You will find below the publication list of our pole.
For the publication list of each pole member, please see his/her personal webpage.
2015 |
Artificial Metalloenzymes Derived from Three-Helix Bundles. Article de journal Alison G Tebo; Vincent L Pecoraro Current Opinion in Chemical Biology, 25C , p. 65-70, 2015. @article{Tebo:2015a, title = {Artificial Metalloenzymes Derived from Three-Helix Bundles.}, author = {Alison G Tebo and Vincent L Pecoraro}, doi = {10.1016/j.cbpa.2014.12.034}, year = {2015}, date = {2015-01-01}, journal = {Current Opinion in Chemical Biology}, volume = {25C}, pages = {65-70}, abstract = {Three-helix bundles and coiled-coil motifs are well-established de novo designed scaffolds that have been investigated for their metal-binding and catalytic properties. Satisfaction of the primary coordination sphere for a given metal is sufficient to introduce catalytic activity and a given structure may catalyze different reactions dependent on the identity of the incorporated metal. Here we describe recent contributions in the de novo design of metalloenzymes based on three-helix bundles and coiled-coil motifs, focusing on non-heme systems for hydrolytic and redox chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Three-helix bundles and coiled-coil motifs are well-established de novo designed scaffolds that have been investigated for their metal-binding and catalytic properties. Satisfaction of the primary coordination sphere for a given metal is sufficient to introduce catalytic activity and a given structure may catalyze different reactions dependent on the identity of the incorporated metal. Here we describe recent contributions in the de novo design of metalloenzymes based on three-helix bundles and coiled-coil motifs, focusing on non-heme systems for hydrolytic and redox chemistry. |
Bioanalytical applications of the fluorescence-electrochemistry combination Article de journal F Lemaître; M Guille-Collignon Actualite Chimique, (400-401), p. 17–19, 2015. @article{Lemaitre:2015, title = {Bioanalytical applications of the fluorescence-electrochemistry combination}, author = {F Lema\^{i}tre and M Guille-Collignon}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84973499998&partnerID=40&md5=d5fb99aaf2d3336a53a286546cb86bdb}, year = {2015}, date = {2015-01-01}, journal = {Actualite Chimique}, number = {400-401}, pages = {17--19}, abstract = {Both fluorescence and electrochemistry techniques aim at converting a chemical signal into an optical or an electrical one respectively. Particularly, they correspond to appropriate techniques for investigating biological phenomena due to the electroactivity of many biomolecules while cells or proteins can be labeled with fluorophores. Therefore, this article is a non exhaustive presentation of the coupling between electrochemistry and fluorescence for biological investigations. By focusing on exocytosis, it also raises the question of the implementation of such a combination.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Both fluorescence and electrochemistry techniques aim at converting a chemical signal into an optical or an electrical one respectively. Particularly, they correspond to appropriate techniques for investigating biological phenomena due to the electroactivity of many biomolecules while cells or proteins can be labeled with fluorophores. Therefore, this article is a non exhaustive presentation of the coupling between electrochemistry and fluorescence for biological investigations. By focusing on exocytosis, it also raises the question of the implementation of such a combination. |
Biochemical perturbations of the mitotic spindle in Xenopus extracts using a diffusion-based microfluidic assay Article de journal B -K Yoo; A Buguin; Z Gueroui Biomicrofluidics, 9 (4), 2015. @article{Yoo:2015, title = {Biochemical perturbations of the mitotic spindle in Xenopus extracts using a diffusion-based microfluidic assay}, author = {B -K Yoo and A Buguin and Z Gueroui}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84937010959&doi=10.1063%2f1.4926324&partnerID=40&md5=fe9fbd850f2dfba54580e01568a15d50}, doi = {10.1063/1.4926324}, year = {2015}, date = {2015-01-01}, journal = {Biomicrofluidics}, volume = {9}, number = {4}, abstract = {A microfluidic device is a powerful tool to manipulate in a controlled manner at spatiotemporal scales for biological systems. Here, we describe a simple diffusion-based assay to generate and measure the effect of biochemical perturbations within the cytoplasm of cell-free extracts from Xenopus eggs. Our approach comprises a microliter reservoir and a model cytoplasm that are separated by a synthetic membrane containing sub-micrometric pores through which small molecules and recombinant proteins can diffuse. We have used this system to examine the perturbation of elements of the mitotic spindle, which is a microtubule-based bipolar structure involved in the segregation of the replicated genome to daughter cells during cell division. First, we used the small molecule inhibitor monastrol to target kinesin-5, a molecular motor that maintains the microtubule spindle bipolarity. Next, we explored the dynamics of the mitotic spindle by monitoring the exchange between unpolymerized and polymerized tubulin within microtubule fibers. These results show that a simple diffusion-based system can generate biochemical perturbations directly within a cell-free cytoplasm based on Xenopus egg extracts at the time scale of minutes. Our assay is therefore suitable for monitoring the dynamics of supramolecular assemblies within cell-free extracts in response to perturbations. This strategy opens up broad perspectives including phenotype screening or mechanistic studies of biological assembly processes and could be applied to other cell-free extracts such as those derived from mammalian or bacterial cells. © 2015 AIP Publishing LLC.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A microfluidic device is a powerful tool to manipulate in a controlled manner at spatiotemporal scales for biological systems. Here, we describe a simple diffusion-based assay to generate and measure the effect of biochemical perturbations within the cytoplasm of cell-free extracts from Xenopus eggs. Our approach comprises a microliter reservoir and a model cytoplasm that are separated by a synthetic membrane containing sub-micrometric pores through which small molecules and recombinant proteins can diffuse. We have used this system to examine the perturbation of elements of the mitotic spindle, which is a microtubule-based bipolar structure involved in the segregation of the replicated genome to daughter cells during cell division. First, we used the small molecule inhibitor monastrol to target kinesin-5, a molecular motor that maintains the microtubule spindle bipolarity. Next, we explored the dynamics of the mitotic spindle by monitoring the exchange between unpolymerized and polymerized tubulin within microtubule fibers. These results show that a simple diffusion-based system can generate biochemical perturbations directly within a cell-free cytoplasm based on Xenopus egg extracts at the time scale of minutes. Our assay is therefore suitable for monitoring the dynamics of supramolecular assemblies within cell-free extracts in response to perturbations. This strategy opens up broad perspectives including phenotype screening or mechanistic studies of biological assembly processes and could be applied to other cell-free extracts such as those derived from mammalian or bacterial cells. © 2015 AIP Publishing LLC. |
