As a rule, such examples are demonstrated on models of microorganisms. The role of mitochondrial kinase S.сеrdiae was studied, and it was shown that inactivation of the POS5 gene encoding the mentioned enzyme resulted in 28 times increase in the number of carbonyl groups of proteins in mitochondria and many times decrease in the activity of enzymes sensitive to oxidation: aconitases and succinate dehydrogenases as compared to the initial strain. In our laboratory, we studied some indicators of oxidative stress in the same type of yeast and used different strains: the initial and its isogenic derivatives, defective in one of the 2x, as well as both present in the yeast catalases. It turned out that the higher the activity of catalase, the lower the level of carbonyl groups in proteins.
Between the activities of catalase and oxidation-sensitive enzymes, glucose-6-phosphate dehydrogenase and glutathione reductase, a strong positive correlation was found, i.e. the higher the activity of catalase, the lower the level of protein carbonyls, but at the same time the higher the activity of oxidation-sensitive enzymes. In the case of multiple confirmations of the results described above, it is possible to say with some certainty that catalase under in vivo conditions can protect cellular proteins from free-radical oxidation.
The possible protective role of superoxide dismutases in baking yeast was also investigated. Several different methodological approaches were used, but in all cases, the relationship between the activity of superoxide dismutase and the content of carbonyl groups in proteins was analyzed. The dependence understudy turned out to be quite close to the parabolic one. It looks as if depending on the activity of superoxide dismutase it can be both a pro- and antioxidant. In the next paper, the conditions differed somewhat from those used in the previous paper, and the results appeared to be at first glance generally opposite. The dependence of the content of carbonyl groups in proteins on the activity of superoxide dismutase had a dome form. A good positive correlation between catalase and superoxide dismutase activity was also revealed here. Similar results have been obtained by us again recently in the study of the influence of hydrogen peroxide on the activity of superoxide dismutases and catalases in yeast. Therefore, we concluded that in vivo in several different experimental models of catalase and superoxide dismutase can protect proteins from free radical oxidation, although, apparently, the relationship between them is not always linear. In the last few years, it has been shown that the free radical oxidation of certain cellular proteins can induce apoptosis. A very interesting series of works on free radical oxidation of proteins in connection with the state of the organism or individual cells was carried out by T. Nystrom with colleagues. Thus, in the study of the poisonous yeast of Saccharomycescerevisiaeoni found that regardless of the "age" of the mother cell, the content of carbonyl groups of proteins in it in the new bud cell is always a quite low concentration of oxidized proteins. When ES embryonic stem cells were studied by the same researchers, it was unexpectedly revealed that they contain a high content of protein carbonyls and final products of glycolization of proteins. The main oxidatively modified proteins were chaperones and cytoskeleton proteins. Cell differentiation caused a sharp decrease in the concentration of protein carbonyls. The authors believe that they described a part of the previously unknown process of protein-level rejuvenation, which occurs in the early stages of embryonic development. In an excellent review of the role of free radical oxidation of proteins in the cells of different organisms, he concluded that there are several options for development in the process of early development, maturation, production of offspring and aging, but there is still not enough information to obtain a complete picture.