Details

Autor(en) / Beteiligte

• Sublimi Saponetti, Matilde
• Grimaldi, Manuela
• Scrima, Mario
• Albonetti, Cristiano
• Nori, Stefania Lucia
• Cucolo, Annamaria
• Bobba, Fabrizio
• D'Ursi, Anna Maria

Titel

Aggregation of A[beta] on DOPC and DOPC/DHA Bilayers: An Atomic Force Microscopy Study

Ist Teil von

• PloS one, 2014-12, Vol.9 (12)

Ort / Verlag

Public Library of Science

Erscheinungsjahr

2014

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• [beta] amyloid peptide plays an important role in both the manifestation and progression of Alzheimer disease. It has a tendency to aggregate, forming low-molecular weight soluble oligomers, higher-molecular weight protofibrillar oligomers and insoluble fibrils. The relative importance of these single oligomeric-polymeric species, in relation to the morbidity of the disease, is currently being debated. Here we present an Atomic Force Microscopy (AFM) study of A[beta](25-35) aggregation on hydrophobic dioleoylphosphatidylcholine (DOPC) and DOPC/docosahexaenoic 22:6 acid (DHA) lipid bilayers. A[beta](25-35) is the smallest fragment retaining the biological activity of the full-length peptide, whereas DOPC and DOPC/DHA lipid bilayers were selected as models of cell-membrane environments characterized by different fluidity. Our results provide evidence that in hydrophobic DOPC and DOPC/DHA lipid bilayers, A[beta](25-35) forms layered aggregates composed of mainly annular structures. The mutual interaction between annular structures and lipid surfaces end-results into a membrane solubilization. The presence of DHA as a membrane-fluidizing agent is essential to protect the membrane from damage caused by interactions with peptide aggregates; to reduces the bilayer defects where the delipidation process starts.