Table 1

Kinetic analysis of activation of polycyclic aromatic hydrocarbons and their dihydrodiol derivatives by recombinant (bacterial) CYP1A1 and four CYP1B1 allelic variants in S. typhymurium NM2009

	(±)-B[a]P-7,8-diol		7,12-DMBA-3,4-diol		DB[a,l]P-11,12-diol		5-Methychrysene-1,2-diol
	K_m	V_max	V_max/K_m	K_m	V_max	V_max/K_m	K_m	V_max	V_max/K_m	K_m	V_max	V_max/K_m
CYP1A1	1.9	2090	1100	3.0	2180	730	2.8	1600	570	2.1	1520	730
CYP1B1^*1	1.4	1290	920	3.5	1850	530	2.5	1630	650	2.7	1460	540
CYP1B1^*2	1.9	1390	730	4.0	2774	690	2.3	1750	760	3.9	1940	500
CYP1B1^*3	2.6	2270	870	3.2	1850	590	2.4	1610	670	4.0	2000	500
CYP1B1^*6	2.2	1940	880	3.6	2347	650	3.7	2690	730	2.2	1660	750

	B[a]P		7,12-DMBA		DB[a,l]P		5-Methychrysene
	K_m	V_max	V_max/K_m	K_m	V_max	V_max/K_m	K_m	V_max	V_max/K_m	K_m	V_max	V_max/K_m
CYP1A1	7.3	150	20	1.5	620	420	2.9	940	330	4.0	600	150
CYP1B1^*1	5.1	160	31	1.1	270	240	2.9	96	33	5.0	290	57
CYP1B1^*2	7.4	440	60	1.3	440	340	5.9	83	14	7.0	440	63
CYP1B1^*3	3.8	450	119	1.3	380	290	3.8	84	22	4.3	250	58
CYP1B1^*6	5.5	220	39	2.2	290	130	4.4	110	25	4.5	250	56

Substrate concentrations used for PAH dihydrodiols were 0.6, 1.2, 1.8, and 2.4 μM and those for PAH were 1, 3.1, 6.2, 12.5, 25 μM.K_m, μM; V_max, umuunits/min/nmol of P450.