Figure 1.

ϕ-ψ free-energy map. For illustrative purposes, a two-dimensional histogram of ϕ,ψ dihedral angles was constructed across all residues from an MD trajectory of ${\text{Gly}}_{15}$. The histogram was converted to a free-energy map relative to the most populated bin. Regions with values greater than 3.5 kcal/mol are colored white. The map is partitioned into six regions that are used to define a conformational state of oligoglycine. States 2, 3, 4, 5, and 6 correspond to the β, ${\text{ppII}}_R$, ${\text{ppII}}_L$, ${\alpha }_R$, and ${\alpha }_L$ regions, respectively. State 1 corresponds to a high-energy region (Hi).