Soares Thereza A, Vanni Stefano, Milano Giuseppe, Cascella Michele
Department of Fundamental Chemistry, Federal University of Pernambuco, Cidade Universitária , Recife PE 50740-560, Brazil.
Department of Biology, University of Fribourg , 1700 Fribourg, Switzerland.
J Phys Chem Lett. 2017 Aug 3;8(15):3586-3594. doi: 10.1021/acs.jpclett.7b00493. Epub 2017 Jul 20.
Cellular membranes are fundamental constituents of living organisms. Apart from defining the boundaries of the cells, they are involved in a wide range of biological functions, associated with both their structural and the dynamical properties. Biomembranes can undergo large-scale transformations when subject to specific environmental changes, including gel-liquid phase transitions, change of aggregation structure, formation of microtubules, or rupture into vesicles. All of these processes are dependent on a delicate interplay between intermolecular forces, molecular crowding, and entropy, and their understanding requires approaches that are able to capture and rationalize the details of all of the involved interactions. Molecular dynamics-based computational models at atom-level resolution are, in principle, the best way to perform such investigations. Unfortunately, the relevant spatial and time dimensionalities involved in membrane remodeling phenomena would require computational costs that are today unaffordable on a routinely basis. Such hurdles can be removed by coarse-graining the representations of the individual molecular components of the systems. This procedure anyway reduces the possibility of describing the chemical variations in the lipid mixtures composing biological membranes. New hybrid particle field multiscale approaches offer today a promising alternative to the more traditional particle-based simulations methods. By combining chemically distinguishable molecular representations with mesoscale-based computationally affordable potentials, they appear as one of the most promising ways to keep an accurate description of the chemical complexity of biological membranes and, at the same time, cover the required scales to describe remodeling events.
细胞膜是生物体的基本组成部分。除了界定细胞的边界外，它们还参与广泛的生物学功能，这与它们的结构和动力学特性都有关。生物膜在受到特定环境变化时会发生大规模转变，包括凝胶-液相转变、聚集结构变化、微管形成或破裂成囊泡。所有这些过程都依赖于分子间力、分子拥挤和熵之间的微妙相互作用，而要理解它们需要能够捕捉并合理解释所有相关相互作用细节的方法。原则上，基于分子动力学的原子级分辨率计算模型是进行此类研究的最佳方法。不幸的是，膜重塑现象所涉及的相关空间和时间维度将需要高昂的计算成本，目前按常规来说难以承受。通过对系统中各个分子成分的表示进行粗粒化，可以消除这些障碍。然而，这个过程会降低描述构成生物膜的脂质混合物中化学变化的可能性。如今，新的混合粒子场多尺度方法为更传统的基于粒子的模拟方法提供了一个有前景的替代方案。通过将化学上可区分的分子表示与基于中尺度的计算上可承受的势相结合，它们似乎是准确描述生物膜化学复杂性，同时涵盖描述重塑事件所需尺度的最有前景的方法之一。
