Km and V max values for flutamide 2-hydroxylation and inhibition constants (K i) of flutamide for CYP1B1, CYP1A1, and CYP1A2 are shown
| 2-Hydroxylation of Flutamide | Competitive Inhibition of EROD by Flutamide | ||
|---|---|---|---|
| Km | Vmax | Ki | |
| μM | peak height/min/pmol CYP | μM | |
| CYP1B1 | 18.6 ± 10.3 | 0.3 ± 0.1 | 1.0 ± 0.1 |
| CYP1A1 | 102.8 ± 49.2 | 4.5 ± 1.3 | 10.3 ± 1.4 |
| CYP1A2 | 18.0 ± 7.5 | 6.0 ± 2.8 | 1.4 ± 0.3 |
K m and V max values were determined by Eadie-Hofstee replots of velocity data and are given as a mean ± S.D. (n ≥ 3) with flutamide concentrations ranging from 0 to 200 μM in the incubation mixtures.K i values were determined by the inhibition of flutamide on EROD activity and are given as a mean ± S.D. (n ≥ 3) with flutamide concentrations ranging from 0 to 20 μM in the incubation mixtures. Flutamide inhibition on CYP1B1, CYP1A1, and CYP1A2 activity is competitive.