Theoretical conformational analysis of brain peptides. beta-Melanocyte-stimulating hormone.

Using a semi-empirical method, an a priori conformational analysis of the octadecapeptide beta-melanocyte-stimulating hormone (beta-MSH) was carried out. The spatial structure of beta-MSH can be described by eight low-energy conformations, yielded by combinations of the most stable states of the respective free fragments. Calculations produced the values of all dihedral angles of the backbones and side chains of these forms as well as intra- and inter-residue interaction energies.