TABLE 2

Rates [nmol/min/(nmol of P450)] determined for phenacetin metabolism by CYP1A2 WT and mutants^{^a}

CYP1A2	NADPH Oxidized	O₂ Consumed	Product Formed	H₂O₂ Produced	Excess H₂O^{^b}
WT	43 ± 4	22.7 ± 0.9	1.28 ± 0.08	14 ± 2	15 ± 2
T124S	27 ± 2	14.8 ± 0.4	0.29 ± 0.03	10 ± 0	9 ± 1
T223N	41 ± 3	17.3 ± 0.7	0.30 ± 0.00	10 ± 1	14 ± 2
V227G	40 ± 3	16.9 ± 0.5	0.38 ± 0.02	9 ± 1	15 ± 2
N312L	32 ± 2	18.3 ± 0.3	0.31 ± 0.00	13 ± 2	10 ± 1
L382V	84 ± 6	47.0 ± 1.3	3.03 ± 0.06	29 ± 3	30 ± 4
L382V/T223N	98 ± 7	57.9 ± 2.5	3.91 ± 0.10	38 ± 3	32 ± 5
L382V/N312L	70 ± 4	41.0 ± 2.0	3.05 ± 0.15	29 ± 3	18 ± 3
L382V/T223N/N312L	72 ± 5	41.7 ± 1.1	2.18 ± 0.03	28 ± 3	23 ± 3
L382V/T124S/N312L	42 ± 3	34.2 ± 0.9	3.67 ± 0.10	26 ± 2	9 ± 2

↵a Data are means of triplicate determinations.
↵b Excess water (H₂O) was calculated from the equation: H₂O = NADPH − H₂O₂ − product.