FORMATION OF LONG-LIVED REACTIVE SPECIES OF BLOOD SERUM PROTEINS BY THE ACTION OF HEAT

Background: Proteins oxidized by the action of X-rays represent long-lived reactive species, which trigger the secondary generation of reactive oxygen species (ROS). A change in the hydrogen peroxide (H2O2) content induced by various physical impacts may be an important factor of the therapeutic effect and the adaptation of the organism to unfavorable environmental conditions. Moderate hyperthermia and a number of physiotherapeutic procedures leading to a local warming of tissues are widely used in medical practice. However, the biological mechanisms of their curative effect are poorly understood. The prolonged generation of H2O2 long-lived reactive protein species (LRPS) after heating may be one of the mechanisms of activation of protective cellular mechanisms and thus to contribute to overcoming the disease. Aim: To investigate if the serum proteins bovine serum albumin (BSA) and bovine gamma-globulin (BGG) can form LRPS under moderate hyperthermia and show that heat induces LRPS, which in turn continuously generate ROS, in particular H2O2. Materials and methods: LRPS were studied by measuring the heat-induced chemiluminescence of protein solutions using a specially elaborated highly sensitive photon-counting chemiluminometer Biotoks-7 AM. The Results: Here we studied the possibility of formation of long-lived species of the blood serum proteins BSA and BGG in air-saturated solutions under the action of heat. It is shown that heat induces the generation of long-lived protein species, which in turn generate ROS (1O2, О2-•, OH•, H2O2). The formation of the long-lived reactive species of BSA and BGG with a half-life of about 4 h induced by moderate hyperthermia was revealed using the chemiluminescence of protein solutions. It was found that long-lived reactive species of BSA and BGG cause prolonged generation of H2O2. Conclusion: Thus, we found a new fundamental property of serum proteins: by the action of moderate heating, they are able to transform into LRPS that produce H2O2 over a long period of time. Therefore, it cannot be excluded that the heat treatment during physiotherapeutic procedures in clinical practice is accompanied by local heating and the formation of LRPS. H2O2 generated by these species may participate in signaling pathways and induce adaptive response in humans.