[Hypochromic effect of signal attenuation in 31P-NMR spectra of linear polyphosphates]. / Gipokhromnyi éffekt snizheniia intensivnosti signalov v 31P-IaMR spektrakh lineinykh polifosfatov.

Chemical shifts in 31P-NMR spectra of linear polyphosphates were studied. In each polyphosphate species tested, the sum of signal intensities of the internal (core) phosphate groups was proportional to the concentration of each polyphosphate, but the contribution of such groups to the total intensity of the signal decreased with increasing the length of the polyphosphate chain. An equation for estimating the polyphosphate chain length in biological objects taking into account a decrease in the 31P-NMR spectral intensity is proposed.

[Change in inorganic polyphosphate chain length depending on the stage of Saccharomyces cerevisiae growth]. / Izmenenie dliny tsepi neorganicheskikh polifosfatov v zavisimosti ot stadii rosta Saccharomyces cerevisiae.

The dynamics of the content and the degree of polymerization of polyphosphates (PPs) during the growth of Saccharomyces cerevisiae VKM Y-1176 was studied by chemical methods and P NMR spectroscopy. The overall PP content of Saccharomyces cerevisiae cells growing in orthophosphate-sufficient medium was found to increase until glucose was exhausted in the medium. In the early logarithimic phase, the degree of polymerization of PPs (high-polymeric PPs in particular) fell drastically. Further cultivation of yeast in the glucose-depleted medium led to a decrease in the cellular content of all PP fractions without any considerable shortening of their chain length; by the 24th h, high-polymeric PPs accumulated in the cells. Shortening of PPs against a background of their intense synthesis in yeast cells growing in glucose-and orthophosphate-sufficient medium can be explained by the involvement of so far unknown mechanisms of activation of polyphosphate-depolymerizing enzymes.

[Stability of a new product of oxidative stress in bacterial cells]. / Stabil'nost' novogo produkta okislitel'nogo stress v kletkakh bakterii.

Data on 32P-label incorporation with subsequent addition of non-radiolabelled o-phosphate suggest that the new phosphorus compound, 2-C-methyl-D-erythritol-2,4-cyclopyrophosphate (MEC), accumulated in the cells of some bacterial species in response to oxidative stress does not rapidly exchange phosphorus with external o-phosphate 3 hours after the introduction of its synthesis inducers into the Corynebacterium ammoniagenes culture. The accumulated MEC is retained in the cells despite the action of the cell wall synthesis inhibitor, chloramphenicol, or the energetic poisons, KCN and iodoacetate and also under anaerobic conditions. It has been shown that incubation of the cell-free lysate of a non-induced culture, Micrococcus luteus, with MEC does not result in MEC hydrolysis; therefore, MEC accumulation after the redox-mediator addition is hardly due to the hydrolase inactivation but, rather, is due to the activation of the MEC-synthesizing enzyme. The cells of C. ammoniagenes incorporate 32P from [32P]MEC but not 14C from [14C]MEC. This points to MEC hydrolysis prior to the uptake of its phosphoryl fragment by the cells. In this case 32P is found in the fractions differing by their position from MEC fractions. Experiments with sheep erythrocytes and mouse splenocytes revealed that MEC (10-100 micrograms per 1,000,000 splenocytes) does not influence the antibody production by these cells, whereas used at concentrations of 200-550 micrograms per 1,000,000 cells, MEC enhances the antibody production. However, while doing so, MEC causes the destruction of a considerable portion of splenocytes and sheep erythrocytes.

[Effect of surface-active substances on the dynamics of intracellular pH in Fusidium coccineum]. / Vliianie poverkhnostno-aktivnykh veshchestv na dinamiku vnutrikletochnogo pH u Fusidium coccineum.

Correlation between the dynamics of intracellular pH and antibiotic synthesis in Fusidium coccineum strains with different biosynthetic capacity was studied. At the beginning of the intensive antibiotic synthesis the intracellular pH in the low-active and highly-active strains was minimum and maximum respectively. In the highly active strain an increase in the intracellular pH of the cytoplasm after the addition of Tween-80 and Factor-d2 analogs to the growth medium was observed.

[Effect of antiseptics and redox-cycling agents on Corynebacterium ammoniagenes and related microorganisms in relation to synthesis of a new macroergic compound]. / Deistvie antisepticheskikh sredstv i redokstsikliruiushchikh agentov na Corynebacterium ammoniagenes i rodstvennye mikroorganizmy v sviazi s sintezom novogo makroérga.

Sublethal concentration of the antiseptic composition Desoxon-1 was shown to provoke in cells of Corinebacterium ammoniagenes in a liquid medium the biosynthesis and accumulation of a novel macroergic 2-methylbutane-1,2,3,4-tetraol-2,4-cyclopyrophosphate. This substance is also synthesized when C. ammoniagenes is cultivated in a solid agar medium supplemented with benzylviologen. Cells preloaded with the new cyclopyrophosphate maintain its content when treated with 4% phenol, DP-2, Desoxon-1 or boiled and heated in an autoclave. Experiments with Mycobacterium tuberculosis and BCG revealed the ability of these bacteria to grow in a medium supplemented with BV++ possibly due to ability of synthesis of a new cyclopyrophosphate which was shown to correlate with resistance toward redox-cycling drugs. Accumulation of polyphosphates in the control cells of M. tuberculosis was illustrated by 31P-NMR spectroscopy and disappearance of the polyphosphates during cultivation in a BV(++)-supplemented medium. No signal of the new cyclopyrophosphate was yet registered in cells of M. tuberculosis by 31P-NMR.