title: Proteolytic processing of human amyloid beta protein precursor in insect cells. Major carboxyl-terminal fragment is identical to its human counterpart.
abstract: The predominant component of amyloid plaques of Alzheimer's disease is the amyloid beta protein (A beta), a 39-42-amino-acid peptide derived by proteolysis of a family of precursors known as amyloid precursor proteins (APP). In mammalian brain and in cultured mammalian cells, the release of APP amino-terminal fragments into the extracellular medium occurs by a proteolytic cleavage within the A beta domain, thereby precluding amyloidogenesis. Infection of Sf9 insect cells with baculovirus vectors containing APP cDNAs results in high levels of APP expression. The concomitant release of amino-terminal fragments of APP and the production of carboxyl-terminal, cell-associated cleavage products are observed. Here we demonstrate by direct protein microsequencing that the proteolytic processing of APP in the Sf9 cells generates a prominent carboxyl-terminal species that is identical to that produced in human cells, suggesting that the major pathway for proteolytic processing of APP is conserved among metazoans.
authors.affiliation: Laboratory of Molecular and Cellular Neuroscience, Rockefeller University, New York.
authors.forename: T V
authors.initials: TV
authors.lastname: Ramabhadran
authors.forename: S E
authors.initials: SE
authors.lastname: Gandy
authors.forename: J
authors.initials: J
authors.lastname: Ghiso
authors.forename: A J
authors.initials: AJ
authors.lastname: Czernik
authors.forename: D
authors.initials: D
authors.lastname: Ferris
authors.forename: R
authors.initials: R
authors.lastname: Bhasin
authors.forename: D
authors.initials: D
authors.lastname: Goldgaber
authors.forename: B
authors.initials: B
authors.lastname: Frangione
authors.forename: P
authors.initials: P
authors.lastname: Greengard
mesh_terms: D000595:Amino Acid Sequence; D016564:Amyloid beta-Protein Precursor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D002460:Cell Line; D004247:DNA / Q000235:genetics; D010450:Endopeptidases / Q000378:metabolism*; D005822:Genetic Vectors; D006801:Humans; D008969:Molecular Sequence Data; D009036:Moths / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D016564:Amyloid beta-Protein Precursor; D010446:Peptide Fragments; D011994:Recombinant Proteins; D004247:DNA; D010450:Endopeptidases