You will find below the publication list of our pole.
For the publication list of each pole member, please see his/her personal webpage.
2019 |
Photosensitized oxidative addition to gold(i) enables alkynylative cyclization of o-alkylnylphenols with iodoalkynes Article de journal Zhonghua Xia; Vincent Corcé; Fen Zhao; Cédric Przybylski; Agathe Espagne; Ludovic Jullien; Thomas Le Saux; Yves Gimbert; Héloïse Dossmann; Virginie Mouriès-Mansuy; Cyril Ollivier; Louis Fensterbank Nature Chemistry, 11 (9), p. 797-805, 2019, ISSN: 1755-4349. @article{RN1_28, title = {Photosensitized oxidative addition to gold(i) enables alkynylative cyclization of o-alkylnylphenols with iodoalkynes}, author = {Zhonghua Xia and Vincent Corc\'{e} and Fen Zhao and C\'{e}dric Przybylski and Agathe Espagne and Ludovic Jullien and Thomas Le Saux and Yves Gimbert and H\'{e}lo\"{i}se Dossmann and Virginie Mouri\`{e}s-Mansuy and Cyril Ollivier and Louis Fensterbank}, url = {https://doi.org/10.1038/s41557-019-0295-9}, doi = {10.1038/s41557-019-0295-9}, issn = {1755-4349}, year = {2019}, date = {2019-01-01}, journal = {Nature Chemistry}, volume = {11}, number = {9}, pages = {797-805}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Redox-Triggered Control of Cell Adhesion and Deadhesion on Poly(lysine)-g-poly(ethylene oxide) Adlayers. Article de journal Louise Hespel; Julien Dupré de Baubigny; Pierre Lalanne; Simon de Beco; Mathieu Coppey; Catherine Villard; Vincent Humblot; Emmanuelle Marie; Christophe Tribet ACS Applied Bio Materials, 2 (10), p. 4367-4376, 2019. @article{Hespel2019, title = {Redox-Triggered Control of Cell Adhesion and Deadhesion on Poly(lysine)-g-poly(ethylene oxide) Adlayers.}, author = {Louise Hespel and Julien Dupr\'{e} de Baubigny and Pierre Lalanne and Simon de Beco and Mathieu Coppey and Catherine Villard and Vincent Humblot and Emmanuelle Marie and Christophe Tribet}, doi = {10.1021/acsabm.9b00601}, year = {2019}, date = {2019-09-10}, journal = {ACS Applied Bio Materials}, volume = {2}, number = {10}, pages = {4367-4376}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
RNA is a critical element for the sizing and the composition of phase-separated RNA–protein condensates Article de journal Marina Garcia-Jove Navarro; Shunnichi Kashida; Racha Chouaib; Sylvie Souquere; Gérard Pierron; Dominique Weil; Zoher Gueroui Nature Communications, 2019, ISSN: 2041-1723. @article{Garcia-JoveNavarro2019, title = {RNA is a critical element for the sizing and the composition of phase-separated RNA\textendashprotein condensates}, author = {Marina {Garcia-Jove Navarro} and Shunnichi Kashida and Racha Chouaib and Sylvie Souquere and G\'{e}rard Pierron and Dominique Weil and Zoher Gueroui}, doi = {10.1038/s41467-019-11241-6}, issn = {2041-1723}, year = {2019}, date = {2019-01-01}, journal = {Nature Communications}, abstract = {Liquid-liquid phase separation is thought to be a key organizing principle in eukaryotic cells to generate highly concentrated dynamic assemblies, such as the RNP granules. Numerous in vitro approaches have validated this model, yet a missing aspect is to take into consideration the complex molecular mixture and promiscuous interactions found in vivo. Here we report the versatile scaffold "ArtiG" to generate concentration-dependent RNA-protein condensates within living cells, as a bottom-up approach to study the impact of co-segregated endogenous components on phase separation. We demonstrate that intracellular RNA seeds the nucleation of the condensates, as it provides molecular cues to locally coordinate the formation of endogenous high order RNP assemblies. Interestingly, the co-segregation of intracellular components ultimately impacts the size of the phase-separated condensates. Thus, RNA arises as an architectural element that can influence the composition and the morphological outcome of the condensate phases in an intracellular context.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Liquid-liquid phase separation is thought to be a key organizing principle in eukaryotic cells to generate highly concentrated dynamic assemblies, such as the RNP granules. Numerous in vitro approaches have validated this model, yet a missing aspect is to take into consideration the complex molecular mixture and promiscuous interactions found in vivo. Here we report the versatile scaffold "ArtiG" to generate concentration-dependent RNA-protein condensates within living cells, as a bottom-up approach to study the impact of co-segregated endogenous components on phase separation. We demonstrate that intracellular RNA seeds the nucleation of the condensates, as it provides molecular cues to locally coordinate the formation of endogenous high order RNP assemblies. Interestingly, the co-segregation of intracellular components ultimately impacts the size of the phase-separated condensates. Thus, RNA arises as an architectural element that can influence the composition and the morphological outcome of the condensate phases in an intracellular context. |
Self-aggregation of oxidized procyanidins contributes to the formation of heat-reversible haze in apple-based liqueur wine Article de journal M Millet; P Poupard; S Guilois-Dubois; D Zanchi; S Guyot Food Chemistry, 276 , p. 797–805, 2019. @article{Millet:2019, title = {Self-aggregation of oxidized procyanidins contributes to the formation of heat-reversible haze in apple-based liqueur wine}, author = {M Millet and P Poupard and S Guilois-Dubois and D Zanchi and S Guyot}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85055330959&doi=10.1016%2fj.foodchem.2018.09.171&partnerID=40&md5=023402dcebfde4b3a1f3f506c5b74529}, doi = {10.1016/j.foodchem.2018.09.171}, year = {2019}, date = {2019-01-01}, journal = {Food Chemistry}, volume = {276}, pages = {797--805}, abstract = {The ability of tannins to self-associate or form complexes with other macromolecules has important nutritional implications but can also result in defects in beverages. In addition, oxidation may be involved in the aggregation properties of tannins. In order to assess the impact of tannin oxidation on their self-association, oligomeric procyanidins were oxidized in a model solution and their aggregation kinetics were studied using light scattering. Under the conditions tested, only oxidized procyanidins were involved in haze formation. An increase in the level of oxidation and the degree of polymerization of procyanidins enhanced aggregation. Procyanidin oxidation products were depolymerized and the evolution of their markers was monitored throughout the aggregation process using liquid chromatography coupled with mass spectrometry. This revealed the involvement of intramolecular coupling in reversible haze formation. The haze formed in a model solution was partially reversible at high temperature. This property was similar in pommeau, an apple-based beverage. This work highlighted the involvement of oxidized tannins in reversible haze. © 2018 Elsevier Ltd}, keywords = {}, pubstate = {published}, tppubtype = {article} } The ability of tannins to self-associate or form complexes with other macromolecules has important nutritional implications but can also result in defects in beverages. In addition, oxidation may be involved in the aggregation properties of tannins. In order to assess the impact of tannin oxidation on their self-association, oligomeric procyanidins were oxidized in a model solution and their aggregation kinetics were studied using light scattering. Under the conditions tested, only oxidized procyanidins were involved in haze formation. An increase in the level of oxidation and the degree of polymerization of procyanidins enhanced aggregation. Procyanidin oxidation products were depolymerized and the evolution of their markers was monitored throughout the aggregation process using liquid chromatography coupled with mass spectrometry. This revealed the involvement of intramolecular coupling in reversible haze formation. The haze formed in a model solution was partially reversible at high temperature. This property was similar in pommeau, an apple-based beverage. This work highlighted the involvement of oxidized tannins in reversible haze. © 2018 Elsevier Ltd |
