Table 3. Thermodynamic parameters for the binding of substrates and substrate analogues to BoGT6a. Titrations were conducted at 25°C (298 K) with 13 μM BoGT6a in 20 mM HEPES buffer pH 7.5 containing 0.2 M NaCl and 1 mM DTT.
| Ligand | UDP-GalNAc E192Q variant | UDP-GalNAc WT | FAL | FAL |
|---|---|---|---|---|
| Other ligands | UDP (3 mM) | |||
| Ka (*10−3) | 18.0±0.4 | 17.8±0.5 | 0.81±0.02 | 13.02±0.24 |
| ΔG (kcal/mol) | −5.78±0.02 | −5.80±0.02 | −3.97±0.03 | −5.61±0.01 |
| ΔH (kcal/mol) | −16.4±0.2 | −23.5±0.3 | −13.5±0.3 | −15.4±0.1 |
| TΔS (kcal/mol) | −10.6±0.2 | −17.7±0.3 | −9.6±0.7 | −9.8±0.1 |