[Elimination of volatile compounds of leaf tobacco from air emissions using biofiltration]

The composition of the volatile organic compounds (VOCs) of various leaf tobacco brands and their blends has been studied. The differences in the content of nicotine, solanone, tetramethyl hexadecenol, megastigmatrienones, and other compounds, determining the specific tobacco smell, have been revealed. A microbial consortium, which is able to deodorize simulated tobacco emissions and decompose nicotine, has been formed by long-term adaptation to the VOCs of tobacco leaves in a laboratory reactor, functioning as a trickle-bed biofilter. Such a biofilter eliminates 90% of the basic toxic compound (nicotine) and odor-active compounds; the filtration efficiency does not change for tobacco brands with different VOC concentrations or in the presence of foreign substances. The main strains, isolated from the formed consortium and participating in the nicotine decomposition process, belong to the genera Pseudomonas, Bacillus, and Rhodococcus. An examination of the biofilter trickling fluid has shown full decomposition of nicotine and odor-active VOCs. The compounds, revealed in the trickling fluid, did not have any odor and were nontoxic. The obtained results make it possible to conduct scaling of the biofiltration process to eliminate odor from air emissions in the tobacco industry.

[Effects of recombinant mechano-dependent growth factor against the background of chronic alcoholisation in rats]

In alcoholised rats, proliferation of satellite cells consistently decreased as well as the number of myonuclei, while phosphorylation of p90RSK became reduced. The mechano-growth factor abministration increased the proliferate activity of the myogenic precursors and restored the myonuclei pool. Phosphorylation of p90RSK increased too.

Expression, purification, crystallization and preliminary crystallographic analysis of a thermostable DNA ligase from the archaeon Thermococcus sibiricus

DNA ligases join single-strand breaks in double-stranded DNA by catalyzing the formation of a phosphodiester bond between adjacent 5'-phosphate and 3'-hydroxyl termini. Their function is essential to maintain the integrity of the genome in DNA replication, recombination and repair. A recombinant ATP-dependent DNA ligase from the hyperthermophilic anaerobic archaeon Thermococcus sibiricus was expressed in Escherichia coli and purified. Crystals were grown by vapour diffusion using the hanging-drop method with 17%(w/v) PEG 4000 and 8.5%(v/v) 2-propanol as precipitants. A diffraction experiment was performed with a single crystal, which diffracted X-rays to 3.0 Å resolution. The crystal belonged to space group P2(1)2(1)2(1), with unit-cell parameters a = 58.590, b = 87.540, c = 126.300 Å.

Investigation of formate transport through the substrate channel of formate dehydrogenase by steered molecular dynamics simulations

Steered molecular dynamics simulation has revealed the mechanism of formate transport via the substrate channel of formate dehydrogenase. It is shown that the structural organization of the channel promotes the transport of formate anion in spite of the fact that the channel is too narrow even for such a small molecule. The conformational mobility of Arg284 residue, one of the residues forming the wall of the substrate channel, provides for the binding and delivery of formate to the active site.

[Methods of detection and identification of manufactured nanoparticles]

The actual methods of detection and identification of manufactured nanoparticles in both simple and complex multi-component matrix for assessing biological effects and safety of nanotechnology products have been reviewed. The detection of priority species of biologically active nanoparticles, which include fullerenes, single- and multi-walled carbon nanotubes, nanoparticles of silver, gold, titanium oxide, aluminum, cerium, zinc and silicon, has been given a special attention. The requirements for sample preparation have been discussed. The results of the successful application for the detection of manufactured nanoparticles in bioassays with methods of scanning and transmission electron microscopy, confocal laser scanning microscopy, atomic force microscopy, scanning tunneling microscopy, size exclusion chromatography, field-flow fractionation, electrophoretic, light scattering, spectrophotometry, fluorescent spectroscopy, X-ray and other spectrometry, mass spectrometry, "particle counters", immunochemistry have been reviewed. The possibilities and limitations of different techniques, and their complementarity have been analyzed.

