Figure 5.

Electrostatic energy landscape of the proton hole inside the K-channel analog. Electrostatic energies for all deprotonation steps were calculated using the software karlsberg+ (24,25) as described in Materials and Methods. Transport of a proton hole along the K-channel analog starts at Tyr-237, which is deprotonated and donates its proton to the BNC. The proton hole subsequently moves along a linear chain of deprotonatable residues until it reaches Glu-15B. After deprotonation of Tyr-244, this residue moves inside the gap between Ser-309 and Thr-312. The electrostatic energies before and after this conformational change are depicted.