Curvature-undulation coupling as a basis for curvature sensing and generation in bilayer membranes
Curvature-undulation coupling as a basis for curvature sensing and generation in bilayer membranes
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DOI：
10.1073/pnas.1605259113
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发表时间：
2016-08-30
影响因子：
11.1
通讯作者：
Radhakrishnan, Ravi
中科院分区：
文献类型：
--
作者：
Bradley, Ryan P.;Radhakrishnan, Ravi
我们提出了粗粒度的分子动力学模拟的epsin N-末端同源结构域与脂质双层相互作用，并证明了一个严格的理论形式主义和分析方法计算在不同浓度的蛋白质在稀限的诱导曲率场。我们的理论是基于在曲率场的存在下的高度-高度起伏谱的描述。我们制定了一个目标函数，比较从模拟获得的波动谱的理论。我们恢复的曲率场参数，即使在蛋白质诱导的膜曲率是相同的顺序，由于热波动的幅度的限制，通过最小化的目标函数。曲率和起伏之间的耦合导致了重要的预测：（i）在稀释条件下，蛋白质可以在远大于其尺寸的距离处感知自发曲率的位点;（ii）随着蛋白质密度的增加，耦合聚焦并稳定曲率场到蛋白质的位点;以及（iii）蛋白质定位的映射和稳定曲率的诱导是可以通过Hill函数描述的协作过程。
We present coarse-grained molecular dynamics simulations of the epsin N-terminal homology domain interacting with a lipid bilayer and demonstrate a rigorous theoretical formalism and analysis method for computing the induced curvature field in varying concentrations of the protein in the dilute limit. Our theory is based on the description of the height-height undulation spectrum in the presence of a curvature field. We formulated an objective function to compare the acquired undulation spectrum from the simulations to that of the theory. We recover the curvature field parameters by minimizing the objective function even in the limit where the protein-induced membrane curvature is of the same order as the amplitude due to thermal undulations. The coupling between curvature and undulations leads to significant predictions: (i) Under dilute conditions, the proteins can sense a site of spontaneous curvature at distances much larger than their size; (ii) as the density of proteins increases the coupling focuses and stabilizes the curvature field to the site of the proteins; and (iii) the mapping of the protein localization and the induction of a stable curvature is a cooperative process that can be described through a Hill function.