Figure 7. Docked anions in the permeation pathway contribute to the channel closure.

(A) Electrostatic free energy calculation of frPanx1-ΔC (red) in the presence of 1–4 ATP molecules in the deep energy well. (B) A docked ATP molecule on the NTD-flipped down human Panx1 (PDB: 7F8N). (C) Close-up view of the putative ATP binding pocket. Positive residues surrounding the docked ATP are indicated. (D) Peak current density at +110 mV of the wild type and alanine substitutions expressed in HEK293 cells. Cells were clamped at −70 mV and stepped from −110 mV to +110 mV for 0.5 s with 20 mV increments. N=4–15 and error bars indicate SEM. Asterisks indicate significance of p<0.05 determined by one-way ANOVA followed by Dunnett’s test comparing WT to each construct.