Hydroxyl radicals is not a significant intermediate in the vanadate-stimulated oxidation of NAD(P)H by O2.
The vanadate-stimulated oxidation of NADH by an enzymatic flux of O2- is inhibited by superoxide dismutase, but not by catalase. Keller et al. (1989, Free Radical Biol. Med. 6, 15-22) observed inhibition by catalase presumably because they used a commercial preparation contaminated with superoxide dismutase. Their proposal, that H2O2 and hydroxyl radical play significant roles in vanadate-stimulation of NAD(P)H oxidation, may be discounted on the basis of these and of previously reported results.
Liochev
S I
SI
Institute of Physiology, Bulgarian Academy of Sciences, Sofia.
Fridovich
I
I
D002374:Catalase / Q000378:metabolism*; D005609:Free Radicals; D006878:Hydroxides; D017665:Hydroxyl Radical; D007700:Kinetics; D009243:NAD / Q000378:metabolism*; D009249:NADP / Q000378:metabolism*; D010084:Oxidation-Reduction; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides; D014638:Vanadates / Q000494:pharmacology*
D005609:Free Radicals; D006878:Hydroxides; D009243:NAD; D013481:Superoxides; D017665:Hydroxyl Radical; D014638:Vanadates; D009249:NADP; D002374:Catalase; D013482:Superoxide Dismutase