Electric field-induced reorganization of two-component supported bilayer membranes
Electric field-induced reorganization of two-component supported bilayer membranes
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DOI：
10.1073/pnas.94.25.13390
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发表时间：
1997-12-09
影响因子：
11.1
通讯作者：
McConnel, HM
中科院分区：
文献类型：
--
作者：
Groves, JT;Boxer, SG;McConnel, HM
施加与流体双层膜的受限贴片的平面相切的电场可以产生脂质的横向浓度梯度。这种稳态行为的热力学模型开发的二元系统，并在支持的脂质双层的实验进行测试。该模型使用弗洛里近似的混合熵，并允许产生的影响时，组件有不同的分子面积。在等面积分子的特殊情况下，浓度梯度降低到费米-狄拉克分布。该理论扩展到包括膜中带电分子的影响。计算表明，支持衬底上的表面电荷基本上屏蔽膜内的静电相互作用。它还表明，浓度分布可以受到其他分子间相互作用，如聚类。通过比较含磷脂酰丝氨酸和心磷脂的膜，提供了与此预测的定性一致性。
Application of electric fields tangent to the plane of a confined patch of fluid bilayer membrane can create lateral concentration gradients of the lipids. A thermodynamic model of this steady-state behavior is developed for binary systems and tested with experiments in supported lipid bilayers. The model uses Flory's approximation for the entropy of mixing and allows for effects arising when the components have different molecular areas. In the special case of equal area molecules the concentration gradient reduces to a Fermi-Dirac distribution. The theory is extended to include effects from charged molecules in the membrane. Calculations show that surface charge on the supporting substrate substantially screens electrostatic interactions within the membrane. It also is shown that concentration profiles can be affected by other intermolecular interactions such as clustering. Qualitative agreement with this prediction is provided by comparing phosphatidylserine- and cardiolipin-containing membranes.