Cathepsin D is involved in the clearance of Alzheimer's beta-amyloid protein.
The cerebral deposition of 39-42 residue amyloid beta-protein (Abeta) is a histopathological characteristic of Alzheimer's disease. The present study is aimed at finding proteinases responsible for the intracellular clearance of Abeta. The Abeta-degrading proteinase was purified from rat brain. Amino-terminal sequence analysis indicated the Abeta-degrading proteinase was cathepsin D. Purified cathepsin D hydrolyzed Abeta between Phe19 and Phe20. Cathepsin D is likely to be involved in the intracellular clearance of aggregatable Abeta, since Abeta fragments with Phe20 at the amino-terminus have been reported to be secreted from several lines of cultured cells.
Department of Biology, Kitasato University School of Medicine, Kanagawa, Japan.
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H
Hamazaki
D000595:Amino Acid Sequence; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002402:Cathepsin D / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D051381:Rats
D016229:Amyloid beta-Peptides; D002402:Cathepsin D