title: Purification and characterization of ostrich pancreatic secretory trypsin inhibitor.
abstract: Ostrich pancreatic secretory trypsin inhibitor was isolated and purified using acid extraction, salt fractionation. SP-Sephadex C-50 and QAE-Sephadex A-25 chromatography and RP-HPLC. The amino acid sequence of ostrich PSTI showed it is a single peptide chain containing 69 amino acid residues with the highest homology between ostrich and chicken PSTI. The molecular weight, as determined by electronspray mass spectrometry and from amino acid sequence data, is 7650 Da. The isoelectric point of ostrich PSTI was found to be 5.7. Ostrich PSTI specifically inhibited ostrich and commercial bovine trypsin with Ki values of 8.0 x 10(-9) and 2.4 x 10(-7) M, respectively, while no inhibitory effects were observed with other serine proteases.
authors.affiliation: Department of Biochemistry, University of Port Elizabeth, South Africa.
authors.forename: M
authors.initials: M
authors.lastname: Zhao
authors.forename: R J
authors.initials: RJ
authors.lastname: Naudé
authors.forename: K
authors.initials: K
authors.lastname: Muramoto
authors.forename: W
authors.initials: W
authors.lastname: Oelofsen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001717:Birds; D002268:Carboxypeptidases / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D002918:Chymotrypsin / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D007525:Isoelectric Focusing; D008969:Molecular Sequence Data; D010196:Pancreatic Elastase / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014357:Trypsin / Q000378:metabolism; D014359:Trypsin Inhibitor, Kazal Pancreatic / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D014359:Trypsin Inhibitor, Kazal Pancreatic; D002268:Carboxypeptidases; D002918:Chymotrypsin; D010196:Pancreatic Elastase; D014357:Trypsin