Formation of long-lived reactive species of blood serum proteins induced by low-intensity irradiation of helium-neon laser and their involvement in the generation of reactive oxygen species

Abstract It was demonstrated that low-intensity radiation of helium-neon (He-Ne) laser at 632.8 nm, which leads to the transition of oxygen to a singlet state, causes the formation of reactive oxygen species (ROS) – hydrogen peroxide, hydroxyl and superoxide (hydroperoxide) radicals – in aqueous solutions. The oxygen effect – dependence of hydrogen peroxide formation on the concentration of molecular oxygen – was shown, and the participation of singlet oxygen, hydroxyl radicals and superoxide (hydroperoxide) radicals in this process was testified. Laser radiation-induced ROS in solutions of blood serum proteins, bovine serum albumin and bovine gamma-globulin, cause the formation of long-lived reactive protein species (LRPS) with a half-life of about 4 h. The generation of LRPS caused by laser irradiation results in prolonged several-hour generation of ROS – hydrogen peroxide, hydroxyl and superoxide radicals. As affected by LRPS, coupled radical reactions lead to conversion of dissolved molecular oxygen to hydrogen peroxide. Irradiation with light sources away from the oxygen absorption band is not attended by formation of ROS and LRPS. A consideration is provided for the possible molecular mechanisms of ROS formation under the influence of He-Ne laser irradiation, the role of proteins in their generation and the biological significance of these processes.