[The possible role of nitrogen dioxide produced in the field of bifurcation of vessels, in the processes of their damage in hemorrhagic strokes, and the formation of atherosclerotic plaques].

According to modern views the formation of atherosclerotic plaques is associated with accumulation of cholesterol in the vascular wall. This is due to an imbalance between the intake of cholesterol in the intima of vessels, together with the low-density lipoproteins (LDL) and its output with high-density lipoprotein (HDL). Change of LDL (glycosylation, lipid peroxidation, hydrolysis of phospholipids) and the effective release of cholesterol from the endothelium of the vascular wall are the factors that cause an imbalance in cholesterol metabolism. In this paper we propose a new concept of the mechanism of initial formation of atherosclerotic plaques, which can complement the existing concepts. According to this concept an important role in the early stages of atherosclerosis are highly reactive molecules of nitrogen dioxide (NO2), resulting from the violation of the cycles of nitric oxide and superoxide anion radical. Hypothesized that the mechanism of antiradical protection of cells and the organism as a whole, above all, laid out in most of the cyclic organization of metabolic processes that involve the formation of free radicals. Violation of this cyclic mechanism may be one of the causes of many diseases associated with hypoxia/ischemia and inflammation. The review considers the hypothesis of the possibility of participation of NO2 and OH-radicals formed in violation of the cycles of NO and superoxide, in the mechanisms of vascular damage with hemorrhagic stroke and in the formation of atherosclerotic plaques.

[Formation of glycated recombinant leghemoglobin in Escherichia coli cells].

A nonenzymatic glycation of the recombinant leghemoglobin expressed in Escherichia coli cells was demonstrated for the first time. This process involved the heme pocket and gave low-spin leghemoglobin species. A correlation between the degree of E. coli protein glycation and synthesis of poly-beta-hydroxybutyric acid was found, suggesting that the accumulation of reserve carbon sources and nonenzymatic glycation could be alternative processes.

[Hemoglobins: diversity of structures and functions].

This review briefs the modem concepts of the diversity of hemoglobin functions. The hemoglobins discovered in the representatives of all kingdoms of living nature are described. Specific structural features of various groups of these proteins, including flavohemoglobins and truncated hemoglobins, are discussed. The transport, catalytic, and sensory functions of these proteins are described as well as their roles in oxidative, nitrosative, and carbonyl stresses and the changes in their functions caused by modifications of the molecule. The issues of hemoglobin origin and evolution are discussed.

[Method of determination of the content of hemoglobin-like proteins in heterogenic mixtures].

A spectrophotometric method of quantification of hemoglobin-like proteins, which makes it possible to determine their concentration in mixtures of various composition, was proposed. This method is based on comparing the optical density of different redox forms of proteins when their spectra are superposed at the isosbestic point. The coefficients used in calculations were determined by us. The proposed technique is simple and does not require special procedures. It was tested using myoglobin solutions of various concentrations, myoglobin solutions containing other proteins, and solutions of leghemoglobin (a myoglobin-like protein from legumes).