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Kotova V.Y.,State Research Center Gosenetika | Mironov A.S.,State Research Center Gosenetika | Zavilgelsky G.B.,State Research Center Gosenetika
Molecular Biology | Year: 2014

Quinolone antibiotics inhibit DNA gyrase, but the induced degradation of chromosomal DNA is determined by a complex process of the joint action of quinolones and hydroxyl radical, OH’. In this study, we used inducible specific lux biosensors, i.e., Escherichia coli bacteria containing hybrid plasmids pColD’::lux, pSoxS’::lux, and pKatG’::lux, to quantify the level of stress responses and their time dependence in bacterial cells. Quinolones (nalidixic acid and norfloxacin) were shown to induce SOS response and oxidative stress with the formation of superoxide anion in Escherichia coli cells. The main parameters of SOS response and oxidative stress, which depend on the quinolone concentration, were determined. The formation of superoxide anion occurred almost simultaneously with the SOS response. The mutant strain E. coli sodA sodB, which contains no active forms of superoxide dismutases SodA and SodB is characterized by an increased resistance to quinolones compared to wild-type cells. At high concentrations of quinolones (>20 μg/mL nalidixic acid and >500 ng/mL norfloxacin), their bactericidal effect is partially caused by the conversion of the superoxide anion to hydrogen peroxide H2O2conducted by superoxide dismutases SodA and SodB, which is followed by the Fenton reaction and the formation of toxic hydroxyl radical OH’. At low concentrations of quinolones (<20 μg/mL nalidixic acid and <500 ng/mL norfloxacin), the contribution of the reactive oxygen species in the antimicrobial effect is negligible. © 2014, Pleiades Publishing, Inc. Source

Sokolova O.S.,Moscow State University | Bogush V.G.,State Research Center Gosenetika | Davydova L.I.,State Research Center Gosenetika | Polevova S.V.,Moscow State University | And 5 more authors.
Molecular Biology | Year: 2010

The morphology of the fibers formed by recombinant analogs of dragline spider silk proteins, spidroins 1 and 2, was studied. It has been shown that the extension of the initial fiber, the so-called as-spun fiber, leads to remodeling of the spongy matrix with the formation of microfibers, which is accompanied by a decrease in the fiber diameter. The breaking strength of the fiber depends not only on the primary structure of the constituent protein, but also on the way it was formed. Simulation of the assembly of microfibers and the fibers formed of them can clarify the natural spider web spinning and enhance the development of technology for producing biomaterials with unique properties. © Pleiades Publishing, Inc., 2010. Source

Blagodatskikh K.A.,State Research Center Gosenetika | Agapkina Y.V.,State Research Center Gosenetika | Nikitin A.G.,State Research Center Gosenetika | Brovkin A.N.,State Research Center Gosenetika | And 25 more authors.
Molecular Biology | Year: 2010

Association between the rates of poor outcomes in the patient cohort with acute coronary syndrome and polymorphisms G(-174)C in the IL6 gene and G(-1082)A in the IL10 gene were determined. In total, 1145 patients hospitalized for coronary artery disease to cardiological hospitals of Moscow, St. Petersburg, Kazan, Chelyabinsk, Perm, Stavropol, and Rostov-on-Don were examined. The mean observation period was 9.10 ± 5.03 months (maximal, 18 months). Analysis of the survival of the patients with acute coronary syndrome that carried allele A has demonstrated that the presence of IL10 gene polymorphism G(-1082)A is associated with more frequent poor outcomes as compared with GG genotype. The survival time to endpoint for the carriers of GA and AA genotypes was 11.68 ± 0.67 months versus 12.69 ± 0.65 months for the carriers of GG genotype in IL10 gene (χ2 = 4.13, p = 0.042). As for the IL6 gene polymorphism G(-174)C, survival rate analysis did not detect any significant association with the risk for poor outcome. However, joint analysis of these polymorphisms in both genes has demonstrated that characteristic of the patients with acute coronary syndrome that carry GG genotype of IL6 gene and GA and AA genotypes of IL10 is a higher rate of poor outcomes (time to endpoint, 11.01 ± 1.24 months) as compared with the carriers of IL6 gene CC and CG genotypes and IL10 gene GG genotype (time to endpoint, 13.28 ± 0.83 months (ξ2 = 10.23, p = 0.017). These data suggest that the genes IL6 and IL10, whose products are involved in the control of inflammatory response, play an important role by increasing the probability of poor outcomes in the patients with acute coronary syndrome. © 2010 Pleiades Publishing, Ltd. Source

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