The review examines the main stages of cytokinin biosynthesis and metabolism with an emphasis on the important role of cytokinin oxidase/dehydrogenase (CKO/CKX) in cytokinin degradation. In this context, arguments are made for the crucial importance of this enzyme in maintaining a balanced level of cytokinins in plants. The role of CKX genes encoding cytokinin oxidase/dehydrogenase in determining plant resistance to abiotic stress factors and their yield was analyzed. The molecular genetic ways of regulating the activity of CKX genes are characterized. The results of research on the regulation of CKO/CKX activity in increasing the resistance to abiotic stress and crop yield are summarized and the biotechnological ways of realizing such opportunities are described. Prospects for finding substances that inhibit CKO/CKX activity to create preparations for agriculture are outlined separately. Prospective chemical inhibitors of CKO/CKX and their effects on cultivated plants are considered.

Protein kinases represent one of the largest eukaryotic enzyme superfamilies. However, only a few can directly phosphorylate tubulin and contribute to the modulation of the "tubulin code." The authors previously confirmed the structural and functional homology of the plant protein kinase IREH1 and members of the mammalian MAST kinase family. Their participation in the regulation of the microtubule system in plant and animal cells was also experimentally confirmed. At the same time, the direct contribution of MAST/IRE to the "tubulin code" remains unclear. In the current study, based on bioinformatical and structural biology methods, the possibility of such an interaction was evaluated. The target sites of MAST/IRE-phosphorylation of tubulin were predicted based on similarity to the generalized specific profiles. Two potential MAST/IRE specific sites, conserved in human and Arabidopsis tubulins were selected: Thr73 (80) exists in most isotypes of alpha-tubulin and Ser115 was found in the majority of human and plant isotypes of beta-tubulin. It was predicted that phosphorylation of the first site can affect the assembly of alpha/beta-tubulin heterodimer, and phosphorylation of the second may affect the interaction between neighboring protofilaments of microtubules. The last site Ser433, was found in both gamma-tubulin isotypes of A. thaliana, but it was absent in mammals. The external position of Ser433 in plant gamma-tubulin allows for suggesting that phosphorylation of this amino acid can affect the structure of the gamma TuRC complex but it does not affect inner contacts of gamma TuSC and their interaction in the ring.

Aim. The study was aimed at identification and selection of winter common wheat genotypes with null-alleles at the gliadin loci Gli-B1 and Gli-D1. Methods. The search for spontaneous mutants with the absence of synthesis of gliadin blocks was made in winter common wheat hybrid material and cultivars. To identify mutations, APAG electrophoresis and SDS-electrophoresis of seed storage proteins were performed. Results. The frequency of spontaneous mutations resulting in the null-allele at the loci Gli-B1 and Gli-D1 in F2 was 0,1 % and 0,05 %, respectively, in the cross Odesska chervonokolosa × B-16. Via sowing the material with those mutations and marker selection, F6 lines were developed: the line OB-Bnull with the null-allele at the Gli-B1 locus and the line OB-Dnull with the null-allele at the Gli-D1 locus. Another line with the null-allele at Gli-B1 was produced from the cross B3 × D4 by marker selection, as well as a biotype with the null-allele at the Gli-D1 locus was selected from the cultivar Slaven. Conclusions. The developed lines with null-alleles at the gliadin locus Gli-B1 (without omega-5 gliadins) and Gli-D1 (without omega-1,2 gliadins) are initial material for hypoallergenic wheat breeding.

Aim. Search for new inhibitors of the mitotic apparatus of mycobacterium and a number of enzymatic targets. Methods. 3D models of key targets reconstruction and geometry optimization and analysis of biologically active conformations of inhibitors were performed according to a previously developed technique. Results. A revision of mycobacterial inhibitors, which exhibit antimicrobial action against representatives of the genus Mycobacterium, was carried out, which made it possible to create an appropriate reference library of compounds. The complete spatial structure of a number of the main targets of targeted therapy for tuberculosis was reconstructed and verified, and the features of their interaction with selective inhibitors were established. Chemogenomic profiling was performed, which made it possible to draw conclusions regarding the uniqueness of the studied sites and the potential toxicity of compounds related to these sites for humans. Conclusions. A well-developed search algorithm for known inhibitors of proteins with M. tuberculosis allows further study of the features of their interaction with the corresponding homologues of M. bovis and the development of new, more selective compounds using molecular dynamics and docking methods. Keywords: tuberculosis, in silico, anti-tuberculosis drugs.

