TABLE 2.
Thermodynamic parameters for the binding of FK506 and APX879 to human, A. fumigatus, and M. circinelloides FKBP12 proteins determined by ITCa
| KD (nM) | ΔH (kcal/mol) | TΔS (kcal/mol) | Stoichiometry | ΔG° (kcal/mol) | |
|---|---|---|---|---|---|
| FK506 | |||||
| hFKBP12 | 2.7 ± 0.5 | −15.0 ± 1.1 | −3.3 ± 1.2 | 1.09 ± 0.03 | −12.0 ± 1.6 |
| AfFKBP12 | 4.7 ± 0.6 | −6.7 ± 0.3 | 4.6 ± 0.3 | 2.02 ± 0.06 | −11.3 ± 0.4 |
| McFKBP12 | 3.0 ± 0.7 | −9.8 ± 0.1 | 1.9 ± 0.2 | 1.06 ± 0.06 | −11.7 ± 0.2 |
| APX879 | |||||
| hFKBP12 | 119.4 ± 15.8 | −1.8 ± 0.4 | 7.4 ± 0.8 | 1.41 ± 0.03 | −9.2 ± 0.9 |
| AfFKBP12 | 461.6 ± 22.6 | −1.2 ± 0.4 | 7.2 ± 1.0 | 1.96 ± 0.13 | −8.0 ± 1.0 |
| McFKBP12 | 126.4 ± 30.3 | −2.0 ± 0.1 | 7.4 ± 0.2 | 0.93 ± 0.17 | −9.4 ± 0.2 |
a
Average from triplicates performed at 25°C; see Fig. S2 for heat pulse data.