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N V Kaverin

Publications and source records attributed to N V Kaverin.

At least 19 recordsLinked to original sources
PubMed1979

Newcastle disease virus-specific RNA: an analysis of 24 S and 35 S RNA transcripts.

The denaturation of Newcastle disease virus-specific 24 S and 35 S RNA by heat or formamide treatment led to a shift of a large part (60--80%) of RNA into the 18 S zone. The remaining 20--40% could not be dissociated further by repeated denaturation or by centrifugation in dimethyl sulfoxide-sucrose gradient. Hybridization-competition analysis revealed that the majority (approximately 75%) of the non-dissociable 35 S RNA and almost all the material present in the non-dissociable 24 S RNA were represented by nucleotide sequences homologous to 18 S RNA. On the other hand, the non-dissociable 35 S RNA lacked some of the sequences present in 18 S RNA, since no more than 45% of the labelled 18 S RNA could be displaced from the hybrid by an excess of unlabelled non-dissociable 35 S RNA. The possible origin of 24 S and 35 S RNA is discussed.

Base Sequence↗
PubMed1979

Stability in Newcastle disease virus-infected cells of HN protein which lost its functional activity under conditions of protein synthesis inhibition by cycloheximide.

Chick embryo cell cultures were infected with Newcastle disease virus (strains Italia, Beaudette and B1), labelled with 14C-amino acids from 5 to 6 hr post infection (p.i.), incubated in chase conditions from 6 to 10 hr p.i. in the presence or absence of cycloheximide (100 microgram/ml) and analyzed by slab polyacrylamide gel electrophoresis and autoradiography. In chase experiments the HN protein was stable in all three strains. The haemagglutinating activity of cell homogenates was greatly reduced after the addition of cycloheximide in tests with Beaudette and B1 strains; treatment of the homogenates with neuraminidase from Vibrio cholerae did not influence this effect.

Animals↗
PubMed1978

Comparison of influenza viruses isolated from man and from whales.

Four isolates of influenza virus strains from Moscow and Habarovsk that caused outbreaks of influenza in November and December 1977 in several cities of the USSR were studied and their haemagglutinins and neuraminidases were compared with those of other human and animal influenza viruses including A/whale/Pacific Ocean/76. In H1 tests these isolates, designated A/USSR/77, reacted with immune serum against A/FM/1/47 (H1N1) to the homologous titre, and with antiserum against A/whale/PO/19/76 virus to 1/8 of the homologous titre. In neuraminidase inhibition tests all A/USSR/77 isolates showed the presence of human N1 type neuraminidase, more closely related to A/sw/New Jersey/76 (Hsw1N1) than to A/FM/1/47 (H1N1) virus. The haemagglutinin of A/whale/Pacific Ocean/19/76 virus occupies an intermediate position between H0 and H1, but its neuraminidase is close to Nav2. The virus from whales multiplies better at low (28 degrees C) and at high (40 degrees C) temperatures than do the viruses of human origin that were tested.

Adult↗
PubMed1977

Structural proteins of infectious bovine rhinotracheitis virus.

Infectious bovine rhinotracheitis (IBR) virus grown in bovine embryo kidney cell cultures was concentrated and purified in Ficoll density gradients. The polypeptide composition of the virus was studied by polyacrylamide gel electrophoresis. The mature virion was found to contain 18 structural proteins with molecular weights from 250,000 to 29,000 daltons; 8 of them were glycosylated. The similarity of IBR virus protein composition to proteins of other herpetoviruses is discussed.

DNA, Viral↗
PubMed1976

Newcastle disease virus-specific RNA: poly(A)-containing and poly(A)-deficient transcripts as revealed by chromatography on poly(U)-sepharose.

Total [3H]uridine-labeled, virus-specific RNA from Newcastle disease virus-infected cells was fractionated by poly(U)-sepharose chromatography and analyzed by rate zonal gradient centrifugation. The sedimentation pattern of both eluted and nonadsorbed RNA resembled that of the total RNA. However, nonadsorbed RNA was enriched in 50S material, ant its 18S peak was broader and slightly shifted towards the top of the gradient. Poly(U-sepharose chromatography of isolated 18S RNA and 24S RNA resulted in the separation of poly(A)-containing RNA and poly(A)-deficient RNA. In the former the percentage of adenosine content represented by poly(A) sequences was estimated as 10 to 12% (for 18S RNA) or approximately 6.0% (for 24S RNA). The size of poly(A) fragments as measured by their sedimentation rate was the same for 18S and 24S RNA. Polyacrylamide gel electrophoresis of poly(A)-containing RNA revealed a characteristic pattern closely resembling the pattern of nonchromatographed 18S and 24S RNA. The pattern of poly(A)-deficient RNA was heterogenous, and for 18S RNA it shifted towards the anode. The possible origin of poly(A)-deficient transcripts is discussed.