Single-Molecule Localization Microscopy with the Fluorescence-Activating and Absorption-Shifting Tag (FAST) System Article de journal Elizabeth M Smith; Arnaud Gautier; Elias M Puchner ACS Chemical Biology, 14 (6), p. 1115-1120, 2019, ISSN: 1554-8929. @article{Smith2019, title = {Single-Molecule Localization Microscopy with the Fluorescence-Activating and Absorption-Shifting Tag (FAST) System}, author = {Elizabeth M Smith and Arnaud Gautier and Elias M Puchner}, url = {https://doi.org/10.1021/acschembio.9b00149}, doi = {10.1021/acschembio.9b00149}, issn = {1554-8929}, year = {2019}, date = {2019-06-21}, journal = {ACS Chemical Biology}, volume = {14}, number = {6}, pages = {1115-1120}, publisher = {American Chemical Society}, abstract = {We develop and employ the Fluorescence-Activating and absorption-Shifting Tag (FAST) system for super-resolution (SR) imaging and single-molecule tracking based on single-molecule localizations. The fast off rate of fluorogen binding, combined with its spatially well-separated labeling of the densely expressed FAST fusion proteins, allowed single-molecule measurements to be performed in both living and fixed cells. The well-separated fluorescence localization density was achieved by either reversibly controlling the fluorogen concentration or by irreversibly photobleaching the FAST-fluorogen complex. The experimentally determined resolution of 28 nm allowed us to resolve Ensconsin-labeled microtubules and to track single molecules in mitochondria. Our results demonstrate that FAST is well-suited for single-molecule localization microscopy (SMLM). The small size and the availability of spectrally distinct fluorogens present unique advantages of the FAST system as a potential orthogonal labeling strategy that could be applied in conjunction with existing super-resolution dyes and photoactivatable proteins in versatile imaging applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We develop and employ the Fluorescence-Activating and absorption-Shifting Tag (FAST) system for super-resolution (SR) imaging and single-molecule tracking based on single-molecule localizations. The fast off rate of fluorogen binding, combined with its spatially well-separated labeling of the densely expressed FAST fusion proteins, allowed single-molecule measurements to be performed in both living and fixed cells. The well-separated fluorescence localization density was achieved by either reversibly controlling the fluorogen concentration or by irreversibly photobleaching the FAST-fluorogen complex. The experimentally determined resolution of 28 nm allowed us to resolve Ensconsin-labeled microtubules and to track single molecules in mitochondria. Our results demonstrate that FAST is well-suited for single-molecule localization microscopy (SMLM). The small size and the availability of spectrally distinct fluorogens present unique advantages of the FAST system as a potential orthogonal labeling strategy that could be applied in conjunction with existing super-resolution dyes and photoactivatable proteins in versatile imaging applications. |
Tannin-controlled micelles and fibrils of kappa-casein Article de journal W Ma; C Tribet; S Guyot; D Zanchi Journal of Chemical Physics, 151 (24), 2019, ISSN: 0021-9606. @article{RN264, title = {Tannin-controlled micelles and fibrils of kappa-casein}, author = {W Ma and C Tribet and S Guyot and D Zanchi}, url = {<Go to ISI>://WOS:000513160200063}, doi = {10.1063/1.5128057}, issn = {0021-9606}, year = {2019}, date = {2019-01-01}, journal = {Journal of Chemical Physics}, volume = {151}, number = {24}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
The Glowing Panoply of Fluorogen-based Markers for Advanced Bioimaging Book Chapter A Gautier The Glowing Panoply of Fluorogen-based Markers for Advanced Bioimaging, Chapitre 3, 2019. @inbook{Gautier:2019, title = {The Glowing Panoply of Fluorogen-based Markers for Advanced Bioimaging}, author = {A Gautier}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85056600039&doi=10.1039%2f9781788013284-00041&partnerID=40&md5=5d754dc76f6a9652835200ef4214a41a}, doi = {10.1039/9781788013284-00041}, year = {2019}, date = {2019-01-01}, booktitle = {The Glowing Panoply of Fluorogen-based Markers for Advanced Bioimaging}, chapter = {3}, series = {Comprehensive Series in Photochemical and Photobiological Sciences}, abstract = {The biological sciences nowadays rely extensively on imaging tools to decipher the complexity of living organisms. Fluorescence microscopy allows the study of biological processes with unprecedented temporal and spatial resolution. The revolution in fluorescence imaging has been the development of a large toolbox of fluorescent proteins able to reveal the abundance, position and dynamics of proteins. The fluorescence toolbox has recently been expanded with innovative reporters that permit proteins, and other biomolecules such as RNA, to be visualized in new ways. These innovative reporters are bipartite systems composed of a genetically encoded tag forming a fluorescent complex with a small organic fluorogenic chromophore (also called fluorogens). This chapter is a user-oriented presentation of some of the most mature fluorogen-based markers available to biologists. © 2019 European Society for Photobiology.}, keywords = {}, pubstate = {published}, tppubtype = {inbook} } The biological sciences nowadays rely extensively on imaging tools to decipher the complexity of living organisms. Fluorescence microscopy allows the study of biological processes with unprecedented temporal and spatial resolution. The revolution in fluorescence imaging has been the development of a large toolbox of fluorescent proteins able to reveal the abundance, position and dynamics of proteins. The fluorescence toolbox has recently been expanded with innovative reporters that permit proteins, and other biomolecules such as RNA, to be visualized in new ways. These innovative reporters are bipartite systems composed of a genetically encoded tag forming a fluorescent complex with a small organic fluorogenic chromophore (also called fluorogens). This chapter is a user-oriented presentation of some of the most mature fluorogen-based markers available to biologists. © 2019 European Society for Photobiology. |
Tunable and switchable soft adsorption of polymer-coated microparticles on a flat substrate Article de journal Giuseppe Boniello; Christophe Tribet; Emmanuelle Marie; Vincent Croquette; Dražen Zanchi Colloids and Surfaces A: Physicochemical and Engineering Aspects, 575 , p. 199-204, 2019, ISSN: 0927-7757. @article{Boniello2019, title = {Tunable and switchable soft adsorption of polymer-coated microparticles on a flat substrate}, author = {Giuseppe Boniello and Christophe Tribet and Emmanuelle Marie and Vincent Croquette and Dra\v{z}en Zanchi}, editor = {Elsevier}, url = {http://www.sciencedirect.com/science/article/pii/S0927775719301797}, doi = {10.1016/j.colsurfa.2019.04.081}, issn = {0927-7757}, year = {2019}, date = {2019-08-20}, journal = {Colloids and Surfaces A: Physicochemical and Engineering Aspects}, volume = {575}, pages = {199-204}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Ultrafast Oxidation of a Tyrosine by Proton-Coupled Electron Transfer Promotes Light Activation of an Animal-like Cryptochrome Article de journal Fabien Lacombat; Agathe Espagne; Nadia Dozova; Pascal Plaza; Pavel Müller; Klaus Brettel; Sophie Franz-Badur; Lars-Oliver Essen Journal of the American Chemical Society, 141 (34), p. 13394-13409, 2019, ISSN: 0002-7863. @article{RN479, title = {Ultrafast Oxidation of a Tyrosine by Proton-Coupled Electron Transfer Promotes Light Activation of an Animal-like Cryptochrome}, author = {Fabien Lacombat and Agathe Espagne and Nadia Dozova and Pascal Plaza and Pavel M\"{u}ller and Klaus Brettel and Sophie Franz-Badur and Lars-Oliver Essen}, url = {https://doi.org/10.1021/jacs.9b03680}, doi = {10.1021/jacs.9b03680}, issn = {0002-7863}, year = {2019}, date = {2019-01-01}, journal = {Journal of the American Chemical Society}, volume = {141}, number = {34}, pages = {13394-13409}, abstract = {The animal-like cryptochrome of Chlamydomonas reinhardtii (CraCRY) is a recently discovered photoreceptor that controls the transcriptional profile and sexual life cycle of this alga by both blue and red light. CraCRY has the uncommon feature of efficient formation and longevity of the semireduced neutral form of its FAD cofactor upon blue