Biological membranes have been prominent targets for coarse-grained (CG) molecular dynamics (MD) simulations. While minimal CG lipid models with three-beads per lipid and quantitative CG lipid models with >10-beads per lipid have been well studied, in between them, CG lipid models with a compatible resolution to residue-level CG protein models are much less developed. Here, we extended a previously developed three-bead lipid model into a five-bead model and parametrized it for two phospholipids, POPC and DPPC. The developed model, iSoLF, reproduced the area per lipid, hydrophobic thickness, and phase behaviors of the target phospholipid bilayer membranes at the physiological temperature. The model POPC and DPPC membranes were in liquid and gel phases, respectively, in accordance with experiments. We further examined the spontaneous formation of a membrane bilayer, the temperature dependence of physical properties, vesicle dynamics, and the POPC/DPPC two-component membrane dynamics of the CG lipid model, showing some promise. Once combined with standard Cα protein models, the iSoLF model will be a powerful tool to simulate large biological membrane systems made of lipids and proteins.

中文翻译：

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具有与Cα蛋白表示兼容的分辨率的粗粒度隐式溶剂脂质力场

生物膜已成为粗粒（CG）分子动力学（MD）模拟的主要目标。尽管已经对每个脂质三珠的最小CG脂质模型和每个脂质> 10珠的定量CG脂质模型进行了很好的研究，但在它们之间，与残留水平CG蛋白模型具有兼容分辨率的CG脂质模型却很少开发。 。在这里，我们将先前开发的三珠脂质模型扩展为五珠模型，并将其参数化为两种磷脂（POPC和DPPC）。建立的模型iSoLF再现了在生理温度下目标磷脂双层膜的每脂质面积，疏水性厚度和相行为。根据实验，模型的POPC和DPPC膜分别处于液相和凝胶相。我们进一步检查了膜双层的自发形成，CG脂质模型的物理特性，囊泡动力学和POPC / DPPC两组分膜动力学的温度依赖性，显示了一定的希望。一旦与标准Cα蛋白质模型结合，iSoLF模型将成为模拟由脂质和蛋白质组成的大型生物膜系统的强大工具。