Quantitative phosphoproteomic analysis among muscles of different color stability using tandem mass tag labeling

A quantitative analysis of protein phosphorylation in ovine LTL muscle with different color stability was performed in the present study using TMT labeling in combination with TiO2 phosphopeptide enrichment. A total of 3412 phosphopeptides assigned to 1070 phosphoproteins were identified by mass spectrometry, of which 243 proteins were detected to be differentially phosphorylated between muscles of different color stability. Among these differentially phosphorylated proteins, 27 phosphoproteins were identified to be key color-related proteins by informatics analysis. Proteins involved in carbohydrate metabolism, especially glycolytic enzymes, were the largest cluster of protein determined to be color-related. In addition, the phosphorylation of myoglobin at Ser133 plays a negative role in the regulation of meat color stability. In summary, this study revealed that the phosphorylation of some glycolytic enzymes and myoglobin at specific serine residues may play critical roles in the regulation of meat color stability.