Table 3

Apparent Km, Vmax and intrinsic clearances (CLint) for the formation of K11777 metabolites by cDNA expressed CYP enzymes and cDNA expressed FMO3

SampleN-Oxide K11777β-Hydroxy-homoPhe K11777N-Desmethyl K11777
K m[μmol · l−1]
 CYP3A423.2  ± 3.125.3  ± 0.825.0  ± 4.0
 CYP2D622.8  ± 3.5<LOD9.2  ± 1.4
 FMO3109.3  ± 10.8<LOD<LOD
V max
 CYP3A4
 (pmol · min−1 · mg−1 protein)2695  ± 971107  ± 72132  ± 159
 [pmol · min−1 · pmol CYP−1][13.2  ± 0.5][5.4  ± 0.0][10.4  ± 0.8]
 CYP2D6
 (pmol · min−1 · mg−1 protein)212  ± 12<LOD3249  ± 95
 [pmol · min−1 · pmol CYP−1][1.2  ± 0.1][18.8  ± 0.6]
 FMO3
 (pmol · min−1 · mg−1 protein)8565  ± 68<LOD<LOD
CLint (μl · min−1 · mg−1 protein)
 CYP3A4118  ± 1644  ± 186  ± 2
 CYP2D69  ± 2360  ± 53
 FMO378  ± 7

Data are presented as mean ± standard deviation (n = 3).

  • LOD, concentration below lower limit of detection (0.5 ng/ml).