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Biomedical subjects

K B Sherstnev

Publications and source records attributed to K B Sherstnev.

17 recordsLinked to original sources
PubMed1992

[Effects of pyrazidol on resistance of animals to hypobaric hypoxia].

The influence of monoamine oxidase type A inhibitor pyrazidol on rats sensitivity to hypobaric hypoxia was investigated. Preliminary pyrazidol administration shows evident protective effect under hypoxia. It increases animals survival at the altitude of 12,000 m above the sea level, prevents lungs affection and erythrocyte membrane destabilization at the altitude of 9,000 m during 3 hours. Plasma total peroxidase activity, extraerythrocyte hemoglobin concentration and free iron content were used as the indexes of erythrocyte membrane stability reflecting the organism state under stress effects.

Altitude Sickness↗
PubMed1991

[The cytochrome P-450 content and catalytic activity in rat liver microsomes during hyperbaric oxygenation].

The effect of different conditions of hyperbaric oxygenation (HBO) on content and catalytic activity of cytochrome P-450 in rat liver cytochrome has been studied. The intensity of lipid peroxidation in microsomal membranes has been determined by the content of dien conjugates and Schiff's bases. The rate of amidopyrine demethylation has been shown not to change, but the rate of aniline hydroxylation decreases on 34, 57 and 64% under increase of oxygen pressure up to 0.3, 0.5 and 0.7 MPa correspondingly. The level of dien conjugates increase on 66-87% under all studied conditions of HBO. Cytochrome P-450 content decreases on 45% under the action of 0.7 MPa, but content of Schiff's bases increases on 210% as compared with control.

Aminopyrine↗
PubMed1986

[Changes in the fluorescence in preparations of normal human immunoglobulin during deamidation].

It was shown that self-fluorescence of normal human immunoglobulins prepared with the use of donor and placental raw materials lowered after incubation at 37 degrees C for 28 days and after storage under the standard conditions (4-10 degrees C) for 2 years. Dependence of thermostability of the immunoglobulins on the raw material used for their preparation and the storage period was revealed spectrofluorometrically. Resistance of the proteins to thermal denaturation lowered on storage. However, it was higher in the immunoglobulins prepared with the use of donor serum. Thermostability and lowering of self-fluorescence of the proteins depended on the level of their amidization.

Blood↗
PubMed1986

[Effect of chlorgyline on gamma-aminobutyric acid levels in hyperoxia].

Chlorgyline, an inhibitor of type A monoamine oxidase, administered to rats prevented oxygen-induced decrease in gamma-aminobutyric acid brain content in hyperoxia. At the same time chlorgyline had an overall protective effect, increasing two-fold the period prior to the development of oxygen convulsions. The data suggest an important role of the modification of monoamine oxidase catalytic properties in the development of oxygen-induced intoxication and, particularly, in the decrease of gamma-aminobutyric acid content in hyperoxia.

Animals↗
PubMed1984

[Posttranslational deamidation of crystalline lens proteins during animal aging].

The amide content of total proteins and protein fractions (alpha-, beta-, gamma-cristallins and albuminoid) from cortex and nuclear lens zones of cattle has been investigated. The amide content in proteins of cortex and nuclear lens of young animals (1,5-2 years old) is the same. The decrease of the amide content in the proteins of nuclear lenz zone of old animals (6-12 years old) is due to fraction of readily hydrolysed amides. The data obtained prove the posttranslational desamidation of lens proteins at ageing. beta-Cristallines--the proteins with the highest amides content is exposed to posttranslational desamidation most of all.

Aging↗
PubMed1981

[Separation of fractions of phosphoprotein phosphatase and its protein inhibitors by isoelectrofocusing].

Individual molecular forms of phosphoprotein phosphatase from albino rat cardiac muscle were separated by isoelectrofocusing, resulting in a few fractions differing in pI (5.1, 5.4, 5.9-6.1 (double peak) and 7.1, respectively). Isoelectrofocusing of a purified enzyme preparation also allowed to isolate and characterize two protein inhibitors of the enzyme. The first one with pH 6.5-6.7 is similar to the thermostable phosphoprotein phosphatase inhibitor known from literature. This protein inhibits the enzyme activity by 90%; its effect is not decreased after 5-min heating at 95 degrees. The other inhibitor protein with pH 5.6-5.8 is thermolabile. When the enzyme activity was decreased 2.5-fold prior to thermal treatment, the latter protein lost this ability after heating at 95 degrees and inhibited the enzyme only by 9%. It is assumed that inhibitory proteins beside low molecular weight effectors can be involved in the mechanisms of the post-synthetical operative modification of phosphoprotein phosphatase function.

Animals↗
PubMed1980

[Beta-glycosidase system of sunflowers. Isolation of enzyme and study of their substrate specificity].

The beta-glucosidase, beta-galactosidase, beta-xylosidase and alpha-L-arabinosidase activities of a partially purified preparation from sunflower seeds were studied by chromatography, polyacrylamide gel electrophoresis and isoelectrofocusing. beta-Glucosidase was isolated as two fractions with high molecular weights. One form of beta-glucosidase does not possess strict specificity to stereochemistry of hexosides C-4 and C-6 and pentosides C-5, whereas the second form exhibits a narrow specificity for C-4 and is low specific towards substituents of C-5. The sunflower seeds also contain acid beta-galactosidase, which possesses a narrow specificity and is not coupled with the beta-glucosidase activity. The molecular weight of beta-galactosidase is 62000.