Control of brain patterning by engrailed paracrine transfer: A new function of the pbx interaction domain Article de journal C Rampon; C Gauron; T Lin; F Meda; E Dupont; A Cosson; E Ipendey; A Frerot; I Aujard; T Le Saux; D Bensimon; L Jullien; M Volovitch; S Vriz; A Joliot Development (Cambridge), 142 (10), p. 1840–1849, 2015. @article{Rampon:2015, title = {Control of brain patterning by engrailed paracrine transfer: A new function of the pbx interaction domain}, author = {C Rampon and C Gauron and T Lin and F Meda and E Dupont and A Cosson and E Ipendey and A Frerot and I Aujard and T Le Saux and D Bensimon and L Jullien and M Volovitch and S Vriz and A Joliot}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84929206944&doi=10.1242%2fdev.114181&partnerID=40&md5=016ff1da90c2292976a12fee82b3ed59}, doi = {10.1242/dev.114181}, year = {2015}, date = {2015-01-01}, journal = {Development (Cambridge)}, volume = {142}, number = {10}, pages = {1840--1849}, abstract = {Homeoproteins of the Engrailed family are involved in the patterning of mesencephalic boundaries through a mechanism classically ascribed to their transcriptional functions. In light of recent reports on the paracrine activity of homeoproteins, including Engrailed, we asked whether Engrailed intercellular transfer was also involved in brain patterning and boundary formation. Using time-controlled activation of Engrailed combined with tools that block its transfer, we show that the positioning of the diencephalic-mesencephalic boundary (DMB) requires Engrailed paracrine activity. Both zebrafish Eng2a and Eng2b are competent for intercellular transfer in vivo, but only extracellular endogenous Eng2b, and not Eng2a, participates in DMB positioning. In addition, disruption of the Pbx-interacting motif in Engrailed, known to strongly reduce the gain-of-function phenotype, also downregulates Engrailed transfer, thus revealing an unsuspected participation of the Pbx interaction domain in this pathway. © 2015. Published by The Company of Biologists Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Homeoproteins of the Engrailed family are involved in the patterning of mesencephalic boundaries through a mechanism classically ascribed to their transcriptional functions. In light of recent reports on the paracrine activity of homeoproteins, including Engrailed, we asked whether Engrailed intercellular transfer was also involved in brain patterning and boundary formation. Using time-controlled activation of Engrailed combined with tools that block its transfer, we show that the positioning of the diencephalic-mesencephalic boundary (DMB) requires Engrailed paracrine activity. Both zebrafish Eng2a and Eng2b are competent for intercellular transfer in vivo, but only extracellular endogenous Eng2b, and not Eng2a, participates in DMB positioning. In addition, disruption of the Pbx-interacting motif in Engrailed, known to strongly reduce the gain-of-function phenotype, also downregulates Engrailed transfer, thus revealing an unsuspected participation of the Pbx interaction domain in this pathway. © 2015. Published by The Company of Biologists Ltd. |
Discovery and functional analysis of a 4th electron-transferring tryptophan conserved exclusively in animal cryptochromes and (6-4) photolyases Article de journal P Müller; J Yamamoto; P R Martin; S Iwai; K Brettel Chemical Communications, 51 (85), p. 15502-15505, 2015, ISSN: 1359-7345. @article{RN116, title = {Discovery and functional analysis of a 4th electron-transferring tryptophan conserved exclusively in animal cryptochromes and (6-4) photolyases}, author = {P M\"{u}ller and J Yamamoto and P R Martin and S Iwai and K Brettel}, url = {<Go to ISI>://WOS:000363167900005}, doi = {10.1039/c5cc06276d}, issn = {1359-7345}, year = {2015}, date = {2015-01-01}, journal = {Chemical Communications}, volume = {51}, number = {85}, pages = {15502-15505}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Electrochemically driven supramolecular interaction of quinones and ferrocifens: An example of redox activation of bioactive compounds Article de journal Y G De Paiva; F Da Rocha Ferreira; T L Silva; E Labbe; O Buriez; C Amatore; M O F Goulart Current Topics in Medicinal Chemistry, 15 (2), p. 136–162, 2015. @article{DePaiva:2015, title = {Electrochemically driven supramolecular interaction of quinones and ferrocifens: An example of redox activation of bioactive compounds}, author = {Y G De Paiva and F Da Rocha Ferreira and T L Silva and E Labbe and O Buriez and C Amatore and M O F Goulart}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84926286178&doi=10.2174%2f1568026615666141209155300&partnerID=40&md5=d4ea2f1cdfbb9b011dbf22d964fba992}, doi = {10.2174/1568026615666141209155300}, year = {2015}, date = {2015-01-01}, journal = {Current Topics in Medicinal Chemistry}, volume = {15}, number = {2}, pages = {136--162}, abstract = {This review discusses the state of the art, challenges and perspectives in recent applications of electrochemistry in the life sciences. It deals mainly with the elucidation of molecular mechanisms of drug action, drug design and development, involving electron transfer, pharmaco-electrochemistry (the combination of electrochemical and pharmacological assays), and electrochemical studies of membrane models and drug delivery. It aims to shed light on the question: does electrochemistry really contribute to this area? It includes a general introduction for the use of electrochemistry in the life sciences, with a focus on how electrochemistry can uniquely provide both kinetic and thermodynamic information. A number of studies are reported in the literature and from the authors’ laboratories, including the investigation of biooxidative/bioreductive activation of pro-drugs, DNA alkylation, electrochemically-based release of reactive oxygen and nitrogen species, with a particular emphasis on quinones, ferrocifens and compounds with mixed-functionality. Within the context of drug delivery and bioavailability, the electrochemical investigation of supramolecular interactions of the chosen classes of compounds with cyclodextrins and lipid bilayers, in relation to their solubilization and vectorization was also carried out. The updated examples herein illustrate how relevant and challenging the integration of electrochemistry, supramolecular and materials chemistry, biochemistry and medical knowledge for the design and development of redox-selective molecular approaches is. Many questions related to these fields are still unclear and the search for selectivity toward redox therapeutic agents remains of expanding interest. This review hopes to stimulate researchers to become more involved in this fruitful interface between electrochemistry and the life sciences. © 2015 Bentham Science Publishers.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This review discusses the state of the art, challenges and perspectives in recent applications of electrochemistry in the life sciences. It deals mainly with the elucidation of molecular mechanisms of drug action, drug design and development, involving electron transfer, pharmaco-electrochemistry (the combination of electrochemical and pharmacological assays), and electrochemical studies of membrane models and drug delivery. It aims to shed light on the question: does electrochemistry really contribute to this area? It includes a general introduction for the use of electrochemistry in the life sciences, with a focus on how electrochemistry can uniquely provide both kinetic and thermodynamic information. A number of studies are reported in the literature and from the authors’ laboratories, including the investigation of biooxidative/bioreductive activation of pro-drugs, DNA alkylation, electrochemically-based release of reactive oxygen and nitrogen species, with a particular emphasis on quinones, ferrocifens and compounds with mixed-functionality. Within the context of drug delivery and bioavailability, the electrochemical investigation of supramolecular interactions of the chosen classes of compounds with cyclodextrins and lipid bilayers, in relation to their solubilization and vectorization was also carried out. The updated examples herein illustrate how relevant and challenging the integration of electrochemistry, supramolecular and materials chemistry, biochemistry and medical knowledge for the design and development of redox-selective molecular approaches is. Many questions related to these fields are still unclear and the search for selectivity toward redox therapeutic agents remains of expanding interest. This review hopes to stimulate researchers to become more involved in this fruitful interface between electrochemistry and the life sciences. © 2015 Bentham Science Publishers. |
