Fingerprint analysis of insulin and proinsulins.
Proteolysis of insulin or (pre)proinsulin with S. aureus protease V8 in Tris buffer at neutral pH yields a characteristic pattern of peptide fragments that is resolved using high-performance liquid chromatography. Identification of the fragments of interest was achieved by comparison of insulins of different species, of modified insulins and of proinsulin and N-extended proinsulin, and by amino acid analysis. The fingerprint method allows, for example, the simultaneous analysis of porcine and human insulin, the identification of a modified insulin generated in dosing devices, as well as the individual analysis of the two disulfide linkages between the A- and B-chain in refolded insulins.
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D010450:Endopeptidases; D006801:Humans; D007328:Insulin / Q000032:analysis* / Q000235:genetics; D010446:Peptide Fragments / Q000032:analysis / Q000302:isolation & purification; D011323:Primates; D011384:Proinsulin / Q000032:analysis* / Q000235:genetics; D012697:Serine Endopeptidases; D013552:Swine
D000596:Amino Acids; D007328:Insulin; D010446:Peptide Fragments; D011384:Proinsulin; D010450:Endopeptidases; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase