Buscador de Personas - SIGEVA - Universidad Nacional de Córdoba

Biophysical studies of lipid-lipid and lipid protein interactions on simple model membranes (such as liposomes, planar membranes, lipid films, etc) are gaining renewed interest due to the discovery of domains in bio-memranes. Systematic studies of physical and chemical events on simple artificial lipid systems (where the lipid composition and the environmental conditions such as temperature, ionic strength, and pH can be systematically varied) are necessary to understand the basic mechanism of the lateral lipid segregation phenomenon. In this context, it is essential to extract information from simple lipid model systems, to understand the gel/fluid like lipid phase coexistence as observed in lung surfactant (LS) or the postulated ?lipid raft? formation in cellular membranes. The aim of the article is to review recent results obtained in our laboratories on LS , a lipid-protein complex which forms membranous structures at the alveolar air-water interface, and stabilizes the lungs during respiration. Using Langmuir-Blodgett films and giant unilamellar vesicles (GUV) as model system we have examined the phase behavior and ultra-structures of both systems. Experimental results obtained using different experimental techniques such as transmission electron (TEM), fluorescence (FM) and atomic force microscopy (AFM), Raman Micro-spectroscopy (RM), two-photon excitation fluorescence microscopy (TPM), time of flight-secondary ion mass spectrometry (TOF-SIMS) and with molecular dynamics simulations are
discussed. Overall, the studies suggest that the dynamic lateral heterogeneity in such membranes can be observed using biophysical methods sensitive to the lipid
conformational order, and that such nano-scale organization may exist in natural
systems.

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