Ca2+-induced phase separation in phosphatidylserine, phosphatidylethanolamine and phosphatidylcholine mixed membranes.
Ca2+-induced phase separation in phosphatidylserine, phosphatidylethanolamine and phosphatidylcholine mixed membranes.
复制标题
Ca2 诱导磷脂酰丝氨酸、磷脂酰乙醇胺和磷脂酰胆碱混合膜中的相分离。
DOI：
10.1016/0005-2736(81)90073-0
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
S. Ohnishi
中科院分区：
文献类型：
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作者：
S. Tokutomi;R. Lew;S. Ohnishi
使用自旋标记的磷脂酰乙醇胺和磷脂酰胆碱研究了磷脂酰丝氨酸/磷脂酰乙醇胺和磷脂酰丝氨酸/磷脂酰乙醇胺/磷脂酰胆碱模型膜中Ca 2+ 诱导的相分离，并与磷脂酰丝氨酸/磷脂酰胆碱模型膜进行了比较 以前学过。含有磷脂酰乙醇胺的膜的性质与磷脂酰丝氨酸/磷脂酰胆碱模型膜相同。它们之间存在一些数量上的差异。含有磷脂酰乙醇胺的膜的相分离程度较高。例如，含有不同摩尔分数磷脂酰丝氨酸的磷脂酰丝氨酸/磷脂酰乙醇胺膜的相分离度在23℃时为94-100%，在40℃时为84-88%，而磷脂酰丝氨酸/磷脂酰胆碱膜的相应值为23℃时74-85%，在40℃时为84-88%。 40° C 时为 61–79%。磷脂酰丝氨酸/磷脂酰乙醇胺膜相分离所需的 Ca 2+ 浓度低于磷脂酰丝氨酸/磷脂酰胆碱膜；对于磷脂酰丝氨酸-磷脂酰乙醇胺，引起半最大相分离的浓度为1.4·10−7 M，对于磷脂酰丝氨酸/磷脂酰胆碱膜，引起半最大相分离的浓度为1.2·10−6 M。 Ca 2+ 存在下磷脂酰丝氨酸/磷脂酰乙醇胺膜的相图在性质上也与磷脂酰丝氨酸/磷脂酰胆碱相同，只是磷脂酰乙醇胺 (17° C) 和磷脂酰胆碱 (− 15° C) 的相变温度不同。这些差异的解释是，与磷脂酰胆碱相比，磷脂酰乙醇胺更倾向于形成与Ca 2+ 螯合的固相磷脂酰丝氨酸结构域分离的自己的流体相。
Ca 2+-induced phase separation in phosphatidylserine/phosphatidylethanolamine and phosphatidylserine/phosphatidylethanolamine/phosphatidylcholine model membranes was studied using spin-labeled phosphatidylethanolamine and phosphatidylcholine and compared with that in phosphatidylserine/phosphatidylcholine model membranes studied previously. The phosphatidyl-ethanolamine-containing membranes behaved in qualitatively the same way as did phosphatidylserine/phosphatidylcholine model membranes. There were some quantitative differences between them. The degree of phase separation was higher in the phosphatidylethanolamine-containing membranes. For example, the degree of phase separation in phosphatidylserine/phosphatidylethanolamine membranes containing various mole fractions of phosphatidylserine was 94–100% at 23° C and 84–88% at 40° C, while the corresponding value for phosphatidylserine/phosphatidylcholine membranes was 74–85% at 23° C and 61–79% at 40° C. Ca 2+ concentration required for the phase separation was lower for phosphatidylserine/phosphatidylethanolamine than that for phosphatidylserine/phosphatidylcholine membranes; concentration to cause a half-maximal phase separation was 1.4· 10− 7 M for phosphatidylserine-phosphatidylethanolamine and 1.2· 10− 6 M for phosphatidylserine/phosphatidylcholine membranes. The phase diagram of phosphatidylserine/phosphatidylethanolamine membranes in the presence of Ca 2+ was also qualitatively the same as that of phosphatidylserine/phosphatidylcholine except for the different phase transition temperatures of phosphatidylethanolamine (17° C) and phosphatidylcholine (− 15° C). These differences were explained in terms of a greater tendency for phosphatidylethanolamine, compared to phosphatidylcholine, to form its own fluid phase separated from the Ca 2+-chelated solid-phase phosphatidylserine domain.