light illumination. Tyrosine Y373 plays a crucial role by elongating , as fourth member, the electron transfer (ET) chain found in most other cryptochromes and DNA photolyases, which comprises a conserved tryptophan triad. Here, we report the full mechanism of light-induced FADH• formation in CraCRY using transient absorption spectroscopy from hundreds of femtoseconds to seconds. Electron transfer starts from ultrafast reduction of excited FAD to FAD•\textendash by the proximal tryptophan (0.4 ps) and is followed by delocalized migration of the produced WH•+ radical along the tryptophan triad (∼4 and ∼50 ps). Oxidation of Y373 by coupled ET to WH•+ and deprotonation then proceeds in ∼800 ps, without any significant kinetic isotope effect, nor a pH effect between pH 6.5 and 9.0. The FAD•\textendash/Y373• pair is formed with high quantum yield (∼60%); its intrinsic decay by recombination is slow (∼50 ms), favoring reduction of Y373• by extrinsic agents and protonation of FAD•\textendash to form the long-lived, red-light absorbing FADH• species. Possible mechanisms of tyrosine oxidation by ultrafast proton-coupled ET in CraCRY, a process about 40 times faster than the archetypal tyrosine-Z oxidation in photosystem II, are discussed in detail.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The animal-like cryptochrome of Chlamydomonas reinhardtii (CraCRY) is a recently discovered photoreceptor that controls the transcriptional profile and sexual life cycle of this alga by both blue and red light. CraCRY has the uncommon feature of efficient formation and longevity of the semireduced neutral form of its FAD cofactor upon blue light illumination. Tyrosine Y373 plays a crucial role by elongating , as fourth member, the electron transfer (ET) chain found in most other cryptochromes and DNA photolyases, which comprises a conserved tryptophan triad. Here, we report the full mechanism of light-induced FADH• formation in CraCRY using transient absorption spectroscopy from hundreds of femtoseconds to seconds. Electron transfer starts from ultrafast reduction of excited FAD to FAD•– by the proximal tryptophan (0.4 ps) and is followed by delocalized migration of the produced WH•+ radical along the tryptophan triad (∼4 and ∼50 ps). Oxidation of Y373 by coupled ET to WH•+ and deprotonation then proceeds in ∼800 ps, without any significant kinetic isotope effect, nor a pH effect between pH 6.5 and 9.0. The FAD•–/Y373• pair is formed with high quantum yield (∼60%); its intrinsic decay by recombination is slow (∼50 ms), favoring reduction of Y373• by extrinsic agents and protonation of FAD•– to form the long-lived, red-light absorbing FADH• species. Possible mechanisms of tyrosine oxidation by ultrafast proton-coupled ET in CraCRY, a process about 40 times faster than the archetypal tyrosine-Z oxidation in photosystem II, are discussed in detail. |
Ultrafast photoinduced flavin dynamics in the unusual active site of the tRNA methyltransferase TrmFO Article de journal N Dozova; F Lacombat; C Bou-Nader; D Hamdane; P Plaza Physical Chemistry Chemical Physics, 21 (17), p. 8743-8756, 2019, ISSN: 1463-9076. @article{RN115, title = {Ultrafast photoinduced flavin dynamics in the unusual active site of the tRNA methyltransferase TrmFO}, author = {N Dozova and F Lacombat and C Bou-Nader and D Hamdane and P Plaza}, doi = {10.1039/c8cp06072j}, issn = {1463-9076}, year = {2019}, date = {2019-01-01}, journal = {Physical Chemistry Chemical Physics}, volume = {21}, number = {17}, pages = {8743-8756}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
2018 |
A chemically encoded timer for dual molecular delivery at tailored ranges and concentrations Article de journal S Serra; A Alouane; T Le Saux; S Huvelle; R Plasson; F Schmidt; L Jullien; R Labruère Chemical Communications, 54 (49), p. 6396–6399, 2018. @article{Serra:2018, title = {A chemically encoded timer for dual molecular delivery at tailored ranges and concentrations}, author = {S Serra and A Alouane and T Le Saux and S Huvelle and R Plasson and F Schmidt and L Jullien and R Labru\`{e}re}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048683206&doi=10.1039%2fc8cc03253j&partnerID=40&md5=6b7d3eaf2fac02d48f0cfa34e3b730b9}, doi = {10.1039/c8cc03253j}, year = {2018}, date = {2018-01-01}, journal = {Chemical Communications}, volume = {54}, number = {49}, pages = {6396--6399}, abstract = {Spatiotemporal control of molecular distribution is much in demand in many fields of chemistry. To address this goal, we exploit a low molecular weight branched self-immolative architecture, which acts as a triggerable chemically encoded timer for autonomous sequential release of two chemicals. Using a light-activated model liberating two distinct fluorophores, we generated a tunable spatially contrasted molecular distribution. © 2018 The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Spatiotemporal control of molecular distribution is much in demand in many fields of chemistry. To address this goal, we exploit a low molecular weight branched self-immolative architecture, which acts as a triggerable chemically encoded timer for autonomous sequential release of two chemicals. Using a light-activated model liberating two distinct fluorophores, we generated a tunable spatially contrasted molecular distribution. © 2018 The Royal Society of Chemistry. |
A novel diarylethene-based photoswitchable chelator for reversible release and capture of Ca2+ in aqueous media Article de journal N Dozova; G Pousse; B Barnych; J -M Mallet; J Cossy; B Valeur; P Plaza Journal of Photochemistry and Photobiology A: Chemistry, 360 , p. 181–187, 2018. @article{Dozova:2018, title = {A novel diarylethene-based photoswitchable chelator for reversible release and capture of Ca2+ in aqueous media}, author = {N Dozova and G Pousse and B Barnych and J -M Mallet and J Cossy and B Valeur and P Plaza}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85046375200&doi=10.1016%2fj.jphotochem.2018.04.029&partnerID=40&md5=acfff9bc55e2d0bb41580e84374018fc}, doi = {10.1016/j.jphotochem.2018.04.029}, year = {2018}, date = {2018-01-01}, journal = {Journal of Photochemistry and Photobiology A: Chemistry}, volume = {360}, pages = {181--187}, abstract = {The synthesis and characterisation of a novel Reversibly Photoswitchable Chelator (RPC) of calcium ions, designed as a stepping stone towards producing pulses of calcium concentration in an aqueous environment, is reported. This RPC is constituted of a photochromic diarylethene core connected on one side to a BAPTA (1,2-bis(2-aminophenoxy)ethane-N,N,N’,N’-tetraacetic acid) calcium chelator and, on the other side, to an electron-withdrawing group. The operation principle consists in photoswitching on and off an intramolecular charge transfer between one nitrogen atom of the BAPTA moiety and the electron-withdrawing group, thereby modulating the chelating affinity of BAPTA for calcium ions. Solubility of the compound in a partially aqueous solvent was achieved by grafting a short PEG (polyethylene glycol) tail to the electron-withdrawing group. A reduction of the affinity for calcium ions upon photoswitching by a factor of 3\textendash4, in the hundred nM range of dissociation constant, is reported and constitutes a proof of concept of this type of RPC. © 2018 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The synthesis and characterisation of a novel Reversibly Photoswitchable Chelator (RPC) of calcium ions, designed as a stepping stone towards producing pulses of calcium concentration in an aqueous environment, is reported. This RPC is constituted of a photochromic diarylethene core connected on one side to a BAPTA (1,2-bis(2-aminophenoxy)ethane-N,N,N’,N’-tetraacetic acid) calcium chelator and, on the other side, to an electron-withdrawing group. The operation principle consists in photoswitching on and off an intramolecular charge transfer between one nitrogen atom of the BAPTA moiety and the electron-withdrawing group, thereby modulating the chelating affinity of BAPTA for calcium ions. Solubility of the compound in a partially aqueous solvent was achieved by grafting a short PEG (polyethylene glycol) tail to the electron-withdrawing group. A reduction of the affinity for calcium ions upon photoswitching by a factor of 3–4, in the hundred nM range of dissociation constant, is reported and constitutes a proof of concept of this type of RPC. © 2018 Elsevier B.V. |
