The Alzheimer's Disease γ-Secretase Generates Higher 42:40 Ratios for β-Amyloid Than for p3 Peptides.

Alzheimer's disease is characterized by intracerebral deposition of β-amyloid (Aβ). While Aβ is the most abundant form, neurotoxicity is mainly mediated by Aβ. Sequential cleavage of amyloid precursor protein (APP) by β- and γ-secretases gives rise to full-length Aβ (Aβ) and N-terminally truncated Aβ' (Aβ) whereas cleavage by α- and γ-secretases leads to the shorter p3 peptides (Aβ).