Effects of Rationally Designed Peptoids on Amyloid-β 1-40

Alzheimer’s disease (AD) is the most prevalent misfolding protein disease worldwide and is expected to cost society well over one trillion dollars in the next decade. AD is caused by the aggregation of the amyloid-beta protein (Aβ) that results in plaques accumulating between the neural cells in the brain, resulting in dementia and cellular death. Previously, we reported a rationally designed peptoid that is capable of modulating Aβ40 aggregation by specifically decreasing lag time to β-sheet aggregate formation as well as the total number of fibrillar β-sheet structured aggregates formed. Peptoid JPT1 was designed to exhibit helical secondary structure to allow aromatic F groups on the face of the peptoid to interact with carbons i and i+2 in a β-sheet, possibly facilitating pi-pi stacking between the aromatic groups within the peptoid and Aβ aggregates. Our previous work demonstrated that peptoid JPT1 could reduce the total number of fibrillar β-sheet structured aggregates in a concentration dependent manner. Herein, we report the mechanism of Aβ40 aggregation in the presence and absence of peptoid JPT1, specifically the size and morphology of the aggregates formed.