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

Figure 12

Predictive value of the mechanism-based model. Experimental data points (○) were compared with the full progress curves predicted by either the whole model (continuous line), the model without reactions 10-11 and 12-13 (●), or the model without reactions 11 and 13 (long dash line). The short dash line represents the profile predicted by the model in the absence of any substrate inhibition. (a) Experimental full progress curve determined at 4.7 μM NADPH and 270 μM GSSG. (b) Experimental full progress determined at 13.4 μM NADPH and 510 μM GSSG. In both cases an enzyme concentration of 11.5 nM was used. For both panels (a) and (b) the predicted full progress curves were obtained by the set of theoretical rate constants shown in Table S1 except (= 0.072 s ⁻¹) for panel (a) and (= 2.43 s ⁻¹) and (= 0.03 s ⁻¹) for panel (b).

(a)

(b)