Search PubMed⌕ Search

Biomedical subjects

B K Chernov

Publications and source records attributed to B K Chernov.

98 records · Page 6Linked to original sources
PubMedDate not supplied

[Genetic engineering of peptide hormones. III. Cloning of the swine growth hormone cDNA and construction of the gene for expression of the hormone in bacteria].

The clones containing cDNA of porcine growth hormone were obtained using poly(A)-RNA from porcine pituitary as a template for reverse transcriptase. The analysis of their nucleotide sequences revealed that these cDNAs have differences not only on the nucleotide level but also on the amino acid level, i. e. the polymorphism of mRNA and protein occurs in the case of porcine growth hormone. To create the construction for expression of porcine growth hormone in E. coli, the 5'-part of cDNA, coding the first 15 amino acids of the mature hormone, was substituted by the artificial sequence.

Amino Acid Sequence↗
PubMedDate not supplied

[Genetic engineering of peptide hormones].

The application of different approaches for preparing DNAs coding for peptide hormones was demonstrated. The libraries of human, bovine and porcine pituitaries cDNA were obtained starting from their total mRNAs. Screening of these libraries revealed clones containing human, bovine and porcine growth hormone sequences, cDNAs for bovine ACTH-beta-lipotropin precursor and for bovine and porcine prolactin. The gene of human calcitonin was created by combination of chemical and enzymatic synthesis. This synthetic gene was further cloned in pBR322. The expression of cloned human growth hormone cDNA under control of different Escherichia coli promoters was studied and physico-chemical and biological properties of the growth hormone produced by E. coli were tested.

Animals↗
PubMedDate not supplied

[Quantitative PCR-analysis: development of a system for determining the level of an amplified DNA fragment].

A new technique is elaborated for quantitative evaluation of the polymerase chain reaction (PCR) results based on a system for yopA gene identification in Yersinia pseudotuberculosis fragment located on p45 plasmid. The analysis schedule includes amplification of the studied DNA sequence under the conditions when the reverse primer carries chemically bound biotin label on the 5'-end, hybridization of the labelled amplified fragment with the probe immobilized on the microplate surface, the probe being complementary to the inner portion of specific DNA, visualization of the label, and calculation of bound labelled DNA quantity. The lower threshold of analysis sensitivity is some picograms. It makes possible the analysis and detection of PCR product in the period of exponential increase of its content, i.e. in the initial period of reaction when the quantity of amplified DNA in the reaction mixture is not enough for reliable identification by ethidium bromide staining.

Bacterial Outer Membrane Proteins↗
PubMedDate not supplied

[Transcription of antisense RNA for the human c-myc gene].

Antisense RNA transcription of human c-myc gene has been examined in HeLa, Burkitt lymphoma BL-60 t(8;22) cells, and diploid fibroblasts. By means of the primer extension technique two startpoints of antisense transcription have been detected and mapped with the first (untranslated) exon of the c-myc gene. Similarity between the antisense nucleotide sequence of the first c-myc intron and the SV40 DNA fragment containing the binding sites for transcriptions factors GT-I, GT-II, TC-I, and TC-II has been revealed by computer analysis. It has been established that the DNA fragment of the first c-myc intron is able to form complexes with proteins from the HeLa cell extract. Three nucleotide sequences (TTTCTG, TTTTTA, and TGACTTGTC) are involved in the reactions. These data imply that the c-myc antisense transcripts might take part in the regulation of human c-myc gene expression.

Base Sequence↗
PubMedDate not supplied

[Superproduction of Bacillus intermedius 7P ribonuclease (binase) in Escherichia coli].

We have reported previously about the cloning of the binase gene in E. coli. In this work, using an original approach named "homolog gene recombination" method (HGR), vectors for binase expression in E. coli have been constructed. Transcription of the binase gene have been directed through either tac-promoter or PR-promoter of bacteriophage lambda under the control of temperature-sensitive CI857 repressor. The last promoter gave the maximum yield of binase, up to 100 mg of protein per litre of heat-induced bacterial culture. The location of the transcription terminator at the 3' terminus of the binase gene raised the expression approximately two times more. A chromatographic method have been developed and applied for the control of binase accumulation in growth medium without measuring the ribonuclease activity.

Amino Acid Sequence↗