title: Purification and characterization of the 20S proteasome from ostrich skeletal muscle.
abstract: The proteasome is a high molecular weight, multisubunit and multicatalytic enzyme. Here we report the purification and characterization of ostrich skeletal muscle 20S proteasome. It was purified to homogeneity with Mr 700,000, pI 6.67 and a 'ladder' of 22.2-33.5 kDa bands on SDS-PAGE. The amino acid composition and amino-terminal sequences showed large identities to those of other species. For the three major activities, pH and temperature optima ranged between 8.0-11.0 and 40-70 degrees C, and stabilities between 5-12 and up to 40-60 degrees C. Substrate specificity and inhibitory effects were also studied. Many similarities to other sources were shown, with a few significant differences.
authors.affiliation: Department of Biochemistry and Microbiology, University of Port Elizabeth, South Africa.
authors.forename: Adele R
authors.initials: AR
authors.lastname: Thomas
authors.forename: Vaughan
authors.initials: V
authors.lastname: Oosthuizen
authors.forename: Ryno J
authors.initials: RJ
authors.lastname: Naudé
authors.forename: Koji
authors.initials: K
authors.lastname: Muramoto
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D004791:Enzyme Inhibitors; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000201:enzymology*; D010447:Peptide Hydrolases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex; D020310:Struthioniformes; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D000596:Amino Acids; D004791:Enzyme Inhibitors; D010447:Peptide Hydrolases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease