title: Characterisation of two antibodies to oligomeric Abeta and their use in ELISAs on human brain tissue homogenates.
abstract: Oligomeric forms of Abeta are believed to be the major toxic species of this peptide in Alzheimer's disease (AD). Although the characterisation of oligomer-specific antibodies has been reported, these have not been successfully incorporated into an enzyme-linked immunosorbent assay (ELISA), and measurement of the levels of oligomeric Abeta in brain tissue has remained problematic. We have examined the specificity of two monoclonal antibodies, 7 A1a and 1G5, for synthetic oligomers of Abeta(1-42) and for oligomeric Abeta(1-42) in human brain homogenates, and the utility of these two antibodies for measuring oligomeric Abeta(1-42) by sandwich ELISA. Both antibodies were found to recognise a range of synthetic oligomers of Abeta(1-42) but to cross-react in Western blots with a 34 kDa protein, shown by two-dimensional gel electrophoresis and mass spectrometry to be tropomyosin. However, by using 7A1a and 1 G5 in combination with an Abeta(1-42) capture antibody, we were able specifically to detect and to measure the levels of oligomeric Abeta(1-42) in brain homogenates by ELISA. The development of a simple ELISA for measurement of oligomeric Abeta should facilitate further studies of the role of oligomeric species of Abeta in AD.
authors.affiliation: Dementia Research Group, Institute of Clinical Neurosciences, Clinical Science at North Bristol, University of Bristol, Bristol BS16 1LE, UK. zoe.vanhelmond@bristol.ac.uk
authors.forename: Zoë
authors.initials: Z
authors.lastname: van Helmond
authors.forename: Kate
authors.initials: K
authors.lastname: Heesom
authors.forename: Seth
authors.initials: S
authors.lastname: Love
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000473:pathology; D016229:Amyloid beta-Peptides / Q000276:immunology* / Q000378:metabolism; D000906:Antibodies / Q000378:metabolism*; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D016022:Case-Control Studies; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry / Q000379:methods; D008875:Middle Aged; D010446:Peptide Fragments / Q000276:immunology* / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides; D000906:Antibodies; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42)