Abstract:
Biomembranes and vesicles cover a wide range of length scales. Indeed, small nanovesicles have a diameter of a few tens of nanometers whereas giant vesicles can have diameters up to hundreds of micrometers. The remodeling of giant vesicles on the micron scale can be observed by light microscopy and understood by the theory of curvature elasticity, which represents a top-down approach. The theory predicts the formation of multispherical shapes as recently observed experimentally. On the nanometer scale, much insight has been obtained via coarse-grained molecular dynamics simulations of nanovesicles, which provides a bottom-up approach based on the lipid numbers assembled in the two bilayer leaflets and the resulting leaflet tensions. The remodeling processes discussed here include the shape transformations of vesicles, their morphological responses to the adhesion of condensate droplets, the instabilities of lipid bilayers and nanovesicles, as well as the topological transformations of vesicles by membrane fission and fusion. The latter processes determine the complex topology of the endoplasmic reticulum.
摘要:
生物膜和囊泡覆盖宽范围的长度尺度。的确,小的纳米囊泡的直径为几十纳米,而巨大的囊泡的直径可达数百微米。可以通过光学显微镜观察到微米尺度上的巨囊泡的重塑,并通过曲率弹性理论来理解,这代表了一种自上而下的方法。该理论预测了最近通过实验观察到的多球形形状的形成。在纳米尺度上,通过纳米囊泡的粗粒度分子动力学模拟获得了很多见解,这提供了基于在两个双层小叶中组装的脂质数目和所产生的小叶张力的自下而上的方法。这里讨论的重塑过程包括囊泡的形状转变,它们对冷凝液滴粘附的形态反应,脂质双层和纳米囊泡的不稳定性,以及通过膜裂变和融合的囊泡的拓扑转化。后一过程决定了内质网的复杂拓扑结构。