title: Studies on trypsin inhibitors. Part VI. Synthesis of the protected nonapeptide (sequence 44-52) of porcine pancreatic secretory trypsin inhibitor II (Kazal).
abstract: Synthesis is described of the partially protected nonapeptide tert-butyloxycarbonyl-valylleucylisoleucylglutaminyl-N-trifluoroacetyllsylserylglycylprolyl-S-acetamido-methylcysteine corresponding to positions 44-52 of the amino acid sequence of porcine pancreatic secretory trypsin inhibitor II. The hexapeptide free base glutaminyl-N-trifluoroacetyllsylserylglycylprolyl-S-acetamidomethylcysteine, prepared by two alternative routes, was acylated by the azide procedure, with the tripeptide tert-butyloxycarbonylvalylleucylisoleucine hydrazide. The stereochemical homogeneity of the resulting nonapeptide was assessed, after partial deprotection by treatment 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