Table 2

BN N-dealkylation activities in microsomes from human B lymphoblastoid cells expressing CYP enzymes

CYP	Activity		CYP Content	Cytochrome c Reductase Activity
	pmol/min/mg of protein	pmol/min/pmol of CYP	pmol of CYP/mg	nmol/min/mg of protein
1A2	ND^2-a	ND	45	28^2-b
2A6	ND	ND	49	28^2-b
2B6	ND	ND	67	28^2-b
2C9-Cys^2-c	ND	ND	9	180
2C19	ND	ND	17	28^2-b
2D6-Met	ND	ND	147	28^2-b
2E1^2-c	ND	ND	82	140
3A4^2-c	51.61	2.02	26	190

Substrate (100 μM BN) was incubated at 37°C for 120 min with microsomes (0.5 mg/ml) from human B lymphoblastoid cells expressing CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP2E1, or CYP3A4. The lot numbers of the B lymphoblastoid cell preparations were as follows: CYP1A2, 29; CYP2A6, 17; CYP2B6, 20; CYP2C9, 10; CYP2C19, 1; CYP2D6, 38; CYP2E1, 18; CYP3A4, 4.

↵2-a ND, not detectable.
↵2-b Native levels of parental cell lines.
↵2-c cDNA-expressed CYP enzymes coexpressed with NADPH-CYP reductase.