Fӧrster resonance energy transfer between Thioflavin T and unsymmetrical trimethine cyanine dyes on amyloid fibril scaffold

Abstract

The misfolding and aggregation of proteins and peptides into amyloid fibrils lie in the root of many pathological disorders. In the present study we demonstrate that the Förster resonance energy transfer (FRET) between the classical amyloid marker Thioflavin T as a donor and one of a series of trimethine cyanine dyes as an acceptor can be used to differentiate between the non-fibrillized and fibrillar states of insulin. A striking decrease in ThT fluorescence in the presence of cyanine dyes was observed only for the fibrillar insulin, with the magnitude of this effect being dependent on the cyanine chemical structure.