Incubation System | Bufuralol 1′-Hydroxylase Activity | Activity |
---|---|---|
nmol/min/nmol total P-450 | % | |
CYP2D6/pJR7 | 8.54 ± 0.77 | 100 |
CYP2D6/pJR7 + testosterone | 7.65 ± 0.35 | 90 |
CYP2D6/pJR7 + 6β-hydroxytestosterone | 8.65 ± 0.52 | 101 |
CYP3A4/CYP2D6/pJR7 | 3.75 ± 0.27 | 100 |
CYP3A4/CYP2D6/pJR7 + testosterone | 2.15 ± 0.142-a | 57 |
CYP3A4/CYP2D6/pDRlacZ | 0.42 ± 0.02 | 100 |
CYP3A4/CYP2D6/pDRlacZ + testosterone | 0.15 ± 0.012-a | 36 |
Membranes containing 10 pmol P-450 were incubated at 37°C for 10 min in 50 mM potassium phosphate buffer (pH 7.4), containing 10 μM bufuralol, and, when indicated, 100 μM testosterone. Reaction was initiated by addition of a NADPH-regenerating system (seeExperimental Procedures). Reaction was stopped by adding 15 μl 60% perchloric acid. Analysis of metabolites was by HPLC chromatography. Values are given as means of six experiments ±S.D. Incubations were also carried out in the presence of 6β-hydroxytestosterone (10 μM).
↵2-a Significantly different from control p≤ .01, n = 6 independent experiments each in triplicate.