糖基化修饰调控肌球蛋白热诱导凝胶形成的分子机制

肌球蛋白热诱导凝胶是凝胶类肉制品品质的关键，其特性直接决定肉制品的质构和持水性。申请人研究发现，适当的糖基化修饰可以显著促进肌球蛋白热诱导凝胶形成进而改善肉制品品质，但具体机制尚不清楚。本项目以差异显著的糖基化肌球蛋白为研究对象，构建离体反应模型，鉴定糖基化肌球蛋白的修饰位点，解析不同糖基化修饰水平条件下肌球蛋白受热解离过程中氨基酸侧链疏水基团、活性巯基等功能基团的暴露特性；调节肌球蛋白糖基化修饰水平，阐明肌球蛋白热聚集过程中分子间静电作用、疏水相互作用、二硫键及氢键的动态演变规律，明确主要相互作用力与肌球蛋白热诱导凝胶特性的内在关联；采用分子对接和模拟手段，探明糖基化肌球蛋白解离和热聚集过程中头部、尾部构象的演变过程，构建离体模型，验证糖基化修饰对肌球蛋白热诱导凝胶关键结构域的影响，揭示糖基化修饰调控肌球蛋白热诱导凝胶形成的分子机制，为靶向提升凝胶类肉制品品质奠定科学基础。

As a key element to the quality of gel-type meat products, heat-induced gel of myosin could directly determine the texture and water holding capacity of meat products. The applicant found that appropriate glycation modification could significantly promote heat-induced gel formation of myosin and consequently improve meat quality. However, the formation mechanism is unclear. In this study, different glycation levels of myosin will be selected as the research object, and it will be studied in vitro not only to identify glycation modification sites but also to analyse the exposure characteristics of hydrophobic groups, active sulfhydryl groups, and other functional groups of amino acid side chain during thermal dissociation. Moreover, we will regulate the glycation level of myosin and elucidate the dynamic evolution of intermolecular electrostatic interactions, hydrophobic interactions, disulfide bonds, and hydrogen bonds during myosin thermal aggregation. The result will clarify the intrinsic correlation between main interaction forces and heat-induced gel properties of myosin. Furthermore, molecular docking and simulation will be used to detect the conformational change of the head and tail of myosin during dissociation and thermal aggregation of glycated myosin. The key structure domains of heat-induced gel of glycated myosin will be confirmed. The molecular mechanism of heat-induced gel formation of myosin regulated by glycation modification will be revealed. All of the results will provide a scientific foundation for improving the quality of gel-type meat products.