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I G Kharitonenkov

Publications and source records attributed to I G Kharitonenkov.

At least 37 records · Page 2Linked to original sources
PubMed1985

[The use of immunoenzyme methods in virology].

Data on the development of theoretical basis of immunoenzyme (IE)method s (EMIT analysis and ELISA) and on using these methods in virology are presented. The problems arising in the use of most popular version of IE analysis. ELISA, are elucidated: the schemes for different variants of ELISA; the demands to adsorbent, enzyme and substrate for achieving the maximum of sensitivity of the technique; comparison of the advantages of different ELISA variants in identification of various antigens and antibodies. The data on using ELISA for indication and identification of viral antigens and virus specific antibodies are analyzed. The respiratory viruses have been used to demonstrate the possibilities of IE technique for rapid diagnostic of viral diseases and for studies in viral reproduction and structure.

Immunoenzyme Techniques↗
PubMed1984

Interaction of influenza virus proteins with planar bilayer lipid membranes. I. Characterization of their adsorption and incorporation into lipid bilayers.

Alterations in the surface potential difference (delta U) of asolectin planar bilayer lipid membranes were measured following the adsorption of isolated matrix protein (M-protein) or neuraminidase of influenza virus. The method used was based upon measurement of the bilayer lipid membrane capacitance current second harmonic. The delta U dependence on the M-protein and neuraminidase concentration indicates different mechanisms of adsorption of these viral proteins by the lipid bilayer. The conductance (G0) dependence of the bilayer lipid membrane with different compositions on the concentration of isolated surface glycoproteins, hemagglutinin and neuraminidase, M-protein or neuraminidase was investigated. The change in G0 for M-protein was observed only after adsorption saturation had been achieved. Neuraminidase alone does not affect the membrane conductivity. The surface charge and lipid composition of the lipid bilayer influences the adsorption and incorporation of influenza virus M-protein and surface glycoproteins. The reversibility of protein incorporation into the bilayers was investigated by a perfusion technique. The results show reversibility of surface glycoprotein incorporation while M-protein binding appears to be irreversible.

Adsorption↗
PubMed1984

Interaction of influenza virus proteins with planar bilayer lipid membranes. II. Effects of rimantadine and amantadine.

The dependence of the surface potential difference (delta U), transversal elasticity module (E1) and membrane conductivity (G0) on the concentrations of the antiviral drugs, rimantadine and amantadine was studied in the planar bilayer lipid membrane system. The method used was based on independent measurements of the second and third harmonics of the membrane capacitance current. The binding constants of bilayer lipid membranes obtained from the drug adsorption isotherms were 2.1 X 10(5) M-1 and 1.3 X 10(4) M-1 for rimantadine and amantadine, respectively. The changes in G0 took place only after drug adsorption saturation had been achieved. The influence of rimantadine and amantadine on the interaction of bilayer lipid membranes with matrix protein from influenza virus was also investigated. The presence of 70 micrograms/ml rimantadine in the bathing solution resulted in an increase in the concentration of M-protein at which the adsorption and conductance changes were observed. The effects of amantadine were similar to those of rimantadine but required a higher critical concentration of amantadine. The results obtained suggest that the antiviral properties of rimantadine and amantadine may be related to the interaction of these drugs with the cell membrane, which can affect virus penetration into the cell as well as maturation of the viral particle at the cell membrane.

Adamantane↗
PubMed1984

Changes in the antigenic specificity of influenza hemagglutinin in the course of adaptation to mice.

Influenza virus strains A/USSR/90/77 (H1N1) and A/USSR/92/77 (H1N1) have been adapted to mice by successive intranasal passages. In the course of adaptation a loss (for A/USSR/90/77) or a reduction (for A/USSR/92/77) of the reactivity toward two monoclonal antibodies in a panel of seven monoclones has been registered. The changes emerged after two or three passages, long before the acquisition of the lethal effect for mice. Possible significance of the phenomenon for the antigenic variation of influenza A virus is discussed.

Adaptation, Physiological↗
PubMed1981

The role of carbohydrate in determining the immunochemical properties of the hemagglutinin of influenza A virus.

