论文标题
来自脂质和离子扩散的力：通过依赖电压K+通道的优化滤波器区域探测横向膜效应
Forces from Lipids and Ionic Diffusion: Probing lateral membrane effects by an optimized filter region of voltage dependent K+ channels
论文作者
论文摘要
我们研究了细胞膜的脂质双层中聚脂肪酸（PUFA）对电压门控离子通道的选择性滤波器的传导性能的可能影响。这种电导率的任何变化都会对大脑和其他细胞中的电信号传导产生重大影响。在显微镜水平上，PUFA的浓度的变化会导致脂质双层内的压力分布发生变化，这反过来又会导致选择性滤波器的长度变化。为了估算离子通道的电导率的后果，我们对K+离子和H2O分子通过KCSA钾离子通道的选择性过滤器进行了高分辨率分子动力学（MD）模拟。我们的结果表明，选择性滤波器长度的变化略低于4％，与过滤器是更长的或较短的滤波器无关，将K+离子电流减少约50％。进一步的挤压或拉伸约10％可以有效地阻止电流。出于启发性目的，为了进一步解释结果，我们提供了MD模拟中使用的力模型的详细信息。我们最终在膜脂质组成对KV离子渗透的可能影响的背景下讨论了当前的结果。
We investigate the possible influence of poly unsaturated fatty acids (PUFAs) in the lipid bilayer of cell membranes on the conduction properties of the selectivity filter of voltage gated ion channels. Any change of this conductivity can have major consequences on electrical signalling in brain and other cells. At the microscopic level a change in the concentration of PUFAs can cause a change in the pressure distribution within the lipid bilayer, and this in turn can lead to a change in the length of the selectivity filter. In order to estimate the consequences this might entail for the ion channel's conductivity we performed high resolution molecular dynamics (MD) simulations of the passage of K+ ions and H2O molecules through the selectivity filter of the KcsA potassium ion channel. Our results show that a change in length of the selectivity filter of as little as 4%, independent of whether the filter is made longer or shorter, will reduce the K+ ion current by around 50%. And further squeezing or stretching by about 10% can effectively stop the current. For instructive purposes and to facilitate further interpretation of the results, we give details of the force models employed in the MD simulations. We finally discuss the present results in the context of possible effects of membrane lipid compositions on Kv ion permeation.
