TABLE 1

Kinetic parameters for phenacetin O-deethylation by CYP1A1 and CYP1A2

EnzymesPhenacetin O-Deethylation
kcataKmakcat/Kmb
min−1μMμM−1 · min−1
CYP1A10.84 ± 0.08803 ± 1370.001 ± 0.001
CYP1A22.20 ± 0.10120 ± 140.018 ± 0.002

  • ↵a Data are means of triplicate determinations.

  • ↵b kcat/Km (catalytic efficiency) is used here to compare substrate specificities.