Purification of recombinantly expressed and cytotoxic human amyloid-beta peptide 1–42

The amyloid cascade hypothesis assigns the amyloid-beta peptide (Aβ) a central role in the pathogenesis of Alzheimerʹs disease (AD). Although there are strong efforts to biophysically characterize formation of Aβ aggregates and fibrils, as well as their prevention, progress is still severly hampered by the availability of tens of milligrams of recombinant Aβ(1–42). Here, we describe a reliable and easy procedure to recombinantly express and purify Aβ(1–42), which is fully cytotoxic and able to form fibrils without any further refolding steps. The yield of the procedure is 5–8 mg of tag-less peptide per liter culture volume.