FIGURE 4.
TR activity of TGR mutants. The TR activities of wild-type and mutant TGRs were compared using the DTNB assay. The assay was carried out at constant and saturating concentrations of DTNB and NADPH (5 mm and 200 μm, respectively) and different concentrations of each enzyme. The plots of initial velocities (v0) versus enzyme concentration are shown. The selenoenzyme (TGRGCUG, TRGCUG, and TGRGUCG) concentrations used for kcat calculations were corrected according to their selenium contents.