title: Temperature induced denaturation of myosin: evidence of structural alterations of myosin subfragment-1.
abstract: Denaturation of myofibrillar proteins in porcine longissimus thoracis et lumborum muscle was investigated after pre-rigor temperature incubation at 20, 30 and 40°C. At 24h myofibrils were isolated and myosin was further cleaved by chymotrypsin. High temperature pre-rigor induced release of myosin S1 (subfragment-1), less (P < 0.05) Ca(2+)-ATPase activity and structural alterations of the region of the myosin molecule that harbors S1. Surface hydrophobicity of myofibrils from the 40°C group increased (P<0.001), suggesting a temperature-induced structural rearrangement exposing hydrophobic groups on the surface of myofibrils which in turn may explain the reduced water-holding of PSE meat.
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland.
authors.forename: Jiao
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland.
authors.forename: Eero
authors.initials: E
authors.lastname: Puolanne
authors.affiliation: Department of Food and Environmental Sciences, University of Helsinki, 00014 Helsinki, Finland. Electronic address: per.ertbjerg@helsinki.fi.
authors.forename: Per
authors.initials: P
authors.lastname: Ertbjerg
mesh_terms: D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000378:metabolism; D002918:Chymotrypsin / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006358:Hot Temperature; D057927:Hydrophobic and Hydrophilic Interactions; D008460:Meat / Q000032:analysis*; D018482:Muscle, Skeletal / Q000737:chemistry*; D009210:Myofibrils / Q000737:chemistry; D015879:Myosin Subfragments / Q000737:chemistry*; D011489:Protein Denaturation; D013552:Swine
chemical_list: D015879:Myosin Subfragments; D002918:Chymotrypsin; D017301:Ca(2+) Mg(2+)-ATPase
keywords: Ca(2+) ATPase activity; Chymotrypsin; PSE; Surface hydrophobicity; Water-holding capacity