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P V Zelenikhin

Publications and source records attributed to P V Zelenikhin.

3 recordsLinked to original sources

[The effect of anabiosis autoinducers on the bacterial genome].

The mutagenic activity of chemical analogues of microbial anabiosis autoinducers (the autoregulatory d1 factors of cell differentiation), which act to inhibit cell proliferation, to enhance cell tolerance, and to induce the transition of cells to anabiotic state, was studied using the Ames test. In the range of concentrations studied (0.1 to 100 micrograms/ml), alkyl-substituted hydroxybenzenes (AHBs) differing in hydrophobicity, i.e., methylresorcinol (C1-AHB) and hexylresorcinol (C6-AHB), as well as unsubstituted resorcinol, showed different growth-inhibiting and mutagenic effects. C6-AHB was found to inhibit the growth of Salmonella typhimurium TA100 and to induce its mutagenesis at a rate of 1.8 revertants/nmol. C1-AHB taken at low concentrations not only failed to inhibit bacterial growth but even stimulated it and exerted an antimutagenic effect. Unsubstituted resorcinol virtually did not influence bacterial growth and showed weak mutagenic activity. The growth-inhibiting effect of elevated C6-AHB concentrations correlated with the degree of the transition of the original phenotype producing S-type colonies to a phenotype producing R-type colonies. The role of AHB homologues, as microbial autoregulators with mutagenic activity, in the regulation and correlation of two processes (the phenotypic dissociation of microbial populations and the formation of resting microbial forms) is discussed. The accumulation of AHBs in senescent microbial cultures may induce adaptive mutations, change the expression of genes, and promote the development of minor cell subpopulations (phenotypes), thus providing for the adaptation of these cultures to varying environmental conditions.

Dose-Response Relationship, Drug↗

[Induction of apoptosis of tumor cells by binase].

An induction of apoptosis by RNase from Bacillus intermedius (binase) and its mutants characterized with low catalytic activity (Lys26Ala and His101Glu) in human myelogenic erythroleukemia K562 cells, human lung carcinoma A549 cells and human peripheral blood mononuclear cells was studied. For the first time selective apoptogenic effects of binase toward leukemic blood cells was determined. Neither antiproliferative nor apoptotic effects of binase were detected in normal human peripheral blood mononuclear cells. Formation of low molecular weight oligonucleosomal DNA fragments (less than 50 Kb) which are an early marks of apoptosis was registered in solid tumor cells treated by binase. Using mutant RNases it was shown that decrease of catalytic activity to 2.5% of wild type enzyme activity leads to the loss of apoptogenic properties of enzyme. Selective apoptogenicity of binase found towards malignant cells confirmed that antitumor agents based on bacterial RNases could be considered as an alternative to standard chemotherapeutic drugs.

Amino Acid Substitution↗