Izozte-urtze ziklo bidezko mintz-ereduen fusioa

Abstract

Model membranes are models that somehow mimic natural biomembranes. They have being widely used for investigating many cell events as protein-lipids interaction, the architecture of proteins embedded in the membranes or the membrane dynamic. In addition, the design of model membranes can be controlled in order to form specific physicochemical composition and size structures. It is known that the fusion process is very important in the cell; the fertilization of an ovule by a sperm, the constitutive and regulated exocytosis and the biogenesis of organelles are some clear examples of this. In the present study, we try to measure the efficacy of a freeze-thawed mediated fusion process. We have used lipid membranes of different sizes (SUV, LUV and MLV) and compositions (phosphatidylcholine or different amounts containing phosphatidylcholine, sphingomyelin, phosphatidylethanolamine or cholesterol). The fusion efficacy has been measured by fluorescence resonance energy transfer (FRET) experiments. NBD-PE and Rho-PE fluorescent probes have been inserted in model membranes for this purpose. We have proved which would be the best type of model membrane, its lipid composition, the fluorescence percentage needed and the required freeze-thawed cycle number to obtain the optimal fusion results. Finally, we have studied the morphology that the lipid structures confer after the fusion process, concluding that this technique can be useful for the synthesis of the GUV called model membranes.