Figure 3.

Selected minimum energy conformations of Ac-t-(^βPro)Arg-NHMe obtained from B3LYP/6–31+G(d,p) calculations (ΔE^gp < 5.0 kcal/mol, see Table 1): (a) γ_L[u]s⁻g⁺t; (b) γ_L[u]g⁻g⁻s⁺; (c) γ_L[u]g⁻g⁻s⁻; (d) α_L[u]s⁻g⁺t; (e) α_L[u]g⁺g⁻t; (f) α_L[u]g⁻tg⁻; and (g) γ_L[u]s⁻tg⁻. Intramolecular hydrogen bonds are indicated by dashed lines (H…O distances and N–H…O angles are given).