Life Sciences Commons^™

On The Kinetics Of Human Erythrocyte Glutathionedisulfide Reductase: Does The Enzyme Really Play'ping-Pong'?, İ. Hamdi̇ Öğüş, Nazmi̇ Özer

Turkish Journal of Biology

: Human erythrocyte glutathione disulfide reductase studied at 37°C in 100 mM potassium phosphate buffer, pH 7.4, is subject to partial inhibition by GSSG at low [NADPH]. Saturation by NADPH is hyperbolic at low [GSSG] and becomes increasingly sigmoidal at high [GSSG]. NADP+ is a competitive inhibitor with respect to NADPH at 20-1000 µM GSSG and an uncompetitive inhibitor with respect to GSSG at 33-120 µM NADPH. Studied under special conditions (10 µM NADPH and 1000 µM GSSG), NADP+ exhibits a two-fold effect, inhibition being preceded by activation in the 0- 50 µM effector concentration range. The data are consistent …