Actin-Network Architecture Regulates Microtubule Dynamics Article de journal A Colin; P Singaravelu; M Thery; L Blanchoin; Z Gueroui Current Biology, 28 (16), p. 2647-+, 2018, ISSN: 0960-9822. @article{RN18c, title = {Actin-Network Architecture Regulates Microtubule Dynamics}, author = {A Colin and P Singaravelu and M Thery and L Blanchoin and Z Gueroui}, url = {<Go to ISI>://WOS:000442111300035}, doi = {10.1016/j.cub.2018.06.028}, issn = {0960-9822}, year = {2018}, date = {2018-01-01}, journal = {Current Biology}, volume = {28}, number = {16}, pages = {2647-+}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Circularly Permuted Fluorogenic Proteins for the Design of Modular Biosensors Article de journal A G Tebo; F M Pimenta; M Zoumpoulaki; C Kikuti; H Sirkia; M -A Plamont; A Houdusse; A Gautier ACS Chemical Biology, 13 (9), p. 2392–2397, 2018. @article{Tebo:2018, title = {Circularly Permuted Fluorogenic Proteins for the Design of Modular Biosensors}, author = {A G Tebo and F M Pimenta and M Zoumpoulaki and C Kikuti and H Sirkia and M -A Plamont and A Houdusse and A Gautier}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85052286419&doi=10.1021%2facschembio.8b00417&partnerID=40&md5=f7f8a46015d14cb7450f3d6d2b70a529}, doi = {10.1021/acschembio.8b00417}, year = {2018}, date = {2018-01-01}, journal = {ACS Chemical Biology}, volume = {13}, number = {9}, pages = {2392--2397}, abstract = {Fluorescent reporters are essential components for the design of optical biosensors that are able to image intracellular analytes in living cells. Herein, we describe the development of circularly permuted variants of Fluorescence-Activating and absorption-Shifting Tag (FAST) and demonstrate their potential as reporting module in biosensors. Circularly permutated FAST (cpFAST) variants allow one to condition the binding and activation of a fluorogenic ligand (and thus fluorescence) to analyte recognition by coupling them with analyte-binding domains. We demonstrated their use for biosensor design by generating multicolor plug-and-play fluorogenic biosensors for imaging the intracellular levels of Ca2+ in living mammalian cells in real time. © 2018 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Fluorescent reporters are essential components for the design of optical biosensors that are able to image intracellular analytes in living cells. Herein, we describe the development of circularly permuted variants of Fluorescence-Activating and absorption-Shifting Tag (FAST) and demonstrate their potential as reporting module in biosensors. Circularly permutated FAST (cpFAST) variants allow one to condition the binding and activation of a fluorogenic ligand (and thus fluorescence) to analyte recognition by coupling them with analyte-binding domains. We demonstrated their use for biosensor design by generating multicolor plug-and-play fluorogenic biosensors for imaging the intracellular levels of Ca2+ in living mammalian cells in real time. © 2018 American Chemical Society. |
Control of Protein Activity and Gene Expression by Cyclofen-OH Uncaging Article de journal W Zhang; F Hamouri; Z Feng; I Aujard; B Ducos; S Ye; S Weiss; M Volovitch; S Vriz; L Jullien; D Bensimon ChemBioChem, 19 (12), p. 1232–1238, 2018. @article{Zhang:2018, title = {Control of Protein Activity and Gene Expression by Cyclofen-OH Uncaging}, author = {W Zhang and F Hamouri and Z Feng and I Aujard and B Ducos and S Ye and S Weiss and M Volovitch and S Vriz and L Jullien and D Bensimon}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042596408&doi=10.1002%2fcbic.201700630&partnerID=40&md5=e4da60b83f338aba093989913695947b}, doi = {10.1002/cbic.201700630}, year = {2018}, date = {2018-01-01}, journal = {ChemBioChem}, volume = {19}, number = {12}, pages = {1232--1238}, abstract = {The use of light to control the expression of genes and the activity of proteins is a rapidly expanding field. Whereas many of these approaches use fusion between a light-activable protein and the protein of interest to control the activity of the latter, it is also possible to control the activity of a protein by uncaging a specific ligand. In that context, controlling the activation of a protein fused to the modified estrogen receptor (ERT) by uncaging its ligand cyclofen-OH has emerged as a generic and versatile method to control the activation of proteins quantitatively, quickly, and locally in a live organism. We present that approach and its uses in a variety of physiological contexts. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim}, keywords = {}, pubstate = {published}, tppubtype = {article} } The use of light to control the expression of genes and the activity of proteins is a rapidly expanding field. Whereas many of these approaches use fusion between a light-activable protein and the protein of interest to control the activity of the latter, it is also possible to control the activity of a protein by uncaging a specific ligand. In that context, controlling the activation of a protein fused to the modified estrogen receptor (ERT) by uncaging its ligand cyclofen-OH has emerged as a generic and versatile method to control the activation of proteins quantitatively, quickly, and locally in a live organism. We present that approach and its uses in a variety of physiological contexts. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim |
X Liu; L Hu; N Pan; L Grimaud; E Labbé; O Buriez; J Delacotte; F Lemaître; M Guille-Collignon Biophysical Chemistry, 235 , p. 48–55, 2018. @article{Liu:2018, title = {Coupling electrochemistry and TIRF-microscopy with the fluorescent false neurotransmitter FFN102 supports the fluorescence signals during single vesicle exocytosis detection}, author = {X Liu and L Hu and N Pan and L Grimaud and E Labb\'{e} and O Buriez and J Delacotte and F Lema\^{i}tre and M Guille-Collignon}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85042352158&doi=10.1016%2fj.bpc.2018.02.004&partnerID=40&md5=365430d79a0d526895e755729264d88f}, doi = {10.1016/j.bpc.2018.02.004}, year = {2018}, date = {2018-01-01}, journal = {Biophysical Chemistry}, volume = {235}, pages = {48--55}, abstract = {Applications of the Fluorescent False Neurotransmitter FFN102, an analog of biogenic neurotransmitters and a suitable probe for coupled amperometry and TIRFM (total internal reflexion fluorescence microscopy) investigations of exocytotic secretion, were considered here. The electroactivity of FFN102 was shown to very likely arise from the oxidation of its phenolic group through a CE (Chemical-Electrochemical) mechanism. Evidences that the aminoethyl group of FFN102 is the key recognition element by BON N13 cells were also provided. Amperometric measurements were then performed at the single cell level with carbon fiber electrode (CFE) or Indium Tin Oxide (ITO) surfaces. It proved the disparity of kinetic and quantitative parameters of FFN102-stained cells acquired either at cell top and bottom. Moreover, coupled analyses of FFN102 loaded vesicles allowed us to classify three types of optical signals that probably arise from secretion releases thanks to their concomitant detection with an electrochemical spike. Finally, preliminary benefits from the coupling involving FFN102 were reported in terms of origins of overlapped amperometric spikes or assignment of fluorescence extinctions to real exocytotic events. © 2018 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Applications of the Fluorescent False Neurotransmitter FFN102, an analog of biogenic neurotransmitters and a suitable probe for coupled amperometry and TIRFM (total internal reflexion fluorescence microscopy) investigations of exocytotic secretion, were considered here. The electroactivity of FFN102 was shown to very likely arise from the oxidation of its phenolic group through a CE (Chemical-Electrochemical) mechanism. Evidences that the aminoethyl group of FFN102 is the key recognition element by BON N13 cells were also provided. Amperometric measurements were then performed at the single cell level with carbon fiber electrode (CFE) or Indium Tin Oxide (ITO) surfaces. It proved the disparity of kinetic and quantitative parameters of FFN102-stained cells acquired either at cell top and bottom. Moreover, coupled analyses of FFN102 loaded vesicles allowed us to classify three types of optical signals that probably arise from secretion releases thanks to their concomitant detection with an electrochemical spike. Finally, preliminary benefits from the coupling involving FFN102 were reported in terms of origins of overlapped amperometric spikes or assignment of fluorescence extinctions to real exocytotic events. © 2018 Elsevier B.V. |
