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Biomedical subjects

A P Chernov

Publications and source records attributed to A P Chernov.

At least 19 recordsLinked to original sources
PubMed1999

Isolation and characterization of Rous sarcoma virus recombinant reverse transcriptase dimers.

Reverse transcriptase (RT) preparations containing various molecular forms of the enzyme consisting of alpha- and/or beta-subunits have been isolated from E. coli cells transformed with plasmid pMF14 containing the Rous sarcoma virus (RSV) pol gene. The three possible dimeric forms of the enzyme demonstrated DNA polymerase activity, the relative activities of the alphaalpha, betabeta, and alphabeta forms being about 1:3:4. RNase H activity is associated with the betabeta and alphabeta dimers but not with the alphaalpha dimer. Comparison of the enzymic properties of the various dimers and dissociation--reassociation results suggest that the betabeta and alphabeta dimers of the RSV recombinant reverse transcriptase are similar to the corresponding virion RT forms.

Avian Sarcoma Viruses↗
PubMed1995

[Recombinant reverse transcriptase from Rous sarcoma virus. Kinetics and inhibition of DNA polymerase activity].

Preparations of Rous sarcoma virus reverse transcriptase isolated from a culture of E. coli HB101 (pMF14) and purified to homogeneity were used to study the steady state kinetics of DNA polymerization and inhibition of DNA-polymerase activity. DNA synthesis was examined using a system of poly(rA) as template, oligo(dT) as primer and dTTP as nucleotide substrate. Kinetic constants for steady state conditions were determined. The substrate initial velocity patterns point to an ordered mechanism which results in the formation of a ternary complex, in which the template-primer is the first to bind to the enzyme. Inhibition of the DNA-polymerase activity of the enzyme by various inhibitors was studied. Analysis of final products of the DNA-polymerase reaction revealed the presence of distribution syntheses of the DNA chain by the alpha alpha-subunit form of the enzyme.

Avian Sarcoma Viruses↗
PubMed1991

Recombinant reverse transcriptase of Rous sarcoma virus: characterization of DNA polymerase and RNAase H activities.

Enzyme preparations of Rous sarcoma virus (RSV) reverse transcriptase have been isolated from a culture of E. coli HB101(pMF14). The enzyme has been purified to homogeneity and been shown to consist of two subunits, of molecular mass 97.4 and 61.3 kDa, respectively. The optimum conditions for the DNA polymerase and RNAase H activities, fidelity of DNA synthesis on a homogeneous RNA template, and the inhibitory effect of azidothymidine triphosphate have been determined. Data on the use of RSV recombinant reverse transcriptase for cDNA synthesis are given.

Avian Sarcoma Viruses↗
PubMed1991

[Characteristics of regional hemodynamics in the lower extremities of patients with flaccid paralysis].

On the basis of treatment and examination of 2675 patients with residual effects of poliomyelitis and consequences of the nervous system traumata are considered the functioning peculiarities of vascular system of the lower extremities in case of absence or abrupt decrease of pumping function of the skeletal muscles. There have been detected discrepancies between the reovasographic regional blood circulation pattern and the microcirculation state indexes in the tissues of the damaged extremity. They have studied the dynamics of the hemodynamics indexes in the process of preoperative preparation, during early and late postoperative periods as well as during remote postoperative periods. There is suggested the idea of correlation of the regional hemodynamics with the extremity supporting state.

Hemodynamics↗
PubMed1990

[Recombinant RNA-dependent DNA-polymerase from Rous sarcoma virus. Isolation and properties].

Preparations of recombinant reverse transcriptase RSV were isolated from E. coli HB101/pMF14 cell cultures. The enzyme purified to homogeneity was shown to be made up of two subunits with molecular masses of 97 +/- 4 and 61 +/- 3 kDa. A comparison of enzymatic properties of recombinant transcriptase to those of the enzyme isolated from the RSV (Rauss sarcoma) virus demonstrated that in the preparations under study the recombinant reverse transcriptase exists in a subunit form, alpha beta, and may acquire a relatively stable configuration, alpha 2.

Avian Sarcoma Viruses↗
PubMed1989

[Surgical treatment of foot deformities].

The authors analyse their many-year experience gained in the treatment of patients with foot deformities of various origins, carried out at the traumatology clinic of the Kuibyshev D. I. Ulyanov Medical Institute. New surgical techniques for the treatment of congenital talipes, valgus deformity of the first thumb combined with transverse platypodia, paralytic loose, paralytic pes planus and calcaneus are described. The causes of valgus deformities in the patients with infantile cerebral paralysis after achillotomy are discussed on the basis of EMG data. The described methods are superior to the routine ones.

Adolescent↗
PubMed1987

[Various characteristics of the anti-restriction mechanism in bacteriophage T5].

Bacteriophage T5 is not confined by the restriction systems of the second type EcoRII and EcoRV. Bacteriophage T5 DNA is not modified by EcoRII and EcoRV methylases in vivo. The sites of recognition for restriction endonuclease EcoRV are mapped at 24.4; 57.6; 68.5; 70.2% of T5 DNA, while the sites at 5.1; 7.6% are recognized by EcoRII, the sites at 5.75; 6.0 and 6.5% are recognized by HpaI in FST. A high activity of restriction endonucleases EcoRI and EcoRV is demonstrated in crude extracts of E. coli B834 (RI) and E. coli B834 (RV) cells infected by bacteriophage T5. The simultaneous infection of E. coli B834 (RI) or E. coli B834 (RV) cells by the amber mutants of bacteriophage T5 and the suppressing phage lambda NM761 does not result in the protection of lambda DNA by the T5 anti-restriction mechanism. The presented data support the hypothesis that the anti-restriction mechanism of bacteriophage T5 is based on prevention of T5 DNA contacts with restriction enzymes by a specific phage protein.

DNA Restriction Enzymes↗