Table 3.
The activity of wild type and mutant reductases with their redox partners, cytochrome c, cyt P450 2B4 and ferricyanide was determined at 30°C as described in the experimental section.
| CYPOR reductase mutant/WT | Fe3+ cytochrome c | cyt P450 2B4 | Fe(CN)63− | |
|---|---|---|---|---|
| nmol cyt c reduced/s/nmol CYPOR | KmNADPH μM |
nmol CH2O/s/nmol CYPOR | nmol reduced/s/nmol CYPOR | |
| WT CYPOR | 87.1±1.7 (100%) | 6.95±0.62 | 0.68±0.002 (100%) | 131.9±5.9 (100%) |
| Asp632Ala | 2.5±0.1 (2.9%) | 0.67±0.07 | 0.13±0.003 (19%) | 5.3±2.8 (4%) |
| Asp632Glu | 76.3±2.4 (88%) | 16.3±0.60 | 0.56±0.003 (82%) | 120.6±0.6 (92%) |
| Asp632Phe | < 0.1 | nda | < 0.01 | < 0.1 |
| Asp632Asn | 10.7±0.2 (12.3%) | 1.40±0.14 | 0.33±0.003 (48.5%) | 17.5±0.7 (13%) |
| Arg634Ala | 91±9 (100%) | nd | 1.02±0.02 (150%) | nd |
a
nd means not determined.