Control of catalysis in flavin-dependent monooxygenases.
Flavoprotein monooxygenases reduce flavins, speed their reaction with oxygen, and stabilize a C4a-oxygen adduct long enough to use this reactive species to transfer an oxygen atom to a substrate. The flavin-oxygen adduct can be the C4a-peroxide anion, in which case it reacts as a nucleophile. The protonated adduct - the C4a-hydroperoxide - reacts as an electrophile. The elimination of H(2)O(2) competes with substrate oxygenation. This side-reaction is suppressed, preventing the waste of NAD(P)H and the production of toxic H(2)O(2). Several strategies have been uncovered that prevent the deleterious side-reaction while still allowing substrate hydroxylation.
Palfey
Bruce A
BA
Department of Biological Chemistry, University of Michigan Medical School, 1150 W. Medical Center Dr., Ann Arbor, MI 48109-5606, USA. brupalf@umich.edu
McDonald
Claudia A
CA
D055162:Biocatalysis; D005415:Flavins / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000737:chemistry / Q000378:metabolism*; D008958:Models, Molecular; D010084:Oxidation-Reduction; D013379:Substrate Specificity
D005415:Flavins; D006899:Mixed Function Oxygenases