Transmembrane Ca^(2+) gradient-mediated phosphatidylcholine modulating sarcoplasmic reticulum Ca^(2+)-ATPase

作     者：屠亚平 徐红 杨福愉 

作者机构：State Key Laboratory of Biomacromolecules Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China 

出 版 物：《Science China Chemistry》 (中国科学（化学英文版）)

年 卷 期：1995年第38卷第6期

页      面：713-721页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070303[理学-有机化学] 0703[理学-化学] 

基　　金：Project supported by the National Natural Science Foundation of China and the fund from the Chinese Academy of Sciences 

主　　题：phosphatidylcholine transmembrane Ca2+ gradient sarcoplasmic reticulum Ca2+-ATPase. 

摘      要：The sarcoplasmic reticulum (SR) Ca2+-ATPase was purified and reconstituted into the sealed phospholipids vesicles with or without transmembrane Ca2+ gradient. The role ofphospholipids, especially phosphatidylcholine(PC), in the modulation of Ca2+-ATPase by transmembrane Ca2+ gradient was investigated. The results are as follows, (i) Incubated with phospholiplds, the enzyme activity of the delipidated Ca2+-ATPase is inhibited by Ca2+ and the highest inhibition is observed in the presence of PC. (ii) When there exists a transmembrane Ca2+ gradient (higher Ca2+ concentration inside vesicles, 1 000μmol/L:50μmol/L, similar to the physiological condition), the inhibition of Ca2+-ATPase by transmembrane Ca2+ gradient can be only observed in the vesicles containing PC:PE, but not in those containing PS:PE or PG:PE. The highest inhibition is obtained at a 50.50 molar ratio of PC:PE. (iii) By comparing the effects of PC differing in acyl chains, higher inhibition of Ca2+-ATPase is observed in vesicles containing DPPC:PE and DOPC:PE, while no inhibition in DMPC:PE vesicles (iv) If the transmembrane Ca2+ gradient is in the inverse direction, the enzyme activity of Ca2+-ATPase is inhibited whenever reconstituted with acidic or neutral phospholipids.