Base Sequence↗
PubMed1975

Strain-specific degradation of a viral glycoprotein in Newcastle disease virus-infected cells.

In cells infected with mesogenic or lentogenic strain of Newcastle disease virus the level of neuraminidase and hemagglutinin activities sharply decreased after the addition of cycloheximide. With two velogenic strains such decreases did not occur. The infected cells were labelled with 14C-amino acids (leucine or valine) and further incubated with an excess of unlabelled precursor. Polyacrylamide gel analysis revealed a decrease of the peak correspondig to the "large" glycoprotein after the chase in cells infected with meso- or lentogenic strain (Beaudette, B1). In the cells infected with velogenic strains (Italia, Herts) no such decrease was observed. The degradation of the "large" glycoprotein as the cause of the decrease of hemagglutinin and neuraminidase activities in cycloheximide-treated cells and its possible relation to virulence is discussed.

Animals↗
PubMedDate not supplied

[Properties of intracellular virus-specific ribonucleoproteins containing negative and positive hepatitis A virus RNA].

The characteristics of the intracellular virus-specific nucleocapsids containing either a negative or a positive RNA strand were studied. The immunosorption of nucleocapsids by the monoclonal antibodies against the three epitopes of NP protein failed to reveal any antigenic difference between the negative strand or positive strand-containing nucleocapsids. On the other hand, the sensitivity of virus-specific RNA in the nucleocapsids to digestion by the pancreatic ribonuclease proved to be lower for the positive strand-containing nucleocapsids.

Animals↗
PubMedDate not supplied

[Genome of defective interfering influenza virus particles: multiple reactivation of "incomplete" virus detectable by counting hemadsorbing cells].

Gel electrophoresis reveals additional segments of low molecular mass in RNA preparations of "incomplete" (produced by passages of undiluted material according to von Magnus) influenza virus which are lacking in RNA of the standard virus. When MDCK cells are inoculated with the "incomplete" virus, synthesis of virus-specific proteins is observed but the pattern of relationships between the intensity of the synthesis and multiplicity of infection is different from that of the standard virus. Quantitative determination of infectivity by counting of haemadsorbing cells demonston the dilution of the "incomplete" virus in contrast to the linear dependence in infection with the standard virus. Neither the virus-specific protein synthesis nor cell conversion into the haemadsorbing state can be due to the admixture of infectious particles in "incomplete" virus preparations and indicate an effect of the type of multiple activation of virus genome expression.

Animals↗
PubMedDate not supplied

[Interrelationships between the interfering capacity of an "incomplete" virus and its infectivity].

A comparative analysis of UV inactivation curves of the interfering activity of "incomplete" influenza virus and infectivity showed certain differences in the structures responsible for these functions. All the data exclude the role of virus protein and virus-induced interferon of "incomplete" influenza virus and suggest that RNA is responsible for this interference. The size of the "target" of the "incomplete" virus interfering capacity calculated on the basis of sensitivity to UV-light is approximately 40 times as small as that of the "target" responsible for infectivity. The analogous pattern of UV inactivation in the standard influenza virus and the so-called Magnus virus suggests that in the latter the infectivity is due to the presence of complete virions in the preparation.

Animals↗
PubMedDate not supplied

[RNA transcripts of both strands of viral DNA in cells infected with vaccinia virus].

Denaturated 3H-thymidine-labeled vaccinia virus DNA was hybridized with an excess of "late" virus-specific RNA isolated from virus-infected chick embryo cell cultures 8 hours postinfection. The percentage of DNA converted into DNA-RNA hybrid under these conditions never exceeded 50%. If the RNA preparation had been self-annealed prior to hybridization, the percentage was decreased slightly. On the other hand, if the self-annealed RNA had been treated with RN-ase and the double-stranded DNA-RNA hybrids had been denaturated, they became capable of converting into hybrids at least 68% of the labeled DNA. These data indicate that transcription of both DNA strands occurs in a large portion (over 68%) of vaccinia virus genome.

Animals↗
PubMedDate not supplied

[Differences in the polypeptide composition of virulent and avirulent strains of Newcastle disease virus in reproduction in chick embryo fibroblast culture].

The loss of the capacity for secondary infection of the cells in reproduction of avirulent Newcastle disease virus strains in chick embryo fibroblast cultures was found. This loss was shown to be associated with changes in the polypeptide composition of the virions. In virions of the avirulent Queensland strain incapable of infection CEF cultures an additional polypeptide was found with molecular mass of 67,000 daltons which was lacking in virions of the virulent Beaudette strain and corresponded to F0 protein of paramyxoviruses.

Animals↗