TABLE 2.
Kinetic parameters of wild-type and variant acetate kinases assayed in the direction of acetyl phosphate synthesis
| Enzyme | kcat (s−1) | Acetate
|
ATP
|
||
|---|---|---|---|---|---|
| Km (mM) | kcat/Km (s−1 mM−1) | Km (μM) | kcat/Km (s−1 μM−1) | ||
| Wild type | 1,055 ± 57 | 1.5 ± 0.16 | 703 ± 84 | 71.3 ± 7.0 | 14.8 ± 1.7 |
| Val93 Ala | 844 ± 34 | 21.4 ± 1.8 | 39 ± 2.0 | 49.9 ± 3.3 | 16.9 ± 1.3 |
| Val93 Gly | 347 ± 21 | 39.5 ± 1.7 | 8.8 ± 0.7 | 68.7 ± 1.9 | 5.1 ± 0.3 |
| Leu122 Ala | 150 ± 12 | 19.5 ± 1.8 | 7.7 ± 0.9 | 57.6 ± 2.7 | 2.6 ± 0.24 |
| Phe179 Ala | 2.2 ± 0.3 | 10.4 ± 1.1 | 0.21 ± 0.04 | 50.5 ± 0.6 | 0.043 ± 0.006 |
| Pro232 Ala | 132 ± 2 | 32.0 ± 2.6 | 4.1 ± 0.3 | 54.2 ± 1.5 | 2.4 ± 0.08 |