Evidence for the derivation of a peptide ligand from the amyloid beta-protein precursor of Alzheimer's disease.
A monoclonal antibody to a synthetic peptide consisting of residues 8-17 of amyloid beta-protein was used in immunohistochemical studies to reveal binding sites for this peptide in cytoplasmic vesicles in cells of the adrenal zona reticularis and the islets of Langerhans of the pancreas. These binding sites showed some specificity for this peptide and so may represent a membrane receptor. These results suggest that the membrane bound beta-protein precursor may be processed by limited extracellular proteolysis to release a peptide ligand containing the 8-17 sequence. It has been reported recently that the core protein of a heparin sulphate proteoglycan (HSPG) secreted by PC12 cells shows some homology with the beta-protein precursor. This suggests that the binding sites might be due to the presence of a HSPG core protein receptor. Further studies should be carried out to find out if receptors to beta-protein peptides are present in brain tissue, since these might play a role in the catabolism of the beta-protein precursor, and in the formation of cerebral amyloid in Alzheimer's disease (AD).
Allsop
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D
Department of Pathology M-012, University of California, San Diego School of Medicine, La Jolla 92093.
Ikeda
S
S
Glenner
G G
GG
D000544:Alzheimer Disease / Q000378:metabolism*; D000682:Amyloid / Q000032:analysis*; D016564:Amyloid beta-Protein Precursor; D001665:Binding Sites; D006801:Humans; D008024:Ligands; D011498:Protein Precursors / Q000032:analysis*
D000682:Amyloid; D016564:Amyloid beta-Protein Precursor; D008024:Ligands; D011498:Protein Precursors