Amyloid aggregates, found in patients suffering Alzheimer?s disease, are composed by fibril forming peptides in a â-sheet conformation. The beta amyloid peptide 1-42 (Aâ 1-42) is one of the most abundant components in the amyloid plaque. It is proposed that the membrane-peptide interaction is crucial to understand neuronal damage. In this work we report the high surface stability of monolayers composed by Aâ 1-42 against the work of lateral compression. It was also analyzed the effect of transition metal cations (highly concentrated in amyloid aggregates) in the surface behavior of pure Aâ 1-42 monolayers. Besides, the direct membrane-peptide interaction was analyzed by micropipette aspiration and confocal microscopy techniques when giant unilamellar vesicles (GUVs) are exposed to Aâ 1-42. These data were correlated with the results obtained from lipid-peptide mixed monolayers experiments. All the information indicates that Aâ 1-42 interacts with the membrane, penetrating and disrupting the lipid interface.
