Table 3.
Kinetic Parameters of the Serine Binding Residue Mutations
| Enzyme | Km (µM) | kcat (sec−1) | Kia (µM) | kcat/Km ( M−1 sec−1) | Serine I 0.5b (µM) | Hill Coefficient |
|---|---|---|---|---|---|---|
| Native | 170 ± 50 | 2461 ± 281 | 950 ± 120 | 1.4 × 107 | 36 ± 6 | 1.8 ± 0.1 |
| Y461A | 270 ± 60 | 2754 ± 300 | 420 ± 65 | 1.0 × 107 | 6102 ± 106 | 1.7 ± 0.1 |
| D463A | 140 ± 10 | 720 ± 89 | 1090 ± 165 | 0.5 × 107 | 1886 ± 41 | 1.4 ± 0.1 |
| N481A | 120 ± 15 | 603 ± 77 | 2320 ± 337 | 0.5 × 107 | 2313 ± 366 | 1.1 ± 0.1 |
a
Ki refers to substrate inhibition.
b
All mutants are able to be inhibited by serine to < 95%.