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Biomedical subjects

I G Kharitonenkov

Publications and source records attributed to I G Kharitonenkov.

At least 73 records · Page 4Linked to original sources

[The detection of antibodies to HIV protein p24 in human blood sera by the method of lanthanide immunofluorescent analysis].

A competitive time-resolved fluoroimmunoassay (TR-FIA) system for the detection of antibodies to protein p24 of HIV was developed on the basis of monoclonal antibodies. The advantages of this test system over analogous enzyme immunoassay system and commercial test system "Antigen" (USSR) were demonstrated. The newly developed test system of TR-FIA was used for examination of sera from HIV-infected persons.

Antibodies, Monoclonal↗

[The effect of detergents on the physicochemical and immunochemical properties of the isolated M1 protein of the influenza virus].

The degree of solubility of influenza virus protein M1 preparations isolated from virions by acid chloroform-methanol extraction was studied under the effect of a wide spectrum of detergents of different origin. The same detergents were used for solution of a lipid comprising a part of artificially formed liposomes. Only some of the detergents used (sodium dodecyl sulfate, SDS, triton X-100, and disintegron-B) were shown to be optimal for solution of both influenza virus protein M1 and lipid. The degree of effect on the immunochemical properties of protein ML isolated from influenza virus virion of the above-mentioned detergents optimal for solution was also studied. For this purpose, a panel of 18 monoclonal antibodies with different determinant specificity to protein M1 was used. Two of the three detergents (SDS and disintegron-B) were shown not to change the antigenic profile of protein M1. The immunochemical properties of protein M1 of influenza virus isolated from virions by two methods: chloroform-methanol extraction and preparative polyacryl amide gel electrophoresis, were studied. These two methods of protein M1 isolation were shown not to alter its immunochemical properties.

Antibodies, Monoclonal↗

[The demonstration of the Venezuelan equine encephalomyelitis virus by the method of indirect lanthanide immunofluorescent analysis].

A test system of indirect time-resolved fluoroimmunoassay (TR-FIA) was developed and tested on an alpha-virus, Venezuelan equine encephalomyelitis virus. The indirect TR-FIA test system was shown to be highly effective in the detection of antigens of this virus. Not differing in specificity from the direct TR-FIA, the newly developed test system was 4 times as sensitive.

Animals↗

[Physico-chemical properties of the RNA of Sendai virus. III. Interaction with proflavin].

The binding isotherms of the Sendai virus single- and double-stranded RNA-proflavine complexes have been studied. The existence of two regions on the binding curves, corresponding to two subtypes of the strong complex (I1 and I2) has been demonstrated. The association constants and the numbers of binding sites for both subtypes were determined as a function of ionic strength. Both of the single- and for the double-stranded RNA the association constant for I1 complex were higher than those for I2 complex under all ionic strengths conditions. For the double-stranded RNA the variation of the ionic strength is more importance in case of the I1 complex formation. The total number of binding sites increases with a decrease of ionic strength. At low ionic strength (10(-4) M NaCl) the number of binding sites for single- and double-stranded RNA is practically the same and is equal to the number of binding sites for DNA at high ionic strength (1 molecule of proflavine per 3 nucleotides pairs). The heat denaturation of the RNA-proflavine complexes under different ionic conditions has been also investigated. The melting curves for double-stranded RNA-proflavine complex had two waves at high and low ionic strengths. For the single-stranded RNA the high temperature wave occured only at the high ionic strength. The dependence of heat denaturation of single-stranded RNA on ionic strength was examined for the evaluation of RNA structure. In these experiments a significant decrease of the width of melting interval under low ionic strength conditions was observed. It may reflect the existance in the RNA molecule of long helical regions. The occurence of such structures is likely to be responsible for an increase in the number of binding sites at low ionic strength and also for the appearance of the second wave on the melting curves of the single-stranded RNA-proflavine complexes at high ionic strength.

Acridines↗

[Myxovirus structural investigations by spin probe methods. II. Influence of rimantadine on the structure of viral and artificial lipid membranes].

The lipid membrane structure of two myxoviruses (influenza and Sendai viruses), red blood cells and liposomes (prepared from total lipids of Sendai virus) have been investigated in the presence of rimantadine by means of two spin probes C5 and C6--the iminoxyl derivatives of stearic acids. Rimantadine was shown to penetrate the lipid membranes of myxoviruses and red blood sells and change the structure of the lipid phase no less than 0.8 nm apart from the viral surface. In the depth of 2.2 nm the structure of these lipid membranes remains unchanged after addition of rimantadine. Rimantadine also displaces the phase transition points of cell and viral lipid membranes to lower temperatures. Rimantadine does not change the lipid bilayer structure of liposomes 0.8 nm apart from its surface. These finding allow to suggest that rimantadine affects the cell and viral lipoprotein membranes.

Adamantane↗

[Standardization of conditions for detecting the internal proteins of the influenza virus in studying their antigenic properties in solid-phase immunoenzyme analysis].

The influence of the conditions of adsorption and virion destruction by freezing-thawing and detergents on the detection of M1 and NP proteins of different influenza virus strains by solid-phase enzyme immunoassay with direct virion adsorption on polystyrene was studied. It was found that for the detection of M1 protein the optimal conditions included virion disruption with detergent and adsorption to polystyrene at 4 degrees C, and for NP protein disruption by freezing-thawing at adsorption to polystyrene at 37 degrees C. In the study of the antigenic properties of protein M1 of different influenza virus strains using monoclonal antibodies it was shown to be necessary, first, to achieve maximum detection of proteins and, second, to standardize the amount of the adsorbed antigen with polyclonal antibodies.

Adsorption↗

[The spatial interrelationships between influenza virus hemagglutinin and the lipid phase in the liposomal membrane].

A scheme has been proposed demonstrating the location of tryptophan residues of hemagglutinin molecule in relation to the middle of the lipid layer 1.2 nm thick with a fluorescent probe pyrene. In the immediate proximity to it, one tryptophanyl of protein molecule is located in a hydrophobic "pocket". At a distance of 2.85 nm from the middle of the lipid zone 3 tryptophanyls are located and the remaining five at a distance over 3.6 nm. After treatment with proteolytic enzyme bromelin of the liposomes with hemagglutinin incorporated into their bilayer, the hydrophobic "anchor" of protein molecule contains one tryptophanyl which is raised by 0.3 nm and its hydrophobic environment is changed.

Amino Acid Sequence↗

[Heterogeneous distribution of influenza A matrix protein in polyacrylamide gel, detected using an immunoblotting method with monoclonal antibodies].

The immune blotting method using monoclonal antibodies to Ml protein showed protein Ml to migrate in several bands in polyacrylamide gel electrophoresis (PGE) of influenza A virus polypeptides. The heterogeneous distribution of Ml protein in PGE is due to the formation of aggregates: dimers, trimers, and polymers of a higher order. The capacity of Ml protein for aggregation is typical not of all influenza virus strains and most likely is not associated with gel overloading. Since dimers and trimers of Ml protein comigrate in the gel with virus-specific proteins such as NP and proteins of a polymerase complex, this circumstance should be take into consideration in using PGE for isolation of pure influenza virus proteins.

Animals↗