Thioflavin T Promotes Aβ(1-40) Amyloid Fibrils Formation.
Fibrillogenesis of the small peptide Aβ(1-40) is considered to be the hallmark of Alzheimer's disease. Some evidence indicates small oligomers, rather than mature fibrils, as the key cytotoxic agents. The fluorescent dye Thioflavin T (ThT) is often used to detect amyloid deposits in both in vivo and in vitro experiments, and it is used to study kinetic measurements, under the fundamental hypothesis that this probe does not influence the aggregation processes. We report experimental data showing that ThT may promote the Aβ(1-40) peptide amyloid aggregation changing solvent-peptide interactions and stabilizing more ordered β-like conformation. This finding has a two-fold importance: It is a fundamental warning in all fibrillation experiments where ThT is used as fluorescent probe, and it suggests that ThT, accelerating fibril formation, could be used to reduce the presence of transient small oligomers, thus interfering with the pathogenic impact of Aβ peptide.
†Dip. di Fisica, Università degli Studi di Palermo, Via Archirafi 36, I-90123, Palermo, Italy.
Michele
M
D'Amico
†Dip. di Fisica, Università degli Studi di Palermo, Via Archirafi 36, I-90123, Palermo, Italy.
Maria Giovanna
MG
Di Carlo
‡Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
Minna
M
Groenning
†Dip. di Fisica, Università degli Studi di Palermo, Via Archirafi 36, I-90123, Palermo, Italy.
Valeria
V
Militello
†Dip. di Fisica, Università degli Studi di Palermo, Via Archirafi 36, I-90123, Palermo, Italy.
Valeria
V
Vetri
†Dip. di Fisica, Università degli Studi di Palermo, Via Archirafi 36, I-90123, Palermo, Italy.
Maurizio
M
Leone
Aβ(1−40); amyloid fibrils formation; fluorescence; thioflavin T; two-photon fluorescence microscopy