Cavity Lasing of Thioflavin T in the Condensed Phase for Discrimination between Surface Interaction and β-Sheet Groove Binding in Alzheimer-Linked Peptides

Abstract

This study investigates the lasing effects in a Fabry–Perot cavity to discern the binding interactions of thioflavin T (ThT) with various peptides associated with Alzheimer’s disease, including Aβ(1–42), KLVFFA, and diphenylalanine (FF) in the condensed phase. Utilizing kinetic lasing measurements, the research explores ThT emission enhancements due to specific groove binding in β-sheet structures and highlights additional contributions from weak surface interactions and solvent–solute interactions. Lasing spectroscopy reveals a lack of transition of the FF system from its native state to an amyloid-like structure, challenging traditional ThT assay interpretations. These findings show the potential of lasing spectroscopy in elucidating the molecular basis of amyloid fibril formation and the development of diagnostic tools for amyloidogenic diseases.