Figure 3.

The collapse of the peptide Ace-Nle₃₀-Nme under deeply quenched poor solvent conditions monitored by both radius of gyration (Panel A) and energy relaxation (Panel B). MC simulations were performed in dihedral space. 81% of moves attempted to change ϕ/ψ-angles, 9% sampled the ω-angles, and 10% the sidechains. For the randomized case (solid line), all angles were uniformly sampled from the interval −180° to 180° each time. For the stepwise case (dashed line), dihedral angles were perturbed uniformly by a maximum of 10° for ϕ/ψ-moves, 2° for ω-moves, and 30° for sidechain moves. In the mixed case (dash-dotted line), the stepwise protocol was modified to include non-local moves with fractions of 20% for ϕ/ψ-moves, 10% for ω-moves, and 30% for sidechain moves. For each of the three cases, data from 20 independent runs were combined to yields the traces shown. CPU times are approximate since stochastic variations in runtime were observed for the independent runs. Each run was comprised of 3×10⁷ steps. Error estimates are not shown in the interest of clarity, but indicated the results to be robust.