title: Purification and partial characterization of a myofibril-bound serine protease from ostrich skeletal muscle.
abstract: A myofibril-bound serine protease (MBSP) was partially purified from ostrich (Struthio camelus) skeletal muscle. MBSP was dissociated from the myofibrillar fraction by ethylene glycol treatment at pH 8.5, followed by partial purification via Toyopearl Super Q 650 S and p-aminobenzamidine column chromatographies. Ostrich MBSP revealed a major protein band of approximately 21 kDa on SDS-PAGE, showing proteolytic activity after casein zymography. Optima pH and temperature of ostrich MBSP were 8 and 40 degrees C, respectively. Substrate specificity analysis revealed that the enzyme cleaved synthetic fluorogenic substrates at the carboxyl side of arginine residues. Kinetic parameters (K(m) and V(max) values) were calculated from Lineweaver-Burk plots. The kinetic characteristics of ostrich MBSP were compared to values obtained for commercial bovine trypsin in this study, as well as those obtained for MBSP from mouse and various fish species. The results suggest that ostrich MBSP is a tryptic-like serine protease. Ostrich MBSP exhibited low sequence identity to commercial bovine trypsin (44%), MBSP from lizard fish skeletal muscle (33%) and trypsinogen from ostrich pancreas (22%).
authors: Department of Biochemistry and Microbiology, Nelson Mandela Metropolitan University, Port Elizabeth 6031, South Africa.
authors: Shonisani C
authors: SC
authors: Tshidino
authors: Jason
authors: J
authors: Krause
authors: Abayomi P
authors: AP
authors: Adebiyi
authors: Koji
authors: K
authors: Muramoto
authors: Ryno J
authors: RJ
authors: Naudé
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D006863:Hydrogen-Ion Concentration; D051379:Mice; D018482:Muscle, Skeletal / Q000201:enzymology*; D009210:Myofibrils / Q000378:metabolism*; D051381:Rats; D016415:Sequence Alignment; D057057:Serine Proteases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D020310:Struthioniformes; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D057057:Serine Proteases