Interaction energies (van der Waals + electrostatic) contributed by each VSD II residue toward the PTx2 binding process for different PTx2–hNa _V 1.7 VSD II/IV MD simulation systems. Only residues with combined interaction energies across the whole system more favorable than −0.5 kcal/mol when averaged over all replicas are displayed, and only the second half of each MD simulation was used for the analysis.