The effect of 2,4,6‐trinitrobenzenesulfonate on mercuric reductase, glutathione reductase and lipoamide dehydrogenase

Publisher Website
Google Scholar
Abstract
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.