43 research outputs found
Novas abordagens para a avaliação da sustentabilidade económica das empresas de pesca
The importance and necessity of transition to the paradigm of sustainable development of Russian fishing enterprises is associated with the accumulation of many complex and unsolved problems. First of all, they concern the low susceptibility to innovation and the significant technological inferiority in comparison with the developed countries, as well as the lack of systematic implementation of a national industrial policy aimed at ensuring the sustainable development of the industry. The purpose of the study is to propose a methodology for assessing the economic sustainability of fishing enterprises on the basis of generalizing the achievements of economic theory and practice. To achieve the goal, methods of comparative multidimensional analysis, as well as dialectical and general scientific methods were used. The paper provides a critical assessment of common approaches to assessing the economic sustainability of the enterprise. The system of quantitative and qualitative indicators for assessing the economic sustainability of fishing organizations, which takes into account the strategic factors of enterprise development, has been proposed. The work provides an opportunity for an in-depth understanding of the problem of economic sustainability and its comprehensive solution. In particular, the proposed system of indicators can serve as a methodical tool to justify the effectiveness of government support measures because it allows ranking the fishing business structures according to their economic sustainability, and therefore, select government recipients of budgetary funds, preferential credit resources and other government measures. In conclusion, the definition of economic sustainability is clarified.La importancia y la necesidad de la transición al paradigma del desarrollo sostenible de las empresas pesqueras rusas está asociada a la acumulación de muchos problemas complejos y no resueltos. En primer lugar, se refieren a la baja susceptibilidad a la innovación y la significativa inferioridad tecnológica en comparación con los países desarrollados, así como a la falta de implementación sistemática de una política industrial nacional dirigida a garantizar el desarrollo sostenible de la industria. El propósito del estudio es proponer una metodología para evaluar la sostenibilidad económica de las empresas pesqueras sobre la base de generalizar los logros de la teoría y la práctica económica. Para lograr el objetivo, se utilizaron métodos de análisis multidimensional comparativo, así como métodos dialécticos y científicos generales. El documento proporciona una evaluación crítica de los enfoques comunes para evaluar la sostenibilidad económica de la empresa. Se ha propuesto el sistema de indicadores cuantitativos y cualitativos para evaluar la sostenibilidad económica de las organizaciones pesqueras, que tiene en cuenta los factores estratégicos del desarrollo empresarial. El trabajo brinda la oportunidad de comprender en profundidad el problema de la sostenibilidad económica y su solución integral. En particular, el sistema de indicadores propuesto puede servir como una herramienta metódica para justificar la efectividad de las medidas de apoyo del gobierno porque permite clasificar las estructuras de las empresas pesqueras de acuerdo con su sostenibilidad económica y, por lo tanto, seleccionar a los receptores gubernamentales de fondos presupuestarios, recursos crediticios preferenciales y Otras medidas gubernamentales. En conclusión, se aclara la definición de sostenibilidad económica.A importância e necessidade da transição para o paradigma do desenvolvimento sustentável das empresas de pesca russas está associada à acumulação de muitos problemas complexos e não resolvidos. Em primeiro lugar, dizem respeito à baixa suscetibilidade à inovação e à significativa inferioridade tecnológica em comparação com os países desenvolvidos, bem como à falta de implementação sistemática de uma política industrial nacional que vise garantir o desenvolvimento sustentável da indústria. O objetivo do estudo é propor uma metodologia para avaliar a sustentabilidade econômica das empresas pesqueiras com base na generalização das conquistas da teoria e prática econômica. Para atingir o objetivo, métodos de análise comparativa multidimensional, bem como métodos científicos dialéticos e gerais foram utilizados. O documento fornece uma avaliação crítica de abordagens comuns para avaliar a sustentabilidade econômica da empresa. O sistema de indicadores quantitativos e qualitativos para avaliar a sustentabilidade econômica das organizações pesqueiras, que leva em conta os fatores estratégicos de desenvolvimento empresarial, foi proposto. O trabalho oferece uma oportunidade para uma compreensão profunda do problema da sustentabilidade econômica e de sua solução abrangente. Em particular, o sistema proposto de indicadores pode servir como uma ferramenta metódica para justificar a eficácia das medidas de apoio do governo, pois permite classificar as estruturas do negócio pesqueiro de acordo com sua sustentabilidade econômica e, portanto, selecionar beneficiários governamentais de recursos orçamentários, recursos de crédito preferencial e outras medidas governamentais. Em conclusão, a definição de sustentabilidade econômica é esclarecida
