β-Amyloid (10-35), amide

β-Amyloid (10-35) is selected based on the following considerations: (1) β-Amyloid (10-35) incorporates the core region, point mutations of which significantly obstruct fibril formation and have been used to generate inhibitors of fibrillogenesis; (2) β-Amyloid (10-35) retains the ability to add to bona fide Alzheimer’s plaques, in contrast to other truncated peptides, and forms fibrils morphologically similar to those of the full length peptide; (3) Of most importance, the full length peptide, Aβ _(1-42) , is intractable for the controlled formation of fibrils from aqueous media because at the earliest time points, some of the peptide exists as an amorphous precipitate. In contrast, the use of β-Amyloid (10-35) allows the reproducible and controlled formation of fibrils from aqueous solutions, under defined conditions of pH, ionic strength, and peptide concentration and thus yields the required homogeneous fibrils.