The presence of a novel protein in calf serum that recognizes beta amyloid in the formalin-fixed section.
Here we report on a monoclonal antibody, H6-33, that labels various beta-amyloid plaques, including diffuse plaques in the formalin-fixed, paraffin-embedded section from the brain affected with Alzheimer's disease (AD), without formic acid pretreatment. H6-33 also labels some neurofibrillary tangles and all kuru plaques in Gerstmann-Sträussler-Scheinker disease. In sharp contrast, H6-33 did not stain beta amyloid in the leptomeningeal vessel. For specific staining, H6-33 required the presence of fetal calf serum and it was necessary for beta amyloid to be formalin fixed. These results suggest that a novel protein in the calf serum, CSX, binds formalin-fixed beta amyloid, followed by H6-33 binding. The detection of beta amyloid by CSX was nullified by formic acid pretreatment of the tissue section. In accordance with this, CSX reacted only with a polymer form of synthetic beta peptide after fixation, but not with native beta-protein or beta-peptide monomer. These observations strongly suggest that 1) meningovascular beta amyloid should have a beta-pleated sheet structure somewhat dissimilar to that of beta-amyloid cores; and 2) most, if not all, of beta-protein immunoreactivities of diffuse plaques in AD sections are presumably derived from small amounts of amyloid fibrils scattered in the normal-looking neurohil.
Second Laboratory of Clinical Physiology, Tokyo Metropolitan Institute of Gerontology, Japan.
K
K
Kanemaru
M
M
Hasegawa
H
H
Shimada
Y
Y
Ihara
D000544:Alzheimer Disease / Q000473:pathology*; D000682:Amyloid / Q000032:analysis* / Q000276:immunology; D000818:Animals; D000911:Antibodies, Monoclonal; D001798:Blood Proteins / Q000276:immunology*; D001921:Brain / Q000473:pathology; D002417:Cattle; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007118:Immunoassay; D007124:Immunoenzyme Techniques; D013194:Staining and Labeling
D000682:Amyloid; D000911:Antibodies, Monoclonal; D001798:Blood Proteins