[Peculiarities of the Mechanism of Interactions of Catalytic Antibodies with Organophosphorus Substrates].

Catalytic antibodies are a promising model for creating highly specific biocatalysts with predetermined activity. However, in order to realize the directed change or improve their properties, it is necessary to understand the basics of catalysis and the specificity of interactions with substrates. In the present work, a structural and functional study of the Fab fragment of antibody A5 and a comparative analysis of its properties with antibody A17 have been carried out. These antibodies were previously selected for their ability to interact with organophosphorus compounds via covalent catalysis. It has been established that antibody A5 has exceptional specificity for phosphonate X with bimolecular reaction rate constants of 510 ± 20 and 390 ± 20 min^(-1)М^(-1) for kappa and lambda variants, respectively. 3D-Modeling of antibody A5 structure made it possible to establish that the reaction residue L-Y33 is located on the surface of the active site, in contrast to the A17 antibody, in which the reaction residue L-Y37 is located at the bottom of a deep hydrophobic pocket. To investigate a detailed mechanism of the reaction, A5 antibody mutants with replacements L-R51W and H-F100W were created, which made it possible to perform stopped-flow kinetics. Tryptophan mutants were obtained as Fab fragments in the expression system of the methylotrophic yeast species Pichia pastoris. It has been established that the effectiveness of their interaction with phosphonate X is comparable to the wild-type antibody. Using the data of the stopped-flow kinetics method, significant conformational changes were established in the phosphonate modification process. The reaction was found to proceed using the induced-fit mechanism; the kinetic parameters of the elementary stages of the process have been calculated. The results present the prospects for the further improvement of antibody-based biocatalysts.

Evolution of catalytic centers of antibodies by virtual screening of broad repertoire of mutants using supercomputer.

It is proposed to perform quantum mechanical/molecular dynamics calculations of chemical reactions that are planned to be catalyzed by antibodies and then conduct a virtual screening of the library of potential antibody mutants to select an optimal biocatalyst. We tested the effectiveness of this approach by the example of hydrolysis of organophosphorus toxicant paraoxon using kinetic approaches and X-ray analysis of the antibody biocatalyst designed de novo.

A Study of the Protective Properties of an Antibody-Based Antidote Metabolizing Organophosphorus Pesticide Paraoxon.

A catalytic antibody A17 and its mutants highly efficiently interact with organophosphorus pesticide paraoxon. In this work, we studied the protective properties of antibody A17-K47 in paraoxon poisoning using a mouse model. The optimal paraoxon dose simulating the acute toxic effect of organophosphorus compounds was 550 µg/kg. The pharmacokinetic parameters of A17-K47 antibody were t1/2distr =7.2±1.4 min, t1/2el =330±20 min. The antibody did not cause toxic effects when administered at a ten-fold calculated therapeutic dose (610 mg/kg). The drug did not reduce mortality from acute paraoxon poisoning; however, the absence of drug toxicity opens up prospects for its use in symptomatic treatment of chronic paraoxon poisoning.

New Genetic Constructs for Generation of Stable Therapeutic Antibodies to Organophosphorus Toxins in Methylotrophic Yeasts Pichia Pastoris.

We propose a new method of obtaining of stable Fab-fragments of antibodies in Pichia pastoris expression system. Recently, we obtained Fab-fragments of antibodies neutralizing organophosphorus toxins. However, high yield of the target products was not attained because of high level of proteolytic degradation. In the present study, we identified sites of proteolytic degradation in Fab-fragments and endogenous proteases performing degradation, which allowed obtaining optimized genetic constructs for expression of antibody heavy chains (IgGγ1) and kappa and lambda isotypes of light chains. Co-transformation of these vectors allowed obtaining Fab-fragments of antibodies to organophosphorus toxins without proteolytic degradation of the product.

[Expression Of DNA-Encoded Antidote to Organophosphorus Toxins in the Methylotrophic Yeast Pichia Pastoris].

A platform for the cloning and expression of active human butyrylcholinesterase (BuChE) in the yeast Pichia pastoris is first presented. Genetic constructs for BuChE gene expression, separately and in conjunction with a proline-rich peptide called proline-rich attachment domain (PRAD), are based on the vector pPICZαA. It is shown that the highest level of production is achieved in the expression of a BuChE gene without PRAD pPICZαA. It is found that one can obtain up to 125 mg of active enzyme from 1 L of culture medium at an optimal pH environment (pH 7.6), an optical seed culture density of 3 o.u., and an optimum methanol addition mode of (0.5% methanol in the first day and 0.2% thereafter from the second day).

[Tree-rings width variability along latitudinal and paleolatitudinal gradients].

Processed are 57596 dated series of tree-rings width (TRW ) from the International Tree-ring Data Bank. The results obtained indicate that: 1. The TRW is strongly correlated with tree age. Periods of cambium activity are strictly dependent on the age of the trees. Therefore, there is a strong correlation between TRW and periods of radial growth. It is suggested that synchronization of the periods of radial growth in the first 150 years of trees life with cycles of climatic factors leads to increase in TRW . 2. Satisfactory coincidence between latitudinal profiles of TRW , on the one hand, and climatic and biological indicators, on the other hand, is observed. Latitudinal profile of TRW gets its form under the influence of climate and assimilating mass productivity. 3. Latitudinal change of the TRW in the Cretaceous had a pronounced displacement of a maximum from equator toward 30 °NL. Growth gain of Cretaceous gymnosperms was about twice higher than that of modern trees. Such asymmetry of paleolatitudinal profile of TRW sharply distinguishes it from modern latitudinal profiles that follow climatic parameters.

