Binding of alkaline-earth metal cations and some anions to phosphatidylcholine liposomes.
Binding of alkaline-earth metal cations and some anions to phosphatidylcholine liposomes.
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DOI：
10.1111/j.1432-1033.1987.tb13715.x
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发表时间：
1987-12
期刊：
影响因子：
--
通讯作者：
S. Tatulian
中科院分区：
文献类型：
--
作者：
S. Tatulian
本文测定了由卵磷脂（PtdCho）、二肉豆蔻酰甘油磷酸胆碱（Myr_2Gro-P-Cho）和二棕榈酰甘油磷酸胆碱（Pam_2-Gro-P-Cho）组成的多层脂质体的电泳迁移率对几种阳离子和阴离子浓度的依赖性。在Gouy-Stern理论的框架下处理结果，确定了结合位点的表面密度和离子与脂质体膜的内在结合常数。在脂质从凝胶相到液晶相的热致转变时，已经检测到Myr 2Gro-P-Cho和Pam 2Gro-P-Cho脂质体的正表面电位的急剧降低。在Pam 2Gro-P-Cho的情况下，在预转变温度以及约50 ° C下揭示了脂质体表面电位的类似改变。一个模型建议离子结合到PtdCho膜，根据该离子结合位点被认为是点缺陷（空位）的脂质头基的结构中排列在一个三角晶格。
The dependence of electrophoretic mobility of multilamellar liposomes composed of egg phosphatidylcholine (PtdCho), dimyristoyl-glycerophosphocholine (Myr2Gro-P-Cho) and dipalmitoyl-glycerophosphocholine (Pam2-Gro-P-Cho) on the concentration of several cations and anions has been measured. Values of surface densities of binding sites and intrinsic binding constants of ions to liposome membranes were determined by processing the results in the framework of Gouy-Stern theory. Sharp reductions in the positive surface potential of Myr2Gro-P-Cho and Pam2Gro-P-Cho liposomes have been detected at the thermotropic transition of the lipids from the gel to liquid-crystalline phase. Similar alterations of liposome surface potential were revealed at the temperature of pretransition, as well as at about 50 degrees C, in the case of Pam2Gro-P-Cho. A model is suggested for ion binding to PtdCho membranes, according to which the ion-binding sites are considered as point defects (vacancies) in the structure of lipid head-groups arranged over a trigonal lattice.