β-Amyloid peptide (Aβ40) is a 40-amino-acid peptide that plays a central role in the pathogenesis of Alzheimer’s disease (AD) and age-associated Down syndrome. In individuals with Down syndrome, trisomy of chromosome 21 leads to increased expression of amyloid precursor protein (APP), thereby promoting enhanced production and accumulation of Aβ peptides.

Aβ40 is generated through sequential proteolytic processing of the type I transmembrane protein APP, which is encoded by the APP gene located on human chromosome 21. Cleavage by β-secretase followed by γ-secretase produces multiple Aβ species of varying lengths, among which Aβ40 is the most abundant form.

Structurally, the Aβ peptide is derived from the extracellular N-terminal region of APP and extends into the transmembrane domain. The C-terminal region of Aβ40 is hydrophobic, conferring a strong propensity for self-association and aggregation into soluble oligomers, protofibrils, and mature amyloid fibrils. These aggregated species are widely implicated in neuronal dysfunction and disease progression in Alzheimer’s pathology.

TDA-1201-100-datasheet.pdf