Fig. 1.
A schematic view of APP proteolytic cleavage. In the non-amyloidogenic pathway, APP is first cleaved by α-secretase and then by γ-secretase to form truncated Aβ17–40/42 peptides or by β-secretase leading to the formation of the truncated Aβ1–16. In the amyloidogenic pathway, APP is cleaved consecutively by the β- and γ-secretases leading to the formation of full-length Aβ1–40/42 peptides. According to the amyloid cascade hypothesis, the Aβ peptide would be further able to interact with metal ions present in the brain and form oligomers and then fibrils, found in the senile plaques in vivo.