抗菌肽Arg-Ser-Ser与POPG膜相互作用的动力学模拟分析

摘要：目的 进一步验证RSS的抗菌机理。方法 本文通过分子动力学模拟系统探讨了肽膜质心距离、肽膜间的最小距 离、肽膜之间形成的氢键数量以及脂膜的均方根偏差和脂膜有序参数这几个物理量的变化情况来反映RSS对细菌细胞膜的作用 机理。结果 抗菌肽最先与脂膜接触，由于静电作用力，带正电荷的N末端残基与带负电的脂膜相结合，最终RSS呈现倾斜的 状态。随着RSS浓度的增加，增加了RSS与脂膜之间的相互作用，使得氢键数目增加，导致了脂膜的不均匀性，增强了脂膜磷 脂分子的无序波动，这可能会使得细菌内组分泄露，直至死亡。结论 RSS可以通过作用于细胞膜，从而有效抑制铜绿假单胞 菌的生长。该研究利用分子动力学模拟为RSS的抗菌机理提供一定的基础数据和理论支持。

Molecular dynamics simulation analysis of interaction between Arg-Ser-Ser and POPG membrane

Abstract Objective To verify the antibacterial mechanism of RSS. Methods In this study, the changes in the distance of mass centers, minimum distance and the number of hydrogen bonds between RSS and POPG bilayer, mean square displacement and order parameters on POPG bilayer were analyzed using molecular dynamic (MD) simulation method to reflect the action mechanism of RSS on bacterial cell membrane. Results The results show that the peptide firstly contacts with the membrane. Due to electrostatic forces, the positively charged N-terminal residue strongly interacts with the negatively charged lipid membrane, resulting in a skewed RSS. With the increase of RSS concentration, the interaction between RSS and lipid membrane and the number of hydrogen bonds increases, which makes the phospholipid molecules on the surface of the cell membrane present a state of dispersion and disorder, leading to the leakage of the intracellular components of bacteria and even death. Conclusion In conclusion, RSS can effectively inhibit the growth of P. aeruginosa by acting on cell membrane. This study provides some basic data and theoretical support for antibacterial mechanism of RSS by molecular dynamics simulation analysis.