Clery-Barraud C

References (5)

Title : Effects of hydrostatic pressure on the quaternary structure and enzymatic activity of a large peptidase complex from Pyrococcus horikoshii - Rosenbaum_2012_Arch.Biochem.Biophys_517_104
Author(s) : Rosenbaum E , Gabel F , Dura MA , Finet S , Clery-Barraud C , Masson P , Franzetti B
Ref : Archives of Biochemistry & Biophysics , 517 :104 , 2012
Abstract : While molecular adaptation to high temperature has been extensively studied, the effect of hydrostatic pressure on protein structure and enzymatic activity is still poorly understood. We have studied the influence of pressure on both the quaternary structure and enzymatic activity of the dodecameric TET3 peptidase from Pyrococcus horikoshii. Small angle X-ray scattering (SAXS) revealed a high robustness of the oligomer under high pressure of up to 300 MPa at 25 degrees C as well as at 90 degrees C. The enzymatic activity of TET3 was enhanced by pressure up to 180 MPa. From the pressure behavior of the different rate-constants we have determined the volume changes associated with substrate binding and catalysis. Based on these results we propose that a change in the rate-limiting step occurs around 180 MPa.
ESTHER : Rosenbaum_2012_Arch.Biochem.Biophys_517_104
PubMedSearch : Rosenbaum_2012_Arch.Biochem.Biophys_517_104
PubMedID: 21896270

Title : Integrative analytical approach by capillary electrophoresis and kinetics under high pressure optimized for deciphering intrinsic and extrinsic cofactors that modulate activity and stability of human paraoxonase (PON1) - Renault_2010_J.Chromatogr.B.Analyt.Technol.Biomed.Life.Sci_878_1346
Author(s) : Renault F , Carus T , Clery-Barraud C , Elias M , Chabriere E , Masson P , Rochu D
Ref : Journal of Chromatography B Analyt Technol Biomed Life Sciences , 878 :1346 , 2010
Abstract : Paraoxonase (PON1) is working in vivo in a particular dynamic environment including HDL particles and associated molecules. To decipher the respective and/or concomitant role of the different cofactors involved in this molecular organization, an approach using multiple experimental techniques based on capillary electrophoresis and classical kinetics or kinetics under high pressure was implemented. The effects of calcium and phosphate as protein or plasma cofactor, of human phosphate binding protein (HPBP) as enzyme chaperone, and of a PON1 inhibitor as an active site stabilizer, on the catalytic activities and functional oligomerization of PON1 were scrutinized. PON1 displays two distinct catalytic behaviors, one against esters and lactones, the other against organophosphorus compounds; its functional states and catalytic activities against these substrates are differently modulated by the molecular environment; PON1 exists under several active multimeric forms; the binding of HPBP amends the size of the oligomeric states and exerts a stabilizing effect on the activities of PON1; PON1 functional properties are modulated by HPBP, calcium and phosphate. This integrative approach using several optimized analytical techniques allowed performing comparison of catalytic properties and oligomeric states of functional PON1 in different enzyme preparations. Relevance of these data to understand in vivo physiological PON1 functioning is mandatory.
ESTHER : Renault_2010_J.Chromatogr.B.Analyt.Technol.Biomed.Life.Sci_878_1346
PubMedSearch : Renault_2010_J.Chromatogr.B.Analyt.Technol.Biomed.Life.Sci_878_1346
PubMedID: 19945920

