Long-loop unfolding in apo-langerin.A, example structures for a fully folded (A1), intermediate (A2), partially unfolded (A3), and fully unfolded (A4) state. B, example trajectory of the long-loop Cα-RMSD; 22 ns, intermediate state; 30 ns, unfolding event. C, percentage of unfolded trajectories within 220 ns determined by: last folded frame (visual), mean of last folded and first unfolded frame (visual mean), RMSD > 0.2 nm, and hydrogen bonds N287m–D308s (287m) and N288m–D308s (288m). D, decay plot of folded trajectories (last folded frame) and exponential fit (dashed line ±σ), H294+: H294 protonated, D308+: H294 and D308 protonated.