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

E.E. AMBROGGIO; D.H.KIM; F. SEPAROVIC; C.J. BARROW; K.J. BAMHAM; LUIS A. BAGATOLLI; GERARDO D. FIDELIO

BIOPHYSICAL JOURNAL

CELL PRESS

Lugar: United States; Año: 2005 vol. 88 p. 2706 - 2706

0006-3495

myloid aggregates, found in patients that suffer from Alzheimer's disease, are composed of fibril-forming peptides in a β-sheet conformation. One of the most abundant components in amyloid aggregates is the β-amyloid peptide 1?42 (Aβ 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 Aβ 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 Aβ 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. Additio