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Biomedical subjects

N D Beliaev

Publications and source records attributed to N D Beliaev.

14 recordsLinked to original sources
PubMed1985

[New method of encapsulating isolated nuclei into a lipid membrane].

A new method of the coating of isolated cell nuclei with additional phosphatidylcholine membranes is described. The additional membrane was visualized under the electron microscope using ferritin as a label. The coating diminished leakage of the content of the nuclei and restricted permeability of the nuclei for exterior macromolecules.

Animals↗
PubMed1985

[Fluorescence of Tb3 complexes with metaphase chromosomes of mink fibroblasts].

The fluorescence of the Tb3+ complex with metaphase chromosomes of mink fibroblasts was studied. It was shown that the fluorescence intensity of this complex is 6.5 times as high as that of the Tb3+-native DNA complex. The fluorescence of the chromosome-Tb3+ complex is predominantly determined by chromosomal DNA. The high intensity of fluorescence may be due to partial disturbances in the secondary structure of DNA during folding of the metaphasic chromosome.

Animals↗
PubMed1984

[Electron microscopic analysis of the structure of metaphase chromosomes after liposome treatment].

The fine structure of the methaphase chromosomes from the Chinese hamster cell culture was studied after the incubation with lyposomes isolated from hen egg yolk phosphatidilcholine, or from the total rat liver phospholipid. It has been found that during incubation lyposomes surround chromosomes, form a multifold covering considerably decondensing the chromosome matrix. The data obtained indicate that the analogues of cell membrane - lyposomes - may be involved in the regulation of the structural organization of metaphase chromosomes.

Animals↗
PubMed1980

[Mammalian protein synthesis in the cytoplasm of a plant cell].

Using immunochemical and, subsequently, autoradiographic methods, the authors have shown that after the injection of the total fraction of polyribosomes isolated from the rat liver in the Acetabularia cytoplasm a protein interacting with the antiserum against rat thyrosine aminotransferase is synthesized. Prospects of using Acetabularia as a test-system for the translation of heterogenous mRNA and mRNP are discussed.

Acetabularia↗
PubMedDate not supplied

[Mg2+-dependent interaction of DNA with eukaryotic cells].

Interaction of DNA with eukaryotic cells under conditions similar to those providing DNA adsorption onto liposomes was studied. It was revealed that mouse fibroblasts (line A9) and myeloma cells bind phage and plasmid DNA in 0.3 M sucrose solution containing Mg2+-ions. Additional pretreatment of the cells by trypsin did not affect DNA adsorption efficiency. The major part of the adsorbed DNA recovered by salt treatment of the cells, but 10-15% of DNA was found to be irreversible. Up to 50% of the irreversibly bound DNA molecules retain their linear size after treatment of cells with DNAse I. Efficiencies of DNA adsorption and irreversibly binding depend on the concentration of Mg2+ in the medium. The process of DNA irreversible binding is not inhibited by drugs affecting cell metabolism. It is assumed that DNA adsorbs onto the phospholipid domains of the cell membrane, and part of the adsorbed DNA is taken up into the interior of the cells.

Animals↗
PubMedDate not supplied

[Release of proteins from metaphase chromosomes induced by lipid membranes].

The interaction of the isolated chromosomes with the model phospholipid membranes in the presence of divalent cations leads to chromosomal decondensation as we showed previously by using different methods. In this manuscript we report data concerning the mechanism of such membrane-promoted decondensation. Under the action of liposomes at least three proteins are released from the chromosomes. The appearance of these chromosomal proteins was detected by SDS-electrophoresis of the fraction of the liposomes after dissociation of the complexes. One of these proteins with MW 33 kDa is tightly bound with the liposomes while the other two with MW 25 and 68 kDa release without binding. We suggested that the chromosomal decondensation at mitosis is caused by the action of the newly formed nuclear envelope, in particular by its membrane part which is able to provide the release of chromosomal proteins responsible for keeping the chromosomes in the compact state.

Animals↗
PubMedDate not supplied

[Transfection of bacterial cells by DNA of phage M13 entrapped in phospholipid vesicles].

The possibility of transfection of bacterial cells by phage M13 DNA entrapped into phospholipid vesicles (liposomes) has been studied. Two types of liposomes differing in size were used. Entrapped DNA was transferred by liposomes into Ca2+-treated E. coli cells. Efficiency of the transfection in the case of small (ca. 400 A) liposomes was 2--3 orders of magnitude higher than that of free DNA extracted from such liposomes.

Calcium↗
PubMedDate not supplied

[Synthesis of virus-specific products following introduction of tobacco mosaic virus RNA pereparations and the native virus into acetabularia].

The possibility to synthesize the viral-specific products after microinjection of Tobacco mosaic virus (TMV) preparations and the TMV RNA into the single-celled seaweed Acetabularia was studied. The accumulation of the newly synthesized protein and double-stranded RNA 24 hours after injection of TMV RNA and native virus preparations was demonstrated by immunological and immunofluorescent methods. The virus titer sharply dropped 3--4 hours after introduction into Acetabularia and in 48 hours it reached a maximum level. The presented data showed the possibility of TMW RNA replication and translation involving formation of viral-specific proteins and the production of a virus of full value in the Acetabularia cell.

Acetabularia↗