Activity of Antioxidant Defense Enzymes in Rats with Experimental Allergic Encephalomyelitis.

We studied activities of antioxidant system enzymes in tissues of rats with experimental allergic encephalomyelitis. It was shown that the development of pathology is accompanied by deformation of the neurons and axonal degeneration, intensification of free radical oxidation, exhaustion of the reduced glutathione pool, and multidirectional changes in activities of antioxidant enzymes in rat tissues. The observed imbalance in the antioxidant defense system can be associated with excessive glutathione utilization in the glutathione transferase reaction and different severity of the pathological process in the brain and spinal cord. The received data necessitate the search for compounds that can prevent inhibition of antioxidant system components in order to analyze the possibility of their use in the treatment of multiple sclerosis.

[Decomposition of hemoglobin UV absorption spectrum into absorption spectra of prosthetic group and apoprotein by means of an additive model].

The decomposition pathways of hemoglobin UV absorption spectrum into the absorption spectra of the protein and non-protein components are proposed and substantiated by means of an additive model. We have established that the heme component has an absorption band with a maximum at λ(max) = 269.2 nm (ε = 97163) and the apoprotein component has an absorption band with a maximum at λ(max) = 278.4 nm (ε = 48669) for the wavelength range from 240.0 to 320.0 nm. An integral relative proportion of absorption for the heme fraction (78.8%) and apoprotein (21.2%) in the investigating wavelength range is defined.

[Spectral and functional properties of ceruloplasmin under UV irradiation].

During oxydase reaction spectral characteristics of ceruloplasmin at absorption of copper ions and protein part of the molecule are shown to change. It has been ascertained, that when irradiating ceruloplasmin by UV-light the functioning of intramolecular electron transport chain is broken, the degree of positive cooperativity (a Hill's constant) on substrate decreases. It is supposed, that these changes are caused by disturbance of interdomain interactions in a protein molecule.

[Oxygen-binding properties of human hemoglobin solutions UV-irradiated in the presence of iodoacetamide]. / Kislorodsviazyvaiushchie svoistva rastvorov gemoglobina cheloveka, UF-obluchennykh v prisutstvii iodatsetamida.

Changes of oxygen-binding properties of human hemoglobin solutions modified by the different concentrations of iodoacetamide and by this chemical agent together with UV-light in doses 151 and 755 J/m2 has been studied by means of spectroscopy. It has been shown that addition of iodoacetamide to native hemoglobin solution (12:1) results in increase of the oxygen affinity and breach of the hem-hem interaction of hemoprotein. It has been ascertained that influence of UV-radiation on hemoglobin displays in photodissociation of the tetramers to protomers.

[UV-sensitivity of hemoglobin dimers in free state and in valency hybrids: modification by serotonin]]. / UF-chuvstvitel'nost' dimerov gemoglobina v svobodnom sostoianii i v sostave gibridov valentnosti: modifikatsiia serotoninom.

Changes of oxygen-binding activity of hemoglobin dimers modified by the therapeutical doses of UV-light and serotonin in free state and in valency hybrids are analyzed. The prior role of photodissociation to dimers at the UV-radiation action on heme-protein molecules has been shown. It has been observed that the complex between hemoglobin and serotonin is formed in fields of alpha beta-dimers contacts.

[Oligomeric proteins: modulation of UV-sensitivity and characteristics of photochemical transformations]. / Oligomernye belki: moduliatsiia UF-chuvstvitel'nosti i zakonomernosti fotokhimicheskikh prevrashchenii.

The results of our research devoted to the study of photophysical and photochemical transformations of some compound proteins of oxidative, antioxidant, transport and immune systems of an organism under conditions of different microenvironment (presence of chemical modificators, the change of pH, temperature, doses and spectral composition of ultraviolet irradiation) have been analyzed. Methods and the degree of modulation of UV-sensitivity of proteins of the mentioned systems have been discussed. Conditions, on which the used chemical agents show photoprotective and photosensitizing effect on protein molecules, have been found.

[Serotonin as a photoprotector of the oxygen-transporting function of hemoglobin]. / Serotonin kak fotoprotektor kislorodtransportnoi funktsii gemoglobina.

Oxygen-binding properties of human hemoglobin modified by UV-light (240-400 nm) in dose range (1.51 + 6.04) x 10(2) J/m2 together with serotonin (10(-4) M) has been studied by means of spectrophotometry. UV-radiation results in increase of the oxygen affinity of hemoglobin. Serotonin displays the photoprotective effect on the hemoglobin oxygen-transport function. Mechanisms of photoprotection of the biogenic amine are proposed for discussion.

[Structure-activity changes in human hemoglobin induced by UV-light and serotonin]. / Strukturno-funktsional'nye izmeneniia gemoglobina cheloveka, indutsirovannye UF-svetom i serotoninom.

Basic indices of oxygen-binding properties of the human hemoglobin solutions modified by the UV-light (240-390 nm) in dose range 151-604 J/m2 together with serotonin (10(-5)-10(-3) mol/l) have been analysed by means of spectrophotometry registration of the oxyhemoglobin dissociation curves. In these conditions biogenic amine displays maximum photoprotective effect at the concentration 4 x 10(-4) mol/l. At the highest concentrations serotonin exert photosensibilitive that influences the course of the protein molecule disorganisation. It has been demonstrated that three-dimensional surfaces analysis can be used to forecast the influence of the serotonin photoprotection on the hemoglobin functional activity.

[Thermal denaturation of oligomeric proteins: structural and functional modifications, the sequence of steps]. / Teplovaia denaturatsiia oligomernykh belkov: strukturno-funktsional'nye izmeneniia, posledovatel'nost' stadii.

On the basis of literature and own experimental data changes in the structural and functional properties of some oligomeric proteins of the blood system (hemoglobin, lactate dehydrogenase, superoxide dismutase, catalase) exposed to the influence of temperature in a broad range were analyzed. The many-phase character of the temperature modification of protein molecules with different values of functional and kinetic parameters for each of revealed stages was discovered. At a critical temperature and at higher values, the dissociation of oligomeric proteins into separate subunits was shown to occur along with the typical "loosening" of the protein globule. It was shown that low-molecular components (subunits) can subsequently associate with one another and with oligometic proteins, which leads to irreversible denaturation and to the unusual physicochemical behavior of protein molecules. Schemes of processes underlying the temperature modifications of the proteins studied were elaborated.

[The oxygen-binding properties of hemoglobin modified by the action of temperature and sodium dodecyl sulfate]. / Kislorodsviazyvaiushchie svoistva gemoglobina, modifitsirovannogo vozdeistviem temperatury i dodetsilsul'fata natriia.

Oxygen-binding properties of mice hemoglobin modified by temperature (20-45 degrees C) or by this temperature together with sodium dodecyl sulphate (SDS) of different concentrations (3.47 x 10(-5)-3.47 x 10(-4) M) were studied by means of spectrophotometry. The increase of temperature up to 42-45 degrees C resulted in accumulation of the hemoglobin aggregates larger than tetramers. The combined effect of SDS and temperature may change the protein microenvironment as well as to integrate the hemoprotein molecules into subunits, depending upon the SDS concentration.

[Structural and functional characteristics of hemoglobin molecules from the preserved donor blood during long-term storage]. / Strukturno-funktsional'nye kharakteristiki molekul gemoglobina konservirovannoi krovi donorov pri dlitel'nom khranenii.

The human blood haemoglobin molecules keep their quaternary structure for 25 days at a long-term storage of the blood stabilised with glugicyr. The molecules' electronic characteristics did not change during 5 days, and their oxygen-binding ability remained unaltered just during 2 days after taking the blood.