PubMed Health⌕ Search

Biomedical subjects

K G Skriabin

Publications and source records attributed to K G Skriabin.

At least 19 recordsLinked to original sources
PubMed1998

[Isolation and specificity of novel restriction endonucleases Bsp40091 and AsiI, isoschizomers of BamHI].

New type II restriction endonucleases AsiI and Bsp40091 are detected in Azotobacter species N55 and Bacillus species 4009, respectively. Purified preparations of the restriction enzymes free from interfering nucleases and phosphatases were obtained by column chromatography on phosphocellulose and heparin-sepharose (Asil) and phosphocellulose and DEAE-cellulose (Bsp40091). The yield of purified AsiI and Bsp40091 was 16 x 10(3) and 8 x 10(3) units per g of wet cells, respectively. The above restriction endonucleases recognize the 5'-G decreases GATCC-3' sequence on double-stranded DNA and cleave it as shown, thus being true isoschizomers of BamHI restriction endonuclease.

Azotobacter↗
PubMed1998

[Novel site-specific endonucleases from Brevibacterium species].

New site-specific endonucleases BecAI and BecAII have been detected in Brevibacterium species A. Endonuclease BecAII free from contaminating nonspecific endonucleases, exonucleases, and phosphatases was isolated by column chromatography on phosphocellulose, heparin sepharose, and DNA cellulose. It recognizes and cleaves the 5'-GG decreases CC-3' sequence and is a true isoschizomer of HaeIII restriction enzyme. The other restriction endonuclease, BecAI, cleaves Ad2 DNA at least by 2 sites but not the DNA of phage lambda, T7, SV40, phiX174, and plasmides pBR322 and pUC19. The substrate specificity of BecAI indicates its appurtenance to the super rare restriction endonucleases.

Brevibacterium↗
PubMed1996

[Site-specific BcuAI endonuclease from Bacillus cereus A].

A new restriction endonuclease was isolated from the Bacillus cereus BKM B-814 by means of the cell disruption with ultrasonication, ammonium sulfate fractionation of the cell-free extract, and chromatography on DEAE-Sepharose to give about 1400 U of the enzyme per gram of cells. The enzyme revealed the maximum activity at 30-37 degrees C, pH 7.6-8.2, and 5-10 mM MgCl2 under a high ionic strength (50 mM Tris-HCl, 100 mM NaCl). The site-specific endonuclease BcuAI was found to recognize the 5' G decreases G(A/T)CC sequence in double-stranded DNA and cleave it as shown with the arrow, thus being a true isoschisomer of the AvaII restriction endonuclease.

Bacillus cereus↗
PubMed1994

[Isolation, purification, and characteristics of the new restriction enzymes BciBI and BciBII, produced by Bacillus circulans].

New site-specific endonucleases BciBI and BciBII have been detected in Bacillus circulans. The enzymes were purified by fractionation of cell-free extract with polyethylene imine and ammonium sulphate (40-80% of saturation) followed by chromatography on DEAE-sepharose, blue-sepharose and phosphocellulose. The endonucleases BciBI and BciBII were separated only at the final step of the purification--by chromatography on the phosphocellulose column. The yields of BciBI and BciBII were 600 and 10,000 U/g of cells. It was found that restriction endonucleases BciBI and BciBII are isoschizomers of ClaI and BstNI, respectively.

Bacillus↗
PubMed1994

[A prosegment of the yeast alpha-factor controls a heterologous protein (human growth factor) in Saccharomyces cerevisiae culture media].

