Absence of fusion between CPR and CYP2D6 PM during silica bead membrane purification
| Plasma membranes | Dextromethorphan conversion | ||
|---|---|---|---|
| CYP2D6/WRΔ | W(R) | NADPH-dependent activity | CumOOH-dependent activity |
| % | % per mg of protein | ||
| 100 | 0 | 0.1 ± 0.1 | 5 ± 1 |
| 75 | 25 | 0.05 ± 0.05 | 3.3 ± 0.5 |
| 50 | 50 | 0.05 ± 0.05 | 2.7 ± 0.5 |
| 25 | 75 | <0.05 | 1.6 ± 0.5 |
| 0 | 100 | <0.05 | <0.05 |
Dextromethorphan demethylase activities were measured in PM samples prepared from mixtures in variable amounts of spheroplasts from strain expressing CYP2D6 in WRΔ (no CPR) and strain W(R) overexpressing only CPR. Absence of fusion was deduced from the lack of reconstitution of a coupled CPR-P450 system. Values are the mean ± standard deviation of three independent determinations.