Study of Thermal Denaturation of a Plasminogen Molecule Under Induced Oxidation

This article studies the thermal denaturation of a plasminogen molecule during induced oxidation by hypochlorite in a range of concentrations (30, 62.5, 125, and 250 µM). Using differential scanning calorimetry, it is determined that in the presence of an oxidizing agent, the enthalpy of denaturation of the plasminogen molecule decreases. This is most noticeable for the peak showing the melting of the K4–K5 kringle domains. These results are consistent with the previously obtained data on the oxidative modification of amino acid residues of plasminogen treated with different concentrations of hypochlorite using the HPLC-MS/MS method. Taken together, these data and the results of previous studies indicate that the structure of full-length plasminogen is adapted to moderate HOCl-induced oxidation.