Insight into the Mechanistic Basis of the Hysteretic-Like Kinetic Behavior of Thioredoxin-Glutathione Reductase (TGR)

Figure 7

Dependence of the initial and the apparent steady-state velocities on both NADPH and GSSG concentration. Initial (●) and apparent steady-state (○) velocities were obtained from full progress curves by varying the concentration of GSSG at the following initial concentrations of NADPH: (a) 9 μM; (b) 50 μM. Continuous spline lines represent the initial velocities predicted by the rate equation for a ping-pong bi bi kinetic mechanism in the absence of substrate inhibition. Each point represent the average of six experiments.

(a)

(b)