Crystallization of Membrane Proteins: Merohedral Twinning of Crystals

Environmental managemen

Foreign Policy Planning and the Effectiveness Evaluation of the Russian Foreign Ministry’s Bodies

Introduction. The paper aims to study the features of cascading goals and requirements for the activities of the Russian Ministry of Foreign Affairs from the level of strategic documents of foreign policy planning to the duties of diplomatic servants, describe a mechanism for assessing the achievement of these priorities, identify gaps between them and work out ways to optimize. Methods and materials. The author applies the following methods: comparative legal, structural and logical, classification, comparison, analysis of quantitative and qualitative indicators, decomposition of goals. Regulatory legal acts and materials of law enforcement practice are studied. Analysis. An analytical tool was developed to assess the level of effectiveness of foreign agencies of the Ministry of Foreign Affairs. Results. The paper reveals the redundancy and duplication of foreign policy planning goals. It is advisable to formulate foreign policy priorities in the “Foreign Policy” Public program. Gaps between the goals of the state’s foreign policy and the goals that guide diplomatic institutions are identified. The author proposes measures to optimize the control and reporting of overseas agencies. It is proposed to change the personnel paradigm of the diplomatic service from bureaucratic to active (focus on solving large-scale problems) and intermediary (search for compromises). To conduct a coordinated foreign policy, it is necessary to generalize the dynamics of the activities of all foreign agencies, objectively evaluate their contribution to the achievement of foreign policy priorities

Итоги и перспективы развития налоговых органов России

The study aims to identify the milestone events in the development of the tax administration in post-Soviet Russia and to offer recommendations for its further improvement. We tested the hypothesis about the relationship between the development of the tax system and tax administration, which, once established, can play a role in the improvement of the tax administration’s efficiency. The study relies on quantitative (regression and correlation analysis, factor analysis, principal component analysis) and qualitative methods (classification, thesaurus analysis, SWOT-analysis, critical points method). We also analyzed the legal acts describing the goals (target indicators) for the development of the tax system and tax administration and propose a set of integral indices characterizing these processes. The key events (factors) for the period starting from the 1990s to the present were identified and ranked in order of importance. Their impact was investigated with the help of SWOT-analysis and factor analysis methods. We found that in the given period, there was an increase in the correspondence between the goals of the tax administration and the goals of the tax system. This means that the tax administration’s management and staff have become more motivated to upscale their priorities and to orient their activities towards public good. The analysis of indices for the given periods has shown improved performance of the tax system and tax administration. The index of tax administration development is based on four indicators. Between the 1990s and 2010s, the index grew by 13% mainly because of the expanded scope of functions of the tax administration, staff downsizing and optimization of the remuneration system. We found that there is a significant statistical relationship between the indices of development of the tax system and tax administration.For citationBorshchevskiy G.A., Mossaki N.Z. Development of the tax administration in Russia: Results and prospects. Journal of Tax Reform. 2021;7(2):114–133. https://doi.org/10.15826/jtr.2021.7.2.093 Article infoReceived May 27, 2021; Revised July 19, 2021; Accepted August 14, 2021 Цель статьи состоит в выявлении критических точек в развитии налоговых органов в постсоветский период и выработке предложений по дальнейшему совершенствованию налоговых органов. Была выдвинута гипотеза о наличии взаимосвязи между развитием налоговой системы и налоговых органов, которая может быть использована для повышения эффективности налоговых органов. Использованы количественные (регрессионно-корреляционный анализ, факторный анализ, метод главных компонент) и качественные методы (классификация, тезаурусный анализ, SWOT-анализ, метод критических точек). Изучены нормативные правовые акты, содержащие цели (целевые показатели) развития налоговой системы и налоговых органов. Предложены интегральные индексы, характеризующие динамику развития налоговых органов и налоговой системы. Выявлены ключевые события (факторы) с начала 1990-х гг. до настоящего времени, осуществлено их ранжирование по уровню значимости, проведен SWOT-анализ и факторный анализ влияния ключевых событий на развитие налоговых органов и налоговой системы. Исследование показало, что усиливается взаимосвязь целевых показателей деятельности налоговых органов и целей развития налоговой системы. Это ориентирует руководство и служащих налоговых органов на реализацию приоритетов более высокого уровня и достижению общественно значимых результатов. За анализируемые годы значение индексов развития налоговой системы и налоговых органов улучшилось. Индекс развития налоговых органов построен по четырем показателям, и его значение за 1990-е – 2010-е гг. увеличилось на 13%, главным образом, за счет увеличения объема функций при сокращении численности и оптимизации материального обеспечения налоговых служащих. Между индексами развития налоговой системы и развития налоговых органов выявлена значимая статистическая связь.Для цитированияBorshchevskiy G.A., Mossaki N.Z. Development of the tax administration in Russia: Results and prospects. Journal of Tax Reform. 2021;7(2):114–133. https://doi.org/10.15826/jtr.2021.7.2.093 Информация о статье Дата поступления 27 мая 2021 г.; дата поступления после рецензирования 19 июля 2021 г.; дата принятия к печати 14 августа 2021 г

