Figure 5. The comparisons between the representative MD-simulated structures and the crystal structure. (A) The key hydrogen bond network with Glu202 being protonated. (B) The key hydrogen bond network with Glu202 being deprotonated. (C) The catalytic His447 with Glu202 being protonated. (D) The catalytic His447 with Glu202 being deprotonated. (E) The binding mode of ACh with Glu202 being protonated. (F). The binding mode of ACh with Glu202 being deprotonated. The purple dashed lines indicate distances between the hydroxyl oxygen of catalytic Ser203 and the carbonyl carbon of ACh. Atoms are colored and rendered in the same style as in Figure 2.