Table 2

Kinetic parameters for cDNA expressed CYP3A4 and CYP3A5 in the presence of ketoconazole or fluconazole2-a

InhibitorInhibition TypeVmaxKmKi
pmol/min/pmol μM
Ketoconazole
 CYP3A4Noncompetitive5.57  ± 0.6613.13  ± 0.19426.7  ± 1.71 nM
 CYP3A5Noncompetitive4.62  ± 0.5684.64  ± 1.15109  ± 19.7 nM
Fluconazole
 CYP3A4Noncompetitive3.87  ± 0.1372.36  ± 0.2159.21  ± 0.51 μM
 CYP3A5Noncompetitive4.76  ± 0.4234.13  ± 0.73984.6  ± 12.9 μM
  • 2-a For each inhibitor parameter estimates (± asymptotic S.E.) were obtained from a nonlinear regression fit of the complete data set.