Preparation of a Well-Defined and Stable β-Barrel Pore-Forming Aβ42 Oligomer.

The formation of amyloid-β peptide (Aβ) oligomers at the cellular membrane is considered a crucial process that underlies neurotoxicity in Alzheimer's disease (AD). To obtain structural information on this type of oligomers, we were inspired by membrane protein approaches used to stabilize, characterize, and analyze the function of such proteins. Using these approaches, we developed conditions under which Aβ42, the Aβ variant most strongly linked to the aetiology of AD, assembles into an oligomer that inserts into lipid bilayers as a well-defined pore and adopts a specific structure with characteristics of a β-barrel arrangement. We named this oligomer β-barrel Pore-Forming Aβ42 Oligomer (βPFO). Here, we describe detailed protocols for its preparation and characterization. We expect βPFO to be useful in establishing the involvement of membrane-associated Aβ oligomers in AD.