Most of the carbohydrate was removed from influenza virus MRC II (H3N2) and its purified hemagglutinin (HA) on treatment with glycosidases, including alpha-mannosidase, beta-N-acetylglucosaminidase, beta-galactosidase and alpha-fucosidase. The release of 50 per cent of the carbohydrate from intact virus particles significantly affected hemagglutinating activity. The ability of untreated and glycosidase-treated virus to inhibit the binding of antibodies directed against the hemagglutinin was almost indistinguishable by competitive radioimmunoassay (RIA). Up to 60 per cent of the carbohydrate from the purified HA of influenza virus could be removed. The antigenicity of glycosidase treated HA molecules decreased 8-fold compared to intact HAs as measured by competitive RIA. In addition, glycosidase digestion of 125I-labeled HA resulted in a decrease in its reactivity in direct RIA. We conclude that the carbohydrate portion of the HA of influenza virus is not of major importance in defining the antigenicity of HA.

Acetylglucosaminidase↗
PubMed1980

Secondary structures of influenza and Sendai Virus RNAs.

The secondary structures of influenza and Sendai virus RNAs were investigated by thermal denaturation, circular dichroism and proflavine binding methods. In 0.1 M NaCl about 60% of the bases of both RNAs were involved in secondary structure. The melting temperatures (Tm) of both viral RNAs were linear functions of the logarithm of the sodium ion concentration in solution, but under all ionic conditions the melting temperatures of Sendai virus RNA were higher than those of influenza virus RNA. At all ionic strengths the melting range of Sendai virus RNA was less than influenza virus RNA, indicating that the helical regions in Sendai virus RNA were longer than those in influenza virus RNA. Although Sendai virus RNA had a higher thermal stability than influenza virus RNA, hyperchromicity and circular dichroism data showed that Sendai virus RNA had less G+C content (34%) within the double stranded regions than influenza virus RNA (48%). The binding isotherms of Sendai and influenza virus RNA-proflavine complexes were studied at different ionic strengths. The number of binding sites of proflavine with influenza virus RNA were significantly lower than those with Sendai virus RNA. These results demonstrate the essential difference between the secondary and tertiary structures of the RNAs under study.

Base Composition↗
PubMed1980

Influenza virus haemagglutinin: estimation of tryptophan and tyrosine content and localization of tryptophan residues.

The tryptophan and tyrosine content of the bromelain-released subtype H3 haemagglutinin (H3 BHA) of influenza virus were measured by u.v. absorption and fluorescence techniques. The values obtained (8 and 18 residuces, respectively) are in close agreement with those derived from amino acid analysis. Essentially all of th tryptophan residues are demonstrated to be localized on the surface of the BHA molecule.

Bromelains↗
PubMed1980

Incorporation of influenza virus M-protein into liposomes.

M-protein from influenza virus vaccine was purified by sodium dodecyl sulfate-gel chromatography and incorporated into liposomes by solubilization with octylglucoside and subsequent dialysis. Liposomes containing M-protein formed a distinct population with a density of 1.22 g/ml on sucrose-gradient centrifugation, regardless of the net charge on the liposomes. Treatment of the liposomes by freeze-fracture followed by electron microscopic examination showed multilamellar structures in those liposomes without M-protein; liposomes containing M-protein were mulberry-like structures which appeared unilamellar. These studies show incorporation of M-protein into the lipid bilayer.

Chemical Phenomena↗
PubMed1980

Comparative study of influenza virus H2 (Asian) hemagglutinins isolated from human and avian sources.

The hemagglutinin of an influenza virus isolated from a wild duck (Pintail, Anas acuta) in the USSR in 1976 had been found to be antigenically indistinguishable from the hemagglutinin of H2N2 viruses of human origin isolated in 1957. The hemagglutinins from viral preparations of the A/Anas acuta/Primorie/695/76 (H2Nav2) and A/Singapore/1/57 (H2N2) strains were purified by SDS gel chromatography as the subunits HA1 and HA2. Comparison of amino acid compositions and peptide maps of tryptic peptides containing [14C]-carboxymethylcysteine showed a striking degree of similarity between the H2 hemagglutinins.

Amino Acids↗
PubMed1979

Structure of bromelain-released influenza virus haemagglutinin as revealed by electrophoresis, sedimentation and electron microscopy.