Evaluation of photosynthetic electrons derivation by exogenous redox mediators Article de journal Guillaume Longatte; Han-Yi Fu; Olivier Buriez; Eric Labbé; Francis-André Wollman; Christian Amatore; Fabrice Rappaport; Manon Guille-Collignon; Frédéric Lemaître Biophysical Chemistry, 205 , p. 1-8, 2015. @article{RID:0721150706473-48b, title = {Evaluation of photosynthetic electrons derivation by exogenous redox mediators}, author = {Guillaume Longatte and Han-Yi Fu and Olivier Buriez and Eric Labb\'{e} and Francis-Andr\'{e} Wollman and Christian Amatore and Fabrice Rappaport and Manon Guille-Collignon and Fr\'{e}d\'{e}ric Lema\^{i}tre}, year = {2015}, date = {2015-01-01}, journal = {Biophysical Chemistry}, volume = {205}, pages = {1-8}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Expanding discriminative dimensions for analysis and imaging Article de journal J Querard; A Gautier; T Le Saux; L Jullien Chemical Science, 6 (5), p. 2968–2978, 2015. @article{Querard:2015, title = {Expanding discriminative dimensions for analysis and imaging}, author = {J Querard and A Gautier and T Le Saux and L Jullien}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84928139717&doi=10.1039%2fc4sc03955f&partnerID=40&md5=aeed36c64e258429fa7a7aa11b8baba8}, doi = {10.1039/c4sc03955f}, year = {2015}, date = {2015-01-01}, journal = {Chemical Science}, volume = {6}, number = {5}, pages = {2968--2978}, abstract = {Eliminating the contribution of interfering compounds is a key step in chemical analysis. In complex media, one possible approach is to perform a preliminary separation. However purification is often demanding, long, and costly; it may also considerably alter the properties of interacting components of the mixture (e.g. in a living cell). Hence there is a strong interest for developing separation-free non-invasive analytical protocols. Using photoswitchable probes as labelling and titration contrast agents, we demonstrate that the association of a modulated monochromatic light excitation with a kinetic filtering of the overall observable is much more attractive than constant excitation to read-out the contribution from a target probe under adverse conditions. An extensive theoretical framework enabled us to optimize the out-of-phase concentration first-order response of a photoswitchable probe to modulated illumination by appropriately matching the average light intensity and the radial frequency of the light modulation to the probe dynamics. Thus, we can selectively and quantitatively extract from an overall signal the contribution from a target photoswitchable probe within a mixture of species, photoswitchable or not. This simple titration strategy is more specifically developed in the context of fluorescence imaging, which offers promising perspectives. © The Royal Society of Chemistry 2015.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Eliminating the contribution of interfering compounds is a key step in chemical analysis. In complex media, one possible approach is to perform a preliminary separation. However purification is often demanding, long, and costly; it may also considerably alter the properties of interacting components of the mixture (e.g. in a living cell). Hence there is a strong interest for developing separation-free non-invasive analytical protocols. Using photoswitchable probes as labelling and titration contrast agents, we demonstrate that the association of a modulated monochromatic light excitation with a kinetic filtering of the overall observable is much more attractive than constant excitation to read-out the contribution from a target probe under adverse conditions. An extensive theoretical framework enabled us to optimize the out-of-phase concentration first-order response of a photoswitchable probe to modulated illumination by appropriately matching the average light intensity and the radial frequency of the light modulation to the probe dynamics. Thus, we can selectively and quantitatively extract from an overall signal the contribution from a target photoswitchable probe within a mixture of species, photoswitchable or not. This simple titration strategy is more specifically developed in the context of fluorescence imaging, which offers promising perspectives. © The Royal Society of Chemistry 2015. |
Fluorogen-Based Reporters for Fluorescence Imaging: A Review Article de journal Ludovic Jullien; Arnaud Gautier Methods and Applications in Fluorescence, 3 (4), p. 042007, 2015, ISSN: 2050-6120. @article{RN38, title = {Fluorogen-Based Reporters for Fluorescence Imaging: A Review}, author = {Ludovic Jullien and Arnaud Gautier}, doi = {10.1088/2050-6120/3/4/042007}, issn = {2050-6120}, year = {2015}, date = {2015-01-01}, journal = {Methods and Applications in Fluorescence}, volume = {3}, number = {4}, pages = {042007}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Kinetics of formation of oil-in-water emulsions using in situ rheo-optical measurements Article de journal R Covis; E Marie; A Durand; C Baravian AIChE Journal, 61 (1), p. 277–284, 2015. @article{Covis:2015a, title = {Kinetics of formation of oil-in-water emulsions using in situ rheo-optical measurements}, author = {R Covis and E Marie and A Durand and C Baravian}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84920019195&doi=10.1002%2faic.14626&partnerID=40&md5=e7f1a416a2ac1f9fb32befa9f84b8812}, doi = {10.1002/aic.14626}, year = {2015}, date = {2015-01-01}, journal = {AIChE Journal}, volume = {61}, number = {1}, pages = {277--284}, abstract = {The kinetics of mechanical emulsification in vane geometry was investigated using an original rheo-optic device. Hexadecane-in-water micronic emulsions were prepared using a nonionic polymeric surfactant (Brij700®) as stabilizer. The viscosity of aqueous phase was adjusted using a commercial viscosifier (Emkarox®) which ensured Newtonian behavior to the continuous phase. The influences of two variables (rotational speed and oil volume fraction) on the kinetics of droplet fragmentation were examined in detail. Rotational speed was varied between 50 and 100 rad s-1 and had a strong effect on the kinetics of emulsion formation which was discussed on the basis of droplet fragmentation by shear forces. On the contrary, oil volume fraction (between 20 and 60% v/v) showed no marked effect, which appeared as an important result for scale-up considerations. A theoretical description of fragmentation mechanism was proposed and experimental results were compared to calculated values. © 2014 American Institute of Chemical Engineers.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The kinetics of mechanical emulsification in vane geometry was investigated using an original rheo-optic device. Hexadecane-in-water micronic emulsions were prepared using a nonionic polymeric surfactant (Brij700®) as stabilizer. The viscosity of aqueous phase was adjusted using a commercial viscosifier (Emkarox®) which ensured Newtonian behavior to the continuous phase. The influences of two variables (rotational speed and oil volume fraction) on the kinetics of droplet fragmentation were examined in detail. Rotational speed was varied between 50 and 100 rad s-1 and had a strong effect on the kinetics of emulsion formation which was discussed on the basis of droplet fragmentation by shear forces. On the contrary, oil volume fraction (between 20 and 60% v/v) showed no marked effect, which appeared as an important result for scale-up considerations. A theoretical description of fragmentation mechanism was proposed and experimental results were compared to calculated values. © 2014 American Institute of Chemical Engineers. |
