FIGURE 5.

C-Cadherin secondary structure elasticity. (A) Force versus end-to-end distance profile for constant-velocity stretching simulations with crystallographic Ca²⁺ ions (blue and indigo, SimCa2-SimCa2E) and without Ca²⁺ (red and orange, SimApo2-SimApo2E). (B–E) Snapshots of the unfolding pathway during simulation SimCa2E. Views show the EC1-linker-EC2 domain in cartoon representation with the corresponding surface drawn in transparent orange. The C_α atom of the N-terminus is shown as a red sphere and Ca²⁺ ions as green spheres. Residue Glu¹¹ is shown in licorice representation. Disruption of secondary structure elements (secondary structure elasticity) proceeds only upon rupture of a bridge formed by Glu¹¹ and a Ca²⁺ ion.