Thermodynamic features of bovine and human serum albumins under ozone and hydrogen peroxide induced oxidation studied by differential scanning calorimetry

Abstract

Serum albumin is the prevailing protein of blood bearing not less than 70% of the free radical-trapping activity of serum. The effect of ozone and hydrogen peroxide on the thermal stability of human (HSA) and bovine (BSA) serum albumins is studied by the aid of the differential scanning calorimetry (DSC) method. A decrease and increase of denaturation enthalpy and temperature for both investigated proteins upon ozone-induced and peroxide induced oxidation are analyzed and the role of endogenous ligands (specifically fatty acids) in the protein oxidation is clarified. Both the thermal stability of long-chain fatty acids LCFA-poor HSA molecules and relative resistance of LCFA-rich HSA molecules to oxidation are shown not to depend on the oxidant type with the key role of LCFA-rich HSA species in thermal stability of the HSA under oxidation.