Related Experiment Video
Updated: Mar 21, 2026

In Vitro Aggregation Assays Using Hyperphosphorylated Tau Protein
Published on: January 2, 2015
Binding Modes of Thioflavin T on the Surface of Amyloid Fibrils Studied by NMR
Valerie A Ivancic1, Oshini Ekanayake2, Noel D Lazo3
1Carlson School of Chemistry and Biochemistry, Clark University, 950 Main St, Worcester, MA, 01610, USA.
Abstract:
The mechanism for the interaction of thioflavin T (ThT) with amyloid fibrils at the molecular level is not known. Here, we used (1) H NMR spectroscopy to determine the binding mode of ThT on the surface of fibrils from lysozyme and insulin. Relayed rotating-frame Overhauser enhancements in ThT were observed, indicating that the orientation of ThT is orthogonal to the fibril surface. Importantly, the assembly state of ThT on both surfaces is different. On the surface of insulin fibrils, ThT is oligomeric, as indicated by rapid (1) H spin-lattice relaxation rate in the rotating frame (R1ρ ), presumably due to intermolecular dipole-dipole interactions between ThT molecules. In contrast, ThT on the surface of lysozyme fibrils is a monomer, as indicated by slower (1) H R1ρ . These results shed new light into the mechanism for the enhancement of ThT fluorescence and may lead to more efficient detectors of amyloid assemblies, which have escaped detection by ThT in monomer form.
Related Concept Videos
Amyloid Fibrils
Amyloid deposits were observed as early as 1639 in the liver and the spleen. In 1854, Rudolph Virchow performed iodine staining,...
Amyloid Fibrils
NMR Spectroscopy Of Amines
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
NMR Spectroscopy: Spin–Spin Coupling

