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P3‐051: Insertion of Aβ alters the local mechanical properties of lipid membranes
Author(s) -
Legleiter Justin,
Burke Kathleen,
Yates Elizabeth
Publication year - 2012
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2012.05.1270
Subject(s) - lipid bilayer , membrane , biophysics , chemistry , amyloid (mycology) , bilayer , cell membrane , microbiology and biotechnology , biochemistry , biology , inorganic chemistry
Background: Background:Compelling data suggest that the aggregation of the b-amyloid peptide plays a central role in AD. Importantly for AD and other amyloid diseases, lipid bilayer properties canmodulate protein conformation and exert influence on the protein’s aggregation state. Cell membranes may also be a direct target of amyloid-forming peptides, resulting in cell death. This may be due to the ability of amyloid-forming peptides to induce membrane permeabilization by altering bilayer structure or by forming unregulated pore-like structures. We performed a series of studies to dynamically assess the impact that Ab and other amyloid-forming proteins have on the mechanical properties of lipid membranes. Methods: We used an atomic-force microscopy technique to measure with nanoscale spatial resolution, the mechanical properties of brain-lipid extract bilayers exposed to Ab and other amyloid-forming proteins.Results:When exposed to monomeric Ab, regions of increased surface roughness formed in the lipid membranes. These regions were often associated with the formation of aggregates. These regions of membrane disruption were associated with a softening of the membrane locally and decreased adhesion to the AFM probe.Conclusions: These results suggest that Ab decreases the order of lipid components comprising a lipid bilayer, which could potentially lead to membrane dysfunction.