Independent adsorption of monovalent cations and cationic polymers at PE/PG lipid membranes

19th International School on Condensed Matter Physics: Advances in Nanostructured Condensed Matter: Research and Innovations

Khomich, Daria A.^1 ; Nesterenko, Alexey M.^1,2 ; Kostritskii, Andrei Yu.^3 ; Kondinskaia, Diana A.^3 ; Ermakov, Yuri A.^4 ; Gurtovenko, Andrey A.^3,5

Biological Faculty, Lomonosov Moscow State University, Russia^1

Belozersky Institute of Physico-Chemical Biology MSU, Russia^2

Faculty of Physics, St. Petersburg State University, Russia^3

Frumkin Institute of Physical Chemistry and Electrochemistry, RAS, Russia^4

Institute of Macromolecular Compounds, RAS, Russia^5

关键词: Anti-microbial activity;    Anti-microbial effects;    Computational experiment;    Electric field distributions;    Electrostatic effect;    Membrane-water interface;    Phosphatidylethanolamine;    Phosphatidylglycerols;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/794/1/012010/pdf
DOI  :  10.1088/1742-6596/794/1/012010

来源: IOP

【 摘 要 】

Synthetic cationic polymers constitute a wide class of polymeric biocides. Commonly their antimicrobial effect is associated to their interaction with bacterial membranes. In the present study we analyze the interaction of various cationic polymers with model bacterial membranes comprised of a mixture of phosphatidylethanolamine (PE) and phosphatidylglycerol (PG). We describe a polymer-membrane interaction as a process of modification of the surface charge. It is well known that small monovalent inorganic cations (Na+, K+) cannot overcharge the surface of a bilayer containing anionic lipids. In contrast, polycations are able to overcharge anionic membranes and demonstrate a very large input to the electric field distribution at the membrane-water interface. We aimed here to study the electrostatic effects associated with the interaction of polycations of different types with a model lipid membrane whose composition closely resembles that of bacterial membranes (PE:PG = 1:4). Four different cationic polymers (polyvinylamine, polyallylamine, poly-L-lysine and polyethylenimine) were adsorbed at a model PE/PG bilayer in MD simulations. Adsorption of sodium cations was inspected separately for PE/PG bilayers of different composition and cation's binding parameters were determined. From computational experiments and consequent theoretical analysis we concluded that sodium adsorption at anionic binding sites does not depend on the presence of polycations. Therefore, we hypothesize that antimicrobial activity of the studied cationic polymers should depend on the ionic composition of the medium.