TABLE 5.
Effect of CaM and NADPH on FMN shielding in fully reduced nNOSred and the Lys842 mutants
An excess of each prereduced NOSr protein in the presence or absence of NADPH and CaM was mixed with cytochrome c in a stopped-flow instrument under anaerobic conditions at 10 °C. All reactions were initiated by mixing 16 μm photoreduced nNOSred proteins with 4 μm cytochrome c. The observed rates of absorbance increase at 550 nm are reported as the mean ± S.D. of 5–6 single mixing experiments and are representative of at least two different enzyme preparations.
| NADPH/CaM | Wild type | K842A | K842E |
|---|---|---|---|
| s− | s− | s− | |
| −/− | 11.6 ± 0.3 | 14.8 ± 0.3 | 18.8 ± 0.5 |
| +/− | 3.8 ± 0.06 | 12.9 ± 0.3 | 14.6 ± 0.1 |
| +/+ | 35.7 ± 0.2 | 36.8 ± 0.8 | 35.4 ± 0.5 |