Glycoside Hydrolases↗
PubMed1979

[Characteristics of myelin basic protein from dog spinal cord].

Some characteristics of the myelin basic protein from dog spinal cord were studied. The basic protein has a molecular weight of 18,000; the isoelectric point is 9.5. The amino acid composition of the protein was determined. Electrophoresis in 15% polyacrylamide gel revealed the heterogeneity of the basic protein. The EAE-activity of the basic protein was tested on guinea pigs.

Amino Acids↗
PubMed1978

[Nonenzymatic deamidation as a factor in protein aging].

Amidation of two protein fractions of brain, heart and liver of senite rats was found to decrease by 15--21% as compared with that of young animals. This decrease was shown to be due to unstable amide groups. Strong evidence is presented favouring the preposition that in proteins the unstable amide groups are those of asparagine and the stable ones those of glutamine. The possibility of the nonenzymatic deamidation of proteins was investigated. Deaminated proteins were found to be more easily attacked by proteinases which could be one of the possible ways of breakdown of aging proteins.

Aging↗
PubMed1977

[Substrate specificity of sweet almond beta-glucosidase].

Beta-Glucosidase, beta-galactosidase, beta-xylosidase and alpha-L-arabinosidase activities of partially purified preparation of almond emulsin were investigated using chromatography, electrophoresis in polyacrylamide gel and isoelectric focusing. Beta-Glucosidase was found to exist as two components having equal molecular weight. Aggregation of the components with inactive proteins probably results in the appearance of multiple native forms which have similar specific activities. In no case separation of the beta-glucosidase activity from the accompanied activities was achieved. It is concluded therefore that these activities are exhibited by an enzyme which is not strictly specific to the C4, C6 stereochemistry for hexosides and to that of C4, C5 for pentozides.

Arabinose↗
PubMedDate not supplied

[Degradation of nucleic acids during generation of superoxide-anion in the presence of copper ions].

The efficiency of Escherichia coli nucleic acids samples: covalently closed circular DNA, linear chromosomal DNA, total RNA degradation mediated by the action of high oxygen pressure; hydrochloric hydroxylamine in alkaline conditions in the presence of cooper ions and in analogous conditions without cooper ions was studied. The nativity of nucleic acids was determined by means of fluorometric analysis of nucleic acids/ethidium bromide complexes. Experiments revealed, that the destructive effect of active oxygen species decreased in the following order: NH2OH.HCl in alkaline conditions in the presence of copper ions-NH2.HCl in alkaline conditions--high pressure of pure oxygen. The stability of nucleic acids decreased in the following order: covalently closed circular DNA-linear DNA-RNA.

Copper↗
PubMedDate not supplied

[Monoamine oxidase activity and gamma-aminobutyric acid levels in hyperoxia. The effect of clorgyline].

Under conditions of hyperoxia mitochondrial monoamine oxidase (MAO) of the A type from rat brain proved to be able to deaminate gamma-aminobutyric acid (GABA); the transformation in the enzymatic properties appears to be responsible for a decrease in content of the intermediator in brain. Preadministration of chlorgiline (inhibitor of MAO of the A type) into animals before hyperoxygenation prevented completely the GABA content decrease, not affecting the glutamate decarboxylase activity, which was decreased in hyperoxia. At the same time, chlorgiline exhibited the total protective effect increasing 2-fold the period before oxygen convulsions.

Animals↗
PubMedDate not supplied

[Synaptosome membrane proteins of the rat brain in convulsions caused by increased oxygen pressure].

High oxygen pressure (0.7 MPa during 30-40 min) increased the quantity of high molecular proteins with simultaneous decrease in amount of low molecular proteins in rat brain synaptosomes. At the same time, the significant increase of lipoprotein fluorescence with emission at 435 nm was observed. Oxygen at high pressure inhibited incorporation of 14C-leucine into synaptosomal membrane proteins. Possible mechanisms of these alterations are discussed.

Animals↗
PubMedDate not supplied

[Spontaneous deamidation of gamma-globulin].

gamma-Globulin from human blood serum was incubated in thermostat at 37 degrees within 15, 30, 45, 60 and 72 days. Amount of readily and poorly hydrolyzed amide groups as well as an increase in amino acid content were estimated in the protein at zero time and at these periods. The sterility of the preparation was examined in each case. Spontaneous deamidation of gamma-globulin, observed during incubation, caused an increase in negative charge and altered electrophoretic mobility of the protein molecule. gamma-Globulin was attacked by prothelin more effectively as amount of amide groups was decreased in the protein. Spontaneous deamidation appears to be one of reasons of the protein molecules ageing.

Amides↗
PubMedDate not supplied

[Structural heterogeneity of prealbumin fraction rat brain].

Biochemical and immunochemical studies were carried out to prove the structural heterogeneous and supermolecular nature of the rat brain BTB-protein. Microheterogeneity of the BTB-protein--6 subfractions--was found by disc electrophoresis in 30% gel and isoelectric focusing (pH 3-5). Two of the proteins are RNA-proteids. The presence of neurophysin in BTB-protein is suggested. Heterogeneity of BTB-protein according to its antigenic specificity was found by methods of immunodiffusion, immunoelectrophoresis and immunodisc electrophoresis. Heterofunctional complexes are supposed to exist in the nervous tissue which possesses various structural qualities and functional activities within the complex.

Animals↗