FIG. 6.

Two pathways of β-hairpin formation. Pathway 1 (trajectory 1) follows a fast “zipper out” route, pathway 2 (trajectory 4) follows a “zipper in” route as discussed in the text. Shown are the backbone atoms of the β-hairpin region (region 38-53) in cartoon (gold) and licorice representations (carbon atoms in light blue, nitrogen in dark blue, oxygen in red, and hydrogen in white). Hydrogen bonds are highlighted through black dashed lines between carbonyl oxygen and amine nitrogen atoms. Hydrogen bonded residues are labeled. A cartoon representation of the β-hairpin is shown at the bottom of each pathway to illustrate the hydrogen-bonding pattern.