腌制过程中高钠离子强度诱导肌球蛋白ATPase失活机制研究

肌球蛋白 ATPase在肌肉腌制过程中参与调控肌节"小片化"，促使细胞骨架蛋白有限降解和肌球蛋白适度溶出，进而形成肉食品的凝胶、持水和风味特性。本项目组前期研究表明，高钠离子强度能诱导肌球蛋白ATPase失活，但具体机制目前尚不清楚。本项目拟借助蛋白质纯化与鉴定、电泳与印迹、红外光谱与圆二色谱等技术，系统研究肌肉腌制过程中肌球蛋白调节轻链、必需轻链含量、比例和Ca2+/Mg2+强度对肌球蛋白ATPase活性的作用；不同钠离子强度导致调节轻链、必需轻链降解与轻链磷酸激酶钝化与肌球蛋白ATPase失活的本质联系；钠离子改变肌球蛋白重链S1构象对肌球蛋白ATPase活性的作用。以上研究可以揭示出肌肉腌制过程中高钠离子强度诱导肌球蛋白ATPase失活的机制，最终为丰富和发展肌肉的腌制机制提供新的理论参考。

Myosin ATPase activity could catalyze cytoskeletal proteins degradation and myosin proteolysis to form "myofibril fragmentation" in the salting process, which results in the different gel property, water holding capacity and flavor of muscle food. Based on previous data, the high sodium ionic strength will inactive the myosin ATPase in the salting, but the essential mechnism is insufficient. By protein purification, mass spectrum identification, SDS-PAGE，Western blotting, Infrared chromatography and circular dichroism spectra techniques, three researches will be carried out. Firstly, the biological characteristics of essential light chain and regulatory light chain and the effect of Ca2+/Mg2+ ionic strength on myosin ATPase activity is being studied. Secondly, the degradation of essential light chain and regulatory light chain, the activity of myosin light chain kinase and myosin light chain phosphorylation under differential sodium ionic strength will be investigated. Thirdly, the mechanism of myosin ATPase inactivation influenced by myosin conformation is performed. Though the previous experiments, the inactivation mechanism of myosin ATPase induced by high sodium ionic strength will be fully explained, which will supply new theory to the muscle salting process..