THE AMYLIN, CGRP AND CALCITONIN FAMILY OF PEPTIDES

The calcitonins are a group of 32 amino acid, disulphide bridged, C-te rminally amidated peptides, first isolated from the thyroid and charac terised as hormones which regulate blood calcium levels. Observations on alternative splicing of mRNA derived from the calcitonin gene resul ted in the identification of the potent vasodilator: calcitonin gene-r elated peptide (CGRP), a 37 amino acid, disulphide bridged peptide, ag ain with a C-terminal amide. More recently a third type of peptide, am ylin, has been isolated from pancreases of Type 2 diabetics. This also is a 37 amino acid residue, disulphide bridged C-terminally amidated peptide, and acts as a regulator of blood glucose levels in conjunctio n with insulin. Two other molecules may also be somewhat related to th ese: adrenomedullin, which has weak structural homology with CGRP and amylin and shows vasodilatory properties, and maxadilan, which is stru cturally unrelated but resembles CGRP biologically. This review summar ises recent progress on the characterisation, structural elucidation, receptorology, medicinal chemistry and patent literature of these extr aordinarily potent molecules.