title: The thermodynamics and kinetics of electron transfer in the cytochrome P450cam enzyme system.
abstract: In anaerobic environments the first electron transfer in substrate-free P450cam is known to be thermodynamically unfavourable, but in the presence of dioxygen the reduction potential for the reaction shifts positively to make electron transfer thermodynamically favourable. Nevertheless a slower rate of electron transfer is observed in the substrate-free P450cam compared to substrate-bound P450cam. The ferric haem centre in substrate-free P450cam changes from six co-ordinate to five co-ordinate when reduced whereas in substrate-bound P450cam the iron centre remains five co-ordinate in both oxidation states. The slower rate of electron transfer in the substrate-free P450cam is therefore attributed to a larger reorganisation energy as predicted by Marcus theory.
authors.affiliation: Inorganic Chemistry Laboratory, Oxford, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Honeychurch
authors.forename: A O
authors.initials: AO
authors.lastname: Hill
authors.forename: L L
authors.initials: LL
authors.lastname: Wong
mesh_terms: D000818:Animals; D019475:Camphor 5-Monooxygenase / Q000737:chemistry* / Q000378:metabolism*; D004579:Electron Transport; D006801:Humans; D007700:Kinetics; D013816:Thermodynamics
chemical_list: D019475:Camphor 5-Monooxygenase