TABLE 1.
Summary of kinetic constants and dissociation t1/2 for the inhibition of CYP17A1 by abiraterone and D4A
| Inhibitor | CYP17A1 Activity |
 (nM)a
|
 (min−1)b
|
 (min−1)b
|
 (nM)c
|
 (nM) |
Dissociation t1/2 (h) |
|---|---|---|---|---|---|---|---|
| Abiraterone | 17α-Hydroxylase | 132 ± 2.02 | 0.0353 | 0.000275 | 50.7 | 0.39 | 42.0 |
| C17,20-Lyase | 118 ± 1.13 | 0.0224 | 0.000384 | 24.8 | 0.42 | 30.1 | |
| D4A | 17α-Hydroxylase | 76 ± 1.21 | 0.0218 | 0.000396 | 23.5 | 0.42 | 29.2 |
| C17,20-Lyase | 163 ± 3.02 | 0.0219 | 0.000121 | 57.4 | 0.32 | 95.5 |
a
From plot of 
vs. [I]. Data represented as means ± S.D. of triplicate determinations.
b
From plot of 
vs. [I].
c
Value of Ki,app corrected for mixed-mode inhibition.