FIGURE 1.

Influence of ions on C-cadherin equilibrium dynamics. (A and B) Models used as starting conformations in simulations of the complete C-cadherin extracellular domain with and without Ca²⁺ ions, respectively. The protein is shown in cartoon representation and its surface is drawn in transparent orange. Crystallographic Ca²⁺ and terminal C_α atoms are shown as green and red spheres. Water and bulk ions are not shown. (C–F) Snapshots of the complete extracellular domain of C-cadherin after 10 ns of equilibration in the presence of Ca²⁺ ions (SimCa1, C), in the absence of Ca²⁺ ions (SimApo1, D), with K⁺ (SimK1, E), and with Na⁺ ions (SimNa1, F), respectively. While C-cadherin remains curved when simulated in the presence of Ca²⁺, its shape is lost after 10 ns of dynamics in the absence of Ca²⁺. Both K⁺ and Na⁺ ions begin to unbind from C-cadherin during 10 ns of dynamics (black circles).