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Biomedical subjects

E E Gussakovskiĭ

Publications and source records attributed to E E Gussakovskiĭ.

15 recordsLinked to original sources
PubMed1986

[Fluorescence proper of phospholipase A2 and orientotoxin from the venom of the giant hornet in the presence of ionic modulators of their membrane activity].

The own fluorescence of phospholipase A2 and orientotoxin at interaction of these components from Oriental hornet venom with calcium, strontium, lantan, magnesium ions has been investigated. Ca2+, La3+, Sr2+--activators of phospholipase activity--increase the quantum output of fluorescence. In the presence of Ca2+ the temperature of semitransitional process of thermoinactivation of investigated polypeptides increases by 2 degrees C.

Animals↗
PubMed1982

[Condensation of residues of diiodotyrosine with thyroxine near the surface of the thyroglobulin molecule by means of differential spectrophotometry].

Aromatic amino acids including iodotyrosines and thyroxin in intact, extraiodinated and acetylated bovine thyroglobulin were studied by the differential spectrophotometric technique. Modifications (i. e. acetylation, iodination) changed the accessibility of these chromophores to ethylene glycol. The data obtained suggest that thyroxin can be formed from two diiodotyrosine residues in the surface regions of the thyroglobulin molecule which are available for ethylene glycol.

Animals↗
PubMed1980

[Extinction coefficient of thyroglobulin].

The extinction coefficient at 280 nm of the solution (pH 7,2-7,4) of thyroglobulin from normal thyroid and nodular euthyroid goiter was measured with the values of 0,6-0,7 to 0,9 ml.mg-1.cm-1. The value of E1%280 as function of the iodoamino acid content depends on the morphological state of the thyroid gland. A simple method for determination of the E1%280 value by measuring of the protein absorption spectrum is proposed.

Amino Acids↗
PubMedDate not supplied

[Utraviolet adsorption and fluorescence of human thyroalbumin].

Some spectral properties of human thyroalbumin have been studied. Ultra-violet absorption of the aqueous solution of this protein has two maxima: at the wavelengths of 276 and 296--298 nm. Under the excitation by a monochromatic light with the wavelength of 280 nm the thyroalbumin has the fluorescence spectrum with the maximum at 430 nm and the quantum yeild of fluorescence about 5,4%. It has been established that thyroalbumin fluorescence consists of two components with the maxima at 385 and 450 nm. Moreover the "sortwave" component is principally attributed for by the presence do iodoamino acids.

Humans↗
PubMedDate not supplied

[Tryptophan fluorescence of Na+,K+-ATPase preparations].

On the strength of the study of tryptophan fluorescence of Na+, K+-ATPase preparation a conclusion about conformational changes of the enzume molecule at the level of its tertiary structure is made. The largest changes of intensity and position of fluorescence spectrum consequently the macromolecule structure are discovered at the formation of Mg-ATP-enzyme complex.

Adenosine Triphosphatases↗
PubMedDate not supplied

[Effect of cryopreservation of thyroid parenchyma on iodoamino acid composition of thyroglobulin and its iodination].

The content and distribution of iodoamino acids in thyroglobulin of the cryopreserved thyrotoxically-changed thyroid parenchyma were studied, as was thyroglobulin iodination. Thyroid tissue obtained during operations of patients with diffuse-toxic goiter was investigated. The thyroid parenchyma was cryopreserved according to the method developed at the Institute of Cryobiology and Cryomedicine Problems, Academy of Sciences of the Ukrainian SSR. The tissues were stored for 4-6 months. Thyroglobulin was isolated by gel filtration of the thyroid saline extract through a column packed with Sephadex G-200. Thyroglobulin was iodinated with KI + I2 water solution, pH 9.2, at 37 C for 30 min. The amount of iodine added was 100 moles of I2 per protein mole. Protein concentration was determined by the biuret reaction. Thyroglobulin iodoamino acid composition was determined by direct spectrophotometry. Absorption spectra were measured by an EPS-3T recording spectrophotometer ("Hitachi", Japan). The processes of freezing (-196 degrees C) and thawing of the thyroid parenchyma were shown to induce no changes in the thyroglobulin iodoamino acid composition. Cryopreservation of the thyroid parenchyma considerably affected iodine incorporation and formation of iodoamino acids in the thyroglobulin during its in vitro iodination. It may be supposed that cryopreservation of the thyroid tissue affects the thyroglobulin conformational status, that results in increased iodination of this iodoprotein.

Culture Media↗
PubMedDate not supplied

[Differences in the secondary structure of thyroglobulin under normal conditions and in nodular goiter].

Intact and iodine-treated thyroglobulin from normal thyroid gland and from nodular euthyroid goiter were studied by means of circular dichroism to detect differences in the protein secondary structure. Contents of alpha- and beta-structures in thyroglobulins were differentiated only by several per cents but artificial iodination of the protein increased markedly the difference between thyroglobulins of various origin. Extrapolation of the data to "zero" content of iodine-containing amino acids demonstrated that the initial steps of thyroglobulin synthesis occurring before iodination "in vitro", appears to be also responsible for alterations in the protein secondary structure.

Circular Dichroism↗
PubMedDate not supplied

[The inherent fluorescence of thyroglobulin].

Properties of tryptophane and tyrosine fluorescence of intact and iodinated thyroglobulin from normal human thyroid and nodular euthyroid goiter were studied. It has been shown that practically all (95%) tryptophane residues in "normal" thyroglobulin are in the inner regions of the globule. In "pathological" thyroglobulin in the regions inaccessible for water there are located only 68% of trypthophanyls. After iodination only in "pathological" thyroglobulin redistribution of tryptophan residues takes place on the surface and inside the globule. For bovine thyroglobulin shifts of tryptophane fluorescence spectra to the long wave region were observed, as well as a fall of the quantum yield at pH below 5 and above 11, which is in accord with acid and alkaline denaturation. A conformation transition was observed in the pH region 6--7 which is accompanied by a change in the efficiency of excitation energy transfer from tryptophan to iodoamino acids.

Animals↗
PubMedDate not supplied

[The role of oligomeric structure of human serum albumin during its interaction with polyalbumin receptors in blood serum of patients with viral hepatitis B].

Several oligomers of human blood serum albumin modified by glutaraldehyde differ in their binding ability to polyalbumin receptors in blood serum of patients with viral hepatitis B. Erythrocytes containing the albumin tetramer are able to agglutinate, while the red blood cells coated with dimer or monomer are deprived of this property. At the same time, the albumin dimers and monomers neutralize agglutination of the erythrocytes containing the complete pool of modified albumin in membranes although their effect is distinctly lower than that of tetramer. The albumin tetramer may have two or more sites of binding to erythrocytes or to the surface antigen of hepatitis B virus, bearing polyalbumin receptors, whereas the protein dimer or monomer contained only one site of binding.

Binding Sites↗
PubMedDate not supplied

[Heat denaturation of hemocytocardiotoxin from the venom of the Central Asian cobra].

It has been stated that boiled for three hours haemocytocardiotoxin (HT) from cobra poison loses "direct" hemolytic activity and is unable to potentiate a haemolytic effect of phospholipase A. Surface activity of HT does not change. It is shown that in the course of heat denaturation the aggregation of toxin molecules to dimers and trimers takes place and electrophoretic mobility is decreased. The fluorescence of HT tyroxin residues supported the fact of its irreversible heat denaturation.

Animals↗