Department of Animal Science, Universidade Federal de Viçosa, Viçosa, MG, Brazil; Department of Agriculture, Nutrition, and Food Systems, University of New Hampshire, Durham, NH, USA.
Department of Animal Science, Universidade Federal do Vale do São Francisco, Petrolina, PE, Brazil.
J Proteomics. 2019 May 15;199:51-66. doi: 10.1016/j.jprot.2019.03.004. Epub 2019 Mar 9.
The objective of this study was to evaluate the differential proteome and phosphoproteome between bulls and steers during conversion of muscle to meat, as well as after 14 days of aging. Twelve male Nellore (Bos taurus indicus) calves were used, and six calves were randomly selected for surgical castration. Calves were fed the same diet and were harvested after 230 days on feed. Longissimus muscle was sampled just after stunning (0d postmortem), at deboning (1d postmortem) and after aging (14d postmortem) for differential proteome analysis. Castration upregulated (P < 0.05) the abundance of glycolytic enzymes, while the oxidative phosphorylation protein ATP5B was downregulated (P < 0.05). In addition, abundance of troponin T fast isoform (TNNT3) was upregulated by castration (P < 0.05), while the slow isoform (TNNT1) tended to be decreased (P < 0.10). The creatine kinase M-type was markedly fragmented postmortem. Abundance of phosphorylated PGM1 increased during the first 24 h postmortem and was highly correlated with carcass pH. Further, abundance of the phosphorylated myofibrillar proteins ACTA1 and MYLPF were positively correlated with sarcomere shortening. Overall, our finds demonstrated that abundance and phosphorylation of glycolytic enzymes are associated with changes in beef tenderness and intramuscular fat. SIGNIFICANCE: The design of the present study allowed to clarify the key proteins related to changes during conversion of muscle to meat such as pH decline and sarcomere shortening. In addition, the correlation between some biomarker and meat quality traits were confirmed.
本研究旨在评估公牛和阉牛在肌肉向肉转化过程中的差异蛋白质组和磷酸蛋白质组，以及在 14 天老化后的差异蛋白质组和磷酸蛋白质组。选用 12 头雄性内罗尔（Bos taurus indicus）小牛，随机选择 6 头进行手术去势。小牛喂食相同的饮食，在育肥 230 天后进行收获。宰后 0d（击晕后）、1d（去骨后）和 14d（老化后）取背最长肌进行差异蛋白质组分析。去势增加了糖酵解酶的丰度（P<0.05），而氧化磷酸化蛋白 ATP5B 则下调（P<0.05）。此外，肌钙蛋白 T 快型同工酶（TNNT3）的丰度因去势而上调（P<0.05），而慢型同工酶（TNNT1）则呈下降趋势（P<0.10）。肌酸激酶 M 型在宰后明显片段化。PGM1 的磷酸化水平在宰后 24 小时内增加，并与胴体 pH 高度相关。此外，肌动蛋白和肌球蛋白轻链磷酸化的丰度与肌节缩短呈正相关。总的来说，我们的研究结果表明，糖酵解酶的丰度和磷酸化与牛肉嫩度和肌内脂肪的变化有关。意义：本研究的设计使得能够阐明与肌肉向肉转化过程中的变化相关的关键蛋白质，如 pH 值下降和肌节缩短。此外，还确认了一些生物标志物与肉质特性之间的相关性。
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