Table 1.
Steady State Kinetic Parameters for Nitroalkane Oxidasea
| wild type | D402E | |
|---|---|---|
| nitroethane | ||
| Vmax (s−1) | 15 ± 1 | 3.07 ± 0.06 |
| V/K (mM−1 s−1) | 6.3 ± 0.4 | 0.21 ± 0.01 |
| Km (mM) | 2.3 ± 0.2 | 14.6 ± 0.8 |
| Kai (mM) | 25 ± 3 | —b |
| 1-nitrobutane | ||
| Vmax (s−1) | 6.1 ± 0.4 | 8.4 ± 0.2 |
| V/K (mM−1 s−1) | 220 ± 70 | 47 ± 5.0 |
| Km (mM) | 0.03 ± 0.01 | 0.18 ± 0.02 |
| Kai (mM) | 12 ± 2 | 120 ± 20 |
a
Initial rates of oxygen consumption were measured as described in Experimental Procedures. The conditions were 50 mM Hepes, 0.1 mM FAD, pH 8.0, and 30 °C.
b
Substrate inhibition was not observed with the D402E enzyme.