Research Article

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

Table 1

Comparison of limiting values of the first-order rate constants ( ) for saturating levels of DTNB for wild-type GDH and mutant variants, and of dissociation constants governing binding of DTNB to the enzymes ( ).

j (s-1) × 103 ( M)

Wild-type GDH3.52 ± 0.14990 ± 6.8
F238S7.95 ± 0.221190 ± 17.5
P262S3.45 ± 0.17758 ± 23.1
F238S/P262S5.28 ± 0.36981 ± 13.4
D263K2.50 ± 0.12338 ± 14.5