55 research outputs found

    Structure of oxidative and sulphate-clorinating roasting products of nickel converter matte

    Full text link
    The structure and phase composition of the nickel converter matte roasting products has been studied in the sulphate-chlorinating process stage. In stages of the converter matte oxidation in the "fluidized bed" and flash smelting remainder roasting together with silvinite the distribution of non-ferrous metals on the phase constituents has been estimated. In the article data from optical spectroscopy, as well as X-ray diffraction, microprobe and chemical analyze are used. As following from the composition of the phases formed during sulphate-chlorinating roasting and thermodynamic modeling data a number of reactions proceeding in the process is presented. © 2013 Allerton Press, Inc

    Efficient determination of the accessible conformation space of multi-domain complexes based on EPR PELDOR data

    Get PDF
    Many proteins can adopt multiple conformations which are important for their function. This is also true for proteins and domains that are covalently linked to each other. One important example is ubiquitin, which can form chains of different conformations depending on which of its lysine side chains is used to form an isopeptide bond with the C-terminus of another ubiquitin molecule. Similarly, ubiquitin gets covalently attached to active-site residues of E2 ubiquitin-conjugating enzymes. Due to weak interactions between ubiquitin and its interaction partners, these covalent complexes adopt multiple conformations. Understanding the function of these complexes requires the characterization of the entire accessible conformation space and its modulation by interaction partners. Long-range (1.8-10 nm) distance restraints obtained by EPR spectroscopy in the form of probability distributions are ideally suited for this task as not only the mean distance but also information about the conformation dynamics is encoded in the experimental data. Here we describe a computational method that we have developed based on well-established structure determination software using NMR restraints to calculate the accessible conformation space using PELDOR/DEER data

    The UBA domain of conjugating enzyme Ubc1/Ube2K facilitates assembly of K48/K63‐branched ubiquitin chains

    Get PDF
    The assembly of a specific polymeric ubiquitin chain on a target protein is a key event in the regulation of numerous cellular processes. Yet, the mechanisms that govern the selective synthesis of particular polyubiquitin signals remain enigmatic. The homologous ubiquitin‐conjugating (E2) enzymes Ubc1 (budding yeast) and Ube2K (mammals) exclusively generate polyubiquitin linked through lysine 48 (K48). Uniquely among E2 enzymes, Ubc1 and Ube2K harbor a ubiquitin‐binding UBA domain with unknown function. We found that this UBA domain preferentially interacts with ubiquitin chains linked through lysine 63 (K63). Based on structural modeling, in vitro ubiquitination experiments, and NMR studies, we propose that the UBA domain aligns Ubc1 with K63‐linked polyubiquitin and facilitates the selective assembly of K48/K63‐branched ubiquitin conjugates. Genetic and proteomics experiments link the activity of the UBA domain, and hence the formation of this unusual ubiquitin chain topology, to the maintenance of cellular proteostasis

    СТРУКТУРА ПРОДУКТОВ ОКИСЛИТЕЛЬНОГО И СУЛЬФАТОХЛОРИРУЮЩЕГО ОБЖИГОВ НИКЕЛЕВОГО ФАЙНШТЕЙНА

    Get PDF
    The structure and phase composition of nis matte sulfate-chloridizing roasting processing products have been studied. Distribution of non-ferrous metals in the phase components at the stages of nis matte oxidizing in «fluidized bed» and calcine roasting with sylvinite is estimated. The data of optical spectrometry as well as X-ray phase, micro X-ray spectral and chemical analyses are used in the work. Based on the phase composition being formed in the course of sulfate-chloridizing roasting and the data of thermodynamic simulation, the sequence of reactions proceeding during the roasting is presented.Изучены структура и фазовый состав продуктов передела сульфатохлорирующего обжига никелевого файнштейна. Оценено распределение цветных металлов по фазовым составляющим на стадиях окисления файнштена в «кипящем слое» (КС) и обжига огарка КС с сильвинитом. В работе использованы данные оптической спектрометрии, а также рентгенофазового, микрорентгеноспектрального и химического анализов. Исходя из состава фаз, формирующихся в ходе сульфатохлорирующего обжига, и данных термодинамического моделирования представлена последовательность реакций, протекающих в ходе обжига

    Inflammatory Gene Regulatory Networks in Amnion Cells Following Cytokine Stimulation: Translational Systems Approach to Modeling Human Parturition