Sigma bromelain (EC 3.4.22.4) was used to isolate the haemagglutinin (HA) from the MRC-11 (H3N2) and A/U.S.S.R./90/77 (H1N1) influenza A virus strains. Sedimentation analysis of bromelain-solubilized preparations revealed 9.5S and 5.5S protein components, the former being identified as the bromelain-released haemagglutinin (BHA). No residual neuraminidase (NA) activity was detected in the BHA isolated from the MRC-11 strain whereas up to 80 per cent of the enzymatically active NA was found to be preserved in the electrophoretically pure BHA isolated from the A/U.S.S.R./90/77 strain. Increased electrophoretic mobilities were exhibited by both the light and heavy chains of the BHA subunit. The difference observed in the molecular weights of the polypeptide fragments removed by bromelain from the light chains is interpreted in terms of the different depth of penetration of antigenically distinct HAs through the influenza virus lipid membrane. Splitting off of approximately 15 and 26 per cent of the sugars from the carbohydrate portions of the light and heavy chains respectively, was demonstrated. This suggested involvement of glycosidase impurities present in the bromelain preparation employed. The rod-shaped BHA molecules proved to be 110 +/- 5 Angstrom long and 40 +/- 5 Angstrom wide as measured by electron microscopy. It is proposed that the 45,000-molecular-weight polypeptide observed constantly in egg-grown influenza viruses is host actin.

Bromelains↗
PubMed1976

[Specific modification of free lysine amino groups of histidine decarboxylase from Micrococcus sp. n. by trinitrobenzene sulfonic acid].

It has been found that 14 lysine residues are accessible for trinitrobenzene sulfonic acid (TNBS) in the molecule of histidine decarboxylase (HDC). The other 62 lysine residues in the molecule of native HDC are masked and inaccessible for TNBS. It is demonstrated that the SH- and alpha-amino groups of methionine are not modified by TNBS. A correlation between the decarboxylase activity of the enzyme and the degree of its trinitrophenylation has been studied. HDC, whose molecule contains 3--9 TNP groups, retains up to 90--97% of its initial activity. Trinitrophenylation of 14 lysine residues induces inactivation of HDC by 33--34%, which probably depends on conformational changes or steric hindrances, occurring in the catalytic site of the modified active centre of HDC. Using circular dichroism and fluorescence methods as well as disc-electrophoresis in polyacrylamide gel, it has been shown that trinitrophenylation does not cause any significant changes in the enzyme structure. The TNP groups have been found to be localized in the large and small subunits of the HDC molecule.

Carboxy-Lyases↗
PubMed1976

[Study of the structure of the histidine decarboxylase of Micrococcus sp. n. by the method of circular dichroism].

Ring dichroism spectra (RD) of histidine decarboxylase (HDC) from Micrococcus sp. n. at the regions of peptide bonds (200-240 nm) and aromatic amino acids (250-300 nm) absorption are studied. The treatment of RD spectra according to methods of Greenfield-Fasman, Saksena-Vetlaufer and Mayer permits to conclude that at the pH range within 4-8 the content of ordered structures of alpha-helix type comprises 20%, that of beta-structure type-40%, while the rest 40% are represented with polypeptide chain in a disordered globular state. When pH is varied from 1 to 12, the content of alpha-helices decreases from 17 to 5%. There are two distinct dichroic bands in the spectrum of aromatic chromophores absorption (at 270 and 290 nm), the former containing tirosine, tryptophane and phenylalanine residues and the latter being induced with triptophane residues. The study of HDC RD spectra at the regions of peptide bonds and aromatic acids absorption at different temperatures has shown that a part of triptophane, tyrosine and phenylalanine residues is in an ordered structure of the alpha-helix type. The HDC undergoes irreversible changes under heating to 70 degrees and in 8 M urea. 5 M guanidine chloride eliminates the ordered HDC structure, while sodium dodecylsulphate at concentrations up to 1% does not affect the enzyme structure.

Carboxy-Lyases↗
PubMed1976

[Structural derangements in deoxyribonucleoprotein complex damaged by N-nitroso-N-methylurea].

The effect of deoxyribonucleoproteid (DNP) solubilization under conditions of the ionic strength of the medium approaching the physiological one depended greatly after the treatment with a mutagen - N-nitroso-N-methylurea (NMU) on the NMU concentration. Apparently, for the change of DNA into a soluble state the critical number of groups in the DNA and protein should be modified. On the basis of the data obtained by circular dichroism and viscosimetry a conclusion was drawn that after the NMU treatment the DNP complex became soluble in the solvents with the ionic strength approaching the physiological one, chiefly as the result of labilization and dissociation of DNA-protein bonds.

Chemical Phenomena↗