Effect of L-thyroxine, a Human Serum Albumin Natural Ligand, on the Kinetics of β-amyloid Peptide Fibril Formation

Ligands of human serum albumin (HSA) are capable of modulating its interaction with β-amyloid peptide (Aβ), which is a key factor in the pathogenesis of Alzheimer’s disease (AD). L-thyroxine (L-Tr), a natural HSA ligand, is associated with the pathogenesis of AD according to epidemiological and animal model studies. In this work, we studied the kinetics of Aβ fibril formation in the presence of L-Tr and HSA using a fluorescent test with thioflavin T. L-Tr had no significant effect on the inhibitory effect of HSA on fibril growth. At the same time, L-Tr itself had an inhibitory effect similar to that of HSA. Our data can partially explain the relationship between AD and thyroid pathologies.