The –SH Protection Method for Determining Accurate K_d Values for Enzyme-Coenzyme Complexes of NAD⁺-Dependent Glutamate Dehydrogenase and Engineered Mutants: Evidence for Nonproductive NADPH Complexes

Figure 1

Pseudo-first-order kinetic plots for inactivation of F238S GDH by DTNB.The F2238S GDH mutant (0.1 mg/ml) was incubated in 0.1 M potassium phosphate, pH 7, at 20∘C with DTNB at the following concentrations: 500 μM (Lowest line, circles; 400 μM (squares); 300 μM (triangles); 200 μM (inverted triangles); 100 μM (diamonds); 50 μM (upper line, circles).