| Abstract [eng] |
Conformational changes in amyloid proteins and their aggregation in the form of amyloid fibrils are associated with many neurodegenerative disorders such as Alzheimer’s, Parkinson’s disease, or transmissible spongiform encephalopathies. Currently, there is a lot of research carried out in order to investigate the mechanisms of protein aggregation and how different environmental conditions may affect the aggregation process and the results obtained from studies. It has been observed that temperature, pH, ionic strength and type of shaking change not only the kinetic parameters of aggregation, but also the protein’s conformation, thus forming fibrils of different strains. Amyloidophilic dyes such as Congo red, thioflavin-T or ANS are often used in these studies. In this work, amyloid fibrils of two model proteins - insulin and lysozyme, as well as neurodegenerative-disease-related proteins - mouse prion protein and α-synuclein, were produced. Study of the changes of dye interaction with fibril surface in a mixture of two dye combinations was performed and changes in ThT binding to fibrils at different ionic strength of the solution were evaluated using absorbance and fluorescence spectroscopy methods. It was found that dyes, in some cases, increase the affinity for the surface of fibrils, by interacting with each other, but in other cases they interfere with one another. It has also been observed that at higher ionic strength of the solution, more ThT molecules bind to the surface of amyloid fibrils. |
