牛肉成熟过程中细胞凋亡酶对钙激活酶的作用机制研究

项目名称： 牛肉成熟过程中细胞凋亡酶对钙激活酶的作用机制研究

项目编号： No.31301429

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 农业科学

项目作者： 黄峰

作者单位： 中国农业科学院原子能利用研究所

项目金额： 25万元

中文摘要： 成熟可以有效改善宰后肉（尤其牛、羊肉）的食用品质，但其机理尚未完全阐明。钙激活酶一直被认为是成熟过程中改善肉嫩度的主要作用者，最近的研究表明细胞凋亡酶在成熟早期也参与了部分肌原纤维蛋白的有限降解，从而改善宰后嫩度。同时，已有的结果显示成熟过程中细胞凋亡酶可能影响钙激活酶的活性调节，但目前还缺少直接的实验数据。本项目旨在借助蛋白质电泳与印迹、免疫共沉淀、荧光\紫外吸收光谱等技术，系统研究牛肉成熟过程中，凋亡诱导剂和抑制剂对钙激活酶和钙激活酶抑制蛋白（calpastatin）表达量及活性的影响；凋亡效应酶3和微摩尔钙激活酶对calpastatin的体外降解以及降解产物对钙激活酶抑制活性的变化；外源性钙离子、锌离子和EGTA对细胞凋亡酶、钙激活酶活性变化及相关凋亡因子表达的影响。以上研究可揭示出牛肉成熟过程中细胞凋亡酶对钙激活酶的作用机制，从而为进一步阐明肉的成熟机制提供新的理论依据。

中文关键词： 细胞凋亡酶；钙激活酶；成熟；钙激活酶抑制蛋白；钙离子

英文摘要： Aging is one of the most effective methods improving eating qualities of postmortem muscle, especially of beef or sheep muscle, whereas the aging mechanisn up to date is not fully elucidated. Calpains are widely considered to be a major player during postmortem aging, and recent studies revealed that caspases were involved in meat protein limited degradation and, as such, meat tenderization. Meanwhile, these results showed a possible influence of caspase on calpain activity regulation during postmortem aging, however, the speculation is not proven by direct experimental data. The objective of this study is to investigate the influences of caspase and calpain inhibitor on the expression and activites of calpain and calpastatin, the degradation profiles of calpastatin by caspase-3 or μ-calpain and change in inhibitive activity of calpastatin fragments, influences of Ca2+, Zn2+ and EGTA on the changes in caspase and calpain activity, and apoptotic factors expression during postmortem aging of beef muscle by applying of SDS-PAGE and western blotting, co-immunoprecipitation, Fluorescence\ultraviolet absorption spectrum, and so on. All the results above will contribute to demonstrate the effect of caspase on calpain system during postmortem aging of beef muscle, which is helpful to supply newly theorical evidence for

英文关键词： caspase；calpain；aging；calpastatin；calcium ions