一氧化氮对肌原纤维蛋白的影响及其对钙蛋白酶-1 降解的敏感性。
Effect of nitric oxide on myofibrillar proteins and the susceptibility to calpain-1 proteolysis.
机构信息
Key Laboratory of Meat Processing and Quality Control, MOE; Key Laboratory of Meat Processing, MOA; Jiangsu Synergetic Innovation Center of Meat Processing and Quality Control, Nanjing Agricultural University, Nanjing 210095, PR China; College of Food Science and Engineering, Yangzhou University, Yangzhou 225127, Jiangsu, China.
Department of Animal Science, Iowa State University, Ames 50011, USA.
出版信息
Food Chem. 2019 Mar 15;276:63-70. doi: 10.1016/j.foodchem.2018.10.005. Epub 2018 Oct 3.
This study was designed to investigate the nature of modification of myofibrillar proteins by nitric oxide (NO) and the extent to which S-nitrosylation alters their susceptibility to calpain-1 proteolysis. Isolated myofibrils from porcine semimembranosus muscle were incubated with the NO donor S-nitrosoglutathione (GSNO) at 0, 20, 50, 250, 1000 µM for 30 min at 37 °C and then incubated with purified calpain-1. GSNO treatment decreased the thiol content of myofibrillar proteins and increased their intensity and amount of S-nitrosylation. GSNO caused the formation of proteins cross-linkage through intermolecular disulfide. More desmin and titin (T2, the degraded fragment of original titin) were degraded by calpain-1 when myofibrils were incubated with 1000 µM GSNO. Incubation with 250 and 1000 µM GSNO suppressed calpain-1-catalyzed cleavage of troponin-T. The data suggest that NO could change the redox state of myofibrillar proteins and subsequently affect the extent of proteolysis by calpain-1 in a protein-dependent manner.
本研究旨在探究一氧化氮（NO）对肌原纤维蛋白修饰的性质，以及 S-亚硝基化修饰在多大程度上改变了肌原纤维蛋白对钙蛋白酶-1 水解作用的敏感性。用 NO 供体 S-亚硝基谷胱甘肽（GSNO）孵育来自猪半膜肌的肌原纤维，37°C 孵育 30min，GSNO 终浓度分别为 0、20、50、250、1000µM，然后用纯化的钙蛋白酶-1 孵育。GSNO 处理降低了肌原纤维蛋白的巯基含量，增加了它们的 S-亚硝基化程度和强度。GSNO 通过分子间二硫键导致蛋白质交联的形成。当肌原纤维用 1000µM GSNO 孵育时，更多的结蛋白和肌联蛋白（T2，肌联蛋白的降解片段）被钙蛋白酶-1 降解。用 250 和 1000µM GSNO 孵育可抑制钙蛋白酶-1 催化肌钙蛋白-T 的裂解。数据表明，NO 可以改变肌原纤维蛋白的氧化还原状态，随后以蛋白依赖的方式影响钙蛋白酶-1 的水解作用程度。
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