Mechanism of interaction of monovalent ions with phosphatidylcholine lipid membranes.
Mechanism of interaction of monovalent ions with phosphatidylcholine lipid membranes.
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DOI：
10.1021/jp102389k
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发表时间：
2010-07
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影响因子：
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通讯作者：
Robert Vácha;P. Jurkiewicz;M. Petrov;M. Berkowitz;R. Böckmann;Justyna Barucha-Kraszewska;M. Hof
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文献类型：
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作者：
Robert Vácha;P. Jurkiewicz;M. Petrov;M. Berkowitz;R. Böckmann;Justyna Barucha-Kraszewska;M. Hof
采用分子动力学模拟和荧光溶剂弛豫测量研究了不同阴离子与磷脂膜在盐水溶液中的相互作用。这两种方法都表明阴离子-膜相互作用随着阴离子的大小和柔软度而增加。计算表明，碘化物表现出真正的亲和力的膜，这是由于它的配对与胆碱基团和其倾向的非极性区域的酰基链，后者被增强的极化计算表明，碘化物的数密度分布扩展到甘油水平。使用Laurdan的溶剂弛豫测量证实了在甘油水平上大的软离子对膜组织的影响。相比之下，氯化物仅在表面吸引的阳离子（如钠而不是钾）存在下才在膜表面呈现峰，这表明这种行为仅仅是一种对抗效应。
Interactions of different anions with phospholipid membranes in aqueous salt solutions were investigated by molecular dynamics simulations and fluorescence solvent relaxation measurements. Both approaches indicate that the anion-membrane interaction increases with the size and softness of the anion. Calculations show that iodide exhibits a genuine affinity for the membrane, which is due to its pairing with the choline group and its propensity for the nonpolar region of the acyl chains, the latter being enhanced in polarizable calculations showing that the iodide number density profile is expanded toward the glycerol level. Solvent relaxation measurements using Laurdan confirm the influence of large soft ions on the membrane organization at the glycerol level. In contrast, chloride exhibits a peak at the membrane surface only in the presence of a surface-attracted cation, such as sodium but not potassium, suggesting that this behavior is merely a counterion effect.