大豆下胚轴质膜H^+-ATPase质子转运的测定  

The Determination of Proton Transport by the Plasma Membrane ATPase from Soybean Hypocotyls.

作　　者：邱全胜[1,2] 苏雪峰[1,2] 

机构地区：[1]中国科学院生物物理研究所 [2]北京师范大学生物系

出　　处：《生物化学与生物物理进展》1999年第1期79-83,共5页Progress In Biochemistry and Biophysics

摘　　要：以大豆下胚轴为材料，采用改进的匀浆介质，通过两相法制得具有质子转运活力的高纯度质膜微囊．并且发现冻融处理可以促进质膜微囊的翻转而提高荧光猝灭效率．质子载体和质子转运特性分析表明，由Ｍｇ２＋ＡＴＰ引发的荧光猝灭可以被质子载体ＣＣＣＰ恢复，并被质子通道抑制剂ＤＣＣＤ抑制；并且发现质膜Ｈ＋ＡＴＰａｓｅ专一抑制剂钒酸钠可以完全抑制荧光猝灭，同时发现荧光猝灭依赖于Ｍｇ２＋，并受Ｋ＋刺激，最适ｐＨ为６５．以上证明所测荧光猝灭是由质膜Ｈ＋ＡＴＰａｓｅ所进行的质子转运引起的．结果同时表明，维持Ｈ＋ＡＴＰａｓｅ合适构象和提高质膜微囊封闭性是制备具有Ｈ＋转运活力质膜微囊的两个关键因素．The transport competent plasma membrane vesicles were obtained using a modified homogenization medium by the two phase partitioning method from soybean hypocotyls. It was noted that freeze thaw treatment could increase the amount of inside out vesicles.Further experiments showed that the fluorescence quenching caused by adding of Mg 2+ ATP could be dissipated by the proton ionophore CCCP, and inhibited by the proton transport inhibitor DCCD; it was also found that the plasma membrane H + ATPase specific inhibitor vanadate could quench the fluorescence completely. The fluorescene quenching was Mg 2+ dependent, K + stimulated, with an optimum pH of 6 5. All the above results indicated that the fluorescence quenching was caused by the transport of protons by the plasma membrane H + ATPase. It was also suggested that the maintaining of suitable conformation of the plasma membrane H + ATPase,and the tightness of plasma membrane vescials are the two key factors for the proton transport determination.

关 键 词：大豆 下胚轴 质膜微囊 H^+-ATPASE 质子转运 

分 类 号：Q946.92[生物学—植物学] S565.101[农业科学—作物学]