Kinetic parameters for the formation of R-138727 by human liver microsomal samples and expressed P450s
The conversion rates of R-95913 to R-138727 were determined in triplicate incubations as indicated under Materials and Methods. Values for Km and Vmax are reported as parameter estimate ± the standard error of the parameter estimate.
Km | Vmax | CLint | |
|---|---|---|---|
| μM | pmol/min/mg | μl/min/mg | |
| Microsomal sample | |||
| HLC | 21 ± 4 | 122 ± 12 | 5.8 |
| HLGa | 30 (27-33) | 318 (290-346) | 11 (10-11) |
| HLH | 26 ± 2 | 300 ± 16 | 12 |
|
|
|
pmol/min/pmol P450
| μl/min/pmol P450 |
| Expressed P450 | |||
| CYP2B6 | 2.3 ± 0.4 | 0.39 ± 0.02 | 0.170 |
| CYP2C9 | 11 ± 2 | 0.37 ± 0.02 | 0.032 |
| CYP2C19 | 3.8 ± 0.7 | 0.35 ± 0.01 | 0.092 |
| CYP3A4 | 21 ± 3 | 1.4 ± 0.1 | 0.065 |
↵ a Values for HLG are reported as average value (range) from two separate experiments.