[The Effect of NT-1505 on a Membrane Structure of Endoplasmic Reticulum in vivo].

The effect of neuroprotector NT-1505 on endoplasmic reticulum membranes was studied. It was shown that the dynamics of changes in lipid and near-protein areas microviscosity of endoplasmic reticulum membranes at drug administration is of an antibate nature. This points to the absence of pathological disturbances in the membrane structure. Membrane microviscosity was measured by electron paramagnetic resonance spin labeling of 2,2,6,6-tetramethyl-4-capryloyl-oxylpiperidine-1-oxyl (lipid probe) and 5,6-benzo-2,2,6,6-tetramethyl-1,2,3,4-tetrahydro-γ-carboline-3-oxyl (near protein probe). To obtain more complete information about changes in membrane structure under the action of neuroprotector NT-1505 the temperature dependence of rotational diffusion correlation time was measured in the temperature range of 283-317 K (10-44 degrees C). The two structural transitions were characterized for both areas of .membranes of control group in temperature intervals 16-20 degrees C and 32-38 degrees C which were still present after NT-1505 introduction. Therefore, NT-1505 has no significant effect on membrane structure of the endoplasmic reticulum.

Oxidized modification of fragments D and E from fibrinogen induced by ozone.

Ozone-induced free-radical oxidation of fragments D and E from fibrinogen has been studied. The methods of elastic and dynamic light scattering in combination with electrophoresis of unreduced samples have shown the acceleration of enzymatic covalent crosslinking of molecules of oxidation-modified fragment D under the action of factor XIIIa. UV and IR spectroscopy shows that free-radical oxidation of amino acid residues of polypeptide chains catalyzed by ozone affects the cyclic and amino groups, giving rise to generation of mainly oxygen-containing products. Comparison of the IR spectra obtained for the oxidation-modified D and E fragments revealed more significant transformation of functional groups for the D fragment. EPR spectroscopy showed that the rotational correlation time of spin labels bound to the ozonized proteins decreased in comparison with the non-ozonized proteins. The rotation correlation time of the radicals covalently bound to the ozonized D and E fragments suggests that D fragment of fibrinogen is more sensitive to free-radical oxidation followed by local structural changes. Possible causes of different degrees of oxidation for fragments D and E are discussed.

[Interaction of fibrinogen with magnetite nanoparticles].

The interaction between fibrinogen and magnetite nanoparticles in solution has been studied by the methods of spin labeling, ferromagnetic resonance, dynamic and Rayleigh light scattering. It was shown that protein molecules adsorb on the surface of nanoparticles to form multilayer protein covers. The number of molecules adsorbed on one nanoparticle amounts to approximately 65 and the thickness of the adsorption layer amounts to approximately 27 nm. Separate nanoparticles with fibrinogen covers (clusters) form aggregates due to interactions of the end D-domains of fibrinogen. Under the influence of direct magnetic field, nanoparticles with adsorbed proteins form linear aggregates parallel to force lines. It was shown that the rate of protein coagulation during the formation of fibrin gel under the action of thrombin on fibrinogen decreases approximately 2 times in the presence of magnetite nanoparticles, and the magnitude of the average fiber mass-length ratio grows.

[EPR-spectroscopy of human blood preparations. Remote sequelae of the Chernobyl accident]. / EPR-spektroskopiia preparatov krovi cheloveka. Otdalennye posledstviia Chernobyl'skoi avarii.

It was shown, that as a result of Chernobyl accident the intensity of the EPR-signal of hemoproteins and ferroporphyrins of people blood increased, that most probably connected with disturbing of ferroprotein metabolism. Maximum intensity values had people, irradiated with low doses (to 2 cGy), that corroborate the theory of danger these doses for the people organism.