Table 1.
Thermodynamic parameters for binding of MUP-I mutants to pheromones
| Protein | Ligand | Kd (μM) | Stoichiometry (n) | ΔH (kcal/mol) | −TΔS (kcal/mol) | ΔG (kcal/mol) | Kd(mutant)/Kd(wild type) |
| Wild type | SBT | 1.1 ± 0.1 | 0.9 ± 0.1 | −10.9 ± 0.2 | +2.6 ± 0.2 | −8.3 ± 0.1 | 1 |
| T21V | SBT | 0.7 ± 0.1 | 0.7 ± 0.1 | −12.1 ± 0.1 | +3.6 ± 0.8 | −8.5 ± 0.1 | 0.64 |
| Y120F | SBT | 18 ± 10 | 1.4 ± 0.4 | −4 ± 2 | −3 ± 2 | −7 ± 3 | 16 |
| T21V/Y120F | SBT | 2.5 ± 0.1 | 1.1 ± 0.1 | −9.4 ± 0.1 | +1.6 ± 0.2 | −7.8 ± 0.1 | 2.3 |
| Wild type | HMH | 62 ± 4 | 0.8 ± 0.1 | −13 ± 1 | +7 ± 1 | −6 ± 1 | 1 |
| T21V | HMH | 51 ± 3 | 0.9 ± 0.1 | −12 ± 2 | +6.2 ± 0.2 | −6 ± 2 | 0.82 |
| Y120F | HMH | (no detectable signal) | |||||
| T21V/Y120F | HMH | (weakly exothermic signal) | |||||
All values were obtained by fitting ITC data at 30°C, as described in Materials and Methods.