INTERMOLECULAR INTERACTIONS IN THE SOLUTIONS OF SERUM ALBUMIN.

The mechanisms of intermolecular protein complex formation were studied by the example of monomers, oligomers and aggregates of bovine serum albumin (BSA) depending on the protein concentration, pH and urea concentration. Using dynamic light scattering (DLS), analytical ultracentrifugation (AUC) and PAG electrophoresis, we have shown that there is dynamic equilibrium between monomers and aggregates in BSA solution. Decreasing pH of the solution (4.0­1.0) resulted in increasing sizes of the aggregates. In the solutions with low urea concentrations (below 2 M), the sizes of aggregates decreased, while higher urea concentrations induced formation of larger aggregates due to the unfolding of the protein.

[Analysis of the secondary structure of linker histone H1 based on IR absorption spectra].

This work was carried out to compare the effectiveness of the methods of infrared spectroscopy in the amide I region and UV circular dichroism to the analyze the protein secondary structure by the example of linker histone H1 and bovine serum albumin (BSA). It has been shown that the application of a diamond ATR cell quantifies the proportion of α-helices and ß-structures in a good agreement with UV circular dichroism spectroscopy. It has been shown that histone H1 is able to aggregate, which results in considerable changes in its secondary structure.