TABLE 2

Derived kinetic constants for morphine glycosidation generated in the absence and presence of BSA (2% w/v) with cofactor (UDP-Glc or UDP-GlcUA) as the variable substrate

Data are shown as the mean ± S.D. of four replicates with pooled HLM.

Cofactor (Pathway)	Without BSA				With BSA
Cofactor (Pathway)	S₅₀	V_max	CL_int	n	S₅₀	V_max	CL_int	n
	mM	pmol/min/mg	µl/min/mg		mM	pmol/min/mg	µl/min/mg
UDP-Glc (M-3-glucoside)	1.98 ± 0.19	1701 ± 48	0.86	0.82 ± 0.02	2.02 ± 0.17	2186 ± 85^{^b}	1.08^{^a}	0.74 ± 0.01^{^b}
UDP-GlcUA (M3G)	0.64 ± 0.05^{^c}	2696 ± 104^{^c}	4.19^{^c}	0.75 ± 0.02	0.39 ± 0.02^{^b}^,^c	2981 ± 133^{^b}^,^{^c}	7.61^{^b}^,^{^c}	0.72 ± 0.02
UDP-GlcUA (M6G)	0.56 ± 0.06^{^c}	378 ± 15^{^c}	0.67	0.77 ± 0.03	0.32 ± 0.04^{^a}^,^{^c}	356 ± 15^{^c}	1.13^{^b}	0.76 ± 0.02

↵^a P < 0.05; comparisons for each cofactor with and without BSA (i.e., across rows).
↵^b P < 0.01; comparisons for each cofactor with and without BSA (i.e., across rows).
↵^c P < 0.01; UDP-GlcUA compared with UDP-Glc (i.e., down columns).