title: Trypsin complexed with alpha 1-proteinase inhibitor has an increased structural flexibility.
abstract: Mutant rat trypsin Asp189Ser was prepared and complexed with highly purified human alpha 1-proteinase inhibitor. The complex formed was purified to homogeneity and studied by N-terminal amino acid sequence analysis and limited proteolysis with bovine trypsin. As compared to uncomplexed mutant trypsin, the mutant enzyme complexed with alpha 1-proteinase inhibitor showed a highly increased susceptibility to enzymatic digestion. The peptide bond selectively attacked by bovine trypsin was identified as the Arg117-Val118 one of trypsin. The structural and mechanistic relevance of this observation to serine proteinase-substrate and serine proteinase-serpin reactions are discussed.
authors.affiliation: Department of Biochemistry, Eötvös University, Budapest, Hungary.
authors.forename: G
authors.initials: G
authors.lastname: Kaslik
authors.forename: A
authors.initials: A
authors.lastname: Patthy
authors.forename: M
authors.initials: M
authors.lastname: Bálint
authors.forename: L
authors.initials: L
authors.lastname: Gráf
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001216:Asparagine; D002417:Cattle; D002845:Chromatography / Q000379:methods; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D011487:Protein Conformation; D051381:Rats; D012694:Serine; D014357:Trypsin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000515:alpha 1-Antitrypsin / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000515:alpha 1-Antitrypsin; D012694:Serine; D001216:Asparagine; D014357:Trypsin