目前我国猪肉低持水力造成的滴水损失或PSE肉是影响消费者接受程度和猪肉产业经济效益的难点问题。宰后猪肉成熟期间产生大量的活性氧类及氮类物质，其中由一氧化氮合成酶催化产生的一氧化氮，会修饰蛋白质的半胱氨酸巯基导致蛋白质亚硝基化并调控蛋白质的结构与功能。前期研究结果表明一氧化氮合成酶在宰后猪肉中存在活性，调控其活性可以影响猪肉成熟过程中的生理生化变化。基于前期研究，本项目重点研究蛋白质亚硝基化对猪肉成熟过程中钙离子释放、能量代谢、钙蛋白酶1活性及肌原纤维蛋白降解的影响，使用免疫组学、蛋白质组学等技术，探讨猪肉成熟过程中关键结构蛋白质和钙蛋白酶1的亚硝基化及对其结构与功能的影响机制，阐明蛋白质亚硝基化与猪肉持水力的关系。本项目研究蛋白质亚硝基化对宰后猪肉成熟过程中持水力的影响机制，深入阐述猪肉成熟过程中肌细胞的生理生化变化，丰富和发展宰后猪肉的成熟理论，为提升我国猪肉品质提供理论依据。

High drip loss or PSE meat resulted from low water holding capacity (WHC) is the key issue affecting consumer acceptance and industry profitability of pork in China. Increased reactive oxygen and nitrogen species could accumulate in pork muscles during postmortem aging. Nitrogen species, including nitric oxide produced by the catalysis of nitric oxide synthase, could react with sulfydryl of protein cysteine to form protein nitrosylation regulating protein structure and function. Previous results have shown that nitric oxide synthase could be activated in postmortem pork and managing the level of nitric oxide synthase could influence biochemical parameters of pork during postmortem aging. Current proposal focuses on investigating the effects of protein nitrosylation on calcium release from sarcoplasmic reticulum, energy metabolism, µ-calpain proteolytic activity, and myofibrillar protein degradation during postmortem aging of porcine skeletal muscles. Employing immunomics, proteomics and other technologies to qualitatively and quantitatively analyze the effects of protein nitrosylation on protein conformation and function, especially for µ-calpain nitrosylation during postmortem aging, is of great significance to investigate the mechanism of WHC in postmortem pork. Our purpose is to explore the basic mechanism about the effect of protein nitrosylation on pork WHC which will further develop the theory of pork aging and provide knowledge to improve pork quality for pork industry.