Quantification of in-plane flexoelectricity in lipid bilayers
Quantification of in-plane flexoelectricity in lipid bilayers
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DOI：
10.1209/0295-5075/134/68003
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发表时间：
2021-01
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影响因子：
--
通讯作者：
Nidhin Thomas;Ashutosh Agrawal
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文献类型：
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作者：
Nidhin Thomas;Ashutosh Agrawal
脂质双层表现为在电场存在下经历极化和变形的2D介电材料。这种效应以前已经建模的连续理论，假设一个垂直于膜表面取向的极化场。然而，脂质的分子结构表明，头基偶极主要与膜表面相切。在这里，我们进行原子和粗粒度的分子动力学模拟，以量化的平面极化所经历的一个平面双层和一个球形囊泡在施加电场的存在下。我们使用这些预测来计算四种不同脂质类型的有效面内挠曲电系数。我们的研究结果提供了第一个分子证明的脂质双层经历的平面内极化，并提供所需的材料参数来量化膜电场相互作用。
Lipid bilayers behave as 2D dielectric materials that undergo polarization and deformation in the presence of an electric field. This effect has been previously modeled by continuum theories which assume a polarization field oriented normal to the membrane surface. However, the molecular architecture of the lipids reveals that the headgroup dipoles are primarily oriented tangential to the membrane surface. Here, we perform atomistic and coarse-grained molecular dynamics simulations to quantify the in-plane polarization undergone by a flat bilayer and a spherical vesicle in the presence of an applied electric field. We use these predictions to compute an effective in-plane flexoelectric coefficient for four different lipid types. Our findings provide the first molecular proof of the in-plane polarization undergone by lipid bilayers and furnish the material parameter required to quantify membrane-electric field interactions.