title: Effect of high hydrostatic pressure on the conversion of alpha-connectin to beta-connectin.
abstract: The factors affecting the conversion of alpha-connectin to beta-connectin induced by pressurization of muscle were investigated over a pressure range from 100 to 400 MPa by using SDS-PAGE and immunoblot analysis. When muscles were exposed to high pressures, the conversion of alpha-connectin to beta-connectin was the most pronounced at a pressure of 300 MPa, and the appearance of 1,200-kDa peptide accompanied by conversion of alpha- to beta-connectin was observed. Connectin was relatively resistant to degradation under a pressure of 400 MPa. The degradative products of beta-connectin reactive with mAb 2D4 were not observed. The effect of high pressure on connectin in isolated myofibrils was similar to that on connectin in muscle. Addition of leupeptin and E-64 to the isolated myofibrils resulted in the prevention of the degradation of connectin at each stage of the pressurization. The ability of calcium-activated protease (calpain) to hydrolyze connectin from alpha to beta gradually declined with increasing pressure. The results indicate that calpain is responsible for the pressure-induced conversion of alpha- to beta-connectin. The rate of this conversion is probably regulated by the pressure-dependent structural change of alpha-connectin and inactivation of calpain.
authors.affiliation: Department of Biosystem Science, Graduate School of Science and Technology, University of Niigata.
authors.forename: K
authors.initials: K
authors.lastname: Kim
authors.forename: Y
authors.initials: Y
authors.lastname: Homma
authors.forename: Y
authors.initials: Y
authors.lastname: Ikeuchi
authors.forename: A
authors.initials: A
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D002118:Calcium / Q000494:pharmacology; D002154:Calpain / Q000378:metabolism; D064211:Connectin; D004533:Egtazic Acid / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D006868:Hydrolysis; D006874:Hydrostatic Pressure; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D007976:Leupeptins / Q000494:pharmacology; D008970:Molecular Weight; D009124:Muscle Proteins / Q000737:chemistry / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D011494:Protein Kinases; D011817:Rabbits
chemical_list: D000911:Antibodies, Monoclonal; D064211:Connectin; D007976:Leupeptins; D009124:Muscle Proteins; D004533:Egtazic Acid; D011494:Protein Kinases; D002154:Calpain; D007930:Leucine; C032854:leupeptin; C024974:E 64; D002118:Calcium