title: Studies on trypsin inhibitors. Part V. Synthesis of the protected octapeptide (sequence 36-43) of porcine pancreatic secretory trypsin inhibitor II (Kazal).
abstract: Synthesis is described of the partially protected octapeptide tert-butyloxycarbonyl-gamma-tert-butylglutamylasparaginyl-N-trifluoroacetyllysyl-N-trifluoracetyllysylarginyl-Ngamma-4,4'-dimethoxybenzhydryglutaminylthreonylproline  corresponding to positions 36-43 of the amino acid sequence of porcine pancreatic secretory trypsin inhibitor II. The tetrapeptide free base arginyl-Ngamma-4,4'-dimethoxybenzhydrylglutaminylthreonylproline was acylated, by the azide proceedure, with the tripeptide benzyloxycarbonyl-asparaginyl-N-trifluoroacetyllsyl-N-trifluoroacetyllysine hydrazide. The resulting protected heptapeptide was partially deblocked by catalytic hydrogenation and reacted with alpha-1-succinimidyl-gamma-tert-butyl tert-butyloxycarbonylglutamate. The stereochemical homogeneity of the ensuing octapeptide was assessed, after partial deprotection with aqueous 90% trifluoroacetic acid, by digestion with papain and aminopeptidase M followed by quantitative amino acid analysis.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D010455:Peptides / Q000032:analysis / Q000138:chemical synthesis*; D014359:Trypsin Inhibitor, Kazal Pancreatic / Q000032:analysis / Q000138:chemical synthesis*; D014361:Trypsin Inhibitors / Q000138:chemical synthesis*
chemical_list: D000596:Amino Acids; D010455:Peptides; D014361:Trypsin Inhibitors; D014359:Trypsin Inhibitor, Kazal Pancreatic