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Biomedical subjects

S A Grigor'ev

Publications and source records attributed to S A Grigor'ev.

9 recordsLinked to original sources
PubMed1984

[3-dimensional model of transcription and the mechanism of RNA elongation].

The spatial aspects of template-dependent synthesis of RNA have been considered. It has been concluded that the idea of helical translocation on DNA double helix does not correspond to the literary experimental data. An alternative model given here proposes that the growing end of an RNA molecule is capable of transient disconnection from its template without dissociation of the whole transcriptional complex and the steric hindrances imposed by DNA helical turns are relaxed via this disconnection. This supposition explains the way of RNA release, the template properties of nucleosome chains and also some features of interrelations between RNA and DNA during transcription.

DNA↗
PubMed1983

[Controlled drainage of the thoracic lymph duct].

A surgical technique and experience with the clinical employment of catheterization of the thoracic lymph duct with the help of silicon cannulae are described. The method of catheterization of the thoracic lymph duct allows controlling the day volume of the lymph loss and prevents different clinical manifestations of lymphostasis in the nearest postoperative period.

Adult↗
PubMed1982

[Products of limited proteolysis of chromatin core particles].

Limited proteolysis of chromatin and its derivatives with trypsin results in stable fragments of histones containing up to 75% of the original number of amino acid residues. The protein moiety of trypsin-treated core particles from chicken erythrocyte chromatin was characterized. The amino acid analysis of purified histones fragments H2A, H2B and H4 revealed that they are similar to the corresponding products of proteolysis of erythrocyte chromatin histones, whose primary structure has already been established. The sequences 28--135 and 50--135 of histone H3 were identified within the trypsin-treated cord particles and their primary structure was established by peptide mapping. Data from amino acid analysis of the protein moiety of trypsin-treated core particles suggest that the bulk of the low molecular weight products of proteolysis corresponding to the N-terminal parts of histones is removed under conditions which facilitate the maintenance of nucleosomal structure of DNA in trypsin-digested core particles.

Amino Acid Sequence↗
PubMedDate not supplied

[Mechanism of formation of associated oligonucleosomes during electrophoresis].

Here we used DNP electrophoresis to study the mechanism of formation of associated oligonucleosomes (A-particles) which have been previously shown by Weintraub to contain the DNA of silent but not of transcriptionally-active genes from chicken erythrocyte nuclei. We found out that A-particles are generated in the course of electrophoresis and that their assembly is inhibited as the result of redistribution of the most mobile fraction of histones H1 and H5. The mechanism and the conditions for the assembly of A-particles at the start line of DNP electrophoresis are discussed in the paper. The DNA molecules constituting A-particles appeared to be about 60 base pairs longer than the DNA of free oligonucleosomes. Thus in course of nuclease treatment of erythrocyte nuclei two chromatin fractions can be observed, one of them containing the DNA of transcriptionally active genes loses its terminal DNA regions owing to rapid degradation of cleaved nucleosome linkers, while the other containing the DNA of repressed genes maintains its terminal linker DNA and gives rise to the associated oligonucleosomes.

Animals↗