title: Purification and characterization of calpastatin from grass prawn muscle (Penaeus monodon).
abstract: Calpastatin, a specific calpain inhibitor was purified to electrophoretical homogeneity from grass prawn (Penaeus monodon) muscle by 100 degrees C heat-treatment, DEAE-Sephacel, and Q-Sepharose chromatographs. No significant change in the inhibitory activity of crude calpastatin was observed even after 20 min incubation at 100 degrees C, pH 7.0. The purified prawn calpastatin had a molecular weight (M(r)) of 80 and 88.7 kDa determined by SDS-PAGE and Sephacryl S-200 HR gel filtration, respectively. According to the active site titration, the purified calpastatin revealed four beef mu-calpain and two beef m-calpain binding domains, respectively. It was stable during 1 h of incubation at 30 degrees C under pH 4.5-10.0 and shown to be a highly specific inhibitor for calpain.
authors.affiliation: Department of Food Science, National Taiwan Ocean University, Keelung, Taiwan 202, ROC. sjiang@mail.ntou.edu.tw
authors.forename: S T
authors.initials: ST
authors.lastname: Jiang
authors.forename: J
authors.initials: J
authors.lastname: Wu
authors.forename: M J
authors.initials: MJ
authors.lastname: Su
authors.forename: S S
authors.initials: SS
authors.lastname: Tzeng
mesh_terms: D000818:Animals; D001665:Binding Sites; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000302:isolation & purification*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009132:Muscles / Q000737:chemistry*; D033561:Penaeidae / Q000737:chemistry*
chemical_list: D002135:Calcium-Binding Proteins; C033668:calpastatin