Differences in the interaction of inorganic and organic (hydrophobic) cations with phosphatidylserine membranes.
Differences in the interaction of inorganic and organic (hydrophobic) cations with phosphatidylserine membranes.
复制标题
无机和有机（疏水）阳离子与磷脂酰丝氨酸膜相互作用的差异。
DOI：
10.1016/0005-2736(75)90120-0
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发表时间：
1975
期刊：
影响因子：
--
通讯作者：
M. Barratt
中科院分区：
文献类型：
--
作者：
H. Hauser;M. Phillips;M. Barratt
磷脂酰丝氨酸分散体与“疏水性”，有机阳离子（乙酰胆碱，四乙基铵离子）的相互作用进行了比较，与简单的无机阳离子（Na+，Ca 2+）;两类离子的水合性质的差异存在于体相明显的自旋-晶格弛豫时间T1，测量。结果表明，反应产物（阳离子磷脂）的物理化学行为显着不同。随着浓度的增加，这两类离子降低磷脂酰丝氨酸表面的电位，单价无机阳离子仅比疏水阳离子稍微更有效。一旦双层的表面电荷降低到一定的阈值，无机阳离子就会引起脂质沉淀。有机阳离子的情况并非如此。这种差异可能与所得复合物的不同水化性质有关。因此，Ca 2+的结合导致水合水的置换并形成不溶于水的无水疏水钙-磷脂酰丝氨酸复合物，而有机阳离子的结合产物是水合的、亲水的和水溶性的。上述发现与NMR结果一致，NMR结果表明磷酸二酯基团参与了两类阳离子的结合，并且是主要水合壳的位点。除了影响双层膜间的相互作用，如那些参与细胞粘附和膜融合，这两类阳离子的结合可以影响双层内的分子包装。
The interaction of phosphatidylserine dispersions with “hydrophobic”, organic cations (acetylcholine, tetraethylammonium ion) is compared with that of simple inorganic cations (Na+, Ca2+); differences in the hydration properties of the two classes of ions exist in the bulk phase as evident from spin-lattice relaxation timeT1, measurements. It is shown that the reaction products (cation-phospholipid) differ markedly in their physicochemical behaviour. With increasing concentration both classes of ions reduce the ζ-potential of phosphatidylserine surfaces, the monovalent inorganic cations being only slightly more effective than the hydrophobic cations. Inorganic cations cause precipitation of the lipid once the surface charge of the bilayer is reduced to a certain threshold value. This is not the case with the organic cations. The difference is probably associated with the different hydration properties of the resulting complexes. Thus binding of Ca2+causes displacement of water of hydration and formation of an anhydrous, hydrophobic calcium-phosphatidylserine complex which is insoluble in water, whereas the product of binding of the organic cations is hydrated, hydrophilic and water soluble. The above findings are consistent with NMR results which show that the phosphodiester group is involved in the binding of both classes of cations as well as being the site of the primary hydration shell. Besides affecting interbilayer membrane interactions such as those involved in cell adhesion and membrane fusion, the binding of both classes of cation can affect the molecular packing within a bilayer.