aim. Investigation of bioprotective action of polycomponent biostimulants of natural origin Regoplant and Stimpo according to physiological and molecular genetic parameters of resistance of winter wheat plants (Triticum aestivum L.) varieties Antonivka ta Hoduval'nytsya odes'ka to the salinity conditions. Methods. The physiological parameters of resistance of experimental wheat plants obtained from seeds treated and untreated with solutions of Regoplant and Stimpo biostimulants used at concentrations of 50 μl/L and 75 μl/L grown under salt stress on 0,1 M sodium chloride solution were studied. Using Dot blotting method the degree of hybridization between cytoplasmic si/miRNA isolated from cells of experimental wheat plants grown under salinity conditions and mRNA of control plants grown in the absence of salinity conditions was determined. In the wheat embryo cell-free system of protein synthesis in vitro the silencing activity of si/miRNA on the template of mRNA isolated from cells of experimental wheat plants grown under salt stress conditions and control plants was studied. Results. It was found that the use of biostimulants Regoplant and Stimpo by soaking the seeds of wheat plants for 24 hours at concentrations of 50 μl/L and 75 μl/L improved the physiological parameters of wheat plants grown under salt stress conditions, which increased on average: seed germination – up to 69-75%, the length of seedlings – up to 28-37%, the length of roots – up to 41-42%, leaf area – up to 25-38%, the raw weight of seedlings – up to 48-53%, the dry weight of seedlings – up to 37-46 %, respectively, compared to control. The Dot-blot hybridization method showed that the largest decrease in the percentage of hybridized mRNA and si/miRNA molecules was observed in experimental wheat plants grown from seeds treated with Regoplant and Stimpo biostimulants under salt stress conditions - up to 66-75%, respectively, compared to control. The increase of silencing activity of si/miRNA on the template of mRNA isolated from experimental wheat plants obtained from seeds treated with Regoplant and Stimpo biostimulants and grown under salt stress conditions was shown to be 39-42%, respectively, compared to control. Conclusions. The use of biostimulants Regoplant and Stimpo in concentrations of 50 μl/L and 75 μl/L for presowing seed treatment contributes to the increase of the resistance of winter wheat plants to salinity conditions. Keywords: Triticum aestivum L., polycomponent biostimulants, resistance of wheat to salinity conditions, RNA interference.

The purpose of this work is to automation of the informativity content analysis of kinetic parameters based onde composing a chemical reaction independent route. The software for determining the basis of nonlinear parametric functions of kinetic measurements for the mechanisms of complex chemical reactions is developed and described.

Aim. Search for new dinitroaniline and phosphorothioamide compounds, capable of selective binding with Plasmodium α-tubulin, affecting its mitotic apparatus. Methods. Structural biology methods of computational prediction of protein-ligand interaction: molecular docking, molecular dynamics and pharmacophore analysis. Selection of compounds based on pharmacophore characteristics and virtual screening results. Results. The protocol and required structural conditions for target (α-tubulin of P. falciparum) preparation and correct modeling of the ligand-protein interaction (docking and virtual screening) were developed. The generalized pharmacophore model of ligand-protein interaction and key functional groups of ligands responsible for specific binding were identified. Conclusions. Based on results of virtual screening, 22 commercial compounds were selected. Identified compounds proposed as potential inhibitors of Plasmodium mitotic machinery and the base of new antimalarial drugs. Keywords: malaria, Plasmodium, intermolecular interaction, dinitroaniline derived, phosphorothioamidate derived.

One of the approaches to solving parametric identification problems is based on numerical methods. In fact, their use is reduced to the process of iterating over the elements of multidimensional areas of the desired parameters. Increasing the density of the introduced grid increases the amount of calculations and time spent on the process of their implementation. Increasing the density of the introduced grid increases the amount of calculations and time spent on the process of their implementation. In this regard, it is desirable to improve the efficiency of the computer systems used. An important direction in the context of the above is the development of procedures for parallelization of programs. The article presents an algorithm for searching the nodal points of multidimensional areas based on the principle of data decomposition. In regard to solving the problem of parametric identification of the diffuse Bass model of the spread of innovation, its practical implementation has been carried out.

Solving problems of parametric identification with uncertainty in the initial data due to their inaccuracy and incompleteness complicates, and, in some cases, even rules out the possibility of using classic mathematical and statistical methods as the latter are meant to deal with sufficiently large amounts of observations. These conditions involve the use of specific methods to directly determine the exact type of functional link and to verify its qualitative characteristics. A set of such characteristics also forms an idea of the informativeness of a model. This paper considers the characterization of this concept in relation to parametric identification problems and presents a method of their solution where the procedure of the analysis of informativeness of the obtained models is formalized Approbation of the developed technique was carried out on the example of parametric identification of the time series model. This time series cannot be linearized. A small number of observations were also known. All these conditions precluded the use of statistical methods to construct a time series model.

