title: Different actions of salt and pyrophosphate on protein extraction from myofibrils reveal the mechanism controlling myosin dissociation.
abstract: BACKGROUND
  Myosin is the major functional protein in muscle foods for water retention, protein binding/gelation and fat holding/emulsification. To maximize its functionality, myosin needs to be released from thick filaments. Understanding of the mechanism controlling myosin extraction will help improve quality traits of meat products.
  
  
  RESULTS
  The data obtained show that actomyosin binding is the rate-limiting constraint for myosin release in rigor condition. Magnesium pyrophosphate (MgPPi) increased myosin extraction by weakening actomyosin interaction and maximized myosin extraction at 0.4 mol L(-1) NaCl, which was not attained at 1.0 mol L(-1) NaCl in the absence of PPi. Interaction between myosin rod domains is another critical constraint for myosin extraction, which is, rather than PPi, salt dependent. Further, our data suggest that MyBP-C (myosin binding protein C) and M-line might not be of significance in the process of NaCl-induced myosin extraction, though further study was needed.
  
  
  CONCLUSIONS
  Our study provides new insight into the mechanism that controls myosin extraction from intact sarcomere, which could be applied to maximize myosin function and to improve meat quality in practice.
authors.affiliation: Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-Products Processing, Ministry of Agriculture, Beijing, 100193, China.|College of Food Science and Technology, Hunan Agricultural University, Hunan, China.
authors.forename: Qingwu W
authors.initials: QW
authors.lastname: Shen
authors.affiliation: Delaware Valley College, Doylestown, PA, 18901, USA.
authors.forename: Darl R
authors.initials: DR
authors.lastname: Swartz
authors.affiliation: College of Food Science and Technology, Hunan Agricultural University, Hunan, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Food Science and Technology, Hunan Agricultural University, Hunan, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Food Science and Technology, Hunan Agricultural University, Hunan, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: College of Food Science and Technology, Hunan Agricultural University, Hunan, China.
authors.forename: Dequan
authors.initials: D
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002417:Cattle; D011756:Diphosphates / Q000737:chemistry*; D009124:Muscle Proteins; D009210:Myofibrils / Q000737:chemistry*; D009218:Myosins / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry*
chemical_list: D011756:Diphosphates; D009124:Muscle Proteins; D012965:Sodium Chloride; D009218:Myosins
keywords: MgPPi; meat; myosin; myosin extraction; salt; turbidity assay