Abstract：
This study aimed to explore the effects of preslaughter transport stress on protein S-nitrosylation levels and S-nitrosylated proteome in post-mortem pork longissimus thoracis (LT) muscle. Pigs (N= 16) were randomly divided into 3 h transport (high-stress group, HS) and 3 h transport followed by 3 h resting treatments (low-stress control group, LS). Results demonstrated that high transport stress levels induced nitric oxide (NO) overproduction by promoting NO synthase (NOS) activity and neuronal NOS (nNOS) expression, which thereby notably increased protein S-nitrosylation levels in post-mortem muscle (p < 0.05). Proteomic analysis indicated that 133 S-nitrosylation-modified cysteines belonging to 85 proteins were significantly differential, of which 101 cysteines of 63 proteins were higher in the HS group (p < 0.05). Differential proteins including cytoskeletal and calcium-handling proteins, glycolytic enzymes, and oxidoreductase were mainly involved in the regulation of muscle contraction and energy metabolism that might together mediate meat quality development. Overall, this study provided direct evidence for changes in S-nitrosylation levels and proteome in post-mortem muscle in response to preslaughter transport stress and revealed the potential impact of S-nitrosylated proteins on meat quality.
摘要：
本研究旨在探讨婚前运输应激对死后猪胸肌（LT）肌肉中蛋白质S-亚硝基化水平和S-亚硝基化蛋白质组的影响。将猪(N=16)随机分为3h运输(高应激组，HS)和3小时运输，然后进行3小时静息治疗(低应激对照组，LS).结果表明，高转运应激水平通过促进一氧化氮合酶（NOS）活性和神经元NOS（nNOS）表达诱导一氧化氮（NO）过度产生，从而显著增加死后肌肉中的蛋白质S-亚硝基化水平(p<0.05)。蛋白质组分析表明，属于85个蛋白质的133个S-亚硝基修饰的半胱氨酸具有显著差异，其中HS组63种蛋白质中的101个半胱氨酸含量较高（p<0.05）。差异蛋白包括细胞骨架和钙处理蛋白，糖酵解酶,和氧化还原酶主要参与肌肉收缩和能量代谢的调节，这可能共同介导肉品质的发展。总的来说,这项研究提供了直接证据,证明死后肌肉中S-亚硝基化水平和蛋白质组对预测运输应激的反应,并揭示了S-亚硝基化蛋白质对肉质的潜在影响.