Kinetics of formation of polysaccharide-covered micrometric oil droplets under mechanical agitation Article de journal R Covis; C Baravian; E Marie; A Durand Colloids and Surfaces A: Physicochemical and Engineering Aspects, 466 , p. 92–99, 2015. @article{Covis:2015, title = {Kinetics of formation of polysaccharide-covered micrometric oil droplets under mechanical agitation}, author = {R Covis and C Baravian and E Marie and A Durand}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84911906507&doi=10.1016%2fj.colsurfa.2014.10.048&partnerID=40&md5=f50de2bdc2c8f7afca00a18b12f62cea}, doi = {10.1016/j.colsurfa.2014.10.048}, year = {2015}, date = {2015-01-01}, journal = {Colloids and Surfaces A: Physicochemical and Engineering Aspects}, volume = {466}, pages = {92--99}, abstract = {Hexadecane-in-water emulsions were prepared by mechanical agitation in vane geometry using amphiphilic derivatives of dextran (nonionic bacterial polysaccharide) as stabilizers. Thanks to a laboratory-made experimental device coupling rheometry and back-scattered light analysis, we investigated the kinetics of droplet formation and the simultaneous variation of global shear stress. Oil volume fraction was varied between 10 and 50% and rotation speed between 40 and 100rads-1. The viscosity of aqueous phase was controlled by addition of sodium alginate and thus exhibited non-Newtonian rheological behavior. After forming a coarse emulsion, droplet rupture led to emulsions with volume-average droplet radius between 5 and 10μm provided that rotation speed and aqueous phase viscosity were high enough. Monitoring was consistent with droplet rupture occurring under shear forces such that capillary number remained approximately constant and close to its critical value. Although rotational speed and sodium alginate concentration had strong effect on emulsification kinetics, oil volume fraction had no significant effect. © 2014 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Hexadecane-in-water emulsions were prepared by mechanical agitation in vane geometry using amphiphilic derivatives of dextran (nonionic bacterial polysaccharide) as stabilizers. Thanks to a laboratory-made experimental device coupling rheometry and back-scattered light analysis, we investigated the kinetics of droplet formation and the simultaneous variation of global shear stress. Oil volume fraction was varied between 10 and 50% and rotation speed between 40 and 100rads-1. The viscosity of aqueous phase was controlled by addition of sodium alginate and thus exhibited non-Newtonian rheological behavior. After forming a coarse emulsion, droplet rupture led to emulsions with volume-average droplet radius between 5 and 10μm provided that rotation speed and aqueous phase viscosity were high enough. Monitoring was consistent with droplet rupture occurring under shear forces such that capillary number remained approximately constant and close to its critical value. Although rotational speed and sodium alginate concentration had strong effect on emulsification kinetics, oil volume fraction had no significant effect. © 2014 Elsevier B.V. |
Light-Activated Proteolysis for the Spatiotemporal Control of Proteins Article de journal Quentin Delacour; Chenge Li; Marie-Aude Plamont; Emmanuelle Billon-Denis; Isabelle Aujard; Thomas Le Saux; Ludovic Jullien; Arnaud Gautier ACS Chemical Biology, 10 (7), p. 1643-1647, 2015, ISSN: 1554-8929. @article{RN37, title = {Light-Activated Proteolysis for the Spatiotemporal Control of Proteins}, author = {Quentin Delacour and Chenge Li and Marie-Aude Plamont and Emmanuelle {Billon-Denis} and Isabelle Aujard and Thomas Le Saux and Ludovic Jullien and Arnaud Gautier}, doi = {10.1021/acschembio.5b00069}, issn = {1554-8929}, year = {2015}, date = {2015-01-01}, journal = {ACS Chemical Biology}, volume = {10}, number = {7}, pages = {1643-1647}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Phagocytosis of immunoglobulin-coated emulsion droplets Article de journal Kalthoum Ben M'Barek; Diana Molino; Sandrine Quignard; Marie-Aude Plamont; Yong Chen; Philippe Chavrier; Jacques Fattaccioli Biomaterials, p. doi–org, 2015. @article{m2015phagocytosis, title = {Phagocytosis of immunoglobulin-coated emulsion droplets}, author = {Kalthoum Ben M'Barek and Diana Molino and Sandrine Quignard and Marie-Aude Plamont and Yong Chen and Philippe Chavrier and Jacques Fattaccioli}, year = {2015}, date = {2015-01-01}, journal = {Biomaterials}, pages = {doi--org}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Phagocytosis of immunoglobulin-coated emulsion droplets Article de journal K Ben M'Barek; D Molino; S Quignard; M -A Plamont; Y Chen; P Chavrier; J Fattaccioli Biomaterials, 51 , p. 270–277, 2015. @article{BenMBarek:2015, title = {Phagocytosis of immunoglobulin-coated emulsion droplets}, author = {K Ben M'Barek and D Molino and S Quignard and M -A Plamont and Y Chen and P Chavrier and J Fattaccioli}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84924916623&doi=10.1016%2fj.biomaterials.2015.02.030&partnerID=40&md5=94df848ca153367029941c2f412fd8bf}, doi = {10.1016/j.biomaterials.2015.02.030}, year = {2015}, date = {2015-01-01}, journal = {Biomaterials}, volume = {51}, pages = {270--277}, abstract = {Phagocytosis by macrophages represents a fundamental process essential for both immunity and tissue homeostasis. The size of targets to be eliminated ranges from small particles as bacteria to large objects as cancerous or senescent cells. Most of our current quantitative knowledge on phagocytosis is based on the use of solid polymer microparticles as model targets that are well adapted to the study of phagocytosis mechanisms that do not involve any lateral mobility of the ligands, despite the relevance of this parameter in the immunological context. Herein we designed monodisperse, IgG-coated emulsion droplets that are efficiently and specifically internalized by macrophages through in-vitro FcγR-mediated phagocytosis. We show that, contrary to solid polymeric beads, droplet uptake is efficient even for low IgG densities, and is accompagnied by the clustering of the opsonins in the zone of contact with the macrophage during the adhesion step. Beyond the sole interest in the design of the material, our results suggest that lateral mobility of proteins at the interface of a target greatly enhances the phagocytic uptake. © 2015 Elsevier Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Phagocytosis by macrophages represents a fundamental process essential for both immunity and tissue homeostasis. The size of targets to be eliminated ranges from small particles as bacteria to large objects as cancerous or senescent cells. Most of our current quantitative knowledge on phagocytosis is based on the use of solid polymer microparticles as model targets that are well adapted to the study of phagocytosis mechanisms that do not involve any lateral mobility of the ligands, despite the relevance of this parameter in the immunological context. Herein we designed monodisperse, IgG-coated emulsion droplets that are efficiently and specifically internalized by macrophages through in-vitro FcγR-mediated phagocytosis. We show that, contrary to solid polymeric beads, droplet uptake is efficient even for low IgG densities, and is accompagnied by the clustering of the opsonins in the zone of contact with the macrophage during the adhesion step. Beyond the sole interest in the design of the material, our results suggest that lateral mobility of proteins at the interface of a target greatly enhances the phagocytic uptake. © 2015 Elsevier Ltd. |
Photo-induced cation translocation in a molecular shuttle based on a calix[4]-biscrown including DCM and DMABN chromophores Article de journal N Dozova; R Kumar; T Pradhan; F Lacombat; B Valeur; J S Kim; P Plaza Chemical Communications, 51 (80), p. 14859–14861, 2015. @article{Dozova:2015, title = {Photo-induced cation translocation in a molecular shuttle based on a calix[4]-biscrown including DCM and DMABN chromophores}, author = {N Dozova and R Kumar and T Pradhan and F Lacombat and B Valeur and J S Kim and P Plaza}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84942474410&doi=10.1039%2fc5cc06054k&partnerID=40&md5=857b5558380ed42e21e82790184d89cb}, doi = {10.1039/c5cc06054k}, year = {2015}, date = {2015-01-01}, journal = {Chemical Communications}, volume = {51}, number = {80}, pages = {14859--14861}, abstract = {We present a new molecular shuttle, consisting of a calixarene core attached to two different photoactive centers, DCM and DMABN. We show that a K+ ion bound to the DCM-grafted crown is translocated towards the other site of the molecule upon photoexcitation, but not released to the bulk. © The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We present a new molecular shuttle, consisting of a calixarene core attached to two different photoactive centers, DCM and DMABN. We show that a K+ ion bound to the DCM-grafted crown is translocated towards the other site of the molecule upon photoexcitation, but not released to the bulk. © The Royal Society of Chemistry. |
