RESUMO
ß-amyloid (Aß) is a hydrophobic peptide with an intrinsic tendency to self-assemble into aggregates. Among various aggregates, Aß oligomer is widely accepted as the leading neurotoxin in the progress of Alzheimer's disease (AD) and is considered to be the crucial event in the pathogenesis of AD. Therefore, Aß oligomer inhibitors might prevent neurodegeneration and have the potential to be developed as disease-modifying treatments of AD. However, different formation protocols of Aß oligomer might lead to oligomers with different characteristics. Moreover, there are not many methods to effectively screen Aß1-42 oligomer inhibitors. An A11 antibody can react with a subset of toxic Aß1-42 oligomer with anti-parallel ß-sheet structures. In this protocol, we describe how to prepare an A11-positive Aß1-42 oligomer-rich sample from a synthetic Aß1-42 peptide in vitro and to evaluate relative amounts of A11-positive Aß1-42 oligomer in samples by a dot blotting analysis using A11 and Aß1-42-specific 6E10 antibodies. Using this protocol, inhibitors of A11-positive Aß1-42 oligomer can also be screened from semi-quantitative experimental results.
