β-Amyloid (25-35) (Amyloid beta-peptide (25-35), Aβ25-35, β-Amyloid peptide (25-35)) , a sequence GSNKGAIIGLM, is a highly toxic synthetic derivative of Amyloid beta-peptide (Aβ-peptides) which forms fibrillary aggregates. β-Amyloid (25-35) is involved in the pathogenesis of Alzheimer’s disease.