Cathepsin B generates the most common form of amyloid A (76 residues) as a degradation product from serum amyloid A.
Amyloid A protein (AA), the chief constituent of reactive amyloid deposits, is derived from serum amyloid A (SAA) and most commonly corresponds to the amino-terminal 76 residues (AA76). Digestion of recombinant human SAA1 with a lysosomal thiol protease, cathepsin B, and analysis of the products by SDS-PAGE and amino-terminal sequencing revealed that AA76 was generated as a minor and transient degradation product. Digestion with neutrophil elastase generated intermediates different from AA76. This finding suggests that cathepsin B may play an important role in amyloid fibrilogenesis by converting SAA to AA.
Yamada
T
T
Department of Medicine, Indiana University School of Medicine, Indianapolis.
Liepnieks
J J
JJ
Kluve-Beckerman
B
B
Benson
M D
MD
D000595:Amino Acid Sequence; D000682:Amyloid / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D002401:Cathepsin B / Q000378:metabolism*; D002417:Cattle; D017931:DNA Primers / Q000737:chemistry; D006801:Humans; D066298:In Vitro Techniques; D019272:Leukocyte Elastase / Q000378:metabolism; D008969:Molecular Sequence Data; D010196:Pancreatic Elastase / Q000378:metabolism; D011498:Protein Precursors; D011994:Recombinant Proteins; D000685:Serum Amyloid A Protein / Q000378:metabolism*
D000682:Amyloid; D017931:DNA Primers; D011498:Protein Precursors; D011994:Recombinant Proteins; D000685:Serum Amyloid A Protein; D010196:Pancreatic Elastase; D019272:Leukocyte Elastase; D002401:Cathepsin B