Steady-state kinetic analysis of the oxidation of model substrates by human and chimpanzee CYP3A4 in the absence and presence of 25 μM ANF
The variation between two experiments is ≤20%. The experiments were carried out simultaneously for more accurate comparison between human (Hum) and chimpanzee (Chimp) CYP3A4 (+ or – ANF).
Sample | kcat | S50 | n |
|---|---|---|---|
| min-1 | μM | ||
| 7-BFC | |||
| Hum 3A4/-ANF | 4.48 ± 0.23a | 21.6 ± 1.8 | 2.2 ± 0.4 |
| Chimp 3A4/-ANF | 6.31 ± 0.27 | 9.90 ± 1.6 | 1.6 ± 0.1 |
| Hum 3A4/+ANF | 11.0 ± 0.46 | 17.0 ± 1.4 | |
| Chimp 3A4/+ANF | 16.3 ± 1.4 | 20.7 ± 4.0 | 1.0 ± 0.1 |
| Testosterone | |||
| Hum 3A4/-ANF | 12.5 ± 0.4 | 54.1 ± 2.7 | 1.6 ± 0.1 |
| Chimp 3A4/-ANF | 11.3 ± 0.9 | 67.7 ± 10 | 1.7 ± 0.2 |
| Hum 3A4/+ANF | 11.8 ± 0.6 | 34.6 ± 4.2 | 1.2 ± 0.1 |
| Chimp 3A4/+ANF | 13.8 ± 1.7 | 90.9 ± 17 | 1.0 ± 0.1 |
| 7-BQ | |||
| Hum 3A4 | 33.8 ± 8.4 | 152 ± 48 | 1.6 ± 0.3 |
| Chimp 3A4 | 25.4 ± 3.0 | 127 ± 12 | 2.2 ± 0.4 |
↵ a Standard errors for fit to the Hill equation.