Structural insight into industrially relevant glucoamylases : flexible positions of starch-binding domains
Glucoamylases are one of the most important classes of enzymes in the industrial degradation of starch biomass. They consist of a catalytic domain and a carbohydrate-binding domain (CBM), with the latter being important for the interaction with the polymeric substrate. Whereas the catalytic mechanisms and structures of the individual domains are well known, the spatial arrangement of the domains with respect to each other and its influence on activity are not fully understood. Here, the structures of three industrially used fungal glucoamylases, two of which are full length, have been crystallized and determined. It is shown for the first time that the relative orientation between the CBM and the catalytic domain is flexible, as they can adopt different orientations independently of ligand binding, suggesting a role as an anchor to increase the contact time and the relative concentration of substrate near the active site. The flexibility in the orientations of the two domains presented a considerable challenge for the crystallization of the enzymes
Both Ca2+ and Zn2+ are essential for S100A12 protein oligomerization and function
Background
Human S100A12 is a member of the S100 family of EF-hand calcium-modulated proteins that are associated with many diseases including cancer, chronic inflammation and neurological disorders. S100A12 is an important factor in host/parasite defenses and in the inflammatory response. Like several other S100 proteins, it binds zinc and copper in addition to calcium. Mechanisms of zinc regulation have been proposed for a number of S100 proteins e.g. S100B, S100A2, S100A7, S100A8/9. The interaction of S100 proteins with their targets is strongly dependent on cellular microenvironment.
Results
The aim of the study was to explore the factors that influence S100A12 oligomerization and target interaction. A comprehensive series of biochemical and biophysical experiments indicated that changes in the concentration of calcium and zinc led to changes in the oligomeric state of S100A12. Surface plasmon resonance confirmed that the presence of both calcium and zinc is essential for the interaction of S100A12 with one of its extracellular targets, RAGE – the Receptor for Advanced Glycation End products. By using a single-molecule approach we have shown that the presence of zinc in tissue culture medium favors both the oligomerization of exogenous S100A12 protein and its interaction with targets on the cell surface.
Conclusion
We have shown that oligomerization and target recognition by S100A12 is regulated by both zinc and calcium. Our present work highlighted the potential role of calcium-binding S100 proteins in zinc metabolism and, in particular, the role of S100A12 in the cross talk between zinc and calcium in cell signaling
Conformational heterogeneity of Savinase from NMR, HDX-MS and X-ray diffraction analysis
Background: Several examples have emerged of enzymes where slow conformational changes are of key importance for function and where low populated conformations in the resting enzyme resemble the conformations of intermediate states in the catalytic process. Previous work on the subtilisin protease, Savinase, from Bacillus lentus by NMR spectroscopy suggested that this enzyme undergoes slow conformational dynamics around the substrate binding site. However, the functional importance of such dynamics is unknown. Methods: Here we have probed the conformational heterogeneity in Savinase by following the temperature dependent chemical shift changes. In addition, we have measured changes in the local stability of the enzyme when the inhibitor phenylmethylsulfonyl fluoride is bound using hydrogen-deuterium exchange mass spectrometry (HDX-MS). Finally, we have used X-ray crystallography to compare electron densities collected at cryogenic and ambient temperatures and searched for possible low populated alternative conformations in the crystals. Results: The NMR temperature titration shows that Savinase is most flexible around the active site, but no distinct alternative states could be identified. The HDX shows that modification of Savinase with inhibitor has very little impact on the stability of hydrogen bonds and solvent accessibility of the backbone. The most pronounced structural heterogeneities detected in the diffraction data are limited to alternative side-chain rotamers and a short peptide segment that has an alternative main-chain conformation in the crystal at cryo conditions. Collectively, our data show that there is very little structural heterogeneity in the resting state of Savinase and hence that Savinase does not rely on conformational selection to drive the catalytic process
Structural and functional characterization of a multi-domain GH92 α-1,2-mannosidase from Neobacillus novalis
Нелинейные локальные деформации мембран эритроцитов: действие токсинов и фармпрепаратов (Часть 2)
