Conformation of aminosuccinyl dipeptides Ac-L-X-L-Asu-NMe from empirical energy calculations.

The aminosuccinyl (Asu) residue is formed as intermediate in some peptide and protein reactions. Potential energy calculations, using the parameters of the empirical conformational energy program for peptides (ECEPP), were performed on blocked X-Asu dipeptides, where X = Gly, Ala, Ser, Val and Pro. Results indicate that intra-residue interactions are dominant, and the low-energy dipeptide conformations correspond to the low-energy single-residue minima. Comparisons were made with previous results from energy calculations on blocked Asu-X dipeptides (X = Gly, Ala, Ser and Val).