The inverse problem of determining the reaction rate constants on the basis of experimental data in the framework of the adopted model of obtaining 4-tert-butylpyrocatechol from the standpoint of achieving a given qualitative level of mathematical description has been studied. The intervals of the reaction rate constants, which ensure the achievement of the specified qualitative characteristics, have been determined for two temperature conditions based on the results of the numerical implementation of the developed method of parametric identification. The presented method also identifies experimental data to be clarified. Based on the use of the kinetic models, the problem of optimizing the studied chemical process has been solved, which made it possible to determine the split oxidizer feeding mode, providing an increase in the yield of 4-tert-butylpyrocatechol, and to obtain the necessary quantitative estimates of the concentrations of the observed substances.

Aim. Obtaining in vitro new lines of potato (Solanum tuberosum L.) cultivar Vernissage with genetically mediated resistance to the parasitic nematode H. schachtii on nutrient MS media with microbial bioregulators. Methods. In vitro conditions the process of organogenesis of potato plants on nutrient MS media containing microbial bioregulators used at concentrations 25-100 μl/l in combination with phytohormones 2 mg/l BAP and 0,1 mg/l NAA was investigated. Using dot blotting method the degree of hybridization between cytoplasmic si/miRNA isolated from cells of potato plants-regenerants, grown on the artificial invasive background, and nematode mRNA was studied. In the wheat seedlings cell-free system in vitro the silencing activity of si/miRNA isolated from cells of potato plants-regenerants on the template of nematode mRNA was investigated. Results. The experiments conducted in vitro conditions showed that the addition of microbial bioregulators at concentrations 25-100 μl/l in combination with phytohormones 2 mg/l BAP and 0,1 mg/l NAA into MS media increased the efficiency of regeneration of potato shoots to 43–47 % as compared with similar indices obtained on control MS media. The increase of the degree of hybridization to 19-38 % between cytoplasmic mRNA isolated from cells of nematode H. schachtii and si/miRNA isolated from cells of experimental potato plants-regenerants grown in vitro conditions on nutrient media containing bioregulators on the artificial invasive background was shown. Conclusions. Using microbial bioregulators in vitro conditions as components of nutrient MS medium increases potato shoot regeneration efficiency and enhances RNAi-mediated resistance of plants-regenerants to parasitic nematode H. schachtii. Keywords: microbial bioregulators, potato organogenesis in vitro, potato resistance to nematode Heterodera schachtii, RNA interference.

Aim. Identification of amino acid residues participating in specific binding of dinitroaniline and phosphorothioamidate compounds with α-tubulin in Plasmodium falciparum. Methods. Protein structure modelling, protein structure optimization using molecular dynamics method, ligand-protein docking, alanine scanning mutagenesis. Results. Molecular docking of canonical compounds and alanine scanning mutagenesis, indicate two key (Arg2, Val250) and one minor (Glu3) residues involved in binding of both - dinitroaniline and phosphorothioamidate compounds. At the same time, it was revealed two minor residues (Asp251, Glu254) interacting only with some members of dinitroaniline grope. Conclusions. It was identified amino acid residues predetermining existence of joint site and similar interaction of α-tubulin with dinitroani-line and phosphorothioamidate compounds in P. falciparum. Keywords: malaria, Plasmodium, α-tubulin, molecular interaction, dinitroanilines compounds, phosphorothioamidate compounds, alanine scanning mutagenesis.

When solving applied problems, an important aspect of the analysis is the stability of the obtained solution with respect to experimental data errors. Empirical experimental data, although a priori inaccurate, can be represented by intervals of their range of values. In some cases, the limits of their variation may also be known. Obviously, the degree of inaccuracy of input data influences the solution of the parametric identification problem. Therefore, in the case when this solution is not the only one, methods for assessing the influence of experimental error on the stability of each potential solution are of interest as they may provide additional arguments in favour of choosing one of them. In the case of models formalized in the form of systems of linear algebraic equations, a similar effect can be investigated using the condition number. In a case of quantitative analysis of multicomponent mixtures, the paper presents an approach to the parametric identification of linear models based on the calculation of the maximum permissible parameter estimates in combination with the study of the coefficient stability of the system.

