title: Trypsin-catalysed formation of pig des-(23-63)-proinsulin from desoctapeptide-(B23-30)-insulin.
abstract: Incubation of pig desoctapeptide-(B23-30)-insulin with trypsin in solvent systems consisting of dimethyl sulphoxide, butane-1,4-diol and Tris buffer resulted in the formation of an extra peptide bond between Arg-B22 and Gly-A1 in the DOPI molecule. This DOPI derivative can also be regarded as pig des-(23-63)-proinsulin. The structure of the new, previously unreported, proinsulin analogue was determined on the basis of amino acid analysis, dansylation and digestion with Staphylococcus aureus V8 proteinase. Receptor-binding ability of des-(23-63)-proinsulin was 20% of that of pig desoctapeptide-(B23-30)-insulin and 0.02% of that of pig insulin.
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D010450:Endopeptidases; D007328:Insulin / Q000031:analogs & derivatives* / Q000378:metabolism; D010446:Peptide Fragments / Q000032:analysis / Q000138:chemical synthesis*; D011384:Proinsulin / Q000138:chemical synthesis*; D011485:Protein Binding; D012697:Serine Endopeptidases; D013552:Swine; D014357:Trypsin / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D007328:Insulin; D010446:Peptide Fragments; C049342:proinsulin, des-(23-63)-; C024339:insulin, desoctapeptide-; D011384:Proinsulin; D010450:Endopeptidases; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase; D014357:Trypsin