Characterisation of two antibodies to oligomeric Abeta and their use in ELISAs on human brain tissue homogenates.
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.
van Helmond
Zoë
Z
Dementia Research Group, Institute of Clinical Neurosciences, Clinical Science at North Bristol, University of Bristol, Bristol BS16 1LE, UK. zoe.vanhelmond@bristol.ac.uk
Heesom
Kate
K
Love
Seth
S
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
D016229:Amyloid beta-Peptides; D000906:Antibodies; D010446:Peptide Fragments; C078592:amyloid beta-protein (1-40); C075222:amyloid beta-protein (1-42)