Photoswitching Kinetics and Phase-Sensitive Detection Add Discriminative Dimensions for Selective Fluorescence Imaging Article de journal Jérôme Querard; Tal-Zvi Markus; Marie-Aude Plamont; Carole Gauron; Pengcheng Wang; Agathe Espagne; Michel Volovitch; Sophie Vriz; Vincent Croquette; Arnaud Gautier; Thomas Le Saux; Ludovic Jullien Angewandte Chemie International Edition, 54 (9), p. 2633-2637, 2015, ISSN: 1433-7851. @article{RN43b, title = {Photoswitching Kinetics and Phase-Sensitive Detection Add Discriminative Dimensions for Selective Fluorescence Imaging}, author = {J\'{e}r\^{o}me Querard and Tal-Zvi Markus and Marie-Aude Plamont and Carole Gauron and Pengcheng Wang and Agathe Espagne and Michel Volovitch and Sophie Vriz and Vincent Croquette and Arnaud Gautier and Thomas Le Saux and Ludovic Jullien}, doi = {10.1002/anie.201408985}, issn = {1433-7851}, year = {2015}, date = {2015-01-01}, journal = {Angewandte Chemie International Edition}, volume = {54}, number = {9}, pages = {2633-2637}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Prevention of aggregation and renaturation of carbonic anhydrase via weak association with octadecyl- or azobenzene-modified poly(acrylate) derivatives Article de journal N Martin; J Ruchmann; C Tribet Langmuir, 31 (1), p. 338–349, 2015. @article{Martin:2015, title = {Prevention of aggregation and renaturation of carbonic anhydrase via weak association with octadecyl- or azobenzene-modified poly(acrylate) derivatives}, author = {N Martin and J Ruchmann and C Tribet}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921409028&doi=10.1021%2fla503643q&partnerID=40&md5=0c8eb2479f885eab39c148d19fdc93d2}, doi = {10.1021/la503643q}, year = {2015}, date = {2015-01-01}, journal = {Langmuir}, volume = {31}, number = {1}, pages = {338--349}, abstract = {The prevention of aggregation during renaturation of urea-denatured carbonic anhydrase B (CAB) via hydrophobic and Coulomb association with anionic polymers was studied in mixed solutions of CAB and amphiphilic poly(acrylate) copolymers. The polymers were derivatives of a parent poly(acrylic acid) randomly grafted with hydrophobic side groups (either 3 mol % octadecyl group, or 1-5 mol % alkylamidoazobenzene photoresponsive groups). CAB:polymer complexes were characterized by light scattering and fluorescence correlation spectroscopy in aqueous buffers (pH 7.75 or 5.9). Circular dichroism and enzyme activity assays enabled us to study the kinetics of renaturation. All copolymers, including the hydrophilic PAA parent chain, provided a remarkable protective effect against CAB aggregation during renaturation, and most of them (but not the octadecyl-modified one) markedly enhanced the regain of activity as compared to CAB alone. The significant role of Coulomb binding in renaturation and comparatively the lack of efficacy of hydrophobic association was highlighted by measurements of activity regain before and after in situ dissociation of hydrophobic complexes (achieved by phototriggering the polarity of azobenzene-modified polymers under exposure to UV light). In the presence of polymers (CAB:polymer of 1:1 w/w ratio) at concentration ∼0.6 g L-1, the radii of the largest complexes were similar to the radii of the copolymers alone, suggesting that the binding of CAB involves one or a few polymer chain(s). These complexes dissociated by dilution (0.01 g L-1). It is concluded that prevention of irreversible aggregation and activity recovery were achieved when marginally stable complexes are formed. Reaching a balanced stability of the complex plays the main role in CAB renaturation, irrespective of the nature of the binding (by Coulomb association, with or without contribution of hydrophobic association). © 2014 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The prevention of aggregation during renaturation of urea-denatured carbonic anhydrase B (CAB) via hydrophobic and Coulomb association with anionic polymers was studied in mixed solutions of CAB and amphiphilic poly(acrylate) copolymers. The polymers were derivatives of a parent poly(acrylic acid) randomly grafted with hydrophobic side groups (either 3 mol % octadecyl group, or 1-5 mol % alkylamidoazobenzene photoresponsive groups). CAB:polymer complexes were characterized by light scattering and fluorescence correlation spectroscopy in aqueous buffers (pH 7.75 or 5.9). Circular dichroism and enzyme activity assays enabled us to study the kinetics of renaturation. All copolymers, including the hydrophilic PAA parent chain, provided a remarkable protective effect against CAB aggregation during renaturation, and most of them (but not the octadecyl-modified one) markedly enhanced the regain of activity as compared to CAB alone. The significant role of Coulomb binding in renaturation and comparatively the lack of efficacy of hydrophobic association was highlighted by measurements of activity regain before and after in situ dissociation of hydrophobic complexes (achieved by phototriggering the polarity of azobenzene-modified polymers under exposure to UV light). In the presence of polymers (CAB:polymer of 1:1 w/w ratio) at concentration ∼0.6 g L-1, the radii of the largest complexes were similar to the radii of the copolymers alone, suggesting that the binding of CAB involves one or a few polymer chain(s). These complexes dissociated by dilution (0.01 g L-1). It is concluded that prevention of irreversible aggregation and activity recovery were achieved when marginally stable complexes are formed. Reaching a balanced stability of the complex plays the main role in CAB renaturation, irrespective of the nature of the binding (by Coulomb association, with or without contribution of hydrophobic association). © 2014 American Chemical Society. |
Real-time monitoring of chromophore isomerization and deprotonation during the photoactivation of the fluorescent protein Dronpa Article de journal D Yadav; F Lacombat; N Dozova; F Rappaport; P Plaza; A Espagne Journal of Physical Chemistry B, 119 (6), p. 2404–2414, 2015. @article{Yadav:2015, title = {Real-time monitoring of chromophore isomerization and deprotonation during the photoactivation of the fluorescent protein Dronpa}, author = {D Yadav and F Lacombat and N Dozova and F Rappaport and P Plaza and A Espagne}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84922794115&doi=10.1021%2fjp507094f&partnerID=40&md5=6618718bf1ba6e1f5e5f2194c9480d5b}, doi = {10.1021/jp507094f}, year = {2015}, date = {2015-01-01}, journal = {Journal of Physical Chemistry B}, volume = {119}, number = {6}, pages = {2404--2414}, abstract = {Dronpa is a photochromic green fluorescent protein (GFP) homologue used as a probe in super-resolution microscopy. It is known that the photochromic reaction involves cis/trans isomerization of the chromophore and protonation/deprotonation of its phenol group, but the sequence in time of the two steps and their characteristic time scales are still the subject of much debate. We report here a comprehensive UV-visible transient absorption spectroscopy study of the photoactivation mechanism of Dronpa, covering all relevant time scales from ∼100 fs to milliseconds. The Dronpa-2 variant was also studied and showed the same behavior. By carefully controlling the excitation energy to avoid multiphoton processes, we could measure both the spectrum and the anisotropy of the first photoactivation intermediate. We show that the observed few nanometer blue-shift of this intermediate is characteristic for a neutral cis chromophore, and that its anisotropy of ∼0.2 is in good agreement with the reorientation of the transition dipole moment expected upon isomerization. These data constitute the first clear evidence that trans → cis isomerization of the chromophore precedes its deprotonation and occurs on the picosecond time scale, concomitantly