Self-assembly of a peptide with a tandem repeat of the Aβ16-22 sequence linked by a β turn-promoting dipeptide sequence.

Amyloid deposits have been found to be abundant in patients with Alzheimer's disease due to fibril formation by the Aβ peptides. Peptide Aβ16-22, comprising of the seven-residue segment KLVFFAE, spanning residues 16-22 of the full length Aβ42 peptide, aggregates to form fibrils or other nanostructures in isolation, depending on the conditions of dissolution and incubation. In this study, we have examined the self-assembly of PAβ, a tandem repeat peptide of the Aβ16-22 sequence, joined by a β-turn-inducing sequence Asn-Gly.

Effect of introducing a short amyloidogenic sequence from the Aβ peptide at the N-terminus of 18-residue amphipathic helical peptides.

Fibril formation is the hallmark of pathogenesis in Alzheimer's disease and other amyloid disorders caused by conformational alterations leading to the aggregation of soluble monomers. Aβ40 self-associates to form amyloid fibrils. Its central seven-residue segment KLVFFAE (Aβ16-22), which is thought to be crucial for fibril formation of the full-length peptide, forms fibrils even in isolation.