Key Laboratory of Meat Processing and Quality Control, Ministry of Education China, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
Key Laboratory of Meat Processing and Quality Control, Ministry of Education China, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, China.
Food Chem. 2016 Dec 15;213:470-477. doi: 10.1016/j.foodchem.2016.06.104. Epub 2016 Jun 30.
The effect of S-nitrosylation on the autolysis and catalytic ability of μ-calpain in vitro in the presence of 50μM Ca(2 +) was investigated. μ-Calpain was incubated with different concentrations of nitric oxide donor S-nitrosoglutathione (GSNO) and subsequently reacted with purified myofibrils. Results showed that the amount of 80kDa μ-calpain subunit significantly decreased as GSNO increased from 0 to 300μM, but increases of GSNO to 300, 500 and 1000μM did not result in further inhibition. The catalytic ability of nitrosylated μ-calpain to degrade titin, nebulin, troponin-T and desmin was significantly reduced when the GSNO concentration was higher than 300μM. The cysteine residues of μ-calpain at positions 49, 351, 384, and 592 in the catalytic subunit and at 142 in small subunit were S-nitrosylated, which could be responsible for decreased μ-calpain activity. Thus, S-nitrosylation can negatively regulate the activation of μ-calpain resulting in decreased proteolytic ability on myofibrils.
研究了在 50μM Ca(2 +)存在下，S-亚硝基化对μ-钙蛋白酶自溶和催化能力的影响。μ-钙蛋白酶与不同浓度的一氧化氮供体 S-亚硝基谷胱甘肽（GSNO）孵育，然后与纯化的肌原纤维反应。结果表明，随着 GSNO 从 0 增加到 300μM，80kDaμ-钙蛋白酶亚基的量显著减少，但当 GSNO 增加到 300、500 和 1000μM 时，不会导致进一步的抑制。当 GSNO 浓度高于 300μM 时，硝基化μ-钙蛋白酶对肌联蛋白、nebulin、肌钙蛋白-T 和结蛋白的降解能力显著降低。催化亚基中位于位置 49、351、384 和 592 的半胱氨酸残基以及小亚基中的 142 位半胱氨酸残基被 S-亚硝基化，这可能是μ-钙蛋白酶活性降低的原因。因此，S-亚硝基化可以负调控μ-钙蛋白酶的激活，导致肌原纤维上的蛋白水解能力降低。