to the excited-state decay. We found the deprotonation step to follow in ∼10 μs and lead directly from the neutral cis intermediate to the final state. © 2014 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Dronpa is a photochromic green fluorescent protein (GFP) homologue used as a probe in super-resolution microscopy. It is known that the photochromic reaction involves cis/trans isomerization of the chromophore and protonation/deprotonation of its phenol group, but the sequence in time of the two steps and their characteristic time scales are still the subject of much debate. We report here a comprehensive UV-visible transient absorption spectroscopy study of the photoactivation mechanism of Dronpa, covering all relevant time scales from ∼100 fs to milliseconds. The Dronpa-2 variant was also studied and showed the same behavior. By carefully controlling the excitation energy to avoid multiphoton processes, we could measure both the spectrum and the anisotropy of the first photoactivation intermediate. We show that the observed few nanometer blue-shift of this intermediate is characteristic for a neutral cis chromophore, and that its anisotropy of ∼0.2 is in good agreement with the reorientation of the transition dipole moment expected upon isomerization. These data constitute the first clear evidence that trans → cis isomerization of the chromophore precedes its deprotonation and occurs on the picosecond time scale, concomitantly to the excited-state decay. We found the deprotonation step to follow in ∼10 μs and lead directly from the neutral cis intermediate to the final state. © 2014 American Chemical Society. |
Remote control of signaling pathways using magnetic nanoparticles Article de journal L Bonnemay; C Hoffmann; Z Gueroui Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology, 7 (3), p. 342–354, 2015. @article{Bonnemay:2015, title = {Remote control of signaling pathways using magnetic nanoparticles}, author = {L Bonnemay and C Hoffmann and Z Gueroui}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84927129199&doi=10.1002%2fwnan.1313&partnerID=40&md5=5d4464215e0d1dddd7b7cf90947cf32f}, doi = {10.1002/wnan.1313}, year = {2015}, date = {2015-01-01}, journal = {Wiley Interdisciplinary Reviews: Nanomedicine and Nanobiotechnology}, volume = {7}, number = {3}, pages = {342--354}, abstract = {Our ability to quantitatively control the spatiotemporal properties of cellular information processing is key for understanding biological systems at both mechanistic and systemic level. In this context, magnetic field offers a relevant strategy of control over cellular processes that broaden the toolbox currently available in cell biology. Among the increasing number of methods, we will focus on recent advances based on magnetic nanoparticles conjugated to proteins to trigger specific signaling pathways and cellular processes. Extracellular or intracellular manipulations of nanoparticles permit magnetic control of ion channels and membrane receptor activation, protein positioning within cells and cytoskeleton spatial engineering. These approaches provide powerful strategies to examine the organization principles of living cells. © 2014 Wiley Periodicals, Inc.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Our ability to quantitatively control the spatiotemporal properties of cellular information processing is key for understanding biological systems at both mechanistic and systemic level. In this context, magnetic field offers a relevant strategy of control over cellular processes that broaden the toolbox currently available in cell biology. Among the increasing number of methods, we will focus on recent advances based on magnetic nanoparticles conjugated to proteins to trigger specific signaling pathways and cellular processes. Extracellular or intracellular manipulations of nanoparticles permit magnetic control of ion channels and membrane receptor activation, protein positioning within cells and cytoskeleton spatial engineering. These approaches provide powerful strategies to examine the organization principles of living cells. © 2014 Wiley Periodicals, Inc. |
Synthesis, Characterization, and Biological Properties of Osmium-Based Tamoxifen Derivatives – Comparison with Their Homologues in the Iron and Ruthenium Series Article de journal Hui Zhi Shirley Lee; Olivier Buriez; François Chau; Eric Labbé; Rakesh Ganguly; Christian Amatore; Gérard Jaouen; Anne Vessières; Weng Kee Leong; Siden Top European Journal of Inorganic Chemistry, p. n/a, 2015. @article{RID:0827151219509-49b, title = {Synthesis, Characterization, and Biological Properties of Osmium-Based Tamoxifen Derivatives \textendash Comparison with Their Homologues in the Iron and Ruthenium Series}, author = {Hui Zhi Shirley Lee and Olivier Buriez and Fran\c{c}ois Chau and Eric Labb\'{e} and Rakesh Ganguly and Christian Amatore and G\'{e}rard Jaouen and Anne Vessi\`{e}res and Weng Kee Leong and Siden Top}, year = {2015}, date = {2015-01-01}, journal = {European Journal of Inorganic Chemistry}, pages = {n/a}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Three-electrode analytical and preparative electrochemistry in micro-volume hanging droplets Article de journal Ana Isabel Perez Jimenez; Lylian Challier; Margherita Di Pisa; Manon Guille-Collignon; Frédéric Lemaître; Solange Lavielle; Christelle Mansuy; Christian Amatore; Eric Labbé; Olivier Buriez Electrochemistry Communications, 54 (0), p. 41-45, 2015. @article{RID:0721150706473-46b, title = {Three-electrode analytical and preparative electrochemistry in micro-volume hanging droplets}, author = {Ana Isabel Perez Jimenez and Lylian Challier and Margherita Di Pisa and Manon Guille-Collignon and Fr\'{e}d\'{e}ric Lema\^{i}tre and Solange Lavielle and Christelle Mansuy and Christian Amatore and Eric Labb\'{e} and Olivier Buriez}, year = {2015}, date = {2015-01-01}, journal = {Electrochemistry Communications}, volume = {54}, number = {0}, pages = {41-45}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Transport Properties of Polyelectrolyte Solutions. Effect of Confinement in Thin Liquid Films Article de journal J Delacotte; D Langevin Zeitschrift fur Physikalische Chemie, 229 (7-8), p. 1177–1188, 2015. @article{Delacotte:2015, title = {Transport Properties of Polyelectrolyte Solutions. Effect of Confinement in Thin Liquid Films}, author = {J Delacotte and D Langevin}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84939126068&doi=10.1515%2fzpch-2014-0544&partnerID=40&md5=e0b2693fead66b6e3fa7b65f28a49780}, doi = {10.1515/zpch-2014-0544}, year = {2015}, date = {2015-01-01}, journal = {Zeitschrift fur Physikalische Chemie}, volume = {229}, number = {7-8}, pages = {1177--1188}, abstract = {The role of condensed counterions in transport properties, such as electrical conductivity and viscosity, has been investigated with solutions of a flexible polyelectrolyte. Comparisons with existing theories are proposed. Viscosity is strongly affected by confinement in thin films, depending whether polyelectrolyte chains are adsorbed or not at the film surfaces. The role of counterion mobility is however difficult to assess because the measurements are not accurate enough. It is proposed that this role could be tested by electrical conductivity measurements. © 2014 Walter de Gruyter Berlin/Boston.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The role of condensed counterions in transport properties, such as electrical conductivity and viscosity, has been investigated with solutions of a flexible polyelectrolyte. Comparisons with existing theories are proposed. Viscosity is strongly affected by confinement in thin films, depending whether polyelectrolyte chains are adsorbed or not at the film surfaces. The role of counterion mobility is however difficult to assess because the measurements are not accurate enough. It is proposed that this role could be tested by electrical conductivity measurements. © 2014 Walter de Gruyter Berlin/Boston. |
