TABLE 4.

Kinetic parameters of recombinant GOX for different sugars^a

Substrate	Vmax (U mg−1)	Km (mM)	kcatb (s−1)	kcat/Km (s−1 mM−1)
d-Glucose	926 ± 9	6.2 ± 0.5	2,003	323.0
2-Deoxy-d-glucose	38 ± 1	8.3 ± 0.7	83	10.0
d-Mannose	186 ± 6	106 ± 8	401	3.8
d-Galactose	73 ± 5	952 ± 9	159	0.2
d-Xylose	33 ± 1	384 ± 27	72	0.2

^aInitial reaction velocities of GOX were determined for each sugar at 25°C under oxygen saturation in 0.1 M sodium acetate, pH 6.0. Data are the means (± standard deviations for V_max and K_m) of at least three independent measurements. 

^bThe k_cat values were calculated per mole of native GOX, since only the dimeric form of the enzyme exhibits activity.