Table 3.
Thermodynamic parameters obtained for (GlcNAc)2 binding to VhCBP variants
| VhCBP variant | n | Kd (μM) | ΔHο (kcal.mol−1) | −TΔSο (kcal.mol−1) | ΔGο (kcal.mol−1) | ΔΔGο (kcal.mol−1) |
|---|---|---|---|---|---|---|
| WT | 1 | 0.03 ± 0.01 | −3.9 ± 0.1 | −6.4 ± 0.2 | −10.3 ± 0.3 | - |
| E10A | 1 | 0.71 ± 0.07 | −8.8 ± 0.1 | 0.4 ± 0.2 | −8.4 ± 0.1 | +1.9 ± 0.2 |
| N204A | 1 | 0.83 ± 0.17 | −0.75 ± 0.05 | −7.6 ± 0.2 | −8.3 ± 0.1 | +2.1 ± 0.3 |
| S221A | 1 | 0.07 ± 0.06 | −5.3 ± 0.7 | −4.9 ± 1.4 | −10.2 ± 1.0 | +0.1 ± 1.0 |
| W363A | 1 | 80.20 ± 19.9 | −1.9 ± 1.8 | −3.7 ± 2.0 | −5.6 ± 0.1 | +4.7 ± 0.4 |
| D365A | 1 | 65,033 ± 4550 | −11.3 ± 0.4 | 9.7 ± 0.4 | −1.6 ± 0.0 | +8.6 ± 0.3 |
| N409A | 1 | 0.45 ± 0.1 | −9.6 ± 0.6 | 1.0 ± 0.7 | −8.7 ± 0.1 | +1.6 ± 0.2 |
| F411A | 1 | 0.40 ± 0.07 | −3.3 ± 0.1 | −5.4 ± 0.1 | −8.7 ± 0.1 | +1.6 ± 0.3 |
| F437A | 1 | 29.73 ± 0.5 | −11.0 ± 0.4 | −4.8 ± 0.4 | −6.2 ± 0.0 | +4.1 ± 0.3 |
| W513A | 1 | 36.83 ± 7.4 | −5.8 ± 0.0 | −0.3 ± 0.1 | −6.1 ± 0.1 | +4.2 ± 0.3 |
| W363A/W513A | ND | - | - | - | - | - |
ND represents no detectable binding.
VhCBP variants were titrated with (GlcNAc)2 under the conditions given in Experimental procedures. Thermodynamic values (Kd, ΔGο, ΔHο, −TΔSο) are derived from the corresponding thermograms shown in Figure 5 and are presented as the mean ± SD, which were obtained from three separate sets of experiments.