ABSTRACT
By two biophysical methods – the spectral measuring of intensity of intrinsic protein's fluorescence and registration of changes of protein microdomain organization by adiabatic differential scanning calorimetry (DSC) – we examined biological effects of biological activity substance – antioxidant (AO) potassium salt of phenosan, on free and membrane proteins structure: bovine serum albumin (BSA) and proteins microdomains of erythrocyte ghosts.
We show by spectral method (on fluorescence intensity of two tryptophane residues at BSA molecule) that potassium salt of phenosan (potassium phenosan) at 10−4 M reduces the fluorescence intensity and shifts the wavelengths of emission. These indicate that the environment around the tryptophane is hydrophilizated when large concentrations of phenoksan, due to globule loosening of molecule BSA and quenched by oxygen, dissolved 62in water. Potassium phenosan solutions at concentrations of 10−17 – 10−6 M increase the intensity of intrinsic BSA fluorescence, as compared to control without AO. This phenomenon may be explained by the preservation of tryptophane residues emission from quenching by the adsorbed potassium phenosan molecules.
By the applauding of adiabatic process, DSC has been shown the shifts of temperature denaturation of proteins microdomains at erythrocyte ghosts in the presence of AO. The proteins of erythrocytes membranous cytoskeleton intimately mutually operate with each other and form the membranous domains, the denaturation of which forms structural heat transitions: five identified structural transitions of proteins family: spektrin, ancyrin, bands proteins 4.1 and 4.2 and band protein 3, are mutual of membranous cytoskeleton in practice of all cells at animal organism. The general DSC ghost melting parameter Tmax shifts were determined. Tmax were changed without shape changing of protein microdomains peaks. Potassium phenosan causes restructuring in protein microdomains organization; however, its domains were remaining.
The obtained in vitro data suggest that influencing of potassium phenosan to free soluble protein (BSA) and proteins, which are membrane-bounded (erythrocyte ghosts), is in strong dependence on potassium phenosan concentration at experimental mediums.
