The state of dog's metabolism after long interval after oxide tritium administration

An attempt to evaluate the influence of tritium oxide on the metabolism by some indices of lipid metabolism (common lipids, beta-lipoproteins, cholesterin), protein metabolism (cholinesterasa) and carbohydrate metabolism (blood sugar) was made. It was established that the introduction into organism of tritium oxide in the quantities, which could form lethal and sublethal doses of internal radiation, provoked the main changes of values of mentioned indices of metabolism. The character of metabolism changes in the remote period allows us to judge about the development of sclerosis processes, which can be the result of radiation-stipulated acceleration of organism aging.     

Parameters of reactive oxygen species and nitric oxide metabolism in people with high arterial blood pressure

An exchange of active forms of oxygen and nitric oxide in normal conditions and under the development of oxidative stress in humans with high of arterial blood pressure was studied. The activity of NO-synthase was estimated in the human thrombocytes. The nitric oxide formations were determined by the quantity level of its final metabolites--nitrites and nitrates. The peroxynitrite formations were determined by the quantity level of 3-nitrotyrosine. An analysis of the investigation results has shown the increase of processes of oxidative stress, violation of nitric oxide formation in humans with high arterial blood pressure. Application of ascorbic acid allows to reduce the level of free radicals and to increase the formation of nitric oxide, but does not result in statistically reliable changes of the parameters describing formation of peroxynitrite and products of peroxide oxidation of lipids in humans with high arterial blood pressure. Application of ascorbic acid does not result in changes of researched parameters in the control group.     

Detailed analysis of RNA-protein interactions within the ribosomal protein S8-rRNA complex from the archaeon Methanococcus jannaschii

The crystal structure of ribosomal protein S8 bound to its target 16 S rRNA from a hyperthermophilic archaeon Methanococcus jannaschii has been determined at 2.6 A resolution. The protein interacts with the minor groove of helix H21 at two sites located one helical turn apart, with S8 forming a bridge over the RNA major groove. The specificity of binding is essentially provided by the C-terminal domain of S8 and the highly conserved nucleotide core, characterized by two dinucleotide platforms, facing each other. The first platform (A595-A596), which is the less phylogenetically and structurally constrained, does not directly contact the protein but has an important shaping role in inducing cross-strand stacking interactions. The second platform (U641-A642) is specifically recognized by the protein. The universally conserved A642 plays a pivotal role by ensuring the cohesion of the complex organization of the core through an array of hydrogen bonds, including the G597-C643-U641 base triple. In addition, A642 provides the unique base-specific interaction with the conserved Ser105, while the Thr106 - Thr107 peptide link is stacked on its purine ring. Noteworthy, the specific recognition of this tripeptide (Thr-Ser-Thr/Ser) is parallel to the recognition of an RNA tetraloop by a dinucleotide platform in the P4-P6 ribozyme domain of group I intron. This suggests a general dual role of dinucleotide platforms in recognition of RNA or peptide motifs. One prominent feature is that conserved side-chain amino acids, as well as conserved bases, are essentially involved in maintaining tertiary folds. The specificity of binding is mainly driven by shape complementarity, which is increased by the hydrophobic part of side-chains. The remarkable similarity of this complex with its homologue in the T. thermophilus 30 S subunit indicates a conserved interaction mode between Archaea and Bacteria.     

Sample preparation in separation of the extracellular chitinolytic enzymes of the human intestinal bacterium Clostridium paraputrificum J4 from the culture fluids

Membrane ultrafiltration (UF) was used in sample preparation of the culture fluids of the human intestinal bacterium Clostridium paraputrificum strain J4 containing seven extracellular chitinolytic isoenzymes (38-90 kDa). The subsequent filtration of the bacteria-free supernatants was carried out through Millipore membranes with cut-off 100 and 30 kDa for separation of undigested components of the culture medium and bacterial metabolites with molecular weight higher and lower than that of the target enzymes. The chitinolytic enzymes, which were the minor components in the culture fluids, were concentrated at UF as well. The aim of the research consisted in evaluation of the effect of component composition of bacteria-free supernatants and the chemical nature of membrane active layer on partial fractionation of the chitinolytic enzymes, their recovery in retentates and purification degree. On the basis of the obtained experimental results, the sample preparation procedure of the culture fluids of C. paraputrificum J4 was established to be used further in chromatographic separations of the chitinolytic enzymes.     

The primary production of Amursky Bay (Sea of Japan) in the summer of 2008

In July 2015, the assimilation number (An) of phytoplankton in Amursky Bay was measured using optical dissolved oxygen sensors (Rinko). The primary production (PP) in the photic layer of Amursky Bay was calculated based on the measured An and chlorophyll vertical profiles obtained during a hydrochemical survey on August 23?28, 2008. The total production in the bay at that period was 840 tC/day. During a phytoplankton bloom, the excess production of biomass leading to the hypoxia of the bottom water was estimated to be approximately (1.0?2.0) × 10³ tC/day.     

Isolation, Crystallization, and Investigation of Ribosomal Protein S8 Complexed with Specific Fragments of rRNA of Bacterial or Archaeal Origin

The core ribosomal protein S8 binds to the central domain of 16S rRNA independently of other ribosomal proteins and is required for assembling the 30S subunit. It has been shown with E. coli ribosomes that a short rRNA fragment restricted by nucleotides 588-602 and 636-651 is sufficient for strong and specific protein S8 binding. In this work, we studied the complexes formed by ribosomal protein S8 from Thermus thermophilus and Methanococcus jannaschii with short rRNA fragments isolated from the same organisms. The dissociation constants of the complexes of protein S8 with rRNA fragments were determined. Based on the results of binding experiments, rRNA fragments of different length were designed and synthesized in preparative amounts in vitro using T7 RNA-polymerase. Stable S8–RNA complexes were crystallized. Crystals were obtained both for homologous bacterial and archaeal complexes and for hybrid complexes of archaeal protein with bacterial rRNA. Crystals of the complex of protein S8 from M. jannaschii with the 37-nucleotide rRNA fragment from the same organism suitable for X-ray analysis were obtained.     

The photochemistry of purine components of nucleic acids. II. Photolysis of deoxyguanosine.

UV-irradiation (lambda = 254 nm) of liquid aqueous solutions of deoxyguanosine in the presence of oxygen at pH less than 7 causes an intensive degradation of nucleoside. The quantum yield estimated from A254 decrease for the reaction mixture was found to be 1.5X10(-4) at doses to 150 E/mole. The rate of A254 decrease was found to grow with increasing doses. The structures of the products isolated from the reaction mixture after irradiation suggest that one of the ways of deoxyguanosine degradation is a breakdown of a purine cycle without splitting of N-glycoside bond. Simultaneously another type of photoinduced modification of guanine nucleus takes place, which is followed by appearance of free 2-deoxyribose. Deoxyguanosine degradation in both directions is kinetically one-step process proceeding with comparable quantum yields of approximately 1X10(-4).