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Updated: Jul 18, 2026

Purification and Aggregation of the Amyloid Precursor Protein Intracellular Domain
Published on: August 28, 2012
Amyloid beta/A4 precursor protein (APP) processing in lysosomes
K Tagawa1, K Maruyama, S Ishiura
1National Institute of Neuroscience, NCNP, Tokyo, Japan.
Abstract:
Alzheimer's disease (AD) is characterized by the formation of senile plaques, the main component of which is amyloid beta protein. The processing of the amyloid beta/A4 protein has been implicated in the pathogenesis of AD. We have reported cathepsin B as a candidate APP secretase. By using APP-transfected COS-1 cells, we determined that the putative APP secretase, lysosomal cathepsin B, is involved in the constitutive processing of the precursor molecule. Digestion experiments demonstrated that cathepsin B cleaves the APP molecule into two fragments with molecular masses 115 kDa and 9 kDa, representing presumptive proteolytic fragments of constitutive processing.
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