Delocalized hole transport coupled to sub-ns tryptophanyl deprotonation promotes photoreduction of class II photolyases Article de journal F Lacombat; A Espagne; N Dozova; P Plaza; E Ignatz; S Kiontke; L O Essen Physical Chemistry Chemical Physics, 20 (39), p. 25446-25457, 2018, ISSN: 1463-9076. @article{RN114, title = {Delocalized hole transport coupled to sub-ns tryptophanyl deprotonation promotes photoreduction of class II photolyases}, author = {F Lacombat and A Espagne and N Dozova and P Plaza and E Ignatz and S Kiontke and L O Essen}, url = {<Go to ISI>://WOS:000448345400028}, doi = {10.1039/c8cp04548h}, issn = {1463-9076}, year = {2018}, date = {2018-01-01}, journal = {Physical Chemistry Chemical Physics}, volume = {20}, number = {39}, pages = {25446-25457}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Development of a Rubredoxin-Type Center Embedded in a de Dovo-Designed Three-Helix Bundle Article de journal Alison G Tebo; Tyler B J Pinter; Ricardo García-Serres; Amy L Speelman; Cédric Tard; Olivier Sénèque; Geneviève Blondin; Jean-Marc Latour; James Penner-Hahn; Nicolai Lehnert; Vincent L Pecoraro Biochemistry, 57 (16), p. 2308-2316, 2018. @article{Tebo:2018b, title = {Development of a Rubredoxin-Type Center Embedded in a de Dovo-Designed Three-Helix Bundle}, author = {Alison G Tebo and Tyler B J Pinter and Ricardo {Garc\'{i}a-Serres} and Amy L Speelman and C\'{e}dric Tard and Olivier S\'{e}n\`{e}que and Genevi\`{e}ve Blondin and Jean-Marc Latour and James {Penner-Hahn} and Nicolai Lehnert and Vincent L Pecoraro}, doi = {10.1021/acs.biochem.8b00091}, year = {2018}, date = {2018-03-01}, journal = {Biochemistry}, volume = {57}, number = {16}, pages = {2308-2316}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Downstream Simultaneous Electrochemical Detection of Primary Reactive Oxygen and Nitrogen Species Released by Cell Populations in an Integrated Microfluidic Device Article de journal Y Li; C Sella; F Lemaître; M Guille-Collignon; C Amatore; L Thouin Analytical Chemistry, 90 (15), p. 9386–9394, 2018. @article{Li:2018, title = {Downstream Simultaneous Electrochemical Detection of Primary Reactive Oxygen and Nitrogen Species Released by Cell Populations in an Integrated Microfluidic Device}, author = {Y Li and C Sella and F Lema\^{i}tre and M Guille-Collignon and C Amatore and L Thouin}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85049664645&doi=10.1021%2facs.analchem.8b02039&partnerID=40&md5=8f713011165b3b5e06d267ffccea9277}, doi = {10.1021/acs.analchem.8b02039}, year = {2018}, date = {2018-01-01}, journal = {Analytical Chemistry}, volume = {90}, number = {15}, pages = {9386--9394}, abstract = {An innovative microfluidic platform was designed to monitor electrochemically four primary reactive oxygen (ROS) and reactive nitrogen species (RNS) released by aerobic cells. Taking advantage of the space confinement and electrode performances under flow conditions, only a few experiments were sufficient to directly provide significant statistical data relative to the average behavior of cells during oxidative-stress bursts. The microfluidic platform comprised an upstream microchamber for cell culture and four parallel microchannels located downstream for separately detecting H2O2, ONOO-, NO·, and NO2 -. Amperometric measurements were performed at highly sensitive Pt-black electrodes implemented in the microchannels. RAW 264.7 macrophage secretions triggered by a calcium ionophore were used as a way to assess the performance, sensitivity, and specificity of the integrated microfluidic device. In comparison with some previous evaluations achieved from single-cell measurements, reproducible and relevant determinations validated the proof of concept of this microfluidic platform for analyzing statistically significant oxidative-stress responses of various cell types. Copyright © 2018 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An innovative microfluidic platform was designed to monitor electrochemically four primary reactive oxygen (ROS) and reactive nitrogen species (RNS) released by aerobic cells. Taking advantage of the space confinement and electrode performances under flow conditions, only a few experiments were sufficient to directly provide significant statistical data relative to the average behavior of cells during oxidative-stress bursts. The microfluidic platform comprised an upstream microchamber for cell culture and four parallel microchannels located downstream for separately detecting H2O2, ONOO-, NO·, and NO2 -. Amperometric measurements were performed at highly sensitive Pt-black electrodes implemented in the microchannels. RAW 264.7 macrophage secretions triggered by a calcium ionophore were used as a way to assess the performance, sensitivity, and specificity of the integrated microfluidic device. In comparison with some previous evaluations achieved from single-cell measurements, reproducible and relevant determinations validated the proof of concept of this microfluidic platform for analyzing statistically significant oxidative-stress responses of various cell types. Copyright © 2018 American Chemical Society. |
Electrochemical switching fluorescence emission in rhodamine derivatives Article de journal M Čížková; L Cattiaux; J -M Mallet; E Labbé; O Buriez Electrochimica Acta, 260 , p. 589–597, 2018. @article{Cizkova:2018a, title = {Electrochemical switching fluorescence emission in rhodamine derivatives}, author = {M \v{C}\'{i}\v{z}kov\'{a} and L Cattiaux and J -M Mallet and E Labb\'{e} and O Buriez}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85038870042&doi=10.1016%2fj.electacta.2017.12.104&partnerID=40&md5=6a1537d7de8ad37549ef796b0c6f2642}, doi = {10.1016/j.electacta.2017.12.104}, year = {2018}, date = {2018-01-01}, journal = {Electrochimica Acta}, volume = {260}, pages = {589--597}, abstract = {Three rhodamine derivatives exhibiting electrofluorochromic properties were investigated by cyclic voltammetry and UV\textendashVis/fluorescence spectroelectrochemistry. Rhodamine 101 (Rh101, compound 1) was used as a reference model. In compound 2, the carboxylate anion of Rh101 was replaced by an alkyne moiety to allow further functionalization. The compound 3 was prepared from 2 by conversion of the alkyne to a triazole group bearing an alkyl chain with an alcohol function. These three rhodamine derivatives exhibited similar electrochemical behaviors. Their mono-electronic reductions produced the corresponding radical species which were stable on the time-scale of cyclic voltammetry. Additional reduction of electrogenerated radicals produced unstable anions which underwent subsequent chemical reaction, most likely protonation. Based on cyclic voltammetry investigations, absorption and fluorescence spectroelectrochemistry were then performed on compounds 1, 2, 3 and their parent reduced radicals 1a, 2a, 3a. UV\textendashVis spectroelectrochemistry, combined with TD-DFT calculation, confirmed the formation of radicals upon mono-electronic reduction of starting rhodamines. Fluorescence spectroelectrochemistry showed that, contrary to their parent molecules, electrogenerated radicals were non-fluorescent. Electrochemical fluorescence extinction was successfully achieved with all studied compounds. Moreover, compound 1 underwent on/off switching between fluorescent and non-fluorescent states repeatedly. Also, recovery of fluorescence in compound 3 was observed, which open interesting opportunities for the development of versatile rhodamine-based probes. © 2017 The Authors}, keywords = {}, pubstate = {published}, tppubtype = {article} } Three rhodamine derivatives exhibiting electrofluorochromic properties were investigated by cyclic voltammetry and UV–Vis/fluorescence spectroelectrochemistry. Rhodamine 101 (Rh101, compound 1) was used as a reference model. In compound 2, the carboxylate anion of Rh101 was replaced by