title: Intramolecular enzymatic peptide synthesis: trypsin-mediated coupling of the peptide bond between B22-arginine and B23-glycine in a split crosslinked insulin.
abstract: The resealing of a split peptide bond (B22/23) in a crosslinked insulin derivative by a trypsin-mediated coupling reaction in Tris buffer/glycerol/dimethylsulphoxide 1 : 1 : 1 at pH 6.5 is described. The coupling yield obtained with N alpha A1, N epsilon B29-(carbonyl-bis-methionyl) insulin [OC(Met)2] was 55-60%, and reproducible yields of OC(Met)2-insulin were 40%. After removing the crosslink and purification, crystalline resynthesized insulin of high biological activity was obtained in a yield of 43% and an overall yield, based on split OC(Met)2-insulin, of 18%.
mesh_terms: D000818:Animals; D001120:Arginine; D002417:Cattle; D003432:Cross-Linking Reagents; D005998:Glycine; D007328:Insulin / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D008722:Methods; D013379:Substrate Specificity; D014357:Trypsin / Q000378:metabolism*
chemical_list: D003432:Cross-Linking Reagents; D007328:Insulin; C031685:insulin, carbonyl-bis-Met,N(alphal),N(epsilon)(B29)-; D001120:Arginine; D014357:Trypsin; D005998:Glycine