艾氏腹水癌细胞膜质子跨膜外转运与脂质体融合:Ca^(2+)及脂质体膜脂成份的作用  

FUSION OF EHRLICH'S ASCITES CELL PLASMA MEMBRANE WITH LIPOSOMES DRIVEN BY TRANSMEMBRANE PRONTON EFFLUX:EFFECTS OF CALCIUM IONS AND LIPOSOME PHOSPHOLIPID COMPOSITION~*

作　　者：焦选茂[1] 李清焕[1] 须梅[1] 熊敬维[1] 李林江[1] 邵兰[1] 刘树森[1] 沈子威[2] 

机构地区：[1]中国科学院动物研究所生物膜与膜生物工程国家重点实验室,北京100080 [2]清华大学生命科学与技术与膜生物工程国家重点实验室,北京100084

出　　处：《动物学报》2002年第5期660-666,共7页ACTA ZOOLOGICA SINICA

基　　金：国家自然科学基金资助项目 (No .3 9770 166)~~

摘　　要：研究了Ca2 + 及脂质体膜脂成分对艾氏腹水癌细胞质膜质子跨膜转运驱动的脂质体融合中的作用。结果表明Ca2 + 促进质子跨膜转运驱动的质子跨膜转运驱动艾氏腹水癌细胞与脂质体间的融合 ,膜融合程度与膜表面电荷密度的相关曲线显示 ,在下述条件膜融合与膜表面电荷密度呈正相关 :(1)介质Ca2 + 浓度小于 6mmol/L ,脂质体磷脂组成为PE∶PC∶CL =6∶2∶2 ;(2 )介质Ca2 + 浓度为 6mmol/L ,脂质体磷脂组成为PE∶PC∶CL =6∶2∶2 ;(3)无Ca2 + 介质 ,脂质体磷脂组成为PE∶CL =8∶2 ;(4)介质Ca2 + 浓度 10mmol/L ,脂质体磷脂组成为PE∶CL=8∶2。脂质体PE/PC含量对膜融合的影响表明 ,当PE含量减少PC含量增加时 ,膜融合程度不断下降 ,提示影响膜融合的另一因素可能是生物膜结构形成“柄”融合中介体的能力。The Effects of Ca 2+ and the surface electric charge density of plasma membranes on membrane fusions driven by proton translocation were studied.It was shown that Ca 2+ could promote the membrane fusion of Ehrlichs ascites cells with liposomes driven by proton translocation across plasma membranes,but the extent of the membrane fusion was not related to the concentration of calcium.The relationship between fusion extent and surface electric charge density of membranes was shown to be closely correlated with each other under various concentrations of Ca 2+ , and liposomes composed of different lipids Ca 2+ <6 mmol/L and PE∶PC∶CL=6∶2∶2,Ca 2+ >6 mmol/L as well as PC∶PE∶CL=6∶2∶2. No correlation was seen with Ca 2+ and PE∶CL=8∶2,Ca 2+ =10 mmol/L and PE∶CL=8∶2.Besides, the effects of the ratio of PE to PC in the liposome on membrane fusion indicated that the extent of membrane fusion of Ehrlichs ascites cells with liposomes decreased with the decrement of PE and increment of PC. This implies that the ability to forme ‘stalk intermediates was one other factor to influence membrane fusion of Ehrlichs ascites cells with liposomes.

关 键 词：艾氏腹水癌细胞膜 质子跨膜外转运 脂质体融合 CA^2+ 脂质体膜脂成份 作用 膜融合 PE/PC 质膜表面电荷密度 

分 类 号：Q26[生物学—细胞生物学]