an alkyne moiety to allow further functionalization. The compound 3 was prepared from 2 by conversion of the alkyne to a triazole group bearing an alkyl chain with an alcohol function. These three rhodamine derivatives exhibited similar electrochemical behaviors. Their mono-electronic reductions produced the corresponding radical species which were stable on the time-scale of cyclic voltammetry. Additional reduction of electrogenerated radicals produced unstable anions which underwent subsequent chemical reaction, most likely protonation. Based on cyclic voltammetry investigations, absorption and fluorescence spectroelectrochemistry were then performed on compounds 1, 2, 3 and their parent reduced radicals 1a, 2a, 3a. UV–Vis spectroelectrochemistry, combined with TD-DFT calculation, confirmed the formation of radicals upon mono-electronic reduction of starting rhodamines. Fluorescence spectroelectrochemistry showed that, contrary to their parent molecules, electrogenerated radicals were non-fluorescent. Electrochemical fluorescence extinction was successfully achieved with all studied compounds. Moreover, compound 1 underwent on/off switching between fluorescent and non-fluorescent states repeatedly. Also, recovery of fluorescence in compound 3 was observed, which open interesting opportunities for the development of versatile rhodamine-based probes. © 2017 The Authors |
Fast and complete electrochemical conversion of solutes contained in micro-volume water droplets Article de journal L Godeffroy; F Chau; O Buriez; E Labbé Electrochemistry Communications, 86 , p. 145–148, 2018. @article{Godeffroy:2018, title = {Fast and complete electrochemical conversion of solutes contained in micro-volume water droplets}, author = {L Godeffroy and F Chau and O Buriez and E Labb\'{e}}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85038019547&doi=10.1016%2fj.elecom.2017.12.007&partnerID=40&md5=e4be97ff9584068f86e05922768a8567}, doi = {10.1016/j.elecom.2017.12.007}, year = {2018}, date = {2018-01-01}, journal = {Electrochemistry Communications}, volume = {86}, pages = {145--148}, abstract = {An elegant hanging-droplet or meniscus-based setup is proposed to carry out quantitative electrolyses from either an organic (hydroquinone) or an inorganic (permanganate) substrate. These examples validate the concept of using such easily accessible, fast (1\textendash3 min) and low-cost operating conditions not only for preparative applications (electrosynthesis), but also for pedagogical purposes in minute samples. © 2017 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An elegant hanging-droplet or meniscus-based setup is proposed to carry out quantitative electrolyses from either an organic (hydroquinone) or an inorganic (permanganate) substrate. These examples validate the concept of using such easily accessible, fast (1–3 min) and low-cost operating conditions not only for preparative applications (electrosynthesis), but also for pedagogical purposes in minute samples. © 2017 Elsevier B.V. |
Fluorogenic Probing of Membrane Protein Trafficking Article de journal C Li; A Mourton; M -A Plamont; V Rodrigues; I Aujard; M Volovitch; T Le Saux; F Perez; S Vriz; L Jullien; A Joliot; A Gautier Bioconjugate Chemistry, 29 (6), p. 1823–1828, 2018. @article{Li:2018a, title = {Fluorogenic Probing of Membrane Protein Trafficking}, author = {C Li and A Mourton and M -A Plamont and V Rodrigues and I Aujard and M Volovitch and T Le Saux and F Perez and S Vriz and L Jullien and A Joliot and A Gautier}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85047641063&doi=10.1021%2facs.bioconjchem.8b00180&partnerID=40&md5=bcbb74499b742fa8b0762b8c52ebf5dd}, doi = {10.1021/acs.bioconjchem.8b00180}, year = {2018}, date = {2018-01-01}, journal = {Bioconjugate Chemistry}, volume = {29}, number = {6}, pages = {1823--1828}, abstract = {Methods to differentially label cell-surface and intracellular membrane proteins are indispensable for understanding their function and the regulation of their trafficking. We present an efficient strategy for the rapid and selective fluorescent labeling of membrane proteins based on the chemical-genetic fluorescent marker FAST (fluorescence-activating and absorption-shifting tag). Cell-surface FAST-tagged proteins could be selectively and rapidly labeled using fluorogenic membrane-impermeant 4-hydroxybenzylidene rhodanine (HBR) analogs. This approach allows the study of protein trafficking at the plasma membrane with various fluorometric techniques, and opens exciting prospects for the high-throughput screening of small molecules able to restore disease-related trafficking defects. © 2018 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Methods to differentially label cell-surface and intracellular membrane proteins are indispensable for understanding their function and the regulation of their trafficking. We present an efficient strategy for the rapid and selective fluorescent labeling of membrane proteins based on the chemical-genetic fluorescent marker FAST (fluorescence-activating and absorption-shifting tag). Cell-surface FAST-tagged proteins could be selectively and rapidly labeled using fluorogenic membrane-impermeant 4-hydroxybenzylidene rhodanine (HBR) analogs. This approach allows the study of protein trafficking at the plasma membrane with various fluorometric techniques, and opens exciting prospects for the high-throughput screening of small molecules able to restore disease-related trafficking defects. © 2018 American Chemical Society. |
Fluorogenic Protein-Based Strategies for Detection, Actuation, and Sensing Article de journal A Gautier; A G Tebo BioEssays, 40 (10), 2018. @article{Gautier:2018, title = {Fluorogenic Protein-Based Strategies for Detection, Actuation, and Sensing}, author = {A Gautier and A G Tebo}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053180336&doi=10.1002%2fbies.201800118&partnerID=40&md5=92409e91810fa2bf17d3eef357bc1bc9}, doi = {10.1002/bies.201800118}, year = {2018}, date = {2018-01-01}, journal = {BioEssays}, volume = {40}, number = {10}, abstract = {Fluorescence imaging has become an indispensable tool in cell and molecular biology. GFP-like fluorescent proteins have revolutionized fluorescence microscopy, giving experimenters exquisite control over the localization and specificity of tagged constructs. However, these systems present certain drawbacks and as such, alternative systems based on a fluorogenic interaction between a chromophore and a protein have been developed. While these systems are initially designed as fluorescent labels, they also present new opportunities for the development of novel labeling and detection strategies. This review focuses on new labeling protocols, actuation methods, and biosensors based on fluorogenic protein systems. © 2018 WILEY Periodicals, Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Fluorescence imaging has become an indispensable tool in cell and molecular biology. GFP-like fluorescent proteins have revolutionized fluorescence microscopy, giving experimenters exquisite control over the localization and specificity of tagged constructs. However, these systems present certain drawbacks and as such, alternative systems based on a fluorogenic interaction between a chromophore and a protein have been developed. While these systems are initially designed as fluorescent labels, they also present new opportunities for the development of novel labeling and detection strategies. This review focuses on new labeling protocols, actuation methods, and biosensors based on fluorogenic protein systems. © 2018 WILEY Periodicals, Inc. |