Variable Primary Coordination Environments of Cd(II) Binding to Three Helix Bundles Provide a Pathway for Rapid Metal Exchange. Article de journal Alison G Tebo; Lars Hemmingsen; Vincent L Pecoraro Metallomics, 7 (12), p. 1555-1561, 2015. @article{Tebo:2015, title = {Variable Primary Coordination Environments of Cd(II) Binding to Three Helix Bundles Provide a Pathway for Rapid Metal Exchange.}, author = {Alison G Tebo and Lars Hemmingsen and Vincent L Pecoraro}, doi = {10.1039/c5mt00228a}, year = {2015}, date = {2015-01-01}, journal = {Metallomics}, volume = {7}, number = {12}, pages = {1555-1561}, abstract = {Members of the ArsR/SmtB family of transcriptional repressors, such as CadC, regulate the intracellular levels of heavy metals like Cd(II), Hg(II), and Pb(II). These metal sensing proteins bind their target metals with high specificity and affinity, however, a lack of structural information about these proteins makes defining the coordination sphere of the target metal difficult. Lingering questions as to the identity of Cd(II) coordination in CadC are addressed via protein design techniques. Two designed peptides with tetrathiolate metal binding sites were prepared and characterized, revealing fast exchange between CdS3O and CdS4 coordination spheres. Correlation of (111m)Cd PAC spectroscopy and (113)Cd NMR spectroscopy suggests that Cd(II) coordinated to CadC is in fast exchange between CdS3O and CdS4 forms, which may provide a mechanism for rapid sensing of heavy metal contaminants by this regulatory protein.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Members of the ArsR/SmtB family of transcriptional repressors, such as CadC, regulate the intracellular levels of heavy metals like Cd(II), Hg(II), and Pb(II). These metal sensing proteins bind their target metals with high specificity and affinity, however, a lack of structural information about these proteins makes defining the coordination sphere of the target metal difficult. Lingering questions as to the identity of Cd(II) coordination in CadC are addressed via protein design techniques. Two designed peptides with tetrathiolate metal binding sites were prepared and characterized, revealing fast exchange between CdS3O and CdS4 coordination spheres. Correlation of (111m)Cd PAC spectroscopy and (113)Cd NMR spectroscopy suggests that Cd(II) coordinated to CadC is in fast exchange between CdS3O and CdS4 forms, which may provide a mechanism for rapid sensing of heavy metal contaminants by this regulatory protein. |
Vesicular Exocytosis and Microdevices - Microelectrode Arrays Article de journal Christian Amatore; Jerome Delacotte; Manon Guille-Collignon; Frederic Lemaitre Analyst, 140 (11), p. 3687-3695, 2015, ISSN: 0003-2654, (WOS:000354650300003). @article{Amatore:2015, title = {Vesicular Exocytosis and Microdevices - Microelectrode Arrays}, author = {Christian Amatore and Jerome Delacotte and Manon {Guille-Collignon} and Frederic Lemaitre}, doi = {10.1039/c4an01932f}, issn = {0003-2654}, year = {2015}, date = {2015-01-01}, journal = {Analyst}, volume = {140}, number = {11}, pages = {3687-3695}, abstract = {Among all the analytical techniques capable of monitoring exocytosis in real time at the single cell level, electrochemistry (particularly amperometry at a constant potential) using ultramicroelectrodes has been demonstrated to be an important and convenient tool for more than two decades. Indeed, because the electrochemical sensor is located in the close vicinity of the emitting cell ("artificial synapse" configuration), much data can be gathered from the whole cell activity (secretion frequency) to the individual vesicular release (duration, fluxes or amount of molecules released) with an excellent sensitivity. However, such a single cell analysis and its intrinsic benefits are at the expense of the spatial resolution and/or the number of experiments. The quite recent development of microdevices/microsystems (and mainly the microelectrode arrays (MEAs)) offers in some way a complementary approach either by combining spectroscopy-microscopy or by implementing a multianalysis. Such developments are described and discussed in the present review over the 2005-2014 period.}, note = {WOS:000354650300003}, keywords = {}, pubstate = {published}, tppubtype = {article} } Among all the analytical techniques capable of monitoring exocytosis in real time at the single cell level, electrochemistry (particularly amperometry at a constant potential) using ultramicroelectrodes has been demonstrated to be an important and convenient tool for more than two decades. Indeed, because the electrochemical sensor is located in the close vicinity of the emitting cell ("artificial synapse" configuration), much data can be gathered from the whole cell activity (secretion frequency) to the individual vesicular release (duration, fluxes or amount of molecules released) with an excellent sensitivity. However, such a single cell analysis and its intrinsic benefits are at the expense of the spatial resolution and/or the number of experiments. The quite recent development of microdevices/microsystems (and mainly the microelectrode arrays (MEAs)) offers in some way a complementary approach either by combining spectroscopy-microscopy or by implementing a multianalysis. Such developments are described and discussed in the present review over the 2005-2014 period. |
2014 |
Eric Labbe 2014. @book{Eric_Labbe11860917b, title = {Advances in Organometallic Chemistry and Catalysis : The Silver/Gold Jubilee International Conference on Organometallic Chemistry Celebratory Book, First Edition. Edited by Armando J. L. Pombeiro.}, author = {Eric Labbe}, url = {http://doi.org/10.1002/9781118742952}, doi = {10.1002/9781118742952}, year = {2014}, date = {2014-01-01}, keywords = {}, pubstate = {published}, tppubtype = {book} } |
Amperometric Detection of Vesicular Exocytosis from BON Cells at Carbon Fiber Microelectrodes Article de journal Anne Meunier; Marine Bretou; Francois Darchen; Manon Guille Collignon; Frederic Lemaitre; Christian Amatore Electrochimica Acta, 126 , p. 74-80, 2014, ISSN: 0013-4686. @article{RN25b, title = {Amperometric Detection of Vesicular Exocytosis from BON Cells at Carbon Fiber Microelectrodes}, author = {Anne Meunier and Marine Bretou and Francois Darchen and Manon Guille Collignon and Frederic Lemaitre and Christian Amatore}, doi = {10.1016/j.electacta.2013.07.110}, issn = {0013-4686}, year = {2014}, date = {2014-01-01}, journal = {Electrochimica Acta}, volume = {126}, pages = {74-80}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Amphiphilic Macromolecules on Cell Membranes: From Protective Layers to Controlled Permeabilization Article de journal E Marie; S Sagan; S Cribier; C Tribet Journal of Membrane Biology, 247 (9-10), p. 861–881, 2014. @article{Marie:2014, title = {Amphiphilic Macromolecules on Cell Membranes: From Protective Layers to Controlled Permeabilization}, author = {E Marie and S Sagan and S Cribier and C Tribet}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84910118231&doi=10.1007%2fs00232-014-9679-3&partnerID=40&md5=2902d0eb4d955e4adbccc4a486976725}, doi = {10.1007/s00232-014-9679-3}, year = {2014}, date = {2014-01-01}, journal = {Journal of Membrane Biology}, volume = {247}, number = {9-10}, pages = {861--881}, abstract = {Antimicrobial and cell-penetrating peptides have inspired developments of abiotic membrane-active polymers that can coat, penetrate, or break lipid bilayers in model systems. Application to cell cultures is more recent, but remarkable bioactivities are already reported. Synthetic polymer chains were tailored to achieve (i) high biocide efficiencies, and selectivity for bacteria (Gram-positive/Gram-negative or bacterial/mammalian membranes), (ii) stable and mild encapsulation of viable isolated cells to escape immune systems, (iii) pH-, temperature-, or light-triggered interaction with cells. This review illustrates these recent achievements highlighting the use of abiotic polymers, and compares the major structural determinants that control efficiency of polymers and peptides. Charge density, sp. of cationic and guanidinium side groups, and hydrophobicity (including polarity of stimuli-responsive moieties) guide the design of new copolymers for the handling of cell membranes. While polycationic chains are generally used as biocidal or hemolytic agents, anionic amphiphilic polymers, including Amphipols, are particularly prone to mild permeabilization and/or intracell delivery. © 2014, Springer Science+Business Media New York.