The role of the yeast pheromone prosegment--alpha-factor--in the export of the heterologous protein, the human growth hormone (hGH), in the culture medium of S. cerevisiae has been studied. Using genetic engineering constructions, it has been shown that different N-terminal signal peptides (SP) are not able to provide the hGH export. Transformant cells carrying the plasmid with a hybrid sequence encoding the prosegment-hGH (without SP) accumulate non-glycosylated pro-hGH in the cytosol. Only the combination of SP and the prosegment as the N-terminal fragment of the hGH precursor results in the processing and export of the mature form of the hormone. The origin (or type) of SP is of no significance. The glycosylation inhibitors--2-deoxy-D-glucose and tunicamycin--suppress the export but not the entry of hGH into the periplasm, thus indicating a critical role of the intactness of the prosegment polymannose chains for the efficient export of heterologous protein. A conclusion is drawn that the two preprosegment parts play different roles. The SP constituent of prepro-hGH introduces pro-GH into the general secretory pathway, while the prosegment resulting from the SP cleavage directs hGH from the cell into the culture medium.

Amino Acid Sequence↗
PubMed1992

[Specific endonuclease BbvBI from Bacillus brevis].

A new restriction endonuclease BbvBI free from contaminating nonspecific nucleases and phosphatases was isolated from the Bacillus brevis cells. The enzyme was purified by fractionating the sonicated cell-free extract in a two-phase PEG/dextran system and subsequent chromatographies on DEAE-sepharose, blue sepharose and heparin sepharose. The endonuclease BbvBI displayed the maximal activity at 45 degrees C, pH between 8.0 and 8.5, MgCl2 concentration in the range of 5-10 mM and at the low ionic strength. It is shown that the enzyme cleaves the sequence G'GYPC'C, with the preferential cleavage of GGTACC and GGCACC sites as compared with GGTGCC and GGCGCC. Thus, the restriction endonuclease BbvBI is a true isoschizomer of nuclease BanI.

Bacillus↗
PubMed1991

[BsoAI--a new site specific endonuclease from Bacillus coagulans].

A new site-specific endonuclease was detected in toluene lysates of Bacillus coagulans AUCM B-732 and designated as BcoAI. The enzyme was purified by fractionation of the cell-free extract in the two-phase PEG/dextran system followed by chromatography on DEAE-sepharose and phosphocellulose and shown to be free of nonspecific nucleases and phosphatases. BcoAI has three cleavage sites on lambda DNA, but does not cleave SV40, pBR322 and pUC19 DNA. BcoAI recognizes the sequence 5' CAC decreases GTG 3' on double-stranded DNA and cleaves it as indicated by the arrow to yield blunt-ended DNA fragments. Thus, BcoAI is a true isoschizomer of PmaCI from Pseudomonas maltophila C.

Autoradiography↗
PubMed1991

[Localization of acid phosphatase in Saccharomyces cerevisiae and its export into culture media depends on the type of the N-terminal signal peptide].

The aim of this work was to study the character of intracellular distribution and efficiency of yeast acid phosphatase export depending on the type of the N-terminal signal peptide used. A number of plasmids carrying the acid phosphatase genes with different signal peptides sequences was constructed. The main site of the enzyme accumulation for the variant containing its own acid phosphatase signal peptide was the periplasm. Approximately the same pattern was observed when the hybrid signal peptide consisting of acid phosphatase signal peptide and alpha-factor preprosegment tandem was used. Unlike the above-mentioned systems the strain carrying acid phosphatase under the control of alpha factor preprosegment was able to export the enzyme into the culture medium. The experiments have shown the possibility of changing the final localization of secretory proteins by replacing the N-terminal signal peptide.

Acid Phosphatase↗
PubMed1989

[Biosynthesis of the membrane protein of the acquired immunodeficiency syndrome virus (HIV) with a deleted hydrophobic region in E. coli cells].

Effect of the structure of cloned env gene of HIV virus on the level of its expression has been studied. The deletion of the hydrophobic region from the env gene has been shown to increase considerably the biosynthesis of antigen-specific proteins in Escherichia coli cells. At the same time, the low level of expression of the gene fragment the transcription of which is controlled by a powerful lac-promoter suggests the presence of toxic regions of nonhydrophobic nature in the synthesized antigen.

DNA, Viral↗