title: Real-Time Monitoring of Alzheimer's-Related Amyloid Aggregation via Probe Enhancement-Fluorescence Correlation Spectroscopy.
abstract: This work describes the use of fluorescence correlation spectroscopy (FCS) and a novel amyloid-binding fluorescent probe, ARCAM 1, to monitor the aggregation of the Alzheimer's disease-associated amyloid β-peptide (Aβ). ARCAM 1 exhibits a large increase in fluorescence emission upon binding to Aβ assemblies, making it an excellent candidate for probe enhancement FCS (PE-FCS). ARCAM 1 binding does not change Aβ aggregation kinetics. It also exhibits greater dynamic range as a probe in reporting aggregate size by FCS in Aβ, when compared to thioflavin T (ThT) or an Aβ peptide modified with a fluorophore. Using fluorescent burst analysis (via PE-FCS) to follow aggregation of Aβ, we detected soluble aggregates at significantly earlier time points compared to typical bulk fluorescence measurements. Autocorrelation analysis revealed the size of these early Aβ assemblies. These results indicate that PE-FCS/ARCAM 1 based assays can detect and provide size characterization of small Aβ aggregation intermediates during the assembly process, which could enable monitoring and study of such aggregates that transiently accumulate in biofluids of patients with Alzheimer's and other neurodegenerative diseases.
authors.affiliation: Department of Systems Biology, Harvard Medical School , Boston, Massachusetts 02115, United States.
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Guan
authors.affiliation: Department of Chemistry and Biochemistry, University of California at San Diego , La Jolla, California 92093-0358, United States.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Cao
authors.forename: Adam
authors.initials: A
authors.lastname: Cantlon
authors.affiliation: Department of Chemistry and Biochemistry, University of California at San Diego , La Jolla, California 92093-0358, United States.
authors.forename: Kristyna
authors.initials: K
authors.lastname: Elbel
authors.affiliation: Department of Chemistry and Biochemistry, University of California at San Diego , La Jolla, California 92093-0358, United States.
authors.forename: Emmanuel A
authors.initials: EA
authors.lastname: Theodorakis
authors.forename: Dominic M
authors.initials: DM
authors.lastname: Walsh
authors.affiliation: Department of Chemistry and Biochemistry, University of California at San Diego , La Jolla, California 92093-0358, United States.
authors.forename: Jerry
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Systems Biology, Harvard Medical School , Boston, Massachusetts 02115, United States.
authors.forename: Jagesh V
authors.initials: JV
authors.lastname: Shah
mesh_terms: D000178:Acrylamides / Q000138:chemical synthesis / Q000737:chemistry; D000544:Alzheimer Disease / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000737:chemistry / Q000378:metabolism*; D052160:Benzothiazoles; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry; D007700:Kinetics; D015394:Molecular Structure; D009281:Naphthalenes / Q000138:chemical synthesis / Q000737:chemistry; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism*; D066329:Protein Aggregates; D012995:Solubility; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013844:Thiazoles / Q000737:chemistry / Q000378:metabolism
chemical_list: C000608215:2-cyano-N-(2-(2-(2-methoxyethoxy)ethoxy)ethyl)-3-(6-(piperidin-1-yl)naphthalen-2-yl)acrylamide; D000178:Acrylamides; D016229:Amyloid beta-Peptides; D052160:Benzothiazoles; D005456:Fluorescent Dyes; D009281:Naphthalenes; D010446:Peptide Fragments; D066329:Protein Aggregates; D013844:Thiazoles; C075222:amyloid beta-protein (1-42); C009462:thioflavin T
keywords: Alzheimer’s disease; Amyloid β-protein; aggregate-binding fluorescent probe; fluorescence correlation spectroscopy