TABLE 2

NADPH consumption rates associated with reconstituted CYP3A4 and CYP2C9 in the presence of type II ligands

P450s were reconstituted with human P450 reductase and lipid as described under Materials and Methods.

Substratea
CYP3A4
CYP2C9
Concentration
Rateb
 Concentration
Rateb
DMSO control 2% (v/v) 13.7 ± 0.3 2% (v/v) 9.7 ± 0.8
Midazolam (positive control) 0.1 mM 19.0 ± 0.8 N.D.
(S)-Flurbiprofen (positive control) N.D. 0.1 mM 114 ± 13
Imidazole 25 mM 12.1 ± 0.6 25 mM 8.6 ± 0.7
Aniline 25 mM 18.4 ± 0.1 25 mM 16.1 ± 0.5
1,2,4-Triazole 40 mM 14.3 ± 0.3 40 mM 10.4 ± 0.8
PH-302 0.05 mM 13.4 ± 0.7 0.5 mM 12.0 ± 1.8
Itraconazole 0.003 mM 14.2 ± 0.5 0.1 mM 14.4 ± 1.5
Fluconazole 0.1 mM 13.2 ± 0.7 0.5 mM 12.1 ± 1.1
Sulfaphenazole
N.D.
0.1 mM
11.3 ± 1.3

  • N.D., not determined.

  • ↵ a Substrate concentrations are assumed to be close to saturating based on binding experiments.

  • ↵ b The rate (nmol/min/nmol P450) is derived from a coupled enzyme reaction as described under Materials and Methods.