Lipid Bilayer Reorganization by Amyloid-beta Oligomers

Project Summary

How do misfolded peptide aggregates interact with lipid membranes? More specifically, how do amyloid-Beta (ABeta) oligomers affect neuronal cell membranes? ABeta is a 40 or 42 amino acids long fragment of the amyloid precursor protein APP which has long been implicated t play a crucial role in the etiology of Alzheimer's Disease (AD) . A progressively larger body of evidence has recently accrued that the toxic form of ABeta is a soluble aggregation of the protein, and that such ABeta 'oligomers' interact strongly with cell membranes. Using novel synthetic membrane models, we have developed suitable experimental tools to address the questions posed above in structural, functional and dynamic terms on the molecular level. In this ADR Pilot Grant award, we will to study the response of such synthetic membranes to ABeta oligomers as a function of membrane composition. We are particularly interested in membrane compositions that mimic the lipid characteristics of neuronal cell membranes in order to investigate whether ABeta oligomers interact with such membranes strongly. The proposed research may have implications for a molecular-scale understanding of the damage that ABeta oligomers inflict on neuronal membranes and may in the long run also help to devise synthetic strategies for the early detection of ABeta oligomers in patient samples. The specific aims of this research are to investigate the interaction of ABeta oligomers with synthetic lipid membranes of well-defined compositions and to correlate the structural, functional and dynamic response of such membranes to ABeta with the aggregation state of the peptide.