title: Surface plasmon resonance imaging of amyloid-β aggregation kinetics in the presence of epigallocatechin gallate and metals.
abstract: A number of human protein misfolding disorders, including Alzheimer's disease (AD), are closely related to the accumulation of β-sheet-rich amyloid fibrils or aggregates. Neuronal toxicity in AD has been linked to the interactions of amyloid-β (Aβ) with metals, especially Zn(2+), Cu(2+), and Fe(3+), which leads to the production of reactive oxygen species. Nucleation-dependent Aβ aggregation, or "seeding", is thought to propagate fibril formation. In this surface plasmon resonance imaging (SPRi) study, we have shown that the fibril seeds formed with the incubation of Aβ in the presence of metals are better at promoting monomer elongation compared to Aβ alone or in the presence of a well-described polyphenol, (-)-epigallocatechin-3-gallate (EGCG). This is a novel attempt to simultaneously monitor the effects of multiple modulators on fibril elongation using a single chip. EGCG was shown in transmission electron microscopy (TEM) and thioflavin T (ThT) studies to promote the formation of off-pathway, highly stable unstructured oligomers, supporting the SPRi results. These findings suggest that SPRi provides a promising platform as a screening tool for small molecules that can affect the aggregation pathways in neurodegenerative diseases.
authors.affiliation: Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario M1C 1A4, Canada.
authors.forename: Xin R
authors.initials: XR
authors.lastname: Cheng
authors.forename: Ben Y H
authors.initials: BY
authors.lastname: Hau
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Veloso
authors.forename: Sanela
authors.initials: S
authors.lastname: Martic
authors.forename: Heinz-Bernhard
authors.initials: HB
authors.lastname: Kraatz
authors.forename: Kagan
authors.initials: K
authors.lastname: Kerman
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism / Q000473:pathology; D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000378:metabolism*; D052160:Benzothiazoles; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D003300:Copper / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D006801:Humans; D007477:Ions / Q000737:chemistry; D007700:Kinetics; D008670:Metals / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism; D020349:Surface Plasmon Resonance; D013844:Thiazoles / Q000737:chemistry / Q000378:metabolism; D015032:Zinc / Q000737:chemistry
chemical_list: D016229:Amyloid beta-Peptides; D052160:Benzothiazoles; D005290:Ferric Compounds; D007477:Ions; D008670:Metals; D010446:Peptide Fragments; D013844:Thiazoles; C078592:amyloid beta-protein (1-40); C009462:thioflavin T; D003300:Copper; D002392:Catechin; C045651:epigallocatechin gallate; D015032:Zinc