Interaction of Dextran Sulfate with cationic and anionic membranes

FE LURGO, CI CÁMARA, ML FANANI, E AMBROGGIO, N. WILKE

Tucumán

Congreso; Reunión conjunta: III LAFeBS, IX Iberoamerican Congress of Biophysics, XLV SAB.; 2016

Polysaccharides have been associated with various biological functionsthrough their binding to membranes, but their specific role is still underdebate. The aim of this work was to study the interaction of cationicand anionic lipids with Dextran Sulphate, an anionic polymer, and theinfluence of this interaction on the membrane mechanical stability. Theinteraction was studied by determinations of the zeta potential usingLUVs and of the interface reflectivity with Brewster Angle Microscopyusing Langmuir monolayers. The membrane stability was studied inLUVs by following the response upon osmotic shocks or the addition ofdetergent. The evolution of the vesicles was followed with neferometry,Dynamic Light Scattering and by the fluorescence increment due to therelease of carboxyfluorescein. In addition, GUVs were observed in the absence and in the presence of the polymer and the shape fluctuationswere analyzed.The results indicate that the polymer interacts with the cationic membrane,and also with the anionic membrane but in this case, in a Ca2+-dependent manner. The influence of the polymer on the stability upondetergent and osmotic shocks, as well as on the shape fluctuations dependson the membrane composition.