Rationally Designed Peptoids Modulate Aggregation of Amyloid-Beta 40

Alzheimer's disease (AD) is the most common form of dementia and the sixth leading cause of death in the United States. Plaques composed of aggregated amyloid-beta protein (Aβ) accumulate between the neural cells in the brain and are associated with dementia and cellular death. Many strategies have been investigated to prevent Aβ self-assembly into disease-associated β-sheet amyloid aggregates; however, a promising therapeutic has not yet been identified. In this study, a peptoid-based mimic of the peptide KLVFF (residues 16-20 of Aβ) was tested for its ability to modulate Aβ aggregation. Peptoid JPT1 includes chiral, aromatic side chains to induce formation of a stable helical secondary structure that allows for greater interaction between the aromatic side chains and the cross β-sheet of Aβ. JPT1 was found to modulate Aβ40 aggregation, specifically decreasing lag time to β-sheet aggregate formation as well as the total number of fibrillar, β-sheet structured aggregates formed. These results suggest that peptoids may be able to limit the formation of Aβ aggregates that are associated with AD.