TABLE 2.

Activity of wild type, EcGDH^K116C and EcGDH^K116Q/N348M towards various γ-carbonyl acid and its derivatives ^a .

Substrate	Structural formula	EcGDH (U/mg)	EcGDHK116C (mU/mg)	EcGDHK116Q/N348M (mU/mg)
S1		156.4 ± 11.4	21.8 ± 2.6	294.2 ± 51.0
S2		N.A. b	10.1 ± 0.2	108.6 ± 1.5
S3		N.A.	N.A.	10.3 ± 0.7
S4		N.A.	N.A.	19.5 ± 3.7

^aEach value was calculated from three independent experiments. The mixture composed of Tris-HCl (100 mM, pH 8.5), NH₄Cl-NH₄OH (0.8 M, pH 8.5), 0.2 mM NADPH, and 80 mM substrate was incubated at 30°C for 1 min before adding purified enzyme. Optimization of conditions for specific activity determination see Supplementary Figure S2.

^bN.A. = No measurable activity.