  Electron paramagnetic resonance signal parameters of TEMPO dichlorotriazine
and TEMPO maleimide spin labels attached to protein human serum albumin
molecules have been monitored at various temperatures, salts and sucrose
concentrations. The method for measuring the correlation time of the protein
rotational dynamics using viscosity isotherms was utilized. The correlation
time is proportional to the effective protein volume dependent on protein
structure dynamic stability in a certain temperature range which can thus be
determined. Sharp temperature changes in the effective volume and their
dependence on the concentration of NaCl, ammonium sulphate, polyethylene
glycol, and heavy water are interpreted as interconversions of stable low and
hightemperature protein conformers with the participation of intermediates. Few
variants of the qualitative phase diagrams of water-salt dispersion of the
protein were presented on the basis of the results obtained. The regions have
been marked, where thermo and salt induced liquid liquid phase transitions can
occur, as well as intermediates and supramolecular structures of the protein
can form in their course.
