Action of a cysteine proteinase from pupae of the blowfly Aldrichina grahami on the oxidized B-chain of bovine insulin.
A cysteine proteinase purified from pupae of the blowfly (A. grahami) was tested for its peptide-bond specificity against the oxidized B-chain of insulin. Fifteen peptides were separated on HPLC using both gradient and isocratic elution methods. Analyses of amino acid content and N-terminal amino acids indicated that these were eleven homogeneous peptides produced by digestion and undigested insulin B-chain. Glu13-Ala14 and Tyr26-Thr27 were the major cleavage sites, and Asn3-Gln4, Cys7-Gly8, Tyr16-Leu17, Leu17-Val18 and Cys19-Gly20 were also often cleaved. These findings show the similarity between this enzyme and cathepsin L.
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003546:Cysteine Endopeptidases; D010450:Endopeptidases / Q000378:metabolism*; D006927:Hymenoptera / Q000201:enzymology*; D007328:Insulin; D010446:Peptide Fragments / Q000032:analysis
D007328:Insulin; D010446:Peptide Fragments; D010450:Endopeptidases; D003546:Cysteine Endopeptidases