    Get PDF
    A majority of the studies examining the molecular regulation of human labor have been conducted using single gene approaches. While the technology to produce multi-dimensional datasets is readily available, the means for facile analysis of such data are limited. The objective of this study was to develop a systems approach to infer regulatory mechanisms governing global gene expression in cytokine-challenged cells in vitro, and to apply these methods to predict gene regulatory networks (GRNs) in intrauterine tissues during term parturition. To this end, microarray analysis was applied to human amnion mesenchymal cells (AMCs) stimulated with interleukin-1β, and differentially expressed transcripts were subjected to hierarchical clustering, temporal expression profiling, and motif enrichment analysis, from which a GRN was constructed. These methods were then applied to fetal membrane specimens collected in the absence or presence of spontaneous term labor. Analysis of cytokine-responsive genes in AMCs revealed a sterile immune response signature, with promoters enriched in response elements for several inflammation-associated transcription factors. In comparison to the fetal membrane dataset, there were 34 genes commonly upregulated, many of which were part of an acute inflammation gene expression signature. Binding motifs for nuclear factor-κB were prominent in the gene interaction and regulatory networks for both datasets; however, we found little evidence to support the utilization of pathogen-associated molecular pattern (PAMP) signaling. The tissue specimens were also enriched for transcripts governed by hypoxia-inducible factor. The approach presented here provides an uncomplicated means to infer global relationships among gene clusters involved in cellular responses to labor-associated signals

    Growth factor concentrations and their placental mRNA expression are modulated in gestational diabetes mellitus: possible interactions with macrosomia

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Gestational diabetes mellitus (GDM) is a form of diabetes that occurs during pregnancy. GDM is a well known risk factor for foetal overgrowth, termed macrosomia which is influenced by maternal hypergycemia and endocrine status through placental circulation. The study was undertaken to investigate the implication of growth factors and their receptors in GDM and macrosomia, and to discuss the role of the materno-foeto-placental axis in the <it>in-utero </it>regulation of foetal growth.</p> <p>Methods</p> <p>30 women with GDM and their 30 macrosomic babies (4.75 ± 0.15 kg), and 30 healthy age-matched pregnant women and their 30 newborns (3.50 ± 0.10 kg) were recruited in the present study. Serum concentrations of GH and growth factors, <it>i.e</it>., IGF-I, IGF-BP3, FGF-2, EGF and PDGF-B were determined by ELISA. The expression of mRNA encoding for GH, IGF-I, IGF-BP3, FGF-2, PDGF-B and EGF, and their receptors, <it>i.e</it>., GHR, IGF-IR, FGF-2R, EGFR and PDGFR-β were quantified by using RT-qPCR.</p> <p>Results</p> <p>The serum concentrations of IGF-I, IGF-BP3, EGF, FGF-2 and PDGF-B were higher in GDM women and their macrosomic babies as compared to their respective controls. The placental mRNA expression of the growth factors was either upregulated (FGF-2 or PDGF-B) or remained unaltered (IGF-I and EGF) in the placenta of GDM women. The mRNA expression of three growth factor receptors, <it>i.e</it>., IGF-IR, EGFR and PDGFR-β, was upregulated in the placenta of GDM women. Interestingly, serum concentrations of GH were downregulated in the GDM women and their macrosomic offspring. Besides, the expression of mRNAs encoding for GHR was higher, but that encoding for GH was lower, in the placenta of GDM women than control women.</p> <p>Conclusions</p> <p>Our results demonstrate that growth factors might be implicated in GDM and, in part, in the pathology of macrosomia via materno-foeto-placental axis.</p

    Differences in the pattern and regulation of mineral deposition in human cell lines of osteogenic and non-osteogenic origin

    Get PDF
    Bone marrow-derived mesenchymal stem cells (MSCs) are widely used as a cellular model of bone formation, and can mineralize in vitro in response to osteogenic medium (OM). It is unclear, however, whether this property is specific to cells of mesenchymal origin. We analysed the OM response in 3 non-osteogenic lines, HEK293, HeLa and NTera, compared to MSCs. Whereas HEK293 cells failed to respond to OM conditions, the 2 carcinoma-derived lines NTera and HeLa deposited a calcium phosphate mineral comparable to that present in MSC cultures. However, unlike MSCs, HeLa and NTera cultures did so in the absence of dexamethasone. This discrepancy was confirmed, as bone morphogenetic protein inhibition obliterated the OM response in MSCs but not in HeLa or NTera, indicating that these 2 models can deposit mineral through a mechanism independent of established dexamethasone or bone morphogenetic protein signalling

    Adaptation Processes in Implementation of Russian National Projects

    Full text link
    Реализация национальных проектов в России объективно сопровождается адаптационными процессами различного направления и уровней, прежде всего социально-экономического плана. Исследования показывают, что одним из критериев качества системы адаптации может стать оценка минимально необходимого времени для завершения процесса адаптации.The implementation of national projects in Russia is objectively accompanied by adaptation processes of various directions and levels, above all a socio-economic plan. According to the results of the research, one of the criteria for the quality of the adaptation system can be used to estimate the minimum required time to complete the adaptation process.Статья подготовлена в соответствии с планом НИР Института экономики УрО РАН за 2019-2021
    corecore