Surface behavior and lipid interaction of Alzheimer beta-amyloid peptide 1-42: a membrane-disrupting peptide.

AMBROGGIO ERNESTO; KIM DENNIS; SEPAROVIC FRANCES; BARROW C.J.; BARNHAM KEVIN; BAGATOLLI LUIS A.; FIDELIO GERARDO D.

BIOPHYSICAL JOURNAL

Año: 2005 vol. 88 p. 2706 - 2706

0006-3495

p class="abstract">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 of vesicle rupture. Additionally, Abeta 1-42 triggers the indu