TABLE 2.

Catalytic parameters for human P450 2D6 and P450 3A4

Enzyme	Substrate	Product	Km	kcat	kcat//Km
			μm	pmol/min/pmol P450	mm−1s−1
P450 2D6	(R)-Reticuline	Corytuberine	2.7 ± 0.37	0.015 ± 0.001	0.09
		Pallidine	1.8 ± 0.26	0.045 ± 0.002	0.42
		Salutaridine	2.5 ± 0.21	0.011 ± 0.001	0.08
		Isoboldine	1.9 ± 0.36	0.390 ± 0.026	3.42
	Thebaine	Oripavine	48 ± 9.6	4.55 ± 0.54	1.60
	Codeine	Morphine	250a	14a	0.93
			190b	6.4b	0.56
P450 3A4 with cytochrome b5	(R)-Reticuline	Corytuberine	384 ± 40	1.3 ± 0.1	0.06
		Pallidine	474 ± 30	14.7 ± 0.3	0.52
		Salutaridine	1961 ± 181	12.3 ± 0.5	0.12
		Isoboldine	4860 ± 860	158 ± 17	0.54
P450 3A4	(R)-Reticuline	Corytuberine	534 ± 66	0.16 ± 0.14	0.005
		Pallidine	490 ± 38	2.97 ± 0.14	0.101
		Salutaridine	993 ± 220	2.20 ± 0.36	0.037
		Isoboldine	577 ± 130	9.37 ± 1.34	0.271

^a Data taken from Ref. 40.

^b Data taken from Ref. 41.