ON THE ROLE OF THE C-TERMINUS OF ALPHA-CALCITONIN-GENE-RELATED PEPTIDE (ALPHA-CGRP) - THE STRUCTURE OF DES-PHENYLALANINAMIDE(37)-ALPHA-CGRPAND ITS INTERACTION WITH THE CGRP RECEPTOR

Alpha-Calcitonin-gene-related peptide (alphaCGRP) lacking its C-termin al phenylalaninamide residue was found not to bind to its receptor as did full-length (amidated) alphaCGRP. Investigation of the structure o f these peptides by c.d. and n.m.r. revealed no significant difference , so it seemed that the effect of deleting the C-terminal phenylalanin amide on the biological activity of alphaCGRP was not by disruption of the peptide's structure. Thus the C-terminal phenylalaninamide is an important factor in this ligand-receptor interaction, and the group it self may interact directly with the receptor.