title: Glyceraldehyde-3-phosphate dehydrogenase-catalyzed chain oxidation of reduced nicotinamide adenine dinucleotide by perhydroxyl radicals.
abstract: The chain oxidation of glyceraldehyde-3-phosphate dehydrogenase.NADH by perhydroxyl radicals and propagated by molecular oxygen was studied by the xanthine-xanthine oxidase system, 60Co gamma-ray, and pulse radiolysis. The chain length, amount of NADH oxidized per HO2 generated, increases with increasing acidity of the medium and reaches a value of 73 at pH 5.0. The rate constant for the oxidation of the glyceraldehyde-3-phosphate dehydrogenase.NADH complex by HO2 was estimated to be 2 X 10(7) M-1 S-1 at ambient temperatures (23-24 degrees C). Rate studies as a function of pH indicate that O2- is unreactive toward the glyceraldehyde-3-phosphate dehydrogenase.NADH complex. Other dehydrogenases (malate dehydrogenase, glutamate dehydrogenase, and isocitric dehydrogenase) studied showed no catalytic activity in the oxidation of NADH by HO2/O2-.
mesh_terms: D000818:Animals; D002417:Cattle; D005609:Free Radicals; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007521:Isocitrate Dehydrogenase / Q000378:metabolism; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D008291:Malate Dehydrogenase / Q000378:metabolism; D009132:Muscles / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology; D009243:NAD / Q000378:metabolism*; D010084:Oxidation-Reduction; D011817:Rabbits; D013552:Swine
chemical_list: D005609:Free Radicals; D009243:NAD; D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase; D007521:Isocitrate Dehydrogenase; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases