大豆液泡膜H^+-ATPase功能与构象关系的初步研究  

Preliminary Study on Relationship Between Function and Conformation of Vacuolar H^+-ATPase of Soybean.

作　　者：董彩华[1] 王志强[1] 王延枝[1] 

机构地区：[1]武汉大学生命科学学院,武汉430072

出　　处：《生物化学与生物物理进展》2000年第6期625-628,共4页Progress In Biochemistry and Biophysics

基　　金：国家自然科学基金资助项目!(395 70 434);中国科学院生物物理研究所大分子国家重点实验室外部课题

摘　　要：大豆液泡膜V型H+ ATPase是ATPases中的一种 ,它在植物细胞的生长发育中有重要的作用 .利用竹红菌乙素 (HB)和KI这两种分别猝灭蛋白质疏水区域内源荧光和亲水区域内源荧光的荧光猝灭剂 ,在不同pH值、温度条件下对纯化的大豆液泡膜V型ATPase进行荧光猝灭实验 ,初步探讨了V型H+ ATPase的水解活性同其蛋白质折叠状态间的关系 .研究表明 ,通过比较不同 pH值、温度条件下蛋白质疏水区域和亲水区域内源荧光的荧光猝灭常数 (KSV) ,发现当环境pH值、温度偏离酶的最适 pH值和温度时 ,蛋白质的内源荧光强度降低且疏水区域和亲水区域内源荧光的荧光猝灭常数 (KSV)降低 ,说明伴随着酶的水解活性降低 ,蛋白质的折叠状态发生了变化 .我们认为蛋白质在膜内的折叠状态变化是酶失活机制的一个重要方面 。Soybean vacuolar H + ATPase is one of the ATPases and play an important role in the growing period of the plant. Hypocrellin B and KI quench the intrinsic fluorescence of outside and inside membrane domain respectively. This two quench probes have been used to quench the proteins intrinsic fluorescence under different pH and temperature. The relationship between hydrolysis activity and folding condition of V ATPase has been preliminarily studied. The K SV of outside and inside membrane domain under different pH and temperature had been compared. It shows that the intrinsic fluorescence of the protein and K SV of outside and inside membrane domain all dropped with the deviation of pH and temperature from the optimum condition and the activity of the enzyme dropped too. This illustrates that the folding condition had been changed with the dropping of the enzymes activity. The changing of the folding condition of the protein plays an important role in the inactivation mechanism.

关 键 词：V型H^+-ATPase 大豆 液泡膜 功能 构象 

分 类 号：Q55[生物学—生物化学] S565.101[农业科学—作物学]