title: A critical role of protein-bound water in the catalytic cycle of cytochrome P-450 camphor.
abstract: The rates of NADH oxidation during the hydroxylation of camphor by cytochrome P-450cam were followed in the presence of co-solvents used to increase the osmotic pressure surrounding the protein-bound water. As a result, the measured Vmax decreases independently of the perturbant tested. Roughly 28 molecules of water, involved during the catalytic cycle, are deduced from the variation of Vmax as a function of osmotic pressure. These molecules, in part, could be those present in the cytochrome P-450cam-putidaredoxin interface.
authors.affiliation: INSERM-INRA U310, Institut de Biologie Physico-Chimique, Paris, France.
authors.forename: C
authors.initials: C
authors.lastname: Di Primo
authors.forename: S G
authors.initials: SG
authors.lastname: Sligar
authors.forename: G H
authors.initials: GH
authors.lastname: Hoa
authors.forename: P
authors.initials: P
authors.lastname: Douzou
mesh_terms: D019475:Camphor 5-Monooxygenase; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D007700:Kinetics; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D009243:NAD / Q000378:metabolism*; D009997:Osmotic Pressure; D010084:Oxidation-Reduction; D014867:Water / Q000378:metabolism*
chemical_list: D014867:Water; D009243:NAD; D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D019475:Camphor 5-Monooxygenase