TABLE 1

Kinetic parameters of H3 and H4 formation from thiolactone 2 by human cDNA-expressed CYP isoforms

CYP IsoformThiol IsomerIncubation TimeKmVmaxnaCLint, in vitroEnzyme AbundanceCLint, expressed P450fmP450
minμMpmol/min/pmol P450μL/min/pmol P450pmol P450/mg proteinμL/min/mg protein%
CYP2B6H3102.130.7370.3463913.525.5
H40.8870.1380.1566.0718.5
CYP2C9H33028.80.06990.00243960.2330.440
H438.40.05640.001470.1410.429
CYP2C19H3101.590.7352.130.461198.7616.5
H41.920.8641.950.4518.5726.1
CYP2D6H31077.00.9770.0127100.1270.240
H444.31.970.04440.4441.35
CYP3A4H31011.23.140.28010830.357.2
H415.52.530.16317.653.5
CYP3A5H31042.61.820.042710.04270.0807
H432.11.330.04130.04130.126
  • a Hill coefficient.