Figure 2.

View of the lowest-energy conformations of ALA₁₀ found in the set of simulations at different dielectric constants: (a) ɛ = 2, (b) ɛ = 40, and (c) ɛ = 80. All of the atoms have been colored in gray, except for the carbonyl O (red) and the amino HN (green). The backbone of the chain is traced with a gray ribbon, and the solvent-accessible surfaces of the oxygen and polar hydrogens are displayed using dots. Only a fraction of the backbone HN groups, not involved in intramolecular hydrogen bonds, remain exposed to the solvent when the dielectric constant ɛ is 40. (d) Top view of the lowest-energy conformation encountered in the runs for ɛ = 2, showing that all of the polar hydrogen (green) atoms are buried in a helix.