Analysis of the level of oxidative stress by assessing the damage to the plasma protein serum albumin under the influence of an oxidizing agent

Abstract

Oxidative stress, which leads to oxidative modification of various macromolecules, including proteins, is now considered an important pathogenetic link in many diseases. In this work, oxidative damage to a blood plasma protein, bovine serum albumin BSA, under the action of an oxidizing agent, hydrogen peroxide H2O2, was studied by spectrofluorometric method. The H2O2 concentration-dependent quenching of the intrinsic fluorescence of BSA is shown. BSA fluorescence quenching constants in hydrogen peroxide solutions are calculated by mathematical modeling methods. The dependences found in the fluorescence quenching constants are explained both by oxidative damage to the microenvironment of BSA tryptophan residues and by changes in the native conformation of protein globules upon oxidative damage. More significant peroxide damage to BSA occurs at lower pH values due to the fact that H2O2, as an oxidizing agent, acts more strongly in an acidic environment. The registered quenching of the protein's own fluorescence when damaged by an oxidizing agent can be used as a medical method for assessing the level of oxidative stress in the body in the diagnosis of a number of diseases.