LICHENS' B-OLIGOSACCHARIDES IN THE CORRECTION OF METABOLIC DISORDERS IN TYPE 2 DIABETES MELLITUS.

INTRODUCTION: Lichens of the genus Cladonia are used as medicinal plants in folk medicine. Biologically active food supplement (BAFS) on the basis of lichens p. Cladonia was derived by mechanical-chemical biotechnology in the Educational-Research-Engineering Laboratory "Mechanical-Chemical Biotechnology" of the North-Eastern Federal University (NEFU). As a result of biotech impact, the solid ß-glycoside bonds are destructed on ß-oligosaccharide molecules, and other groups of lichen BAS is mobilized. The content of hydrolysable carbohydrates in samples of lichen increased 8 times after mechanical activation. AIM: The aim of investigation was to study the effects of BAFS "Yagel-Detox" in patients with type 2 diabetes mellitus (DM 2). MATERIALS AND METHODS: The 150 patients (group 1--100 patients receiving "Yagel-Detox", group 2--50 patients receiving placebo) with a diagnosis DM 2 were examined. The research included: general clinical and instrumental examination, biochemical and clinical blood tests. "Yagel-Detox" was used 1 capsule 3 times a day, the rate of admission was 3 months. RESULTS: Clinical trials have shown that 3-month intake of BAFS "Yagel-Detox" reduces the concentration of blood glucose 1.3 1.6 times (in the control group--1.2 ÷ 1.4 times), glycosylated hemoglobin--from 9.8 ÷ 11.4% to 7.6% (in the control group--1.0%). The concentration of low-density lipoprotein (LDL) reduced on 1.3% through 6 months. Patients of both groups were on the similar tablet glucose-lowering therapy (randomized treatment), which have not been adjusted. CONCLUSIONS: The obtained results allow us to recommend BAFS "Yagel-Detox" as an additional remedy to normalize blood glucose concentration in patients with DM 2.

Factors Affecting Aggregate Formation in Cell Models of Huntington's Disease and Amyotrophic Lateral Sclerosis.

Most neurodegenerative pathologies stem from the formation of aggregates of mutant proteins, causing dysfunction and ultimately neuronal death. This study was aimed at elucidating the role of the protein factors that promote aggregate formation or prevent the process, respectively, glyceraldehyde-3-dehydrogenase (GAPDH) and tissue transglutaminase (tTG) and Hsp70 molecular chaperone. The siRNA technology was used to show that the inhibition of GAPDH expression leads to a 45-50% reduction in the aggregation of mutant huntingtin, with a repeat of 103 glutamine residues in a model of Huntington's disease (HD). Similarly, the blockage of GAPDH synthesis was found for the first time to reduce the degree of aggregation of mutant superoxide dismutase 1 (G93A) in a model of amyotrophic lateral sclerosis (ALS). The treatment of cells that imitate HD and ALS with a pharmacological GAPDH inhibitor, hydroxynonenal, was also shown to reduce the amount of the aggregating material in both disease models. Tissue transglutaminase is another factor that promotes the aggregation of mutant proteins; the inhibition of its activity with cystamine was found to prevent aggregate formation of mutant huntingtin and SOD1. In order to explore the protective function of Hsp70 in the control of the aggregation of mutant huntingtin, a cell model with inducible expression of the chaperone was used. The amount and size of polyglutamine aggregates were reduced by increasing the intracellular content of Hsp70. Thus, pharmacological regulation of the function of three proteins, GAPDH, tTG, and Hsp70, can affect the pathogenesis of two significant neurodegenerative diseases.

[Analysis of illness pathology causes of digestive organs in the Chuvash Republic and prospects of its reduction].

The main principles of organization of gastroenterological service of the Chuvash Republic are presented. The main significant causes of incidence rate of digestive apparatus pathology and the ways of their elimination are discussed. The peculiarities of population dietary habits are analyzed. The complex of measures carried out in Chuvashia for improving the quality of production and processing of alimentary products taking into account the peculiarities of every biogeochemical subregion and requirements of various population groups is presented. The forms and methods of healthy life-style formation, training of people responsible attitude to their health are described. Priority guidelines of gastroenterological assistance to the population of the Chuvash Republic are enumerated.

[Polymorphism of the STR-locus of Y chromosomes in Eastern Slavs in three populations from Belorussia, Russia and the Ukraine]. / Polimorfizm STR-lokusov Y-khromosomy u vostochnykh slavian v trekh populiatsiiakh iz Belorussii, Rossii i Ukrainy.

Allelic polymorphism of five microsatellite loci of the human Y chromosome (DYS19, DYS390, DYS391, DYS392, and DYS393) was analyzed in samples of male populations from Ukraine, Russia, and Belarus (152 subjects in total). The allelic diversity indices (Dg) were determined for all loci; they varied from 0.23 to 0.72. The mean values of this parameter in the Ukrainian, Russian, and Belarussian populations were 0.45, 0.47, and 0.52, respectively. A total of 53 different haplotypes were found in 152 subjects from three populations. The most frequent haplotype was found in 14.5% of the subjects, whereas 35 haplotypes (23%) were each found in only one person. The haplotypic diversity index (Dhp) was 0.94. The genetic distances between the populations studied and some populations of Western and Central Europe were estimated. These data were used to construct a phylogram (tree) of genetic similarity between the populations, which demonstrated that the three Eastern Slavic populations are genetically close to one another and remote from Western European populations.