TY - JOUR
T1 - Specific recognition of biologically active amyloid-β oligomers by a new surface plasmon resonance-based immunoassay and an in vivo assay in Caenorhabditis elegans
AU - Stravalaci, Matteo
AU - Bastone, Antonio
AU - Beeg, Marten
AU - Cagnotto, Alfredo
AU - Colombo, Laura
AU - Di Fede, Giuseppe
AU - Tagliavini, Fabrizio
AU - Cantù, Laura
AU - Del Favero, Elena
AU - Mazzanti, Michele
AU - Chiesa, Roberto
AU - Salmona, Mario
AU - Diomede, Luisa
AU - Gobbi, Marco
PY - 2012/8/10
Y1 - 2012/8/10
N2 - Soluble oligomers of the amyloid-β (Aβ) peptide play a key role in the pathogenesis of Alzheimer's disease, but their elusive nature makes their detection challenging. Here we describe a novel immunoassay based on surface plasmon resonance (SPR) that specifically recognizes biologically active Aβ oligomers. As a capturing agent, we immobilized on the sensor chip the monoclonal antibody 4G8, which targets a central hydrophobic region of Aβ. This SPR assay allows specific recognition of oligomeric intermediates that rapidly appear and disappear during the incubation of synthetic Aβ1-42, discriminating them from monomers and higher order aggregates. The species recognized by SPR generate ionic currents in artificial lipid bilayers and inhibit the physiological pharyngeal contractions in Caenorhabditis elegans, a new method for testing the toxic potential of Aβ oligomers. With these assays we found that the formation of biologically relevant Aβ oligomers is inhibited by epigallocatechin gallate and increased by the A2V mutation, previously reported to induce early onset dementia. The SPR-based immunoassay provides new opportunities for detection of toxic Aβ oligomers in biological samples and could be adapted to study misfolding proteins in other neurodegenerative disorders.
AB - Soluble oligomers of the amyloid-β (Aβ) peptide play a key role in the pathogenesis of Alzheimer's disease, but their elusive nature makes their detection challenging. Here we describe a novel immunoassay based on surface plasmon resonance (SPR) that specifically recognizes biologically active Aβ oligomers. As a capturing agent, we immobilized on the sensor chip the monoclonal antibody 4G8, which targets a central hydrophobic region of Aβ. This SPR assay allows specific recognition of oligomeric intermediates that rapidly appear and disappear during the incubation of synthetic Aβ1-42, discriminating them from monomers and higher order aggregates. The species recognized by SPR generate ionic currents in artificial lipid bilayers and inhibit the physiological pharyngeal contractions in Caenorhabditis elegans, a new method for testing the toxic potential of Aβ oligomers. With these assays we found that the formation of biologically relevant Aβ oligomers is inhibited by epigallocatechin gallate and increased by the A2V mutation, previously reported to induce early onset dementia. The SPR-based immunoassay provides new opportunities for detection of toxic Aβ oligomers in biological samples and could be adapted to study misfolding proteins in other neurodegenerative disorders.
UR - http://www.scopus.com/inward/record.url?scp=84865040298&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84865040298&partnerID=8YFLogxK
U2 - 10.1074/jbc.M111.334979
DO - 10.1074/jbc.M111.334979
M3 - Article
C2 - 22736768
AN - SCOPUS:84865040298
VL - 287
SP - 27796
EP - 27805
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 33
ER -