Conformational Study of Met-Enkephalin Based on the ECEPP Force Fields

We report a computational study of the small peptide Met-enkephalin based on the ECEPP/2 and ECEPP/3 force fields using the basin paving method. We have located a new global minimum when using the ECEPP/3 force field with peptide angles ω fixed at 180°. With this new result, we can conclude that the lowest energy configurations of Met-enkephalin predicted based on all four versions of ECEPP have a classic γ-turn centered at residue Gly3 and a β-turn at residues Gly3-Phe4. However, minor differences between the structures also exist.