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Biomedical subjects

S V Konev

Publications and source records attributed to S V Konev.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

[Transmembrane electric potential as a regulator of functional activity of biomembranes].

The role of the transmembrane electric potential difference in producing structural tension of biological membranes is analysed. A suggestion is made that delta psi can optimize conditions of protein-protein interactions by ordering the membrane lipid. For energy-coupling membranes this makes it possible to explain the dependence of ATP synthesis on both electron transport and delta psi in terms of local bioenergetic coupling. The energized biomembrane is considered as a self-supporting structure, delta psi being a regulator of efficiency of molecular machines performing different membrane functions, including energization as well.

Adenosine Triphosphate↗
PubMedDate not supplied

[Effect of arachidonic acid on the physical properties of bilayer and annular lipids of synaptic membranes].

It has been found by fluorescence analysis of pyrene excimerization that arachidonic acid while decreasing microviscosity of lipid bilayer increases it in the annular lipid zone. After incorporation of fatty acid into the membrane the annular lipid acquires the properties of a cooperative system manifested in the appearance of thermal transition near 25 degrees C.

Animals↗
PubMedDate not supplied

[Protein damage after treatment with ozone of protoplasts and isolated E. coli membranes].

The features of ozone-induced damage of E. coli plasma membrane proteins are investigated. A conclusion is made that protein fluorescence quenching is connected with modification of amino acid residues in the vicinity of tryptophane residues. Such modification may be a consequence of reaction with either ozone itself or products of its interaction with membrane lipids and/or proteins. The suggestion of Goldstein and McDonagh that ozone has a predilection for more hydrophilical membrane domains is confirmed. The data obtained are in agreement with a supposition about the leading role of proteins in deleterious action of ozone on cells.

Amino Acids↗
PubMedDate not supplied

[Regulation of mechanical stability of erythrocytes by serum immunoglobulins].

Autologic plasma protects human erythrocytes from hemolysis induced by their suction through glass microfiber filters. The protective effect is related to the protein fraction with molecular mass above 100 kD and reproduced by gamma-globulin. The action of proteins is abolished after heating the erythrocytes above 45 degrees C as well as in the presence of galactose and ribose but not glucose, mannose and lactose. It is suggested that an increase in mechanical stability of erythrocytes is caused by interaction of immunoglobulins with glycoproteid and glycolipid membrane receptors and mediated by the changes of structural state of the cytoskeleton.

Erythrocyte Aging↗
PubMedDate not supplied

[Effect of microenvironment on the conformation of m-cholinoreceptors in brain synaptic membranes].

Sensitivity of m-cholinergic receptor of synaptic membranes to SH-reagents (PChMB and NEM) was compared before and after its solubilization with detergents. PChMB blocked specific binding of m-antagonist QNB to both forms of the receptor in equal extent, while NEM was effective only after solubilization. After the membranes modification with butanol or arachidonic acid the membrane-bound receptor became sensitive to NEM. The solubilized receptor lost its ability to allosteric inhibition by acid. It is suggested that the receptor conformation is under the control of the membrane microenvironment.

Allosteric Regulation↗
PubMedDate not supplied

[Study of the role of microtubules in the regulation of activity of highly permeable contact membranes].

It was shown that various antitubulines-colchicin (10(-4) M), vinblastin-sulfate (10(-5) M) and vinoristin-sulfate (10(-5) M) do not affect the intercellular diffusion exchange of small inorganic ions and organic dye fluorescein in Drosophila virilis larva salivari gland. It is suggested that microtubules do not take part in functional activity regulation of gap junction high-permeable membranes.

Animals↗
PubMedDate not supplied

[Role of acetylcholinesterase in the transmembrane transfer of anions in erythrocytes].

Data are presented in favour of the regulatory role of AChE in passive transmembrane transfer of anions: 1) gradual inhibition of the enzyme with proserin brings about the change of the transport activation energy and irregular shift of temperature in the salient point on Arrhenius curves; 2) complexing of different AChE inhibitors (succinyl cholinechlorine, tetraethyl ammonium, tetramethyl ammonium, d-tubocurarin, proserin) results in the change of transport velocity. A significant increase of membrane binding of highly efficient and specific inhibitor of SITS anion transport forming complexes with membrane transport sites under the effect of acetylcholine AChE substrate is recorded. Proserin acts in the same direction, but to a much lesser degree. The removal of acetylcholine effect which activates SITS binding with the AChE inhibitor points to the initiation of structural disturbances from this enzyme. The scheme of AChE regulatory effect is suggested: modification of the enzyme conformation at the interaction with the inhibitors or substrate--structural rearrangement of the membranes--modulation of anion channels.

Acetylcholinesterase↗