Estimated free enthalpies of binding in the pore for NPPB, 3NB, and 3PP
| Drug | Kd(0 mV) | ΔGobinding |
| kT | ||
| NPPB | 150 µM | −8.8 |
| 3NB | 12 mM | −4.4 |
| 3PP | 10 mM | −4.6 |
| Drug | Kd(0 mV) | ΔGobinding |
| kT | ||
| NPPB | 150 µM | −8.8 |
| 3NB | 12 mM | −4.4 |
| 3PP | 10 mM | −4.6 |
For NPPB, Kd(0) was taken from Csanády and Töröcsik (2014). For 3NB, Kd(0) was calculated (see Materials and methods) from the apparent Kd values measured at −120 and 60 mV (Fig. 3 C). For 3PP, Kd(0) was estimated from the value measured at 60 mV (Fig. 3 H), assuming voltage-independent binding (z = 0) in the pore. (Assuming z values of 0.1, 0.2, and 0.5 for 3PP would yield Kd(0) estimates of 12.6, 16, and 32 mM and ΔGobinding values of 4.4, 4.1, and 3.4 kT, respectively.)