Gel‐based phosphoproteomics analysis of sarcoplasmic proteins in postmortem porcine muscle with pH decline rate and time differences

Abstract

Meat quality development is highly influenced by the pH decline caused by the postmortem (PM) glycolysis. Protein phosphorylation is an important mechanism in regulating the activity of glycometabolic enzymes. Here, a gel-based phosphoproteomic study was performed to analyze the protein phosphorylation in sarcoplasmic proteins from three groups of pigs with different pH decline rates from PM 1 to 24 h. Globally, the fast pH decline group had the highest phosphorylation level at PM 1 h, but lowest at 24 h, whereas the slow pH decline group showed the reverse case. The same pattern was also observed in most individual bands in 1-DE. The protein phosphorylation levels of 12 bands were significantly affected by the synergy effects of pH and time (p<0.05). Protein identification revealed that most of the phosphoproteins were glycometabolism-related enzymes, and the others were involved in stress response, phosphocreatine metabolism, and other functions. The phosphorylation of pyruvate kinase and triosephosphate isomerase-1 showed to be related to PM muscle pH decline rate. Our work sheds light on the potential role of protein phosphorylation on regulating meat quality development.

Tackling proteome changes in the longissimus thoracis bovine muscle in response to pre-slaughter stress

“…In 514 particular, phosphoproteomic analysis of sarcoplasmic proteins in post-mortem porcine 515 muscle revealed high levels of phosphorylation in stress response proteins [55]. We 516 found that two phosphorylated fast skeletal myosin light chain 2 isoforms (i.e.…”

“…It should also be highlighted that increased levels of pH in 527 DFD compared to normal meat may run against the activity of acid phosphatases [55]. 528…”

In-depth characterisation of the lamb meat proteome from longissimus lumborum

“…Examples include post-mortem protein degradation [77,78], increased level of oxidation [79,80] and phosphorylation [36,67] of specific muscle proteins during post-mortem storage. Therefore, whether post-mortem changes have a role in reducing the abundance and/or confound the identification of these proteins may require further study.…”

“…Protein maps or catalogues of the skeletal muscle have been generated for several vertebrate species such as human [30,31], cattle [32][33][34], pigs [35,36], rabbits [37,38], mice [39][40][41][42] and cod [43]. In this study, we aimed to characterise the proteome of lamb meat derived from longissimus lumborum muscle.…”

Regulation of post-mortem glycolysis in ruminant muscle

“…These data strongly argue that activated AMPK, possibly through modulation of phosphofructokinase 1 and 2 activities-the latter catalyses the production of fructose 2,6-bisphosphate and increases PFK1 activity-may impact post-mortem metabolism and subsequent meat quality development. Others supported this notion by showing that global phosphorylation patterns, possibly through AMPKmediated events or otherwise, occur post-mortem and may alter the transformation of muscle to meat (Huang et al 2011;Lametsch et al 2011).…”