title: Cleavage specificities of aspartic proteinases toward oxidized insulin B chain at different pH values.
abstract: The cleavage specificities of typical aspartic proteinases: pepsin A, gastricsin, cathepsin D and rhizopuspepsin, were examined at different pH values with oxidized insulin B chain as a substrate with special attention to the specificities near neutral pH. Significant differences in relative specificity for scissile bonds were observed between pH 2.0 and 5.5-6.5, which may be partly related with the changes in dissociation states of the His and Glu residues in the substrate and the ionizable residues in the active site of each enzyme.
authors.affiliation: School of Life Science, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo, 192-0392, Japan.
authors.forename: Senarath B P
authors.initials: SB
authors.lastname: Athaudaa
authors.forename: Kenji
authors.initials: K
authors.lastname: Takahashia
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000737:chemistry / Q000378:metabolism*; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007328:Insulin / Q000378:metabolism*; D008969:Molecular Sequence Data; D013379:Substrate Specificity
chemical_list: D007328:Insulin; D016282:Aspartic Acid Endopeptidases