Water-soluble tripeptide Abeta (9-11) forms amyloid-like fibrils and exhibits neurotoxicity.

A water-soluble, hydrophilic tripeptide GYE, having sequence identity with the N-terminal segment of amyloid peptides Abeta(9-11), upon self-association exhibits amyloid-like fibrils and significant neurotoxicity towards the Neuro2A cell line. However, the tripeptides GFE and GWE, in which the centrally located tyrosine residue has been replaced by phenylalanine or tryptophan, fail to show amyloidogenic behavior and exhibit little or no neurotoxicity.