A comparative analysis of phosphoproteome in ovine muscle at early postmortem in relationship to tenderness.

BACKGROUND: Tenderness is considered to be the most important quality characteristic of meat as it is the main cause of unacceptability of meat. Post-translational modification regulates protein functions that involve in postmortem changes in muscle and meat quality formation. Specifically, phosphorylation was proved to regulate postmortem glycolytic rates and meat tenderisation. However, the relationship between protein phosphorylation and meat tenderness remains unclear. This study examined the phosphoproteomes found in ovine muscle with different degrees of tenderness over time (at 0.5 h, 4 h, and 24 h postmortem).

RESULTS: This study detected five, eight and nine phosphoprotein spots (>two-fold change, P < 0.05) at each respective time point. The different phosphoproteins found included glyceraldehyde-3-phosphate dehydrogenase, tropomyosin α-1 chain, pyruvate kinase, myosin binding protein H, glycogen phosphorylase, α-actinin-3, and an uncharacterised protein (GN, myosin-binding protein C2, MYBPC2). Most of the different phosphoproteins maintained sarcomeric functions, or were involved in glycometabolism.

CONCLUSION: Phosphorylation levels of multiple proteins that are involved in glycolysis, muscle contraction or sarcomeric structure integrity were identified in ovine muscles with different tenderness. The differential phosphorylation of these proteins explains in part the difference in meat tenderness. © 2017 Society of Chemical Industry.