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Antimicrobial and cell-penetrating peptides have inspired developments of abiotic membrane-active polymers that can coat, penetrate, or break lipid bilayers in model systems. Application to cell cultures is more recent, but remarkable bioactivities are already reported. Synthetic polymer chains were tailored to achieve (i) high biocide efficiencies, and selectivity for bacteria (Gram-positive/Gram-negative or bacterial/mammalian membranes), (ii) stable and mild encapsulation of viable isolated cells to escape immune systems, (iii) pH-, temperature-, or light-triggered interaction with cells. This review illustrates these recent achievements highlighting the use of abiotic polymers, and compares the major structural determinants that control efficiency of polymers and peptides. Charge density, sp. of cationic and guanidinium side groups, and hydrophobicity (including polarity of stimuli-responsive moieties) guide the design of new copolymers for the handling of cell membranes. While polycationic chains are generally used as biocidal or hemolytic agents, anionic amphiphilic polymers, including Amphipols, are particularly prone to mild permeabilization and/or intracell delivery. © 2014, Springer Science+Business Media New York. |
Anti-oxidant Mn-complexes: evaluation in cellular models of oxidative stress Article de journal Clotilde Policar; Anne-Sophie Bernard; Nicolas Delsuc; Geraldine Gazzah; Manon Guille; Frederic Lemaitre; Christian Amatore; Maria Bachelet; Joelle Masliah Journal of Biological Inorganic Chemistry, 19 , p. S739-S740, 2014, (Times Cited: 0 2 12th European Biological Inorganic Chemistry Conference (EuroBIC) Aug 24-28, 2014 Zurich, SWITZERLAND Univ Zurich). @article{, title = {Anti-oxidant Mn-complexes: evaluation in cellular models of oxidative stress}, author = {Clotilde Policar and Anne-Sophie Bernard and Nicolas Delsuc and Geraldine Gazzah and Manon Guille and Frederic Lemaitre and Christian Amatore and Maria Bachelet and Joelle Masliah}, year = {2014}, date = {2014-01-01}, journal = {Journal of Biological Inorganic Chemistry}, volume = {19}, pages = {S739-S740}, note = {Times Cited: 0 2 12th European Biological Inorganic Chemistry Conference (EuroBIC) Aug 24-28, 2014 Zurich, SWITZERLAND Univ Zurich}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Disassembly kinetics of quinone-methide-based self-immolative spacers that contain aromatic nitrogen heterocycles Article de journal A Alouane; R Labruère; K J Silvestre; T Le Saux; F Schmidt; L Jullien Chemistry - An Asian Journal, 9 (5), p. 1334–1340, 2014. @article{Alouane:2014, title = {Disassembly kinetics of quinone-methide-based self-immolative spacers that contain aromatic nitrogen heterocycles}, author = {A Alouane and R Labru\`{e}re and K J Silvestre and T Le Saux and F Schmidt and L Jullien}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84899466220&doi=10.1002%2fasia.201400051&partnerID=40&md5=a330e468d911417e1ffcc3eae297f08a}, doi = {10.1002/asia.201400051}, year = {2014}, date = {2014-01-01}, journal = {Chemistry - An Asian Journal}, volume = {9}, number = {5}, pages = {1334--1340}, abstract = {We prepared several pyridine- and pyrimidine-based self-immolative spacer groups to evaluate the significance of the resonance energy of the spacer aromatic ring on the kinetics of 1,4- and 1,6-elimination reactions, which govern spacer disassembly. Subsequently, we relied on a photoactivation procedure to accurately analyze the disassembly kinetics. Beyond providing new results that are relevant for deriving quantitative structure-property relationships, herein, we demonstrate that pH value can be used as an efficient parameter to finely control the disassembly time of a self-immolative spacer after an initial activation. Burn rubber: Kinetic analysis of the pH-dependent disassembly of self-immolative spacers that contain aromatic nitrogen heterocycles was performed. Electron-poor pyrimidine cores exhibited the longest disassembly times. This study confirms the trend that electron-rich aryl cores accelerate self-immolation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We prepared several pyridine- and pyrimidine-based self-immolative spacer groups to evaluate the significance of the resonance energy of the spacer aromatic ring on the kinetics of 1,4- and 1,6-elimination reactions, which govern spacer disassembly. Subsequently, we relied on a photoactivation procedure to accurately analyze the disassembly kinetics. Beyond providing new results that are relevant for deriving quantitative structure-property relationships, herein, we demonstrate that pH value can be used as an efficient parameter to finely control the disassembly time of a self-immolative spacer after an initial activation. Burn rubber: Kinetic analysis of the pH-dependent disassembly of self-immolative spacers that contain aromatic nitrogen heterocycles was performed. Electron-poor pyrimidine cores exhibited the longest disassembly times. This study confirms the trend that electron-rich aryl cores accelerate self-immolation. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
Effect of dendrimer generation on the interactions between human serum albumin and dendrigraft polylysines Article de journal N Sisavath; T Le Saux; L Leclercq; H Cottet Langmuir, 30 (15), p. 4450–4457, 2014. @article{Sisavath:2014, title = {Effect of dendrimer generation on the interactions between human serum albumin and dendrigraft polylysines}, author = {N Sisavath and T Le Saux and L Leclercq and H Cottet}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84899455303&doi=10.1021%2fla5002144&partnerID=40&md5=5c18434d71e5e48ced21ec7f39a5e08f}, doi = {10.1021/la5002144}, year = {2014}, date = {2014-01-01}, journal = {Langmuir}, volume = {30}, number = {15}, pages = {4450--4457}, abstract = {This work aims at studying the interaction between human serum albumin and different generations of dendrigraft poly-l-lysine (DGL) in physiological conditions. The binding constants and stoichiometry of the interaction were successfully determined using frontal analysis continuous capillary electrophoresis. The effect of generation on the interaction was evaluated for the five first generations of DGL. An increase of the binding constant accompanied with a decrease of the HSA:DGL (1:n) stoichiometry and a decrease of the cooperativity with dendrimer generation was observed. These findings were in good agreement with the increase of ligand (DGL) size, the increase of electrostatic ligand-ligand repulsion, and the localization of two negatively charged interaction sites on the HSA. The effect of the ligand topology (linear vs dendrigraft) on the HSA interaction revealed that linear poly(l-lysine) leads to much lower stoichiometry compared to DGL of similar molar mass due to much higher flexibility and contour length. © 2014 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } This work aims at studying the interaction between human serum albumin and different generations of dendrigraft poly-l-lysine (DGL) in physiological conditions. The binding constants and stoichiometry of the interaction were successfully determined using frontal analysis continuous capillary electrophoresis. The effect of generation on the interaction was evaluated for the five first generations of DGL. An increase of the binding constant accompanied with a decrease of the HSA:DGL (1:n) stoichiometry and a decrease of the cooperativity with dendrimer generation was observed. These findings were in good agreement with the increase of ligand (DGL) size, the increase of electrostatic ligand-ligand repulsion, and the localization of two negatively charged interaction sites on the HSA. The effect of the ligand topology (linear vs dendrigraft) on the HSA interaction revealed that linear poly(l-lysine) leads to much lower stoichiometry compared to DGL of similar molar mass due to much higher flexibility and contour length. © 2014 American Chemical Society. |