TABLE 5.
Kinetic parameters of NADH and NADPH oxidation by wild-type and mutated NDH-II proteinsa
| Enzyme |
Km (μM) |
Vmax (U/mg) |
kcat (s−1) |
|||
|---|---|---|---|---|---|---|
| NADH | NADPH | NADH | NADPH | NADH | NADPH | |
| WT NDH-II | 50 ± 4 | <5 | 10 ± 1 | <5 | 88 ± 2 | <5 |
| NDH-IID213G | 78 ± 4 | 103 ± 1 | 4 ± 1 | 4 ± 1 | 32 ± 2 | 34 ± 2 |
| NDH-IID213N | 150 ± 9 | 180 ± 1 | 9 ± 1 | 4 ± 1 | 80 ± 3 | 32 ± 3 |
| NDH-IID213Q | 110 ± 11 | 172 ± 16 | 7 ± 1 | 7 ± 1 | 63 ± 3 | 56 ± 3 |
a
Kinetic parameters were measured at pH 7.5 for NADH and NADPH, using Q0 (100 μM) as an acceptor, in the reaction medium.