Рассматриваются процессы полимеризации на катализаторах Циглера-Натта. Исследован вопрос о механизме процессов как необходимом наборе элементарных стадий кинетической схемы. Приведена общая схема допустимых стадий процесса, включающая стадии инициирования, роста цепи, передач цепи и обрыва цепи. Указано, что часть элементарных реакций может быть убрана из кинетической схемы за счет способа приготовления самого катализатора, а часть - на основании получаемых кинетических зависимостей. Но гипотеза о наличии или отсутствии элементарных стадий может быть доказана не только экспериментальным, но и вычислительным путем. Приводимые в работе табличные данные свидетельствуют о практически нулевом значении константы скорости элементарной стадии материального обрыва цепи - дезактивации активных центров, что, в свою очередь, вызывает оптимизацию кинетической схемы. Тогда рассматриваемые процессы могут быть отнесены к типу безобрывной полимеризации. Составление кинетической и математической моделей для исследуемых процессов позволяет поставить прямые и обратные кинетические задачи. Решение последних может быть получено методом многократного решения прямых кинетических задач и сравнения расчетных значений молекулярных характеристик с их экспериментальными аналогами. Однако целесообразнее проводить предварительный этап нахождения областей локальных минимумов по оптимизируемым значениям констант путем построения базисной поверхности и при поиске допустимых наборов значений констант скоростей оперировать найденными областями минимумов This paper considers the processes of polymerization on Ziegler-Natta catalysts. The question of the mechanism of the processes as a necessary set of elementary stages of the kinetic scheme is investigated. A general scheme of the permissible stages of the process is given, including the stages of initiation, chain growth, chain transfers and chain termination. It is indicated that part of the elementary reactions can be removed from the kinetic scheme due to the method of preparation of the catalyst itself, and part on the basis of the obtained kinetic dependences. However, the hypothesis about the presence or absence of elementary stages can be proved not only experimentally but also computationally. The tabular data presented in the work indicate a practically zero value of the rate constant of the elementary stage of material chain termination - deactivation of active centers, which, in turn, leads to optimization of the kinetic scheme. Then the processes under consideration can be attributed to the type of non-break polymerization. Compilation of kinetic and mathematical models for the processes under study makes it possible to pose direct and inverse kinetic problems. The solution of the latter can be obtained by the method of multiple solution of direct kinetic problems and comparison of the calculated values of molecular characteristics with their experimental counterparts. However, it is more expedient to carry out the preliminary stage of finding the regions of local minima by the optimized values of the constants by constructing the base surface. When searching for admissible sets of values of the rate constants, operate with the found areas of minima

The subject of this study is the inverse problems of identifying the mechanisms of complex chemical reactions. A graph-theoretic method for determining the basis of the parametric functions of the kinetic parameters of mathematical models for complex catalytic reactions is proposed. Based on the developed algorithm, a program for analyzing the information content of a mathematical model of the mechanism of catalytic reactions has been implemented. The operation of the algorithm is illustrated by the reaction of isotopic exchange of protium for deuterium.

Mathematical modeling of catalytic processes is necessary for the complete and accurate description, as well as for controlling the quality and physicochemical studied of catalysts. In the paper, theoretical issues of industrial catalysis are discussed. The work is devoted to theoretical graph analysis of informativity of kinetic parameters of the model of a complex chemical reaction. The aim is the development and automation of algorithm for determining basis of nonlinear parameter functions in solving inverse problems of chemical kinetics in order to define the number and form of independent combinations of rate constants of elementary stages. A program package for analysis of informativity of kinetic parameters of the mathematical model of a complex catalytic reaction is developed and described. The obtained functional relations between the kinetic parameters can be useful for experimentalists in physicochemical interpretation and analysis of mechanisms of chemical reactions. In other words, the proposed method allows independent combinations of kinetic constants to be distinguished that results in shortening the number of the model parameters and, as a consequence, enhance the accuracy of the mathematical model. The mechanism of hydrogen oxidation over a platinum catalyst is given as an example of the use of the software.

Introduction. The model of a given structure should be identified based on the results of solving the problem of parametric identification. This model should provide the best possible the database development reproduction of the experimental data. The concept of “best” is not strictly structured. Therefore, the procedure for identifying such a model is subject to natural logic and includes the stages of data a determination of a set of acceptable models and subsequent selection of the best of them. If the set of acceptable models is large, the procedure for determining the best one can be time-consuming. In this regard, the development of methods for parametric identification, which at the stage of creating a set of acceptable models allows taking into account the qualitative aspects of the identified dependence, which are of interest to the researcher, is of particular importance. Materials and Methods. The set of acceptable methods in the problems of parametric identification largely depends on the type of the experimental data. Uncertainty for example, probabilistic and statistical methods are useful if the observed factors are random and subject to any law of probability distribution. If the conditions for the use of such methods are not met, it may be useful to present an approach based on identifying the boundaries of location of the model parameters that ensure the achievement of specified levels of quality characteristics. Results. The procedure of parametric identification of models is formalized. It is based on the use of maximum permissible parameter estimates and allows one to determining the set of parameter values that guarantee the achievement of the required qualitative level of experimental data description, including from the standpoint of analyzing the impact of changes in accord with requirements to the accuracy of their reproduction. The approbation of the developed method on the example of the construction of a one-factor model of chemical kinetics is presented. Discussion and Conclusion. It is shown that the obtained value of the chemical reaction rate constant, in accordance with the introduced criteria, provides acceptable accuracy, adequacy, and stability of the identified kinetic model. At the same time, the results of calculations revealed the information that can form the basis for planning experiments carried out in order to improve the accuracy of the experimental data.