Chemistry: Formation, Exchange, Selection, and Modulation Processes Journal Article In: JOURNAL OF ORGANIC CHEMISTRY, 74 (21), pp. 8428–8432, 2009, ISSN: 0022-3263. |
Preface Journal Article In: RESEARCH ON CHEMICAL INTERMEDIATES, 35 (8-9), pp. 839–840, 2009, ISSN: 0922-6168. |
Self-assembly of soft nanoparticles with tunable patchiness Journal Article In: NATURE NANOTECHNOLOGY, 4 (11), pp. 721–726, 2009, ISSN: 1748-3387. |
Genetic Variant m HK1 Is Associated With a Proanemic State and A1C but Not Other Glycemic Control-Related Traits Journal Article In: DIABETES, 58 (11), pp. 2687–2697, 2009, ISSN: 0012-1797. |
Inhibition of HSP90 with Pochoximes: SAR and Structure-Based Insights Journal Article In: CHEMBIOCHEM, 10 (17), pp. 2753–2759, 2009, ISSN: 1439-4227. |
Hsp90 Inhibition with Resorcylic Acid Lactones (RALs) Journal Article In: CURRENT TOPICS IN MEDICINAL CHEMISTRY, 9 (15), pp. 1419–1435, 2009, ISSN: 1568-0266. |
Plasmonic candle: towards efficient nanofocusing with channel plasmon polaritons Journal Article In: NEW JOURNAL OF PHYSICS, 11 , 2009, ISSN: 1367-2630. |
STM spectroscopy of magnetic molecules Journal Article In: COORDINATION CHEMISTRY REVIEWS, 253 (19-20, SI), pp. 2387–2398, 2009, ISSN: 0010-8545. |
Segmented Transition Pathway of the Signaling Protein Nitrogen Regulatory Protein C Journal Article In: JOURNAL OF MOLECULAR BIOLOGY, 392 (3), pp. 823–836, 2009, ISSN: 0022-2836. |
Folding of a SH3 Domain: Standard and “Hydrodynamic” Analyses Journal Article In: JOURNAL OF PHYSICAL CHEMISTRY B, 113 (38), pp. 12759–12772, 2009, ISSN: 1520-6106. |
Tailoring Bicomponent Supramolecular Nanoporous Networks: Phase Segregation, Polymorphism, and Glasses at the Solid-Liquid Interface Journal Article In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131 (36), pp. 13062–13071, 2009, ISSN: 0002-7863. |
Single-Molecule Wires Get a Lift Journal Article In: SMALL, 5 (17), pp. 1927–1930, 2009, ISSN: 1613-6810. |
The genetic association between HK1 and increased HbA(1c) but not other glycaemic control related traits reveals the link between anaemia and HbA(1c) Journal Article In: DIABETOLOGIA, 52 (1), pp. S146, 2009, ISSN: 0012-186X. |
Three-Component Noncovalent Assembly Consisting of a Central Tetrakis-4-pyridyl Porphyrin and Two Lateral Gable-Like Bis-Zn Porphyrins Journal Article In: INORGANIC CHEMISTRY, 48 (17), pp. 8263–8270, 2009, ISSN: 0020-1669. |
The HSP90 binding mode of a radicicol-like E-oxime determined by docking, binding free energy estimations, and NMR N-15 chemical shifts Journal Article In: BIOPHYSICAL CHEMISTRY, 143 (3), pp. 111–123, 2009, ISSN: 0301-4622. |
Self-Assembly of a Donor-Acceptor Dyad Across Multiple Length Scales: Functional Architectures for Organic Electronics Journal Article In: ADVANCED FUNCTIONAL MATERIALS, 19 (15), pp. 2486–2494, 2009, ISSN: 1616-301X. |
Opening the light extraction cone of high index substrates with plasmonic gratings: Light emitting diode applications (vol 95, 021101, 2009) Journal Article In: APPLIED PHYSICS LETTERS, 95 (6), 2009, ISSN: 0003-6951. |
Crucial Role of the Adhesion Layer on the Plasmonic Fluorescence Enhancement Journal Article In: ACS NANO, 3 (7), pp. 2043–2048, 2009, ISSN: 1936-0851. |
CHARMM: The Biomolecular Simulation Program Journal Article In: JOURNAL OF COMPUTATIONAL CHEMISTRY, 30 (10, SI), pp. 1545–1614, 2009, ISSN: 0192-8651. |
Calculation of Free-Energy Differences by Confinement Simulations. Application to Peptide Conformers Journal Article In: JOURNAL OF PHYSICAL CHEMISTRY B, 113 (29), pp. 9728–9740, 2009, ISSN: 1520-6106. |
Competitive Physisorption Among Alkyl-Substituted pi-Conjugated Oligomers at the Solid-Liquid Interface: Towards Prediction of Self-Assembly at Surfaces from a Multicomponent Solution Journal Article In: SMALL, 5 (13), pp. 1521–1526, 2009, ISSN: 1613-6810. |
`Injecting' yeast Journal Article In: NATURE METHODS, 6 (7), pp. 513–U64, 2009, ISSN: 1548-7091. |
Synthesis of pochoxime prodrugs as potent HSP90 inhibitors Journal Article In: BIOORGANIC & MEDICINAL CHEMISTRY LETTERS, 19 (14), pp. 3836–3840, 2009, ISSN: 0960-894X. |
Opening the light extraction cone of high index substrates with plasmonic gratings: Light emitting diode applications Journal Article In: APPLIED PHYSICS LETTERS, 95 (2), 2009, ISSN: 0003-6951. |
Asymmetric lipid bilayer formation stabilized by DNA at the air/water interface Journal Article In: BIOCHIMIE, 91 (6), pp. 765–773, 2009, ISSN: 0300-9084. |
Modulation of Photochemical Properties in Ion-Controlled Multicomponent Dynamic Devices Journal Article In: EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, (18), pp. 2621–2628, 2009, ISSN: 1434-1948. |
A Zinc Porphyrin Bearing Two Lateral dpp-Containing Rings and Its [3]Pseudorotaxane (dpp: 2,9-diphenyl-1,10-phenanthroline) Journal Article In: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, (17), pp. 2795–2800, 2009, ISSN: 1434-193X. |
Various Synthetic Routes to a Gable-Like Bis(porphyrin) Constructed on a 1,10-Phenanthroline Chelate Journal Article In: EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, (17), pp. 2801–2805, 2009, ISSN: 1434-193X. |
The Relationship between Nanoscale Architecture and Charge Transport in Conjugated Nanocrystals Bridged by Multichromophoric Polymers Journal Article In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 131 (20), pp. 7055–7063, 2009, ISSN: 0002-7863. |