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

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 Fo spacing diaeresis rster 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.

Automated summary

This study demonstrates that the Fo spacing diaeresis rster resonance energy transfer (FRET) technique can differentiate between the non-fibrillized and fibrillar states of insulin. The presence of cyanine dyes causes a significant decrease in ThT fluorescence, with the magnitude of this effect depending on the cyanine chemical structure.