School of Tourism and Cuisine, Industrial Engineering Center for Huaiyang Cuisine of Jiangsu Province, Yangzhou University, Yangzhou, Jiangsu 225127, 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, Jiangsu 210095, China.
J Agric Food Chem. 2024 Oct 2;72(39):21772-21780. doi: 10.1021/acs.jafc.4c06663. Epub 2024 Sep 18.
This study aimed to explore the effects of S-nitrosylation on caspase-3 modification and its subsequent effects on beef myofibril degradation in vitro. Recombinant caspase-3 was reacted with different concentrations of S-nitrosoglutathione (GSNO, nitric oxide donor) at 37 °C for 30 min and subsequently incubated with purified myofibrillar protein from bovine muscle. Results indicated that the activity of caspase-3 was significantly reduced after GSNO treatments ( < 0.05) and showed a dose-dependent inhibitory effect, which was attributed to the increased S-nitrosylation extent of caspase-3. LC-MS/MS analysis revealed that caspase-3 was S-nitrosylated at cysteine sites 116, 170, 184, 220, and 264. Moreover, the degradation of desmin and troponin-T was notably suppressed by S-nitrosylated caspase-3 ( < 0.05). To conclude, protein S-nitrosylation could modify the cysteine residues of caspase-3, which accounts for the reduced caspase-3 activity and further represses its proteolytic ability on beef myofibrillar protein.
本研究旨在探讨 S-亚硝基化对 caspase-3 修饰及其对体外牛肉肌原纤维降解的后续影响。重组 caspase-3 与不同浓度的 S-亚硝基谷胱甘肽（GSNO，一氧化氮供体）在 37°C 下反应 30 分钟，然后与来自牛肌肉的纯化肌原纤维蛋白孵育。结果表明，GSNO 处理后 caspase-3 的活性显著降低（<0.05），且呈剂量依赖性抑制作用，这归因于 caspase-3 的 S-亚硝基化程度增加。LC-MS/MS 分析表明，caspase-3 在半胱氨酸残基 116、170、184、220 和 264 处发生 S-亚硝基化。此外，S-亚硝基化的 caspase-3 显著抑制了肌球蛋白重链和肌钙蛋白-T 的降解（<0.05）。综上所述，蛋白质 S-亚硝基化可以修饰 caspase-3 的半胱氨酸残基，从而导致 caspase-3 活性降低，并进一步抑制其对牛肉肌原纤维蛋白的蛋白水解能力。
