Kinetic parameters for the formation of 8-hydroxyefavirenz from efavirenz in recombinant human P450s
Kinetic data are presented as amean ± S.D. (n = 3 independent experiments performed in duplicate) or bparameter estimated, with standard error of parameter estimates obtained from WinNonlin in parentheses. Kinetic parameters were estimated by fitting the velocity vs. substrate concentrations to single site Michaelis-Menten equation.
Kinetic Parameters | CYP2B6a | CYP2B6 + b5b | CYP1A2b | CYP3A5b | CYP3A4b |
---|---|---|---|---|---|
Vmax (pmol/min/pmol P450) | 5.20 ± 0.76 | 3.50 (0.07) | 0.60 (0.04) | 0.60 (0.03) | 0.16 (0.01) |
Km (μM) | 12.40 ± 1.80 | 6.40 (0.5) | 8.30 (2.40) | 19.10 (3.14) | 23.50 (3.10) |
Vmax/Km (μl/min/pmol P450) | 0.42 ± 0.06 | 0.55 | 0.07 | 0.03 | 0.007 |