title: Myofibril-bound serine protease and its endogenous inhibitor in mouse: extraction, partial characterization and effect on myofibrils.
abstract: The protein content of muscle is determined by the relative rates of synthesis and degradation. The balance between this process determines the number of functional contractile units within each muscle cell. Myofibril-bound protease, protease M previously reported in mouse skeletal muscle could be solubilized from the myofibrillar fraction by salt and acid treatment and partially purified by Mono Q and Superose 12 chromatography. Isolated protease M activity in vitro on whole myofibrils resulted in myosin, actin, troponin T, alpha-actinin and tropomyosin degradation. Protease M is serine type and was able to hydrolyze trypsin-type synthetic substrates but not those of chymotrypsin type. In gel filtration chromatography, protease M showed Mr 120.0 kDa. The endogenous inhibitor (MHPI) is a glycoprotein (110.0 kDa) that efficiently blocks the protease M-dependent proteolysis of myofibrillar proteins in a dose-dependent way, as shown by electrophoretic analysis and synthetic substrates assays. Protease M-Inhibitor system would be implicated in myofibrillar proteins turnover.
authors.affiliation: Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Casilla de Correo 1245, 7600, Mar del Plata, Argentina. msangorr@uncoma.edu.ar
authors.forename: Marcela P
authors.initials: MP
authors.lastname: Sangorrín
authors.forename: Celina B
authors.initials: CB
authors.lastname: Martone
authors.forename: Jorge J
authors.initials: JJ
authors.lastname: Sánchez
mesh_terms: D000818:Animals; D002845:Chromatography; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006023:Glycoproteins / Q000737:chemistry; D006868:Hydrolysis; D007610:Kallikreins / Q000302:isolation & purification* / Q000378:metabolism; D051379:Mice; D009210:Myofibrils / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology; D012697:Serine Endopeptidases / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology*
chemical_list: D006023:Glycoproteins; D011480:Protease Inhibitors; D015842:Serine Proteinase Inhibitors; D011189:Potassium Chloride; D007610:Kallikreins; C491223:Prss18 protein, mouse; D012697:Serine Endopeptidases