Estimated free enthalpies of binding at the gating site for NPPB, 3NB, and 3PP
Drug
Kd
ΔGobinding
kT
NPPB
80 µM
−9.4
3NB
9 mM
−4.7
3PP
6 mM
−5.1
Drug
Kd
ΔGobinding
kT
NPPB
80 µM
−9.4
3NB
9 mM
−4.7
3PP
6 mM
−5.1
For NPPB, Kd was taken from Csanády and Töröcsik (2014). For 3NB and 3PP, Kd was estimated as the apparent K1/2 for stimulating open probability at −80 mV (Fig. 5, D and H), assuming voltage-independent binding at the gating site.