Rapid Growth of Acetylated Aβ(16-20) into Macroscopic Crystals

Aberrant assembly of the amyloid-beta (A beta) is responsible for the development of Alzheimer's disease, but can also be exploited to obtain highly functional biomaterials. The short A beta fragment, KLVFF (A beta(16-20)), is crucial for A beta assembly and considered to be an A beta aggregation inhibitor. Here, we show that acetylation of KLVFF turns it into an extremely fast self assembling molecule, reaching macroscopic (i.e., mm) size in seconds. We show that KLVFF is metastable and that the self-assembly can be directed toward a crystalline or fibrillar phase simply through chemical modification, via acetylation or amidation of the peptide. Amidated KLVFF can form amyloid fibrils; we observed folding events of such fibrils occurring in as little as 60 ms. The ability of single KLVFF molecules to rapidly assemble as highly ordered macroscopic structures makes it a promising candidate for applications as a rapid-forming templating material.