Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581, Japan.
Soft Matter. 2017 Jun 7;13(22):4099-4111. doi: 10.1039/c7sm00305f.
The assembly of banana-shaped rodlike proteins on membranes and the associated membrane shape transformations are investigated by analytical theory and coarse-grained simulations. The membrane-mediated interactions between two banana-shaped inclusions are derived theoretically using a point-like formalism based on fixed anisotropic curvatures, both for zero surface tension and for finite surface tension. On a larger scale, the interactions between the assemblies of such rodlike inclusions are determined analytically. Meshless membrane simulations are performed in the presence of a large number of inclusions of two types, corresponding to the curved rods of opposite curvatures, both for flat membranes and vesicles. Rods of the same type aggregate into linear assemblies perpendicular to the rod axis, leading to membrane tubulation. However, rods of the other type, those of opposite curvature, are attracted to the lateral sides of these assemblies, and stabilize a straight bump structure that prevents tubulation. When the two types of rods have almost opposite curvatures, the bumps attract one another, forming a striped structure. Positive surface tension is found to stabilize stripe formation. The simulation results agree well with the theoretical predictions provided the point-like curvatures of the model are scaled-down to account for the effective flexibility of the simulated rods.
通过分析理论和粗粒模拟研究了膜上香蕉形棒状蛋白的组装以及相关的膜形状转变。使用基于固定各向异性曲率的点状形式主义，从理论上推导了在零表面张力和有限表面张力下两种香蕉形夹杂物之间的膜介导相互作用。在更大的尺度上，分析确定了这种棒状夹杂物组装体之间的相互作用。在存在大量两种类型的夹杂物的情况下进行无网格膜模拟，这两种类型的夹杂物分别对应于曲率相反的弯曲棒，包括在平板膜和囊泡中。相同类型的棒聚集成长度与棒轴垂直的线性组装体，导致膜管化。然而，曲率相反的其他类型的棒被吸引到这些组装体的侧面，并稳定了一个防止管化的直凸起结构。当两种类型的棒具有几乎相反的曲率时，凸起相互吸引，形成条纹结构。发现正表面张力稳定条纹形成。模拟结果与理论预测吻合良好，前提是模型的点状曲率按比例缩小以考虑模拟棒的有效柔韧性。
