Non-amyloidogenic cleavage of the beta-amyloid precursor protein by an integral membrane metalloendopeptidase.
The beta-amyloid precursor protein (beta-APP) is a membrane spanning glycoprotein. The small beta-protein domain within the precursor is presumed to be the source of amyloid found in plaques characteristic of Alzheimer's disease. The amino terminus of beta-APP is released from cells by cleavages that produce both potentially amyloidogenic and nonamyloidogenic fragments of the carboxyl terminus. We developed a cell free system that imposes specificity and co-localization to characterize the proteolytic activity that cleaves the precursor within the beta-protein domain. A reporter protein containing the carboxyl-terminal 105 amino acids of beta-APP provided a specific substrate for cleavage at Lys16 of the beta-protein. The protease inhibitor profile and solubility characteristics of the activity demonstrate the cleavage is produced by an integral membrane metalloendopeptidase.
Roberts
S B
SB
Bristol-Myers Squibb Pharmaceutical Research Institute, Department of Biophysics and Molecular Biology, Wallingford, Connecticut 06492.
Ripellino
J A
JA
Ingalls
K M
KM
Robakis
N K
NK
Felsenstein
K M
KM
D000469:Alkaline Phosphatase / Q000096:biosynthesis; D000544:Alzheimer Disease / Q000378:metabolism; D000595:Amino Acid Sequence; D016564:Amyloid beta-Protein Precursor / Q000096:biosynthesis / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D003902:Detergents / Q000494:pharmacology; D004795:Enzyme Stability; D005910:Glioma; D006801:Humans; D007700:Kinetics; D008239:Lysine; D008666:Metalloendopeptidases / Q000378:metabolism*; D008954:Models, Biological; D011480:Protease Inhibitors / Q000494:pharmacology; D011499:Protein Processing, Post-Translational; D013379:Substrate Specificity; D014162:Transfection; D014407:Tumor Cells, Cultured
D016564:Amyloid beta-Protein Precursor; D003902:Detergents; D011480:Protease Inhibitors; D000469:Alkaline Phosphatase; D008666:Metalloendopeptidases; D008239:Lysine