CONICET | Buscador de Institutos y Recursos Humanos

In most studies of peptide-lipid membrane interaction, the main protagonist of theinteraction is the peptide. This is related to the classical image of a cell as acompartmentalized system in which the membrane is a selective barrier of thecontainment of cellular material. However, the enormous variety of lipids,associated with the multiple states of aggregation or microdomains that can beformed in them, makes this a complex surface, which deserves attention when thesystem variables are adjusted.In this case, we present two systems of interaction of peptides with lipidmembranes, where the lipid composition and the phase state of the membranesubstantially modify the quality and the mechanism of interaction.In one of the cases, we have studied, from a molecular approach, the interactionof two cationic antimicrobial peptides with membranes of different composition.The variations in the lipid composition studied are related to the differences in twobacterial strains that present a different susceptibility to the action of thementioned peptides. This structural difference allowed us to evaluate advancedinstances of the interaction, in which the difference of lipids was fundamental todemonstrate the presence or absence of destabilizing structures of the membrane,which in this case is the formation of pores.In the second case, a highly investigated peptide, such as melittin, was studied inits interaction with the lipid membrane model of eukaryotic cells, to evaluate froma molecular approach, the beginnings and the possibilities of interaction with thistype of membranes. In this particular case, the phase state of the membrane wasfundamental, when analyzing the interaction. The studies in the ripple phase ofthe membrane, allow us to evaluate the first steps of the interaction of melittinwith this type of membranes.Both cases, through molecular dynamics simulations, validated with experimentaldata, allow us to reach a molecular un