Department of Animal Sciences, Colorado State University, United States of America.
Department of Animal Sciences, Colorado State University, United States of America; Department of Animal and Food Sciences, Texas Tech University, United States of America.
J Proteomics. 2020 Jun 30;222:103794. doi: 10.1016/j.jprot.2020.103794. Epub 2020 Apr 21.
Previous research has indicated that variation in the proteome profile of longissimus lumborum (LL) and psoas major (PM) post-rigor influences meat quality attributes such as tenderness and color stability during retail display. Tandem mass tag (TMT) labeling is a chemical labeling approach using isobaric mass tags for accurate mass spectrometry-based quantification and identification of biological macromolecules. The objective of this study was to use TMT labeling to examine proteome profile variation between beef LL and PM during the early postmortem period (45 min, 12 h, and 36 h). We identified a total of 629 proteins, of which 71 were differentially abundant (fold change > 1.5, P < .05) from three comparisons between the muscles (PM vs. LL at 45 min, 12 h and 36 h). These proteins were mainly involved in oxidative phosphorylation and ATP-related transport, tricarboxylic acid cycle, NADPH regeneration, fatty acid degradation, muscle contraction, calcium signaling, chaperone activity, oxygen transport, as well as degradation of the extracellular matrix. At early postmortem, more abundant antiapoptotic proteins in LL could cause high metabolic stability, enhanced autophagy, and delayed apoptosis, while overabundant metabolic enzymes and pro-apoptotic proteins in PM could accelerate the generation of reactive oxygen species and initiation of cell death. SIGNIFICANCE: Longissimus lumborum and psoas major are two highly valuable cuts in beef carcass exhibiting different quality attributes such as color and tenderness, partly due to their distinct muscle fiber proportion and metabolic property. We characterized the proteomic change of these two muscles at early postmortem using tandem mass tag labeling for the first time, which highlighted the potential relationships between metabolism, cell death, and color stability. Our work provides a new perspective on muscle-to-meat conversion, especially on the potential effect of muscle-specific cell death on meat color stability.
先前的研究表明，在宰后僵直期，腰最长肌（LL）和腰大肌（PM）的蛋白质组谱变化会影响肉品的嫩度和零售展示过程中的颜色稳定性等品质特性。串联质量标签（TMT）标记是一种使用等质量标记物进行精确质谱定量和生物大分子鉴定的化学标记方法。本研究旨在使用 TMT 标记来检测宰后早期（45min、12h 和 36h）牛肉 LL 和 PM 之间的蛋白质组谱变化。我们共鉴定到 629 种蛋白质，其中 71 种在三种肌肉（45min、12h 和 36h 时的 PM 与 LL）的比较中丰度存在差异（fold change > 1.5，P <.05）。这些蛋白质主要涉及氧化磷酸化和与 ATP 相关的运输、三羧酸循环、NADPH 再生、脂肪酸降解、肌肉收缩、钙信号、伴侣活性、氧运输以及细胞外基质的降解。在宰后早期，LL 中丰富的抗凋亡蛋白可能导致较高的代谢稳定性、增强的自噬和延迟的细胞凋亡，而 PM 中丰富的代谢酶和促凋亡蛋白可能加速活性氧的产生和细胞死亡的启动。意义：腰最长肌和腰大肌是牛胴体中两个非常有价值的部位，其肉质特性存在差异，如颜色和嫩度，部分原因是它们的肌肉纤维比例和代谢特性不同。我们首次使用串联质量标签标记法对这两种肌肉在宰后早期的蛋白质组变化进行了描述，这突出了代谢、细胞死亡和颜色稳定性之间的潜在关系。我们的工作为肌肉到肉的转化提供了新的视角，特别是肌肉特异性细胞死亡对肉色稳定性的潜在影响。
