title: Structure and function of insulin: preparation and biological activity of guinea pig des B-Asp30,des-A-Asn21-insulin.
abstract: Bovine des-B-Ala30,des-A-Asn21-insulin and guinea pig des-B-Asp30,des-A-Asn21-insulin were prepared from bovine and guinea pig insulin by digestion with carboxypeptidase A (EC 3.4.12.2). As reported by other investigators, the biological activity of bovine des-Ala30,des-Asn21-insulin was less than 10% that of bovine insulin. Contrary to theoretical consideration, removal of A-Asn21 and B-Asp30 from the carbosyl termini of guinea pig insulin resulted in a loss of more than 90% of the biological activity. Receptor binding studies of these insulin derivatives demonstrated a good correlation between the loss of biological activity and the decrease in binding affinity. It is suggested that the carboxyl terminal A-Asn21 of insulin may interact directly with the insulin receptor.
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001216:Asparagine; D001224:Aspartic Acid; D001667:Binding, Competitive; D001681:Biological Assay; D002417:Cattle; D006168:Guinea Pigs; D007328:Insulin / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D051381:Rats; D011972:Receptor, Insulin / Q000378:metabolism
chemical_list: D000596:Amino Acids; D007328:Insulin; D001224:Aspartic Acid; D001216:Asparagine; D011972:Receptor, Insulin