Table 2.
Effects of mutations to Trp-676 of cytochrome P450 reductase on cofactor preference
| Mutant | Activity, min−1
|
|||
|---|---|---|---|---|
| NADPH
|
NADH
|
|||
| Cytochrome c | Ferricyanide | Cytochrome c | Ferricyanide | |
| sCPR | 1,890 ± 50 | 2,770 ± 130 | 10 ± 1 | 10 ± 6 |
| sW676H | 410 ± 30 | 1,430 ± 80 | 90 ± 10 | 160 ± 1 |
| sW676A | 20 ± 2 | 30 ± 10 | 490 ± 40 | 780 ± 110 |
The reduction of cytochrome c and ferricyanide were measured with 5 pmol enzyme as described in the legend to Table 1, with final cofactor concentrations of 100 μM. Values represent mean ± SD of triplicate determinations.