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Biomedical subjects

V V Smolianinov

Publications and source records attributed to V V Smolianinov.

At least 19 recordsLinked to original sources
PubMed1989

[New producers of site-specific endonucleases from microorganisms of the Bacillus genus].

52 strains of Bacillus generum have been tested for production of site-specific endonucleases. The sequence recognized by the enzyme was determined for 23 enzymes, the cleavage site inside the sequence was determined for 5 enzymes. All the enzymes under study were found to be isomers of the known enzymes. The selected strains are peculiar for the high level of site-specific endonucleases content and may be used as producents of the enzymes.

Bacillus↗
PubMed1989

[Site-specific restriction endonuclease BtcI from Bacillus thuringiensis var. canadensis].

Efficiency of bacteriophage Tp4 plating on Bacillus thuringiensis var. canadensis H5 (Can) is decreased 10(7)-fold as compared with the efficiency of plating on Bacillus thuringiensis var. galleriae H5 (Gal). Bacteriophage Tp4 having propagated for one cycle in Can cells might be further grown in this strain without restriction. The sitespecific restriction endonuclease BtcI isolated from Bacillus thuringiensis var. canadensis recognises the same nucleotide sequence GATC in DNA as recognised by restriction endonuclease Sau3A.

Bacillus thuringiensis↗
PubMed1988

[Restriction endonucleases from Bifidobacteria].

The sitespecific restriction endonucleases were found in four strains among the twelve strains of anaerobic bacteria of generum Bifidobacterium. Two of the restriction endonucleases studied, BadI from B. adolescentis LVA1 and BbfI from B. bifidum LVA3, are isoshizomers of XhoI and recognize the nucleotide sequence CTCGAG. The restriction endonucleases Bbf7411I from B. bifidum 7411 and Bla7920I from B. lactentis 7920 recognize and hydrolize the nucleotide sequence TCCGGA having the specifity analogous to the one of restriction endonuclease CauB3I. Like CauB3I, these restriction endonucleases are unable to hydrolyize DNA if the adenine residues in the recognition site are methylated.

Base Sequence↗
PubMed1987

[Site-specific endonuclease CauB31 from Chloroflexus aurantiacus B3].

A sequence-specific endonuclease CauB3I has been isolated from cell extracts of Chloroflexus aurantiacus and partially purified by chromatography on heparin-sepharose; the yield was 3000 units per 1 g of cells. The final preparation is free of non-specific nucleases. It is shown that endonuclease CauB3I recognizes 5' T decreases CCGGA 3' sequence in double-stranded DNA and cleaves it as shown by an arrow. Methylation of adenine in the recognition sequence makes it resistant to CauB3I.

Base Sequence↗
PubMed1983

[BbvII--a new site-specific endonuclease from Bacillus brevis 80].

BbvII, a new site-specific endonuclease, has been isolated from Bacillus brevis 80 by gel-filtration and chromatography on heparin-Sepharose. The endonuclease recognizes a non-symmetrical sequence 5'-GTCTTC-3' in double-stranded DNA and cleaves DNA 3'-CAGAAG-5' in both strands outside the recognition sequence.

Bacillus↗
PubMed1982

[Dynamics of initial L-cell adhesion. II. Competition of albumin and serum activating factor].

The initial attachment process of L cells is studied by the combined action of serum and albumin. Both the substances are added jointly in the Eagle medium or one of them was adsorbed on the substrate previously. The results show that there are two factors in the serum: one depressing the cell attachment, like albumin, and the other being just opposite. The simple kinetical competition model is suggested to describe the experimental dependence of final level of attachment on the concentrations of serum and albumin. The examination of the thermal resistance of the serum factor is made; the previous heating to 60-100 degrees C increases the depressing effect of serum and albumin.

Animals↗
PubMed1982

[Highly permeable contacts and the electrical characteristics of normal liver tissue and hepatomas. II. A structural model and calculation of the cell membrane permeability of induced mouse hepatomas].

The values of specific resistances of non-junctional (Rm) and junctional (Rj) membranes of mouse induced hepatoma cells were calculated with the aid of the syncytium theory equations and on the basis of the previously measured input resistances and electrotonic potential spread curves. A three-dimensional model with cable element length equal to two cell diameters, with the length constant value of 600 mkm, and with three contacts per cell was used for calculations. For this model, Rm and Rj were found to be 3300-5600 Ohm . cm2 and 2 . 10(-2) Ohm . cm2, respectively. For the three-dimensional model of normal liver, Rm and Rj amounted to 2400-7200 Ohm . cm2 and 6.5 . 10(-2) Ohm . cm2, respectively.