Improved Chemical-Genetic Fluorescent Markers for Live Cell Microscopy Article de journal A G Tebo; F M Pimenta; Y Zhang; A Gautier Biochemistry, 57 (39), p. 5648–5653, 2018. @article{Tebo:2018a, title = {Improved Chemical-Genetic Fluorescent Markers for Live Cell Microscopy}, author = {A G Tebo and F M Pimenta and Y Zhang and A Gautier}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85053681817&doi=10.1021%2facs.biochem.8b00649&partnerID=40&md5=550c3f9cf88557339074b67771afd7d7}, doi = {10.1021/acs.biochem.8b00649}, year = {2018}, date = {2018-01-01}, journal = {Biochemistry}, volume = {57}, number = {39}, pages = {5648--5653}, abstract = {Inducible chemical-genetic fluorescent markers are promising tools for live cell imaging requiring high spatiotemporal resolution and low background fluorescence. The fluorescence-activating and absorption shifting tag (FAST) was recently developed to form fluorescent molecular complexes with a family of small, synthetic fluorogenic chromophores (so-called fluorogens). Here, we use rational design to modify the binding pocket of the protein and screen for improved fluorescence performances with four different fluorogens. The introduction of a single mutation results in improvements in both quantum yield and dissociation constant with nearly all fluorogens tested. Our improved FAST (iFAST) allowed the generation of a tandem iFAST (td-iFAST) that forms green and red fluorescent reporters 1.6-fold and 2-fold brighter than EGFP and mCherry, respectively, while having a comparable size. © Copyright 2018 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Inducible chemical-genetic fluorescent markers are promising tools for live cell imaging requiring high spatiotemporal resolution and low background fluorescence. The fluorescence-activating and absorption shifting tag (FAST) was recently developed to form fluorescent molecular complexes with a family of small, synthetic fluorogenic chromophores (so-called fluorogens). Here, we use rational design to modify the binding pocket of the protein and screen for improved fluorescence performances with four different fluorogens. The introduction of a single mutation results in improvements in both quantum yield and dissociation constant with nearly all fluorogens tested. Our improved FAST (iFAST) allowed the generation of a tandem iFAST (td-iFAST) that forms green and red fluorescent reporters 1.6-fold and 2-fold brighter than EGFP and mCherry, respectively, while having a comparable size. © Copyright 2018 American Chemical Society. |
Investigation of photocurrents resulting from a living unicellular algae suspension with quinones over time Article de journal G Longatte; A Sayegh; J Delacotte; F Rappaport; F -A Wollman; M Guille-Collignon; F Lemaître Chemical Science, 9 (43), p. 8271–8281, 2018. @article{Longatte:2018, title = {Investigation of photocurrents resulting from a living unicellular algae suspension with quinones over time}, author = {G Longatte and A Sayegh and J Delacotte and F Rappaport and F -A Wollman and M Guille-Collignon and F Lema\^{i}tre}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85056308267&doi=10.1039%2fc8sc03058h&partnerID=40&md5=73d658b7ab313cc1a772ca28dc56aa2d}, doi = {10.1039/c8sc03058h}, year = {2018}, date = {2018-01-01}, journal = {Chemical Science}, volume = {9}, number = {43}, pages = {8271--8281}, abstract = {Plants, algae, and some bacteria convert solar energy into chemical energy by using photosynthesis. In light of the current energy environment, many research strategies try to benefit from photosynthesis in order to generate usable photobioelectricity. Among all the strategies developed for transferring electrons from the photosynthetic chain to an outer collecting electrode, we recently implemented a method on a preparative scale (high surface electrode) based on a Chlamydomonas reinhardtii green algae suspension in the presence of exogenous quinones as redox mediators. While giving rise to an interesting performance (10-60 μA cm-2) in the course of one hour, this device appears to cause a slow decrease of the recorded photocurrent. In this paper, we wish to analyze and understand this gradual fall in performance in order to limit this issue in future applications. We thus first show that this kind of degradation could be related to over-irradiation conditions or side-effects of quinones depending on experimental conditions. We therefore built an empirical model involving a kinetic quenching induced by incubation with quinones, which is globally consistent with the experimental data provided by fluorescence measurements achieved after dark incubation of algae in the presence of quinones. © 2018 The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Plants, algae, and some bacteria convert solar energy into chemical energy by using photosynthesis. In light of the current energy environment, many research strategies try to benefit from photosynthesis in order to generate usable photobioelectricity. Among all the strategies developed for transferring electrons from the photosynthetic chain to an outer collecting electrode, we recently implemented a method on a preparative scale (high surface electrode) based on a Chlamydomonas reinhardtii green algae suspension in the presence of exogenous quinones as redox mediators. While giving rise to an interesting performance (10-60 μA cm-2) in the course of one hour, this device appears to cause a slow decrease of the recorded photocurrent. In this paper, we wish to analyze and understand this gradual fall in performance in order to limit this issue in future applications. We thus first show that this kind of degradation could be related to over-irradiation conditions or side-effects of quinones depending on experimental conditions. We therefore built an empirical model involving a kinetic quenching induced by incubation with quinones, which is globally consistent with the experimental data provided by fluorescence measurements achieved after dark incubation of algae in the presence of quinones. © 2018 The Royal Society of Chemistry. |
Light-assisted dynamic titration: from theory to an experimental protocol Article de journal A Pellissier-Tanon; R Chouket; T Le Saux; L Jullien; A Lemarchand Physical Chemistry Chemical Physics, 20 (37), p. 23998–24010, 2018. @article{Pellissier-Tanon:2018, title = {Light-assisted dynamic titration: from theory to an experimental protocol}, author = {A Pellissier-Tanon and R Chouket and T Le Saux and L Jullien and A Lemarchand}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054097721&doi=10.1039%2fc8cp03953d&partnerID=40&md5=782f885754810c59f73c4a3134f6355f}, doi = {10.1039/c8cp03953d}, year = {2018}, date = {2018-01-01}, journal = {Physical Chemistry Chemical Physics}, volume = {20}, number = {37}, pages = {23998--24010}, abstract = {In order to design a dynamic titration method, we propose a theoretical model harnessing the kinetic properties of the complexation of the titrated species with a titrating photoswitchable reagent. Forced oscillations of illumination are imposed and concentration oscillations of the targeted species are deduced from the equations of chemical kinetics. We determine analytical expressions of the resonance conditions on the control parameters, angular frequency, mean light intensity, and total concentration of the photoswitchable reagent, which optimize the out-of-phase amplitude of concentration oscillations. A user-friendly protocol of dynamic titration is proposed. © the Owner Societies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In order to design a dynamic titration method, we propose a theoretical model harnessing the kinetic properties of the complexation of the titrated species with a titrating photoswitchable reagent. Forced oscillations of illumination are imposed and concentration oscillations of the targeted species are deduced from the equations of chemical kinetics. We determine analytical expressions of the resonance conditions on the control parameters, angular frequency, mean light intensity, and total concentration of the photoswitchable reagent, which optimize the out-of-phase amplitude of concentration oscillations. A user-friendly protocol of dynamic titration is proposed. © the Owner Societies. |
