title: NADH oxidation by quinone electron acceptors.
abstract: The rate constants of NADH oxidation by quinones are increased with the oxidation potential increase: log kox (M-1 X s-1) = -0.25 + 12.2 E0(7) (V) for o-quinones and log kox (M-1 X s-1) = -3.06 + 13.5 E0(7) (V) for p-quinones (pH 7.0, 25 degrees C). It is assumed that the oxidation proceeds via the hydride-ion transfer. The rate constants of NADH oxidation by single-electron quinone acceptors are also increased with the oxidizer potential increase; log kox (M-1 X s-1) = -0.64 + 9.34 E0(7) (V) and correlate with the constants of NADH oxidation by quinone radicals obtained earlier (Grodkowski, J., Neta, P., Carlson, B.W. and Miller, L. (1983) J. Phys. Chem. 87, 3135-3138). Single-electron transfer is the limiting stage of the process.
mesh_terms: D016227:Benzoquinones; D004579:Electron Transport; D000431:Ethanol; D007700:Kinetics; D009243:NAD / Q000378:metabolism*; D009570:Nitriles / Q000378:metabolism; D010084:Oxidation-Reduction; D011809:Quinones / Q000378:metabolism*; D013772:Tetramethylphenylenediamine / Q000378:metabolism
chemical_list: D016227:Benzoquinones; D009570:Nitriles; D011809:Quinones; D009243:NAD; C013703:tetracyanoquinodimethane; D000431:Ethanol; C004532:quinone; D013772:Tetramethylphenylenediamine; C042889:2-methyl-1,4-benzoquinone