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T Iu Shchegoleva

Publications and source records attributed to T Iu Shchegoleva.

15 recordsLinked to original sources
PubMed1993

[The molecular cellular aspects in predicting the course of an acute myocardial infarct].

Ultra-high-frequency dielectrometry was used to determine the dielectric permeability of erythrocyte suspension cell membranes in 48 patients with acute myocardial infarction who were given agonists, antagonists, and modulators of the adenylate cyclase system. The study showed that the functional status of erythrocyte membranes changed correlating with the clinical course of the disease. Changes in this status were followed by complications of improvement. It was evidenced that the trend of a pathological process in coronary stress was associated with the functional status of erythrocyte membranes. Ultra-high-frequency dielectrometry is a sensitive method for evaluating the status of patients with myocardial infarction, controls the natural history of the diseases at the molecular level and to predict the development of complications.

Adenylyl Cyclases↗
PubMed1992

[Molecular mechanisms of the development of cardiovascular pathology].

Changes of a number of functions of beta-receptor complex mechanism have been analyzed by means of the microwave-dielectrometry method on native erythrocytes at various stages of cardiovascular pathology. The control scheme of beta-receptor complex has been analyzed in the adenylate cyclase system and the regions have been extracted which are subjected to an attack of pathological factors of the effect.

Adenylyl Cyclases↗
PubMedDate not supplied

[Globular protein hydration by a differential dielectrometric method].

A differential method is described for measuring dielectric constants and losses in aqueous protein solutions at millimetrerange wavelengths. Employment of the method allows to improve the accuracy of determining the degree of hydratation. A method has also been suggested for taking into account the contribution of ions to the dielectric constant of solutions. The differential method was used to study hydratation of nine globular proteins. The data obtained are compared with the corresponding values provided by other experimental techniques and with theoretical predictions based on some models of hydratation. Good agreement is obtained with results provided by the isopiestic and NMR techniques. The discrepancy shown for hemoglobin is discussed in the paper. As has been shown, the dielectric method registers a monomolecular surface layer of water only. With pH varying between 4.0 and 3.2, a significant increase is observed in the hydratation of serum albumin. Presumably, this effect is connected with a N--F conformational transition.

Electrochemistry↗
PubMedDate not supplied

[UHF-dielectrometry in the study of parameters of native adenylate cyclase complex during modulation of its activity].

Some features of molecular mechanisms of adenylate-cyclase system of native human erythrocytes were studied by the UHF-dielectrometry method. The results obtained show great changes in cell structure hydration when there is some influence on the membrane protein components which are involved in transmembrane signal transformation. The observed effects permit definite conclusions to be drawn concerning some molecular mechanisms of cell regulation. The obtained data demonstrated the following: the key role of N-protein, spatial separation of PGE2 regulatory centres and hormones on the beta-receptor, system modulation by the change of Ca2+ ions concentration in the presence of PGE2 and the connection of the alpha-receptor with the calcium slow channel.

Adenylyl Cyclase Inhibitors↗
PubMedDate not supplied

[The individual choice of drug preparations].

A method of superhigh-frequency dielectric measurement was proposed for control of hormone-stimulated adenylate cyclase system of human erythrocytes. The method was used for the analysis of some adrenoblockers. Differences in their effects in healthy persons and patients with cardiovascular pathology were found.

Adenylyl Cyclases↗
PubMedDate not supplied

[Hydratation of the rubredoxin polypeptide chain from data on the spatial structure].

The hydration water distribution around the main chain protein rubredoxin has been analysed using the crystal data at high resolution obtained earlier. The analysis was based on the consideration of all nearest neighbour atoms around the N and O atoms of peptide groups. The atoms which can form hydrogen binds were the subject of final analysis. The nitrogen atom of a peptide NH group has only one vacancy for neighbours. The oxygen atom of a peptide CO group has one, two or more neighbours, some of them are oxygen-water atoms. About 27% of NH and 53% of CO peptide groups are hydrated, that corresponds to 0.12 H2O per gram of protein. A detailed analysis shows that NH and CO groups of the main chain are hydrated according to the principle of maximum possible in situ saturation of hydrogen bonds. Thus the peptide groups incorporated in the peptide hydrogen bond network were not hydrated as a rule. Consequently, for rubredoxin a pleated sheet region, some regions for the large and small main chain loops, and Fe-containing pocket are not hydrated. A method for evaluation of the main chain hydration is proposed when the coordinates of protein atoms are available.

Crystallization↗
PubMedDate not supplied

[Water distribution around a protein molecule from data on spatial structure].

Water distribution was calculated using the structure data of protein rubredoxin (K. Watenlaugh et al. J. Mol. Biol., 138, 615, 1980). By this method the hydration surrounding of macromolecules was localized in the spheres of the 3,2 A radius with the error 8%. A detailed analysis of the data on water localization in the protein crystal shows that hydration water distribution consists of the associates of water molecules and does not form the "hydration shell".

Biopolymers↗
PubMedDate not supplied

[Adenylate cyclase system and calcium channels].

The molecular mechanisms of the effect of calcium ions on adenylate cyclase function on transmembrane signal transfer in erythrocytes were studied by dielectrometry.

Adenylyl Cyclases↗
PubMedDate not supplied

[The change of erythrocyte hydration environment under hormonal stimulation].

In this work were studied the change of human erythrocytes cell structure hydration by modelling the different way of transmembrane signal transformation in the cell by super high frequency dielectrometry method in water dispersion region. In nondestructive conditions were demonstrated the participate of cytoscelet in hormonal stimulation of cells by various molecular mechanisms. The change of hydration environment of cell by catecholamines binding were direct correlated with hydration parameters agonists and topograph models alpha- and beta-receptor complexes.

Erythrocytes↗
PubMedDate not supplied

[Heat-induced transitions in proteins].

The heat-induced relaxation of globule conformational was studied under mild physiological conditions by extra-high frequency dielectrometry in the range of dispersion of free water. It is shown that macromolecules possess a functionally significant molecular memory, which is due to their spatial organization and, probably, to water associates.

Protein Conformation↗