TABLE 5.
Kinetic constants obtained from crude extracts for XR mutants constructed in the current studya
| Strain | Cofactor | Vmax (U/mg protein) | KmA (μM) | KmB (mM) | KiA (μM) | Rsel |
|---|---|---|---|---|---|---|
| TMB 3420 (selected population) | NADPH | 2.8 ± 0.1 | 28 ± 3 | 90 ± 20 | 40 ± 20 | 1.0 |
| NADH | 1.24 ± 0.05 | 17 ± 2 | 70 ± 10 | 23 ± 9 | ||
| TMB 3421 (N272D/P275Q) | NADPH | 3.51 ± 0.35 | 40 ± 10 | 50 ± 30 | 100 ± 100 | 0.7 |
| NADH | 2.0 ± 0.2 | 26 ± 8 | 80 ± 40 | 50 ± 50 | ||
| TMB 3422 (N272D) | NADPH | 2.4 ± 0.1 | 24 ± 5 | 40 ± 10 | 50 ± 30 | 0.8 |
| NADH | 1.09 ± 0.05 | 4 ± 2 | 36 ± 8 | 30 ± 10 | ||
| TMB 3423 (P275Q) | NADPH | 0.36 ± 0.01 | 5.5 ± 0.9 | 72 ± 9 | −3 ± 1 | NAb |
| NADH | 0.38 ± 0.09 | −2 ± 5 | 160 ± 70 | 6 ± 5 | ||
| TMB 3424 (control) | NADPH | 0.28 ± 0.02 | 1.6 ± 0.6 | 35 ± 8 | 1 ± 1 | 0.1 |
| NADH | 0.21 ± 0.05 | 9 ± 5 | 70 ± 40 | 3 ± 5 |
a
The uncertainty of the presented values is given in terms of 1 standard deviation (σ). For definitions of kinetic constants, see Table 1.
b
NA, not applicable.