title: The purification and characterisation of m-calpain from ostrich brain.
abstract: Calpains are intracellular cysteine proteases activated in a Ca(2+)-dependent manner. The purpose of the present study was to investigate the physico-chemical and kinetic properties of ostrich brain m-calpain. m-Calpain was purified by successive chromatographic steps on Toyopearl-Super Q 650s and Pharmacia Mono Q HR 5/5 columns. A Ca(2+) concentration of 5mM and a casein concentration of 5mg/ml were found to be necessary for optimum calpain activity. Ostrich m-calpain exhibited a M(r) of 84K using SDS-PAGE and a M(min) of 79.3K from amino acid analysis. The pH and temperature optima were found to be 7.5 and 37 degrees C, respectively. The amino acid composition of m-calpain revealed 700 residues. The N-terminal sequence of m-calpain showed sequence identity with chicken (27%), human (23%) and rabbit (18%) and Schistoma mansoni (9%).
authors.affiliation: Department of Biochemistry and Microbiology, University of Port Elizabeth, P.O. Box 1600, Port Elizabeth 6000, South Africa.
authors.forename: Noxolo
authors.initials: N
authors.lastname: Mkwetshana
authors.forename: Ryno J
authors.initials: RJ
authors.lastname: Naudé
authors.forename: Willem
authors.initials: W
authors.lastname: Oelofsen
authors.forename: Koji
authors.initials: K
authors.lastname: Muramoto
authors.forename: Takako
authors.initials: T
authors.lastname: Naganuma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002118:Calcium / Q000378:metabolism; D002154:Calpain / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D002364:Caseins / Q000378:metabolism; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D020310:Struthioniformes / Q000033:anatomy & histology; D013379:Substrate Specificity; D013696:Temperature; D013816:Thermodynamics
chemical_list: D002364:Caseins; D004791:Enzyme Inhibitors; D006454:Hemoglobins; C026018:azocasein; D002154:Calpain; C449000:m-calpain; D002118:Calcium