Modifiers of membranes cause local defects on the cell surface. Measurement of the rigidity at the sites of local defects can provide further information about the structure of defects and mechanical properties of altered membranes.The purpose of the study: a step-by-step study of the process of a nonlinear deformation of red blood cells membranes under the effect of modifiers of different physico-chemical nature.Materials and methods. The membrane deformation of a viscoelastic composite erythrocyte construction inside a cell was studied by the atomic force spectroscopy. Nonlinear deformations formed under the effect of hemin, Zn2+ ions, and verapamil were studied.Results. The process of elastic deformation of the membrane with the indentation of a probe at the sites of local defects caused by modifiers was demonstrated. The probe was inserted during the same step of the piezo scanner z displacement; the probe indentation occured at the different discrete values of h, which are the functions of the membrane structure. At the sites of domains, under the effect of the hemin, tension areas and plasticity areas appeared. A mathematical model of probe indentation at the site of membrane defects is presented.Conclusion. The molecular mechanisms of various types of nonlinear deformations occurring under the effect of toxins are discussed. The results of the study may be of interest both for fundamental researchers of the blood cell properties and for practical reanimatology and rehabilitology. Модификаторы мембран порождают локальные дефекты на поверхности клеток. Измерение жесткости в зонах локальных дефектов может дать дополнительную информацию о структуре дефектов и механических свойствах мембран в целом.Цель работы: пошаговое исследование процесса нелинейной деформации мембран эритроцитов при действии на них модификаторов различной физико-химической природы.Материалы и методы. Методом атомно-силовой спектроскопии провели исследование деформации мембран внутрь клетки вязко-упругой композитной конструкции эритроцита. Исследовали нелинейные деформации при действии гемина, ионов Zn2+, фармпрепарата верапамила.Результаты. Показали процесс упруго-эластичной деформации мембраны по мере индентации зонда в областях локальных дефектов, вызванных модификаторами. На один и тот же шаг смещения z пьезосканера зонд погружался на разные дискретные величины h, которые являются функциями структуры мембраны. В областях доменов при действии гемина возникали зоны натяжения и зоны пластичности. Привели математическая модель индентации зонда в области дефектов мембран.Заключение. Обсудили молекулярные механизмы различных видов нелинейных деформаций, возникающих при действии токсинов. Результаты работы могут представлять интерес как для фундаментальных исследований свойств клеток крови, так и для практической реаниматологии и реабилитологии
Novel Inhibitory Function of the Rhizomucor miehei Lipase Propeptide and Three-Dimensional Structures of Its Complexes with the Enzyme
Many proteins are synthesized as precursors, with propeptides playing a variety of roles such as assisting in folding or preventing them from being active within the cell. While the precise role of the propeptide in fungal lipases is not completely understood, it was previously reported that mutations in the propeptide region of the Rhizomucor miehei lipase have an influence on the activity of the mature enzyme, stressing the importance of the amino acid composition of this region. We here report two structures of this enzyme in complex with its propeptide, which suggests that the latter plays a role in the correct maturation of the enzyme. Most importantly, we demonstrate that the propeptide shows inhibition of lipase activity in standard lipase assays and propose that an important role of the propeptide is to ensure that the enzyme is not active during its expression pathway in the original host
Structural and functional characterization of a multi-domain GH92 α-1,2-mannosidase from Neobacillus novalis
Structural and functional characterisation of three novel fungal amylases with enhanced stability and pH tolerance
Amylases are probably the best studied glycoside hydrolases and have a huge biotechnological value for industrial processes on starch. Multiple amylases from fungi and microbes are currently in use. Whereas bacterial amylases are well suited for many industrial processes due to their high stability, fungal amylases are recognized as safe and are preferred in the food industry, although they lack the pH tolerance and stability of their bacterial counterparts. Here, we describe three amylases, two of which have a broad pH spectrum extending to pH 8 and higher stability well suited for a broad set of industrial applications. These enzymes have the characteristic GH13 α-amylase fold with a central (β/α)8-domain, an insertion domain with the canonical calcium binding site and a C-terminal β-sandwich domain. The active site was identified based on the binding of the inhibitor acarbose in form of a transglycosylation product, in the amylases from Thamnidium elegans and Cordyceps farinosa. The three amylases have shortened loops flanking the nonreducing end of the substrate binding cleft, creating a more open crevice. Moreover, a potential novel binding site in the C-terminal domain of the Cordyceps enzyme was identified, which might be part of a starch interaction site. In addition, Cordyceps farinosa amylase presented a successful example of using the microseed matrix screening technique to significantly speed-up crystallization