The basic structural motif and major biophysical properties of Amyloid-β are encoded in the fragment 18-35

► Residues 18-35 dictate the major features of the Aβ fibril structure. ► Monomers and oligomers of Aβ18-35 and Aβ1-40 are also similar. ► If the turn affects toxicity, then residues18-35 should be a pharmaceutical target.