Macroscale fluorescence imaging against autofluorescence under ambient light Article de journal R Zhang; R Chouket; M -A Plamont; Z Kelemen; A Espagne; A G Tebo; A Gautier; L Gissot; J -D Faure; L Jullien; V Croquette; T Le Saux Light: Science and Applications, 7 (1), 2018. @article{Zhang:2018c, title = {Macroscale fluorescence imaging against autofluorescence under ambient light}, author = {R Zhang and R Chouket and M -A Plamont and Z Kelemen and A Espagne and A G Tebo and A Gautier and L Gissot and J -D Faure and L Jullien and V Croquette and T Le Saux}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85058077105&doi=10.1038%2fs41377-018-0098-6&partnerID=40&md5=958a21f219ba413e687d1860d21c2767}, doi = {10.1038/s41377-018-0098-6}, year = {2018}, date = {2018-01-01}, journal = {Light: Science and Applications}, volume = {7}, number = {1}, abstract = {Macroscale fluorescence imaging is increasingly used to observe biological samples. However, it may suffer from spectral interferences that originate from ambient light or autofluorescence of the sample or its support. In this manuscript, we built a simple and inexpensive fluorescence macroscope, which has been used to evaluate the performance of Speed OPIOM (Out of Phase Imaging after Optical Modulation), which is a reference-free dynamic contrast protocol, to selectively image reversibly photoswitchable fluorophores as labels against detrimental autofluorescence and ambient light. By tuning the intensity and radial frequency of the modulated illumination to the Speed OPIOM resonance and adopting a phase-sensitive detection scheme that ensures noise rejection, we enhanced the sensitivity and the signal-to-noise ratio for fluorescence detection in blot assays by factors of 50 and 10, respectively, over direct fluorescence observation under constant illumination. Then, we overcame the strong autofluorescence of growth media that are currently used in microbiology and realized multiplexed fluorescence observation of colonies of spectrally similar fluorescent bacteria with a unique configuration of excitation and emission wavelengths. Finally, we easily discriminated fluorescent labels from the autofluorescent and reflective background in labeled leaves, even under the interference of incident light at intensities that are comparable to sunlight. The proposed approach is expected to find multiple applications, from biological assays to outdoor observations, in fluorescence macroimaging. © 2018, The Author(s).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Macroscale fluorescence imaging is increasingly used to observe biological samples. However, it may suffer from spectral interferences that originate from ambient light or autofluorescence of the sample or its support. In this manuscript, we built a simple and inexpensive fluorescence macroscope, which has been used to evaluate the performance of Speed OPIOM (Out of Phase Imaging after Optical Modulation), which is a reference-free dynamic contrast protocol, to selectively image reversibly photoswitchable fluorophores as labels against detrimental autofluorescence and ambient light. By tuning the intensity and radial frequency of the modulated illumination to the Speed OPIOM resonance and adopting a phase-sensitive detection scheme that ensures noise rejection, we enhanced the sensitivity and the signal-to-noise ratio for fluorescence detection in blot assays by factors of 50 and 10, respectively, over direct fluorescence observation under constant illumination. Then, we overcame the strong autofluorescence of growth media that are currently used in microbiology and realized multiplexed fluorescence observation of colonies of spectrally similar fluorescent bacteria with a unique configuration of excitation and emission wavelengths. Finally, we easily discriminated fluorescent labels from the autofluorescent and reflective background in labeled leaves, even under the interference of incident light at intensities that are comparable to sunlight. The proposed approach is expected to find multiple applications, from biological assays to outdoor observations, in fluorescence macroimaging. © 2018, The Author(s). |
Mixed Copolymer Adlayers Allowing Reversible Thermal Control of Single Cell Aspect Ratio Article de journal F Dalier; G V Dubacheva; M Coniel; D Zanchi; A Galtayries; M Piel; E Marie; C Tribet Acs Applied Materials & Interfaces, 10 (3), p. 2253-2258, 2018, ISSN: 1944-8244. @article{Dalier:2018, title = {Mixed Copolymer Adlayers Allowing Reversible Thermal Control of Single Cell Aspect Ratio}, author = {F Dalier and G V Dubacheva and M Coniel and D Zanchi and A Galtayries and M Piel and E Marie and C Tribet}, doi = {10.1021/acsami.7b18513}, issn = {1944-8244}, year = {2018}, date = {2018-01-01}, journal = {Acs Applied Materials & Interfaces}, volume = {10}, number = {3}, pages = {2253-2258}, abstract = {Dynamic guidance of living cells is achieved by fine-tuning and spatiotemporal modulation on artificial polymer layers enabling reversible peptide display. Adjustment of surface composition and interactions is obtained by coadsorption of mixed poly(lysine) derivatives, grafted with either repellent PEG, RGD adhesion peptides, or T-responsive poly(N-isopropylacrylamide) strands. Deposition of mixed adlayers provides a straightforward mean to optimize complex substrates, which is here implemented to achieve (1) thermal control of ligand accessibility and (2) adjustment of relative adhesiveness between adjacent micropatterns, while preserving cell attachment during thermal cycles. The reversible polarization of HeLa cells along orthogonal stripes mimics guidance along natural matrices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Dynamic guidance of living cells is achieved by fine-tuning and spatiotemporal modulation on artificial polymer layers enabling reversible peptide display. Adjustment of surface composition and interactions is obtained by coadsorption of mixed poly(lysine) derivatives, grafted with either repellent PEG, RGD adhesion peptides, or T-responsive poly(N-isopropylacrylamide) strands. Deposition of mixed adlayers provides a straightforward mean to optimize complex substrates, which is here implemented to achieve (1) thermal control of ligand accessibility and (2) adjustment of relative adhesiveness between adjacent micropatterns, while preserving cell attachment during thermal cycles. The reversible polarization of HeLa cells along orthogonal stripes mimics guidance along natural matrices. |
Modifying the Steric Properties in the Second Coordination Sphere of Designed Peptides Leads to Enhancement of Nitrite Reductase Activity Article de journal Karl J Koebke; Fangting Yu; Elvin Salerno; Casey Van Stappen; Alison G Tebo; James E Penner-Hahn; Vincent L Pecoraro Angewandte Chemie International Edition, 57 (15), p. 3954-3957, 2018. @article{Koebke:2018a, title = {Modifying the Steric Properties in the Second Coordination Sphere of Designed Peptides Leads to Enhancement of Nitrite Reductase Activity}, author = {Karl J Koebke and Fangting Yu and Elvin Salerno and Casey Van Stappen and Alison G Tebo and James E {Penner-Hahn} and Vincent L Pecoraro}, doi = {10.1002/anie.201712757}, year = {2018}, date = {2018-01-01}, journal = {Angewandte Chemie International Edition}, volume = {57}, number = {15}, pages = {3954-3957}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Redox switchable rhodamine-ferrocene dyad: Exploring imaging possibilities in cells Article de journal M Čížková; L Cattiaux; J Pandard; M Guille-Collignon; F Lemaître; J Delacotte; J -M Mallet; E Labbé; O Buriez Electrochemistry Communications, 97 , p. 46–50, 2018. @article{Cizkova:2018, title = {Redox switchable rhodamine-ferrocene dyad: Exploring imaging possibilities in cells}, author = {M \v{C}\'{i}\v{z}kov\'{a} and L Cattiaux and J Pandard and M Guille-Collignon and F Lema\^{i}tre and J Delacotte and J -M Mallet and E Labb\'{e} and O Buriez}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054592456&doi=10.1016%2fj.elecom.2018.10.009&partnerID=40&md5=10a4aed1c89bb6a788a2a260bbd0a818}, doi = {10.1016/j.elecom.2018.10.009}, year = {2018}, date = {2018-01-01}, journal = {Electrochemistry Communications}, volume = {97}, pages = {46--50}, abstract = {An original redox-responsive fluorescent probe combining a rhodamine derivative and a ferrocenyl moiety used as the fluorescence modulator was designed, synthesized and characterized. The fluorescence of this new dyad could be tuned from the redox state of ferrocene, a feature observed both electrochemically and on cancer cells incubated with this probe. © 2018 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } An original redox-responsive fluorescent probe combining a rhodamine derivative and a ferrocenyl moiety used as the fluorescence modulator was designed, synthesized and characterized. The fluorescence of this new dyad could be tuned from the redox state of ferrocene, a feature observed both electrochemically and on cancer cells incubated with this probe. © 2018 Elsevier B.V. |