State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China.
College of Life Sciences, Jilin University, Changchun 130012, China.
Phys Chem Chem Phys. 2020 Jul 22;22(28):15976-15985. doi: 10.1039/d0cp01006e.
Polyethylene oxide (PEO) and poly(propylene oxide) (PPO), especially their tri-block copolymers PEO-PPO-PEO (poloxamers), have a broad range of applications in biotechnology and medical science. Understanding their specific interactions with biomembranes is the key to unveil the unique features of poloxamers either as membrane-healing or membrane pore-forming agents. Based on the coarse-graining convention of the MARTINI force field and the big multipole water (BMW) model, which has a three charged site topology and can reproduce the correct dipole moment of four-water clusters, we generated coarse-grained (CG) models with analytical and numerical potentials for PEO and PPO homopolymers and poloxamers in dilute solution. The effective bonded interaction potentials between CG beads were determined from the probability distributions of bond lengths, angles and dihedrals that are determined from atomistic simulations. The nonbonded interaction parameters were fine-tuned to reproduce the conformational properties of atomistic PEO and PPO homopolymers and poloxamers via extensive CG simulations of PEO and PPO homopolymers and poloxamers in a BMW water environment. The reported CG models provide a promising framework for a comprehensive understanding of the microstructural, conformational, and dynamic properties of poloxamers and their delicate interactions with other species in an explicit water environment.
聚环氧乙烷（PEO）和聚（丙烯氧化物）（PPO），特别是它们的三嵌段共聚物 PEO-PPO-PEO（泊洛沙姆），在生物技术和医学科学中有广泛的应用。了解它们与生物膜的特定相互作用是揭示泊洛沙姆作为膜修复或膜孔形成剂的独特特征的关键。基于 MARTINI 力场的粗粒化约定和具有三个带电位点拓扑结构并能重现四水分子簇正确偶极矩的大多极水（BMW）模型，我们在稀溶液中生成了用于 PEO 和 PPO 均聚物和泊洛沙姆的分析和数值势的粗粒化（CG）模型。CG 珠之间的有效键相互作用势从键长、角度和二面角的概率分布确定，这些分布是从原子模拟确定的。非键相互作用参数经过微调，以通过在 BMW 水环境中对 PEO 和 PPO 均聚物和泊洛沙姆进行广泛的 CG 模拟，再现原子 PEO 和 PPO 均聚物和泊洛沙姆的构象性质。所报道的 CG 模型为全面了解泊洛沙姆的微观结构、构象和动态性质及其与明水环境中其他物质的精细相互作用提供了一个有前途的框架。
