Table 2.
The effect of the L269Y subsitution on the kinetic parameters of OtCE15A with model substrates
Esterase activity with methyl esters of GlcA and GalA are shown. Errors represent S.D. from triplicate experiments. Ksi, substrate inhibition constant. NA, not applicable.
| Enzyme | Substrate | Km | Ksi | kcat | kcat/Km |
|---|---|---|---|---|---|
| mm | mm | s−1 | s−1 m−1 | ||
| WT | MeGlcA | 2.77 ± 0.15 | NA | 19.0 ± 0.31 | (6.85 ± 0.39) × 103 |
| MeGalA | 5.31 ± 0.51 | NA | 28.8 ± 0.64 | (4.85 ± 0.47) × 103 | |
| L269Y | MeGlcA | 1.69 ± 0.48 | 34.5 ± 11.9 | 16.1 ± 2.1 | (9.54 ± 3.0) × 103 |
| MeGalA | 11.9 ± 0.60 | NA | 2.70 ± 0.052 | (2.26 ± 0.12) × 102 |