title: Uric acid substantially enhances the free radical-induced inactivation of alcohol dehydrogenase.
abstract: Lactate dehydrogenase (LDH) and yeast alcohol dehydrogenase ( YADH ) are inactivated when attacked by hydroxy free radicals (OH). Organic molecules with a high rate constant of reaction with OH such as ascorbate or urate can compete with the enzymes for these strongly oxidising radicals. However, although 10(-3)M ascorbate can substantially protect both LDH and YADH from OH attack, in the presence of 10(-3)M urate only LDH is protected. In the case of YADH an even greater degree of inactivation than with OH occurs. The extent of inactivation is considerably reduced when oxygen is absent, in agreement with a urate peroxy radical perhaps being partly responsible for the increased inactivation of the enzyme.
mesh_terms: D000426:Alcohol Dehydrogenase; D000429:Alcohol Oxidoreductases / Q000037:antagonists & inhibitors* / Q000528:radiation effects; D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D005609:Free Radicals; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors / Q000528:radiation effects; D013552:Swine; D014527:Uric Acid / Q000494:pharmacology*; D015003:Yeasts / Q000201:enzymology
chemical_list: D005609:Free Radicals; D014527:Uric Acid; D000429:Alcohol Oxidoreductases; D000426:Alcohol Dehydrogenase; D007770:L-Lactate Dehydrogenase; D001205:Ascorbic Acid