Kinetic parameters for ethoxyresorufin O-deethylation and methoxyresorufin O-demethylation by recombinant CYP1As and CYP2As
Data are mean ± S.D. of three independent experiments.
Km | Vmax | Vmax/Km | |
|---|---|---|---|
| μM | pmol/min/pmol P450 | μl/min/pmol P450 | |
| Ethoxyresorufin O-deethylation | |||
| CYP1A1 | 0.1 ± 0.0 | 33.5 ± 1.4 | 321.8 ± 5.2 |
| CYP1A2 | 0.2 ± 0.0 | 10.4 ± 1.9 | 65.7 ± 6.1 |
| CYP2A6 | N.D. | N.D. | N.D. |
| CYP2A13 | 7.2 ± 1.5a,b | 2.1 ± 0.3a,b | 0.3 ± 0.0a,b |
| Methoxyresorufin O-demethylation | |||
| CYP1A1 | 0.1 ± 0.0 | 13.3 ± 2.1 | 103.5 ± 11.8 |
| CYP1A2 | 0.1 ± 0.0 | 19.9 ± 0.5 | 177.0 ± 27.5 |
| CYP2A6 | N.D. | N.D. | N.D. |
| CYP2A13 | 5.9 ± 3.5a,b | 0.5 ± 0.1a,b | 0.1 ± 0.0a,b |