Особливості процесу фільтрації ліпосомальної емульсії для виготовлення очних крапель на основі пептидного комплексу

Liposomes are increasingly being studied and implemented as drug delivery systems in the form of eye drops. An important stage in the production of a liposomal preparation in the form of eye drops is the stage of sterilization filtration before filling the medicinal product into a container for final dosage. It is assumed that liposome components interact with the membrane and clog it due to their unique physicochemical properties. Therefore, a deeper understanding of the sterilization filtration of liposomes is needed to make appropriate decisions regarding the choice of filters for sterilization.Resistance and permeability values calculated from the Darcy equation are well suited for comparing different filter membranes or process parameters. Aim. To substantiate the choice of optimal brands of filter membranes and parameters of the liposomal emulsion filtration process for the production of eye drops based on a peptide complex. Materials and methods. The study object was a liposomal emulsion for the production of eye drops based on a peptide complex. A prepared liposomal emulsion of eye drops based on a peptide complex and membrane filters of various brands were used for filtration. Filtration tests were performed on a Zero-T scaling unit manufactured by Sartorius, Germany. For all measurements, the filtrate weight was controlled using a balance. Filtration experiments were evaluated using Zero-T 2.0 software from Sartorius Stedim Biotech, Germany. At the first stage, the recorded data of the results was saved to a file. Based on the data obtained using the Excel table processor, the filtration flow J°, the initial resistance of the membrane R°zag and the throughput Ṽ were calculated according to the calculated measurement time: the beginning of T10 % and the end of T80 %. Results and discussion. According to the results obtained, the optimal brands of sterilizing membranes were determined; it was shown that by increasing the pressure drop, the volumetric throughput was significantly improved by more than 18 times (from 0.7 to 4.1 bar), and in another experiment – by more than 10 times (from 0.3 to 2.1 bar). In addition, the benefit of using a higher pressure drop to filter liposomes through various sterilizing membranes was shown. Conclusions. The obtained values of the initial resistance of the membrane showed that the geometrical aspects and properties of the material of the Supor® (Pall) and Sartopore 2® (Sartorius) membrane brands have a lower ability to block the membrane during filtration and provide the filtration resource due to greater throughput. It has been also shown that the use of a higher pressure drop increases the productivity of the process.Ліпосоми все більше досліджують та впроваджують як системи доставляння ліків у формі очних крапель. Важливим етапом у виробництві ліпосомального препарату у формі очних крапель є процес стерилізаційної фільтрації перед наповненням лікарського засобу в контейнер для кінцевого дозування. Передбачають, що компоненти ліпосом взаємодіють з мембраною та закупорюють її через свої унікальні фізико-хімічні властивості. Отже, треба глибше розуміти стерилізаційну фільтрацію ліпосом, щоб ухвалити відповідні рішення щодо вибору фільтрів для стерилізації. Розраховані з рівняння Дарсі значення опору та пропускної здатності добре підходять для порівняння різних фільтрувальних мембран або параметрів процесу. Мета роботи – обґрунтувати вибір оптимальних марок фільтрувальних мембран та параметрів процесу фільтрації ліпосомальної емульсії для виготовлення очних крапель на основі пептидного комплексу. Матеріали та методи. Об’єктом дослідження була ліпосомальна емульсія для виготовлення очних крапель на основі пептидного комплексу. Для фільтрації використовували приготовану ліпосомальну емульсію очних крапель на основі пептидного комплексу та мембранні фільтри різних марок. Випробування фільтрації здійснюювали на приладі з масштабування Zero-T виробництва фірми Sartorius, Німеччина. Для всіх вимірювань вагу фільтрату контролювали за допомогою ваг. Оцінювали експерименти з фільтрації з використанням програмного забезпечення Zero-T 2.0 фірми Sartorius Stedim Biotech, Німеччина. На першому етапі записані дані результатів зберігали у файлі. За отриманими даними за допомогою табличного процесора Excel розрахували потік фільтрації J°, початковий опір мембрани R°заг і пропускну здатність Ṽ відповідно до визначеного часу вимірювання– початок T10 % та кінецьT80 %. Результати та їх обговорення. За отриманими результатами визначено оптимальні марки стерилізувальних мембран та з’ясовано, що шляхом збільшення перепаду тиску об’ємна пропускна здатність значно покращується – більш ніж у 18 разів (від 0,7 до 4,1 бар), а в іншому експерименті - більш ніж у 10 разів (від 0,3 до 2,1 бар). Крім того, виявлено користь використання більш високого перепаду тиску на фільтрацію ліпосом крізь різні стерилізувальні мембрани. Висновки. Отримані значення початкового опору мембрани засвідчили, що геометричні аспекти і властивості матеріалу марок мембран Supor® (Pall) та Sartopore 2® (Sartorius) мають меншу здатність до блокування мембрани під час фільтрації та забезпечення ресурсу фільтрації за рахунок більшої пропускної здатності. Такождоведено, що використання більш високого перепаду тиску збільшує продуктивність процесу

