Table 2

Examples of autoactivation kinetics (homotropic positive cooperativity)

SubstratePathwayEnzyme SourceReference
DapsoneHydroxylationVaccinia-expressed CYP2C9 Korzekwa et al., 1998
Diazepam3-HydroxylationBaculovirus-expressed CYP3A4 Shou et al., 1999
Diazepam3-HydroxylationB-Lymphoblastoid-expressed CYP3A4 Kenworthy et al., 2001
DiazepamDemethylationBaculovirus-expressed CYP3A4 Shou et al., 1999
Testosterone16β-HydroxylationB-Lymphoblastoid-expressed CYP2B62-a Ekins et al., 1998b
Testosterone6β-HydroxylationB-Lymphoblastoid-expressed CYP3A4 Kenworthy et al., 2001
Acetaminophen O-GlucuronidationHLM Fisher et al., 2000

For a more comprehensive review, see Ekins et al. (1998a) orHouston and Kenworthy (2000).

  • HLM, human liver microsomes.

  • 2-a  Obtained from GENTEST.