Interactions between biocidal surfactants and bacterial membrane mimics: a NR study at the air-water interface

Quaternary ammonium compounds (QACs) have high inhibitory and bactericidal activity against pathogenic microbes and their toxicity has been found to depend upon their structure. However, no simple correlation has been reported. QAC surfactants are thought to interact with cell membranes through association of the positively charged quaternary nitrogen with the polar headgroups of some phospholipids. The hydrophobic tails of the surfactants subsequently interact with the hydrophobic region of the lipid bilayer. Insertion into the membrane can affect the structure and physical properties of the membrane, such as curvature, surface charge and lateral pressure, undermining the functioning of membrane proteins. The aim of this work is to determine how membrane structure changes with QAC biocide binding.

季铵盐类化合物（Quaternary ammonium compounds, QACs）对病原微生物具有强效的抑制与杀菌活性，且其毒性已被证实与其分子结构密切相关。但目前尚未有明确的简单相关性研究报道。现有研究认为，季铵盐表面活性剂可通过带正电的季铵氮与部分磷脂的极性头部基团结合，与细胞膜产生相互作用；随后，表面活性剂的疏水尾链会与脂质双层的疏水区域发生相互作用。此类表面活性剂嵌入细胞膜后，会改变膜的结构与物理特性，例如膜曲率、表面电荷及侧向压力，进而破坏膜蛋白的正常功能。本研究旨在探究季铵盐类杀菌剂与细胞膜结合后，膜结构所发生的具体变化。