Kinetic parameters of azelastine N-demethylase activity in microsomes expressing human CYP in human B-lymphoblast cells or baculovirus-infected insect cells
| Isoform | B-Lymphoblast Cells | Baculovirus-Infected Insect Cells | ||||
|---|---|---|---|---|---|---|
| KM | Vmax | Vmax/KM | KM | Vmax | Vmax/KM | |
| μM | pmol/min/pmol CYP | μl/min/pmol CYP | μM | pmol/min/pmol CYP | μl/min/pmol CYP | |
| CYP1A1 | 15.9 | 1.13 | 0.071 | 19.4 | 4.32 | 0.223 |
| CYP1A2 | 2-a | 125.4 | 16.45 | 0.131 | ||
| CYP2C19 | 36.1 | 0.35 | 0.010 | 8.5 | 0.60 | 0.071 |
| CYP2D6 | 1.4 | 0.44 | 0.314 | 2.1 | 1.60 | 0.762 |
| CYP3A4 | 74.1 | 0.59 | 0.008 | 43.7 | 2.67 | 0.061 |
| CYP3A4 +b 5 | 2-a | 51.1 | 4.45 | 0.087 | ||
All isoforms determined the kinetics were coexpressed with NADPH-CYP reductase except CYP2C19 in B-lymphoblast cells.
↵2-a , Not determined.