Table 3.
Kinetic parameters for acceptor substrate Sia2Lac.
| Mutant | Km (mM) | kcat (s−1) | kcat/Km (s−1 M−1) |
|---|---|---|---|
| wt | 2.26 ± 0.34 | 69.86 ± 0.59 | 30,977 |
| wta | 1.86 ± 0.06 | 134.23 ± 0.32 | 72,103 |
| Q41A | 1.02 ± 0.05 | 3.15 ± 0.00 | 3,092 |
| Q44A | — | — | 0.2 |
| E152A | 1.36 ± 0.22 | 0.38 ± 0.00 | 280 |
| E153A | — | — | — |
| R259A | 2.57 ± 0.34 | 0.46 ± 0.00 | 177 |
| H291A | 3.20 ± 0.12 | 0.76 ± 0.00 | 239 |
| K293A | — | — | 1 |
Determined at constant donor concentration of 5 mM CMP-Neu5Ac. aKinetic parameters for acceptor substrate Sia3Lac. Kinetic values are the mean ± s.e.m.