Bacteria adapt their membrane lipid composition and metabolism in response to environmental signals, such as the temperature, resulting in different interactions with exogenous molecules, e.g. antibacterial agents. In Escherichia coli (E.coli) as a model of Gram negative strains, the antimicrobials have to cross two barriers - the outer and the inner membrane being the latter composed by ~ 77 % phosphatidylethanolamine (PE), ~ 13 % phosphatidylglycerol (PG) and ~ 10 % cardiolipin (CL) lipids. Each one of these lipid families shares the same headgroup, but contains acyl chains with varying length and degree of unsaturation. In this work, Langmuir films containing natural lipids extracted from E.coli are used to prepare model membranes at several PE:lipid ratio and human physiological temperature (37oC) to simulate the changes in membrane lipid composition that bacteria experience adapting to environment. The use of the myriad of each constituting lipid structures in E.coli results in a fluid membrane that correlates with the natural one in terms of lipid-lipid interactions. This simple, realistic and reproducible membrane model serves for analysing the lipid-lipid interactions established at 37oC. The observed athermalicity of the rigidity and physical state of the biomimetic membrane permit the anticipation of the interaction of antimicrobial agents with the bacterial cells at physiologically relevant temperatures.

Lipid interactions at human physiological temperature in Escherichia coli model inner membrane

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.