Redox interconversion of glutathione reductase from Escherichia coli. A study with pure enzyme and cell-free extracts.

摘要: The glutathione reductase from E. coli was rapidly inactivated following aerobic incubation of the pure and cell-free extract enzymes with NADPH, NADH other reductants. inactivation enzyme depended on time temperature (t1/2 = 2 min at 37°C), proportional to |INADPH|/|enzyme| ratio, reaching 50% in presence 0.3 μM NADPH 45 respectively, a subunit concentration 20 nM. Higher pyridine nucleotide concentrations were required inactivate extracts. Two apparent pKa, corresponding pH 5.8 7.3, determined for redox inactivation. remained inactive even after eliminating excess by gel chromatography.