Sandrine Demanèche, Jean‐Paul Chapel, L. Jocteur Monrozier, Hervé Quiquampoix,
We studied bovine serum albumin (BSA) and alpha-chymotrypsin adsorption onto mica surfaces over a large pH range by atomic force microscopy (AFM) measurements in liquid. Data analyses (height, roughness and roughness factor) brought new insights on the conformation of proteins in soil environments, with mica as a model of soil phyllosilicates and non-hydrophobic surfaces. Validation of AFM approach was performed on BSA, whose behavior was previously described by nuclear magnetic resonance and infra- ...
Tópico(s): Polymer Surface Interaction Studies
2009 - Elsevier BV | Colloids and Surfaces B Biointerfaces
Christophe Dussouy, Éric Dubreucq, Patrick Chemardin, Véronique Perrier, Josiane Abadie, Hervé Quiquampoix, Claude Plassard, Jean‐Bernard Behr,
A new myo-inositol pentakisphosphate was synthesized, which featured a dansyl group at position C-5.The fluorescent tag was removed from the inositol by a 6-atom spacer to prevent detrimental steric interactions in the catalytic site of phytases.The PEG linker was used in order to enhance hydrophilicity and biocompatibility of the new artificial substrate.Computational studies showed a favorable positioning in the catalytic site of phytases.Enzymatic assays demonstrated that the tethered myo-inositol ...
Tópico(s): Oral and gingival health research
2021 - Elsevier BV | Bioorganic Chemistry
Jean‐Marc Janot, Michel Boissière, Thierry Thami, E. Tronel-Peyroz, Nordine Helassa, Sylvie Noinville, Hervé Quiquampoix, Siobhán Staunton, Philippe Déjardin,
We studied the kinetics of adsorption of alexa-labeled Bt toxin Cry1Aa, in monomer and oligomer states, on muscovite mica, acid-treated hydrophilic glass, and hydrophobized glass, in the configuration of laminar flow of solution in a slit. Normal confocal fluorescence through the liquid volume allows the visualization of the concentration in solution over the time of adsorption, in addition to the signal due to the adsorbed molecules at the interface. The solution signal is used as calibration for ...
Tópico(s): Protein purification and stability
2010 - American Chemical Society | Biomacromolecules
Jean Guern, Armen Kurkdjian, Hélène Barbier, P Manigault, Hervé Quiquampoix, Jean‐Pierre Renaudin,
RésuméLa mesure de la différence de potentiel de part et d'autre du tonoplaste et l'estimation de la différence de pH entre le cytoplasme et la vacuole montrent qu'un fort gradient de potentiel électrochimique des protons existe entre ces deux territoires de la cellule végétale. Le couplage possible du transport des protons et de l'accumulation dans la vacuole de solutés tels que des sucres est discuté en relation avec les connaissances relatives au plasmalemme.Il est montré que la simple différence ...
Tópico(s): Plant nutrient uptake and metabolism
1982 - Société botanique de France | Bulletin de la Société Botanique de France Actualités Botaniques
Armen Kurkdjian, Hervé Quiquampoix, Jean‐Marc Pradier,
Tópico(s): Algal biology and biofuel production
1982 - Société botanique de France | Bulletin de la Société Botanique de France Actualités Botaniques
Nordine Helassa, Gabrielle Daudin, Sylvie Noinville, Jean‐Marc Janot, Philippe Déjardin, Siobhán Staunton, Hervé Quiquampoix,
The insecticidal toxins produced by genetically modified Bt crops are introduced into soil through root exudates and tissue decomposition and adsorb readily on soil components, especially on clays. This immobilisation and the consequent concentration of the toxins in "hot spots" could increase the exposure of soil organisms. Whereas the effects on non-target organisms are well documented, few studies consider the migration of the toxin in soil. In this study, the residual mobility of Bt Cry1Aa insecticidal ...
Tópico(s): Genetically Modified Organisms Research
2010 - Taylor & Francis | The Philosophical Magazine A Journal of Theoretical Experimental and Applied Physics
Delphine Rapp, Agnès Richaume, Patrick Jame, Peggy Rigou, Human Rézaei, Pierre Alcouffe, Jean‐Paul Chapel, Hervé Quiquampoix, Patrick Potier,
Soils contaminated by prions, the infectious agents responsible for transmissible spongiform encephalopathy diseases, remain infectious to grazing animals for many years. In this study, the ability of enzymes produced by soil microbes to degrade a recombinant prion protein (recPrP) was investigated in a loamy soil. A 15N-labelled recPrP was added to soil in which microbial biomass and soil proteolytic activity had been increased by either simultaneous or prior amendment with lamb brain, and distribution ...
Tópico(s): Prion Diseases and Protein Misfolding
2011 - Wiley | European Journal of Soil Science