title: [Synthesis of a fragment of the active center of the streptococcal proteinase (EC 3.4.22.10), IX].
abstract: The synthesis of the protected pentapeptide tert-butyloxycarbonly-Gln-Ile-Met-Lys(X)-Gly-p-nitrobenzylester (X = benzyloxycarbonyl, 3-chlor-benzyloxycarbonyl) which is part of the carboxylend of a partial sequence of the active center of the streptococcal proteinase is described. Side reactions are observed if the tert-butyloxycarbonyl-protective group is cleaved by trifluoroacetic acid, not with HC1/dioxane. Obviously the presence of methionine is responsible for the formation of by products. Formation of methioninesulfoxide of tert-butylsulfoniummethionine could not be proved. tert-butyloxycarbonyl-Gln-1-hydroxybenzotriazolylester was obtained in a crystalline state from the reaction of tert-butyloxycarbonyl-Gln, dicyclohexylcarbodiimid and 1-hydroxybenzotriazol.
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D010450:Endopeptidases; D008722:Methods; D009842:Oligopeptides / Q000138:chemical synthesis*; D013291:Streptococcus / Q000201:enzymology
chemical_list: D009842:Oligopeptides; D010450:Endopeptidases
vernacular_title: Synthese einer Partialsequenz aus dem aktiven Zentrum der Streptokokken-Proteinase (EC 3.4.22.10), IX