Table 1. Binding Constant, Free Energy, Enthalpy, and Entropy of Binding at 300 K Derived from ITC Measurements for M2TM WT (from Udorn, Upper Table) and the M2TM S31N (Lower Table).
| liganda | Kdb | ΔGc | ΔHd | –TΔSe |
|---|---|---|---|---|
| M2TM WT | ||||
| 1 | 2.17 ± 0.52 | –7.77 ± 0.14 | –6.66 ± 0.50 | –1.11 ± 0.52 |
| 2 | 0.51 ± 0.26 | –8.64 ± 0.30 | –7.60 ± 0.28 | –1.04 ± 0.41 |
| 2-R | 0.32 ± 0.16 | –8.97 ± 0.26 | –7.54 ± 0.34 | –1.42 ± 0.43 |
| 2-S | 0.34 ± 0.12 | –8.88 ± 0.21 | –7.73 ± 0.28 | –1.15 ± 0.35 |
| 3 | 0.13 ± 0.12 | –9.30 ± 0.43 | –4.19 ± 0.28 | –5.12 ± 0.51 |
| 4 | 4.59 ± 2.21 | –7.33 ± 0.28 | –3.29 ± 0.62 | –4.03 ± 0.68 |
| 5 | 3.43 ± 1.05 | –7.50 ± 0.18 | –6.23 ± 0.45 | –1.27 ± 0.48 |
| M2TM S31N | ||||
| 1–3 | f | f | f | f |
| 5 | >10 | f | f | f |
b
Binding constant Kd in μM 2.
c
Free energy of binding in kcal mol–1.
d
Binding enthalpy in kcal mol–1.
e
Entropy of binding in kcal mol–1.
f
Values could not be determined reliably due to the limitations of the methods in the area of very weak binding (see also SI for definition of quantities).