[Sustained release of the antitumor drug paclitaxel from poly(3-hydroxybutyrate)-based microspheres]

Development of systems of medicines with sustained action on the basis of biodegradable polymers is a promising trend in modem pharmacology. Polyhydroxyalkanoates (POA) attract increasing attention due to their biodegradability and high biocompatibility, which make them suitable for development of novel drug dosage forms. We obtained microspheres on the basis of poly(3-hydroxybutyrate) (PHB) loaded with the antitumor drug paclitaxel. Morphology, drug release kinetics and effect on tumor cells in vitro of microspheres were studied. The data on the kinetics of drug release, biocompatibility and biological activity of the biopolymer microspheres in vitro showed that the studied system of prolonged drug release had lower toxicity and higher efficiency compared to the traditional dosage forms of paclitaxel.

Isolation and characterization of nitrate reductase from the halophilic sulfur-oxidizing bacterium Thioalkalivibrio nitratireducens

A novel nitrate reductase (NR) was isolated from cell extract of the haloalkaliphilic bacterium Thioalkalivibrio nitratireducens strain ALEN 2 and characterized. This enzyme is a classical nitrate reductase containing molybdopterin cofactor in the active site and at least one iron-sulfur cluster per subunit. Mass spectrometric analysis showed high homology of NR with the catalytic subunit NarG of the membrane nitrate reductase from the moderately halophilic bacterium Halomonas halodenitrificans. In solution, NR exists as a monomer with a molecular weight of 130-140 kDa and as a homotetramer of about 600 kDa. The specific nitrate reductase activity of NR is 12 micromol/min per mg protein, the maximal values being observed within the neutral range of pH. Like other membrane nitrate reductases, NR reduces chlorate and is inhibited by azide and cyanide. It exhibits a higher thermal stability than most mesophilic enzymes.

Expression, purification and crystallization of a thermostable short-chain alcohol dehydrogenase from the archaeon Thermococcus sibiricus

Alcohol dehydrogenases belong to the oxidoreductase family and play an important role in a broad range of physiological processes. They catalyze the cofactor-dependent reversible oxidation of alcohols to the corresponding aldehydes or ketones. The NADP-dependent short-chain alcohol dehydrogenase TsAdh319 from the thermophilic archaeon Thermococcus sibiricus was overexpressed, purified and crystallized. Crystals were obtained using the hanging-drop vapour-diffusion method using 25%(w/v) polyethylene glycol 3350 pH 7.5 as precipitant. The crystals diffracted to 1.68 A resolution and belonged to space group I222, with unit-cell parameters a = 55.63, b = 83.25, c = 120.75 A.

Atomic Resolution Crystal Structure of NAD(+)-Dependent Formate Dehydrogenase from Bacterium Moraxella sp. C-1

The crystal structure of the ternary complex of NAD+-dependent formate dehydrogenase from the methylotrophic bacterium Moraxella sp. C-1 with the cofactor (NAD+) and the inhibitor (azide ion) was established at 1.1 A resolution. The complex mimics the structure of the transition state of the enzymatic reaction. The structure was refined with anisotropic displacitalicents parameters for non-hydrogen atoms to a R factor of 13.4%. Most of the nitrogen, oxygen, and carbon atoms were distinguished based on the analysis of the titalicperature factors and electron density peaks, with the result that side-chain rotamers of histidine residues and most of asparagine and glutamine residues were unambiguously determined. A comparative analysis of the structure of the ternary complex determined at the atomic resolution and the structure of this complex at 1.95 A resolution was performed. In the atomic resolution structure, the covalent bonds in the nicotinamide group are somewhat changed in agreitalicent with the results of quantum mechanical calculations, providing evidence that the cofactor acquires a bipolar form in the transition state of the enzymatic reaction.

[Small interfering RNAs targeting human myostatin]

Ten human myostatin small interfering RNAs which sequence was found by two different software products were synthesized and tested for activity. It was found that three of them have pronounced biological activity and decrease myostatin mRNA level to 22-27% of control value. These small interfering RNAs stimulate human myoblast proliferation and decrease their differentiation reliably. The obtained small interfering RNAs can be used for development of new approaches for the treatment of sarcopenia and different myodystrophies.