title: Novel fluorescent trimethine cyanine dye 7519 for amyloid fibril inhibition assay.
abstract: Fluorescence spectroscopy was used to study the ability of dye 7519 to follow the transition of monomeric insulin into fibrils and applicability of the dye to the insulin aggregation inhibition assay. The commercially available classic amyloid stain, thioflavin T, was used as the reference dye. For selecting potential inhibitors, the QSAR approach was applied. Dye 7519 appeared to be suitable for monitoring insulin aggregation into fibrils in vitro. The properties of the dye allowed us to test it as a potential probe in the screening assay of potential inhibitors of insulin fibrillization. One hundred forty-four flavonoids were tested as potential inhibitors of amyloid fibril formation using the quantitative structure activity relationship approach. Among them, 10 candidates with high indexes of inhibition were selected for tests in vitro using dye 7519 and the reference amyloid dye thioflavine T. Using dye 7519 fluorescence, we found that two compounds had inhibitory effects on insulin amyloid formation. These results agree with inhibition data using the thioflavine T assay. Our studies demonstrated that the fluorescent cyanine dye 7519 is a sensitive probe for quantitative detection of insulin amyloid formation and can be applied to screen agents capable of affecting aggregation of amyloid proteins.
authors.affiliation: Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, 03143 Kyiv, Ukraine.
authors.forename: K D
authors.initials: KD
authors.lastname: Volkova
authors.forename: V B
authors.initials: VB
authors.lastname: Kovalska
authors.forename: D
authors.initials: D
authors.lastname: Inshin
authors.forename: Y L
authors.initials: YL
authors.lastname: Slominskii
authors.forename: O I
authors.initials: OI
authors.lastname: Tolmachev
authors.forename: S M
authors.initials: SM
authors.lastname: Yarmoluk
mesh_terms: D000682:Amyloid / Q000032:analysis* / Q000037:antagonists & inhibitors; D052160:Benzothiazoles; D001681:Biological Assay; D002232:Carbocyanines / Q000737:chemistry*; D005419:Flavonoids / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000737:chemistry*; D007328:Insulin / Q000378:metabolism*; D021281:Quantitative Structure-Activity Relationship; D012015:Reference Standards; D013050:Spectrometry, Fluorescence / Q000379:methods; D013844:Thiazoles / Q000592:standards
chemical_list: D000682:Amyloid; D052160:Benzothiazoles; D002232:Carbocyanines; D005419:Flavonoids; D005456:Fluorescent Dyes; D007328:Insulin; D013844:Thiazoles; C009462:thioflavin T