A high-throughput screen for compounds that inhibit aggregation of the Alzheimer's peptide

Abstract

Aggregation of the Alzheimer's peptide A beta produces toxic multimeric species that play a key role in the development of Alzheimer's disease. Compounds that inhibit this aggregation may prove useful as therapeutic agents for the prevention or treatment of Alzheimer's disease. Although aggregation inhibitors may already exist in combinatorial libraries, finding these compounds in a cost-effective high-throughput manner poses an enormous challenge. To meet this challenge, we have developed a novel high-throughput screen capable of isolating inhibitors of A beta aggregation from large libraries of inactive candidates. The screen uses a fusion of A beta 42 to GFP. In the absence of inhibition, the rapid misfolding and aggregation of A beta 42 causes the entire fusion protein to misfold, thereby preventing fluorescence. Compounds that inhibit A beta 42 aggregation enable GFP to fold into its native structure and be identified by the resulting fluorescent signal. By implementing the screen on a pilot library of triazine derivatives, we have identified several putative inhibitors. One of the selected compounds was studied in detail by a series of biochemical and biophysical methods. These studies confirmed that the selected compound inhibits aggregation of synthetic A beta 42 peptide. The fluorescence-based method described here is rapid and inexpensive and can be used to screen large libraries for inhibitors of A beta 42 aggregation and/or amyloidogenesis.