Some properties of the insulin core

Abstract

The core of the insulin molecule, produced by the action of chymotrypsin, was further studied. On oxidation of the core 3 ro 4 peptides can be distinguished by electrophoresis. Additional analyses of the distribution of cystine and the aromatic amino acids were made. The number of peptide bonds broken and the distribution of aromatic amino acids between the core and the filtrate suggests that chymotrypsin attacks preferentially peptide bonds involving the carboxyl side of an aromatic residue. The end groups of the core are mainly glycine with a smaller proportion of valine. The implications of this are discussed.