Fast Atomic Charge Calculation for Implementation into a Polarizable Force Field and Application to an Ion Channel Protein

Figure 9

Side chain conformations of Trp-41 and His-37 in the transmembrane channel structure of the homotetrameric M2 protein. Representatives of (a) closed state at pH 8 for Trp-41: (, ) = (−115° ± 50°, +130° ± 30°), His-37: (, ) = (−180° ± 20°, −140° ± 20°) and (b) open state at pH 5 for Trp-41: (, ) = (−60° ± 20°, +110° ± 20°) and His-37: (, ) = (+95° ± 20°, +130° ± 20°) are shown.

(a)

(b)