Fig. 4: Lysine replacements of Asp144 or Glu147 in helix 3 of ScGrx7 accelerate the reductive half-reaction in the GSSCys assay.
a, b Selected \(k_{{\mathrm{cat}}}^{{\mathrm{app}}}\) and \(K_{\mathrm{m}}^{{\mathrm{app}}}\) values of ScGrx7 wild-type enzyme as well as D144A/K and E147A/K mutants for GSSCys and GSH. c Calculated catalytic efficiencies from panels (a) and (b). d Reciprocal Dalziel coefficients, which probably reflect the rate constants of the oxidative and reductive half-reaction with GSSCys and GSH, respectively. e Summary of the altered kinetic parameters for D144A/K and E147A/K. Source data are provided in the Supplementary Information: original plots and kinetic parameters for panels a–c are shown in Supplementary Figs. 7 and 9 and Supplementary Table 5. Statistical analyses and P values for the \(k_{{\mathrm{cat}}}^{{\mathrm{app}}}\) and \(K_{\mathrm{m}}^{{\mathrm{app}}}\) values from panels a and b are listed in Supplementary Table 11. Error bars are the calculated standard error from the curve fits in SigmaPlot 13. Reciprocal Dalziel coefficients for panel d were obtained from Supplementary Figs. 8 and 10 and are listed together with the true kcat values in Supplementary Table 4.
