Fig. 2.
Reductive half-reaction between glutathionylated monothiol class I glutaredoxins and various low-molecular-weight thiols. A) Schematic representation of the predicted transition state of the reductive half-reaction. B) Structures and color coding of the tested thiols. C) Representative monophasic stopped-flow reduction kinetics for the reaction between 1 μM S-glutathionylated monothiol PfGrxE28W/C32S/C88S and variable concentrations of GSH. D) Secondary plot for the kobs values from the single exponential fits for GSH from panel C. E) Brønsted plot of the second-order rate constants from panel D and Fig. S1 (squares) and normalized, pH-independent second-order rate constants (circles). The nucleophile Brønsted coefficient βnuc was determined from the slope of the linear fit. F–H) Monophasic stopped-flow reduction kinetics, secondary plot, and Brønsted plot for ScGrx7G107W as in panels C–E. Kinetic traces and secondary plots for the other thiols are shown in Fig. S1 and Fig. S2. All data sets were generated from at least three independent biological replicates with three technical replicates. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)