title: Role of calpains in postmortem proteolysis in chicken muscle.
abstract: Tenderness is governed by postmortem biochemical processes, particularly proteolysis. In mammals, the calpain system is generally accepted as the main system involved in postmortem proteolysis. In poultry, the 2 calpains (mu and mu/m--a form only found in bird tissue) have greater calcium sensitivity. In this study, we quantified by zymography the changes in postmortem calpain system activity. The mu/m-calpain activity remained steady, whereas the mu-calpain activity had disappeared by 6 h after postmortem, showing an activation by calcium. Changes in the electrophoretic pattern of sarcoplasmic and myofibrillar proteins are observed in the first postmortem hours concomitantly to the decrease in mu-calpain activity. The 30-kDa protein, considered as a good marker of postmortem aging in cattle, appeared from 6 h and then steadily increased. In chicken muscle, the rapid maximum tenderness reached could be explained by a greater activation of the calpain system.
authors.affiliation: Laboratoire de Génie Chimique et Biochimique, Unité Biochimie, Polytech'Clermont-Ferrand, Université Blaise Pascal, 63174 Aubière, France.
authors.forename: H L
authors.initials: HL
authors.lastname: Lee
authors.forename: V
authors.initials: V
authors.lastname: Santé-Lhoutellier
authors.forename: S
authors.initials: S
authors.lastname: Vigouroux
authors.forename: Y
authors.initials: Y
authors.lastname: Briand
authors.forename: M
authors.initials: M
authors.lastname: Briand
mesh_terms: D000003:Abattoirs; D000818:Animals; D001835:Body Weight; D002154:Calpain / Q000502:physiology*; D002364:Caseins / Q000378:metabolism; D002645:Chickens; D004591:Electrophoresis, Polyacrylamide Gel; D009124:Muscle Proteins / Q000302:isolation & purification / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000502:physiology*; D011180:Postmortem Changes; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D013997:Time Factors
chemical_list: D002364:Caseins; D009124:Muscle Proteins; D002154:Calpain; D046988:Proteasome Endopeptidase Complex