Local and global structural changes in wild-type and mutant α7/AChBP in the presence and absence of calcium. (a) Superposition of averaged wild-type α7/AChBP structures following MD simulation in the presence (dark blue backbone) or absence (light blue backbone) of Ca²⁺. Key residues are depicted in stick representation and the Ca²⁺ ion as a purple sphere. (b) Superposition of averaged E158A mutant α7/AChBP structures following MD simulation in the presence (dark blue backbone) or absence (light blue backbone) of Ca²⁺. (c–f) Time evolution of the R_g for the indicated wild-type and mutant α7/AChBP structures in the presence or absence of Ca²⁺.