TABLE 2

Kinetic parameters of CPT-11 hydrolysis by wild-type and Arg²⁰⁶His variant CES2 expressed in COS-1 cells

Results are expressed as the mean ± S.D. from four independent transfection experiments.

CES2	Apparent K_m	V_max	V_max/K_m	Normalized V_max^a	Normalized V_max/K_m^a
	μM	pmol/min/mg protein	nl/min/mg protein	pmol/min/mg protein	nl/min/mg protein
Wild-type	0.46 ± 0.01	3.45 ± 0.29	7.43 ± 0.54	3.46 ± 0.23	7.45 ± 0.50
Arg²⁰⁶His	0.51 ± 0.02^‡	2.81 ± 0.22^†	5.53 ± 0.52^‡	3.44 ± 0.16	6.77 ± 0.46

↵ a V_max values were normalized by the relative protein expression level of the Arg²⁰⁶His variant (0.82 ± 0.07).
↵† Significantly different from that of the wild-type at P < 0.05.
↵‡ P < 0.01.