当前位置: X-MOL 学术J. Phys. Chem. B › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Accurate Estimation of Membrane Capacitance from Atomistic Molecular Dynamics Simulations of Zwitterionic Lipid Bilayers.
The Journal of Physical Chemistry B ( IF 2.8 ) Pub Date : 2020-08-28 , DOI: 10.1021/acs.jpcb.0c03145
Vikram Reddy Ardham 1 , Valeria Zoni 1 , Sylvain Adamowicz 1 , Pablo Campomanes 1 , Stefano Vanni 1
Affiliation  

Lipid membranes are indispensable to life, and they regulate countless cellular processes. To investigate the properties of membranes under controlled conditions, numerous reconstitution methods have been developed over the last few decades. Several of these methods result in the formation of lipid bilayers containing residual hydrophobic molecules between the two monolayers. These contaminants might alter membrane properties, including bilayer thickness, that is usually inferred from measurements of membrane capacitance assuming a simple slab model. However, recent measurements on solvent-free bilayers raised significant questions on the reliability of this approach. To reconcile the observed discrepancies, we developed a protocol to predict membrane capacitance from the dielectric profile of lipid bilayers computed from molecular dynamics simulations. Our methodology shows excellent agreement against available data on solvent-free noncharged bilayers, and it confirms that the uniform slab model is a reliable approximation from which to infer membrane capacitance. We find that the effective electrical thickness contributing to membrane capacitance is different from the hydrophobic thickness inferred from X-ray scattering form factors. We apply our model to estimate the concentration of residual solvent in reconstituted systems, and we propose that our protocol could be used to infer membrane properties in the presence of hydrophobic solvents.

中文翻译:

从两性离子脂质双层的原子分子动力学模拟准确估计膜电容。

脂质膜是生命必不可少的,它们调节着无数的细胞过程。为了研究在受控条件下的膜的性质,在过去的几十年中已经开发了许多重构方法。这些方法中的几种导致形成在两个单层之间包含残余疏水分子的脂质双层。这些污染物可能会改变膜的性能,包括双层厚度,这通常是通过假设简单的平板模型从膜电容的测量得出的。但是,最近对无溶剂双层膜的测量结果对这种方法的可靠性提出了重大质疑。为了调和观察到的差异,我们开发了一种协议,可以根据分子动力学模拟计算出的脂质双层的介电谱来预测膜电容。我们的方法论与不含溶剂的不带电双层的现有数据显示出极好的一致性,并且证实了均匀平板模型是推断膜电容的可靠近似值。我们发现,有助于膜电容的有效电厚度不同于从X射线散射形状因子推断的疏水厚度。我们应用我们的模型来估计重构系统中残留溶剂的浓度,并且我们建议可以将我们的方案用于在存在疏水溶剂的情况下推断膜的性质。并且证实了均匀平板模型是推断膜电容的可靠近似。我们发现,有助于膜电容的有效电厚度不同于从X射线散射形状因子推断的疏水厚度。我们应用我们的模型来估计重构系统中残留溶剂的浓度,并且我们建议可以将我们的方案用于在存在疏水溶剂的情况下推断膜的性质。并且证实了均匀平板模型是推断膜电容的可靠近似。我们发现,导致膜电容的有效电厚度不同于从X射线散射形状因子推断的疏水厚度。我们应用我们的模型来估计重构系统中残留溶剂的浓度,并且我们建议可以将我们的方案用于在存在疏水溶剂的情况下推断膜性能。
更新日期:2020-09-24
down
wechat
bug