Surface Behavior and Lipid Interaction of Alzheimer {beta}-Amyloid Peptide 1-42: a Membrane-disrupting Peptide.

AMBROGGIO EE,; KIM DH,; SEPAROVIC F,; BARROW CJ,; BARNHAM KJ,; BAGATOLLI LA.,; FIDELIO GD

Biophysical Society

Lugar: Aceptado; Año: 2005 vol. 88 p. 2706 - 2706

span lang="en" style="font-size: 12pt; font-family: "Times New Roman";">Amyloid aggregates, found in patients that suffer from Alzheimer`s disease, are composed of fibril-forming peptides in a beta-sheet conformation. One of the most abundant components in amyloid aggregates is the beta-amyloid peptide 1-42 (Abeta 1-42). Membrane alterations may proceed to cell death by either an oxidative stress mechanism, caused by the peptide and synergized by transition metal ions, or through formation of ion channels by peptide interfacial self-aggregation. Here we demonstrate that Langmuir films of Abeta 1-42, either in pure form or mixed with lipids, develop stable monomolecular arrays with a high surface stability. By using micropipette aspiration technique and confocal microscopy we show that Abeta 1-42 induces a strong membrane destabilization in giant unilamellar vesicles composed of palmitoyloleoyl-phosphatidylcholine, sphingomyelin, and cholesterol, lowering the critical tension