TABLE 1.

Kinetic parameters for phenacetin O-deethylation by purified CYP1A2 WT and mutants

CYP1A2	Phenacetin O-Deethylation
	kcata	Kma	kcat/Kmb	[(kcat/Km)mutant/(kcat/Km)WT]
	min	μM	μM/min
WT	1.28 ± 0.08	59.70 ± 1.82	0.02 ± 0.01	1.00
T124S	0.29 ± 0.03	28.90 ± 1.10	0.01 ± 0.01	0.47
T223N	0.30 ± 0.01	26.99 ± 0.01	0.01 ± 0.01	0.52
V227G	0.38 ± 0.02	32.36 ± 2.93	0.01 ± 0.01	0.55
N312L	0.31 ± 0.01	25.26 ± 0.01	0.01 ± 0.01	0.57
L382V	3.03 ± 0.06	5.75 ± 0.57	0.53 ± 0.04	24.77
L382V/T223N	3.91 ± 0.10	7.77 ± 0.80	0.51 ± 0.06	23.65
L382V/N312L	3.05 ± 0.15	16.14 ± 2.05	0.19 ± 0.02	8.87
L382V/T223N/N312L	3.67 ± 0.10	32.42 ± 11.31	0.12 ± 0.04	5.61
L382V/T124S/N312L	2.81 ± 0.03	10.13 ± 2.40	0.28 ± 0.07	13.34

^a Data are means of triplicate determinations.

^b k_cat/K_m represents substrate specificity.