Title : Stabilization of the active form(s) of human paraoxonase by human phosphate-binding protein - Rochu_2007_Biochem.Soc.Trans_35_1616
Author(s) : Rochu D , Chabriere E , Renault F , Elias M , Clery-Barraud C , Masson P
Ref : Biochemical Society Transactions , 35 :1616 , 2007
Abstract : While there is a consensus that human PON1 (paraoxonase-1) has a protective role, its primary biological function remains unclear. A protective role against poisoning by organophosphates [OPs (organophosphorus compounds)] drove earlier works. Clinical interest has recently focused on a protective role of PON1 against vascular diseases. PON1 resides mainly on HDL (high-density lipoprotein) particles, and converging recent works show that both its activities and stability dramatically depend on this versatile and dynamic molecular environment. The discovery that HPBP (human phosphate-binding protein) has a firm tendency to associate with PON1 has steered new directions for characterizing PON1 functional state(s). Storage stability studies provided evidence that HPBP is involved in maintaining physiologically active PON1 conformation(s). Thermal stability studies showed that human PON1 is remarkably thermostable and that its association with HPBP strongly contributes to slowing down the denaturation rate. A hybrid PON1, displaying mutations that stabilized recombinant enzyme expressed in Escherichia coli, was shown to be more thermostable than natural human PON1. Predictably, its stability was unaffected by the presence of HPBP. Synergistic efforts on characterizing natural PON1 and rPON1 (recombinant PON1) provide information for the design of future stable mutants of PON1-based bioscavengers to be used as safe and effective countermeasures to challenge OPs. Maintaining a stable environment for such administrable human rPON1 should, at least, preserve the anti-atherogenic activity of the enzyme.
ESTHER : Rochu_2007_Biochem.Soc.Trans_35_1616
PubMedSearch : Rochu_2007_Biochem.Soc.Trans_35_1616
PubMedID: 18031277

Title : Capillary electrophoresis versus differential scanning calorimetry for the analysis of free enzyme versus enzyme-ligand complexes: in the search of the ligand-free status of cholinesterases - Rochu_2006_Electrophoresis_27_442
Author(s) : Rochu D , Clery-Barraud C , Renault F , Chevalier A , Bon C , Masson P
Ref : Electrophoresis , 27 :442 , 2006
Abstract : Cholinesterases (ChEs) are highly efficient biocatalysts whose active site is buried in a deep, narrow gorge. The talent of CE to discover inhibitors in the gorge of highly purified preparations has fairly altered the meaning of a ChE ligand-free status. To attempt at a description of this one, we investigated the stability of Bungarus fasciatus acetylcholinesterase (AChE), alone or complexed with different inhibitors. Determination of mid-transition temperature for thermal denaturation, using differential scanning calorimetry (DSC) and CE, provided conflicting results. Discrepancies strongly question the reality of a ligand-free AChE state. DSC allowed estimation of the stability of AChE-ligands complexes, and to rank the stabilizing effect of different inhibitors. CE acted as a detector of hidden ligands, provided that they were charged, reversibly bound, and thus dissociable upon action of electric fields. Then, CE allowed quantification of the stability of ligand-free AChE. CE and DSC providing each fractional and nonredundant information, cautious attention must be paid for actual estimation of the conformational stability of ChEs. Because inhibitors used in purification of ChEs by affinity chromatography are charged, CE remains a leading method to estimate enzyme stability and detect the presence of bound hidden ligands.
ESTHER : Rochu_2006_Electrophoresis_27_442
PubMedSearch : Rochu_2006_Electrophoresis_27_442
PubMedID: 16342323

Title : Pressure and heat inactivation of recombinant human acetylcholinesterase. Importance of residue E202 for enzyme stability - Clery-Barraud_2002_Eur.J.Biochem_269_4297
Author(s) : Clery-Barraud C , Ordentlich A , Grosfeld H , Shafferman A , Masson P
Ref : European Journal of Biochemistry , 269 :4297 , 2002
Abstract : The effects of pressure on structure and activity of recombinant human acetylcholinesterase (rHuAChE) were investigated up to a pressure of 300 MPa using gel electrophoresis under elevated hydrostatic pressure, fluorescence of bound 8-anilinonaphthalene-1-sulfonate (ANS) and activity measurements following exposure to high pressure. Study of wild-type enzyme and three single mutants (D74N, E202Q, E450A) and one sextuple mutant (E84Q/E292A/D349N/E358Q/E389Q/D390N) showed that pressure exerts a differential action on wild-type rHuAChE and its mutants, allowing estimation of the contribution of carboxylic amino acid side-chains to enzyme stability. Mutation of negatively charged residues D74 and E202 by polar side-chains strengthened heat or pressure stability. The mutation E450A and the sextuple mutation caused destabilization of the enzyme to pressure. Thermal inactivation data on mutants showed that all of them were stabilized against temperature. In conclusion, pressure and thermal stability of mutants provided evidence that the residue E202 is a determinant of structural and functional stability of HuAChE.
ESTHER : Clery-Barraud_2002_Eur.J.Biochem_269_4297
PubMedSearch : Clery-Barraud_2002_Eur.J.Biochem_269_4297
PubMedID: 12199708