Animals↗
PubMed1982

[Dynamics of initial L-cell adhesion. I. The effect of serum and albumin].

The adhesion of neoplastic mouse fibroblasts of line L was investigated during the formation of initial cell-substrate contact after the settling of spherical cells from suspension. nu (t), part of cell population which remained attached to the substrate after the impulse action of detaching force in the moment t, is used as a quantitative measure of the initial attachment process. The effects of the detaching force value and of the experimental medium composition on the main parameters of sigmoidal function nu (t) are studied. It is shown that 1) with the change of the detachment force three main parameters of function nu (t) are changed; 2) with the increase of the concentration of serum added in the Eagle medium the cell attachment becomes monotonely weaker and slower; albumin has the similar effect.

Animals↗
PubMed1982

[DNA-ligase from Streptomyces albus G].

DNA-ligase was isolated from the cells of Streptomyces albus G by chromatography on phosphocellulose, DEAE-cellulose and oxyapatite. The enzyme was shown to be NAD-dependent and had a molecular weight of 80,000 +/- 5000.

DNA Ligases↗
PubMed1981

[DNA-methylase from Arthrobacter luteus screens DNA from the action of site-specific endonuclease Alu I].

DNA-methylase was isolated from a cell extract of A. luteus and partially purified by chromatography on phosphocellulose. The purified enzyme methylates DNA of phage lambda and plasmids pBr322, thus making them resistant to a subsequent action of endonuclease Alu I. It has been shown that cytosine is the object of methylation within DNA. This modification does not screen DNA from the action of site-specific endonucleases Sal I, Bam HI, EcoR I, EcoR II, Xho I and Xho II. It has been experimentally demonstrated that the isolated methylase is site-specific and identifies in the DNA the nucleotide sequence 5'-AGCT-3', by methylating cytosine in the DNA.

Arthrobacter↗
PubMed1981

[Highly permeable contacts and the electrical characteristics of normal liver and hepatoma tissue. I. The highly permeable contacts in induced mouse hepatomas].

With the aid of intracellular microelectrodes some electrical characteristics of mouse liver were studied in early and late stages of chemical carcinogenesis. In early stages of carcinogenesis as well as in induced hepatomas, the membrane potentials of the cells, the input resistance of cell system and the electrotonic potential distribution in tissue did not differ from the corresponding values in normal liver. It is concluded that at all the stages of carcinogenesis electrical coupling in liver remains unaltered. It is proposed that high-permeable intercellular junctions may play a significant non-specific role in tissue malignization process.

Animals↗
PubMed1976

[Kinematics of crawling locomotion. I. Ideal elastic model].

One-dimensional model of polysegmental ideal-elastic body is considered, movements of which in the free state are described by wave equation. Regimes of creeping without the loss of initial energy are examined, when the moments of attachment of the segment boundaries to the substrate are synchroneous with instantaneous stopping of free oscillations. Possibility of the existence of two coordination patterns--unconcerted and concerted metachrony is shown. In the last case velocity of the metachronal wave is equal to velocity of an elastic wave, which propagates along segments in the result of attachments or deattachments of boundaries.

Locomotion↗
PubMed1975

[Presence of biologically active glutamyl peptide in rabbit bone marrow].

The presence of chromatographically pure and biologically active glutamylpeptide in the rabbit bone marrow was shown and methods of its isolation were given. The substances had an unusual circular dichroism contrary to that of the natural proteins. In a concentration of 10(-5) M the isolated peptide decreased the survival of the Chinese hamster culture cells to 30%. It was analogous to the peptide isolated formerly from plants by a number of physical and chemical characteristics; the latter possessed cytogenetic activity and increased the mutagenic action of the ionizing radiation.

Animals↗
PubMed1975

[The electrical structure of normal liver tissue].

The electrical coupling between cells of mouse liver was investigated in vitro. The membrane potential of liver cells is 15--30 mv immediatly after dissection, and increases to 40--48 mv within 4--7 hours. This level of membrane potential is constant during the next 2--3 hours. The mean input resistance varies within 189+/-9 and 613+/-+25 kohm to be higher in preparations examined in summer than in winter time. The cytoplasm of liver cells is equipotential. The reducing of potential from intracellular source is not exponential. This potential distribution is well approximated by a solution for the two-dimentional model of the liver lamella, when characteristic length is 500 mcm. On the basis of this model the outher membrane resistance and functional membrane resistance were found to be 700-2100 and 1.2 ohm-cm2, resp.

Animals↗