Table 3. Thermodynamic parameters, stoichiometry (n) and dissociation constants (Kd) between PHDVC5HCHNSD1 and C2HRNizp1 wild type (WT) and mutants measured by ITC (T = 22°C).
| PHDvC5HCHNSD1 | C2HRNizp1 | ΔH (kcal/mol) | -TΔS (kcal/mol) | ΔG (kcal/mol) | n | Kd (μM) |
|---|---|---|---|---|---|---|
| WT | WT | 4.1 ± 0.1 | 11.4± 0.1 | -7.3 ± 0.1 | 1.1 ± 0.1 | 3.8 ± 0.7 |
| R2152Q | WT | 3.5 ± 0.2 | 10.7 ± 0.1 | -7.2 ± 0.1 | 1.0 ± 0.1 | 4.9 ± 0.6 |
| E2204A | WT | 0.4 ± 0.1 | 6.3 ± 0.2 | -5.9 ± 0.2 | 0.9 ± 0.1 | 45.2 ± 6.9 |
| H2205R | WT | 1.0 ± 0.1 | 7.2 ± 0.1 | 6.2 ± 0.1 | 1.0 ± 0.1 | 27.2 ± 5.3 |
| WT | R415A | 2.2 ± 0.1 | 9.3 ± 0.1 | -7.1 ± 0.1 | 1.1 ± 0.1 | 6.1 ± 0.4 |
| WT | W416A | N.D. | N.D. | N.D. | N.D. | N.D. |
| WT | R417A | 1.5 ± 0.1 | 7.5 ± 0.1 | 6.0 ± 0.1 | 1.1 ± 0.1 | 36.0 ± 6.0 |
| WT | R422A | 0.7 ± 0.1 | 7.7 ± 0.1 | 7.0 ± 0.1 | 0.9 ± 0.1 | 7.0 ± 0.2 |
| WT | R427A | 1.7 ± 0.1 | 9.0 ± 0.1 | -7.3 ± 0.1 | 1.0 ± 0.1 | 4.0 ± 0.3 |