Structural and functional investigation of flavin binding center of the NqrC subunit of sodium-translocating NADH:Quinone oxidoreductase from Vibrio harveyi

Na+-translocating NADH:quinone oxidoreductase (NQR) is a redox-driven sodium pump operating in the respiratory chain of various bacteria, including pathogenic species. The enzyme has a unique set of redox active prosthetic groups, which includes two covalently bound flavin mononucleotide (FMN) residues attached to threonine residues in subunits NqrB and NqrC. The reason of FMN covalent bonding in the subunits has not been established yet. In the current work, binding of free FMN to the apo-form of NqrC from Vibrio harveyi was studied showing very low affinity of NqrC to FMN in the absence of its covalent bonding. To study structural aspects of flavin binding in NqrC, its holo-form was crystallized and its 3D structure was solved at 1.56 Å resolution. It was found that the isoalloxazine moiety of the FMN residue is buried in a hydrophobic cavity and that its pyrimidine ring is squeezed between hydrophobic amino acid residues while its benzene ring is extended from the protein surroundings. This structure of the flavin-binding pocket appears to provide flexibility of the benzene ring, which can help the FMN residue to take the bended conformation and thus to stabilize the one-electron reduced form of the prosthetic group. These properties may also lead to relatively weak noncovalent binding of the flavin. This fact along with periplasmic location of the FMN-binding domains in the vast majority of NqrC-like proteins may explain the necessity of the covalent bonding of this prosthetic group to prevent its loss to the external medium

Abstract P-40: The Shape and Size of the Recombinant Virus-like Particles Were Checked by Means of Electron Microscope

Background: Nucleocapsid protein of hepatitis-B virus (HBcAg) recombinantly synthesized in prokaryotic and eukaryotic cells is known to be capable to self-assemble into highly immunogenic stable viral-like particles (VLP) of icosahedral shape with a characteristic size of 32 nm (Schödel et al., 1994; Murray and Shiau, 1999). The VLP formation is tolerant to the insertion of some artificial epitopes to N- and C-termini of HBcAg monomer and also into major insertion region (MIR), forming a spike on the surface of VLP (Tordjeman et al., 1993, Peyret et al., 2015). Methods: We have investigated the possibility of heterologous expression of de novo designed gene coding the first 148 amino acid residues of HBcAg (Pumpens and Grens, 1999). The gene was specially designed to be suitable for the insertions of genes coding fluorescent proteins, which are desired for the studies of VLP distribution in tissues by confocal microscopy. Gene was optimized for overexpression in E. coli producer strains and special attention was taken to obtain a simple purification scheme, which reliably reduces the amount of pyrogens in purified VLP. The MIPT scientific platform of electron microscopy equipped with the transmission electron microscope Tecnai Polara G2 (Thermo Scientific (FEI)) was used. Carbon-coated (Lacey Carbon and 10 nm thin carbon) copper 200 mesh grids were treated with glow-discharge and coated with VLP suspension in deionized water. The samples were stained with uranyl acetate solution, air-dried, and inspected at the accelerating voltage of 300 kV. Results: The 32 nm size of heterologously synthesized VLP was successfully proved, and spherical shape was seen using negative contrasting

Structural insights into thrombolytic activity of destabilase from medicinal leech

Destabilase from the medical leech Hirudo medicinalis belongs to the family of i-type lysozymes. It has two different enzymatic activities: microbial cell walls destruction (muramidase activity), and dissolution of the stabilized fibrin (isopeptidase activity). Both activities are known to be inhibited by sodium chloride at near physiological concentrations, but the structural basis remains unknown. Here we present two crystal structures of destabilase, including a 1.1 Å-resolution structure in complex with sodium ion. Our structures reveal the location of sodium ion between Glu34/Asp46 residues, which were previously recognized as a glycosidase active site. While sodium coordination with these amino acids may explain inhibition of the muramidase activity, its influence on previously suggested Ser49/Lys58 isopeptidase activity dyad is unclear. We revise the Ser49/Lys58 hypothesis and compare sequences of i-type lysozymes with confirmed destabilase activity. We suggest that the general base for the isopeptidase activity is His112 rather than Lys58. pKa calculations of these amino acids, assessed through the 1 μs molecular dynamics simulation, confirm the hypothesis. Our findings highlight the ambiguity of destabilase catalytic residues identification and build foundations for further research of structure–activity relationship of isopeptidase activity as well as structure-based protein design for potential anticoagulant drug development.</p