The effect of 2,4,6-trinitrobenzenesulfonate on mercuric reductase, glutathione reductase and lipoamide dehydrogenase.
Among the three closely related enzymes, lipoamide dehydrogenase, mercuric reductase, and glutathione reductase only the latter is inhibited by 2,4,6-trinitrobenzenesulfonate (TNBS). On the other hand, all three enzymes exhibit high rates of TNBS-dependent NADPH oxidation. In the case of glutathione reductase and mercuric reductase this TNBS-dependent activity displays substrate inhibition by excess of NADPH and is strongly stimulated by NADP+. The stimulation is especially pronounced with mercuric reductase, 25-fold under some conditions. Neither substrate inhibition nor stimulation by NAD+ is observed with lipoamide dehydrogenase.
D000818:Animals; D003429:Cross Reactions; D008058:Dihydrolipoamide Dehydrogenase / Q000378:metabolism*; D005980:Glutathione Reductase / Q000378:metabolism*; D006801:Humans; D009249:NADP / Q000378:metabolism; D009578:Nitrobenzenes / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000201:enzymology; D013552:Swine; D014302:Trinitrobenzenesulfonic Acid / Q000494:pharmacology*
D009578:Nitrobenzenes; D009249:NADP; D014302:Trinitrobenzenesulfonic Acid; D010088:Oxidoreductases; C021551:mercuric reductase; D008058:Dihydrolipoamide Dehydrogenase; D005980:Glutathione Reductase