Start Publications Physical states and thermodynamic properties of model ...
KSV NIMA

Physical states and thermodynamic properties of model gram-negative bacterial inner membranes

Year: 2019

Journal: Chem. Phys. Lipids, Volume 218, JAN, page 57–64

Authors: Hoyo, Javier; Torrent-Burgues, Juan; Tzanov, Tzanko

Organizations: Spanish National Project HybridNanoCoat, "Hybrid nanocoatings on indwelling medical devices with enhanced antibacterial and antibiofilm efficiency" [MAT2015-67648-R]

Keywords: Phosphatidylethanolamine; Phosphatidylglycerol; Cardiolipin; Lipid-lipid interactions; Bacterial mimetic membranes; Escherichia coli

Novel antimicrobial agents are focused to interact with the bacterial membrane whose lipid composition (number and position of unsaturations and lipid headgroup) is adapted according to environmental signals. The anticipation of the adapted membrane properties is of high relevance to increase the targetability of such drugs. Herein, natural lipids extracted from Escherichia coli -phosphatidylethanolamine (PE), phosphatidylglycerol (PG) and cardiolipin (CL)- are used to form biomimetic membranes constituted by several PE:lipid ratios using the Langmuir and Langmuir-Blodgett techniques. The use of these techniques and the natural myriad of each lipid structures that constitute the biological E.coli membrane establishes a simple and reproducible model to evaluate the lipid-lipid interactions. PE and PG present similar shape and size, thus establish ideal and fluid -liquid expanded (LE) state - mixtures, whereas the differences between PE and CL motivate the formation of non-ideal and fluid (LE state) mixtures. The same physical state and the minor differences in elasticity (differences in the inverse of the compressibility modulus < 15 mN.m(-1)) between both systems regardless the PE content in the (PE:lipid) mixture suggest that the changes in the lipid composition influence the membrane proteins function rather than affecting the rigidity of the bacterial membrane.