title: Cytochrome P450BM-3 reduces aldehydes to alcohols through a direct hydride transfer.
abstract: Cytochrome P450BM-3 catalyzed the reduction of lipophilic aldehydes to alcohols efficiently. A k(cat) of ∼25 min(-1) was obtained for the reduction of methoxy benzaldehyde with wild type P450BM-3 protein which was higher than in the isolated reductase domain (BMR) alone and increased in specific P450-domain variants. The reduction was caused by a direct hydride transfer from preferentially R-NADP(2)H to the carbonyl moiety of the substrate. Weak substrate-P450-binding of the aldehyde, turnover with the reductase domain alone, a deuterium incorporation in the product from NADP(2)H but not D(2)O, and no inhibition by imidazole suggests the reductase domain of P450BM-3 as the potential catalytic site. However, increased aldehyde reduction by P450 domain variants (P450BM-3 F87A T268A) may involve allosteric or redox mechanistic interactions between heme and reductase domains. This is a novel reduction of aldehydes by P450BM-3 involving a direct hydride transfer and could have implications for the metabolism of endogenous substrates or xenobiotics.
authors.affiliation: Department of Medicinal Chemistry, University of Washington, Box 357610, Seattle, WA 98195-7610, USA.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Kaspera
authors.forename: Tariku
authors.initials: T
authors.lastname: Sahele
authors.forename: Kyle
authors.initials: K
authors.lastname: Lakatos
authors.forename: Rheem A
authors.initials: RA
authors.lastname: Totah
mesh_terms: D000438:Alcohols / Q000138:chemical synthesis* / Q000378:metabolism; D000447:Aldehydes / Q000737:chemistry* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D009251:NADPH-Ferrihemoprotein Reductase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010084:Oxidation-Reduction
chemical_list: D000438:Alcohols; D000447:Aldehydes; D001426:Bacterial Proteins; D003577:Cytochrome P-450 Enzyme System; D009251:NADPH-Ferrihemoprotein Reductase; C052423:flavocytochrome P450 BM3 monoxygenases