Isolation and Amino-Acid Sequence Determination of Monkey Insulin and Proinsulin

Abstract

Insulin was isolated and purified from rhesus monkey pancreas by means of acid-ethanol extraction, gel filtration and ion exchange chromatography. The complete amino acid sequence of the hormone was determined by amino acid analysis of the oxidized A- and B-chains, by end group determination, by the identification of the C-terminal residues (AsnA21 and ThrB30) by carboxypeptidase A digestion and by Edman degradation of the S-carboxymethylated A- and B-chains. The 51-residue monkey insulin was identical to human insulin. From the known insulin and C-peptide sequence the primary sequence of monkey proinsulin was proposed.