Chemical Probes That Selectively Recognize the Earliest Aβ Oligomers in Complex Mixtures

Alzheimer's disease (AD) is characterized by the self-assembly of amyloid beta (A beta) peptides. Recent models implicate some of the earliest A beta oligomers, such as trimers and tetramers, in disease. However, the roles of these structures remain uncertain, in part, because selective probes of their formation are not available. Toward that goal, we generated bivalent versions of the known A beta ligand, the pentapeptide KLVFF. We found that compounds containing sufficiently long linkers (similar to 19 to 24 angstrom) recognized primarily A beta trimers and tetramers, with little binding to either monomer or higher order structures. These compounds might be useful probes for early A beta oligomers.