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Sample records for aluminum-activated malate transporter

  1. SENSITIVE TO PROTON RHIZOTOXICITY1, CALMODULIN BINDING TRANSCRIPTION ACTIVATOR2, and other transcription factors are involved in ALUMINUM-ACTIVATED MALATE TRANSPORTER1 expression.

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    Tokizawa, Mutsutomo; Kobayashi, Yuriko; Saito, Tatsunori; Kobayashi, Masatomo; Iuchi, Satoshi; Nomoto, Mika; Tada, Yasuomi; Yamamoto, Yoshiharu Y; Koyama, Hiroyuki

    2015-03-01

    In Arabidopsis (Arabidopsis thaliana) the root apex is protected from aluminum (Al) rhizotoxicity by excretion of malate, an Al chelator, by ALUMINUM-ACTIVATED MALATE TRANSPORTER1 (AtALMT1). AtALMT1 expression is fundamentally regulated by the SENSITIVE TO PROTON RHIZOTOXICITY1 (STOP1) zinc finger protein, but other transcription factors have roles that enable Al-inducible expression with a broad dynamic range. In this study, we characterized multiple cis-elements in the AtALMT1 promoter that interact with transcription factors. In planta complementation assays of AtALMT1 driven by 5' truncated promoters of different lengths showed that the promoter region between -540 and 0 (the first ATG) restored the Al-sensitive phenotype of atalm1 and thus contains cis-elements essential for AtALMT1 expression for Al tolerance. Computation of overrepresented octamers showed that eight regions in this promoter region contained potential cis-elements involved in Al induction and STOP1 regulation. Mutation in a position around -297 from the first ATG completely inactivated AtALMT1 expression and Al response. In vitro binding assays showed that this region contained the STOP1 binding site, which accounted for the recognition by four zinc finger domains of the protein. Other positions were characterized as cis-elements that regulated expression by repressors and activators and a transcription factor that determines root tip expression of AtALMT1. From the consensus of known cis-elements, we identified CALMODULIN-BINDING TRANSCRIPTION ACTIVATOR2 to be an activator of AtALMT1 expression. Al-inducible expression of AtALMT1 changed transcription starting sites, which increased the abundance of transcripts with a shortened 5' untranslated region. The present analyses identified multiple mechanisms that regulate AtALMT1 expression.

  2. The BnALMT1 and BnALMT2 genes from rape encode aluminum-activated malate transporters that enhance the aluminum resistance of plant cells.

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    Ligaba, Ayalew; Katsuhara, Maki; Ryan, Peter R; Shibasaka, Mineo; Matsumoto, Hideaki

    2006-11-01

    The release of organic anions from roots can protect plants from aluminum (Al) toxicity and help them overcome phosphorus (P) deficiency. Our previous findings showed that Al treatment induced malate and citrate efflux from rape (Brassica napus) roots, and that P deficiency did not induce the efflux. Since this response is similar to the malate efflux from wheat (Triticum aestivum) that is controlled by the TaALMT1 gene, we investigated whether homologs of TaALMT1 are present in rape and whether they are involved in the release of organic anions. We isolated two TaALMT1 homologs from rape designated BnALMT1 and BnALMT2 (B. napus Al-activated malate transporter). The expression of these genes was induced in roots, but not shoots, by Al treatment but P deficiency had no effect. Several other cations (lanthanum, ytterbium, and erbium) also increased BnALMT1 and BnALMT2 expression in the roots. The function of the BnALMT1 and BnALMT2 proteins was investigated by heterologous expression in cultured tobacco (Nicotiana tabacum) cells and in Xenopus laevis oocytes. Both transfection systems showed an enhanced capacity for malate efflux but not citrate efflux, when exposed to Al. Smaller malate fluxes were also activated by ytterbium and erbium treatment. Transgenic tobacco cells grew significantly better than control cells following an 18 h treatment with Al, indicating that the expression of BnALMT1 and BnALMT2 increased the resistance of these plant cells to Al stress. This report demonstrates that homologs of the TaALMT1 gene from wheat perform similar functions in other species.

  3. Functional, structural and phylogenetic analysis of domains underlying the Al-sensitivity of the aluminium-activated malate/anion transporter, TaALMT1

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    TaALMT1 (Triticum aestivum Aluminum Activated Malate Transporter) is the founding member of a novel gene family of anion transporters (ALMTs) that mediate the efflux of organic acids. A small subgroup of root-localized ALMTs, including TaALMT1, is physiologically associated with in planta aluminum (...

  4. The ABC transporter AtABCB14 is a malate importer and modulates stomatal response to CO2.

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    Lee, Miyoung; Choi, Yongwook; Burla, Bo; Kim, Yu-Young; Jeon, Byeongwook; Maeshima, Masayoshi; Yoo, Joo-Yeon; Martinoia, Enrico; Lee, Youngsook

    2008-10-01

    Carbon dioxide uptake and water vapour release in plants occur through stomata, which are formed by guard cells. These cells respond to light intensity, CO2 and water availability, and plant hormones. The predicted increase in the atmospheric concentration of CO2 is expected to have a profound effect on our ecosystem. However, many aspects of CO2-dependent stomatal movements are still not understood. Here we show that the ABC transporter AtABCB14 modulates stomatal closure on transition to elevated CO2. Stomatal closure induced by high CO2 levels was accelerated in plants lacking AtABCB14. Apoplastic malate has been suggested to be one of the factors mediating the stomatal response to CO2 (Refs 4,5) and indeed, exogenously applied malate induced a similar AtABCB14-dependent response as high CO2 levels. In isolated epidermal strips that contained only guard cells, malate-dependent stomatal closure was faster in plants lacking the AtABCB14 and slower in AtABCB14-overexpressing plants, than in wild-type plants, indicating that AtABCB14 catalyses the transport of malate from the apoplast into guard cells. Indeed, when AtABCB14 was heterologously expressed in Escherichia coli and HeLa cells, increases in malate transport activity were observed. We therefore suggest that AtABCB14 modulates stomatal movement by transporting malate from the apoplast into guard cells, thereby increasing their osmotic pressure.

  5. MdMYB1 Regulates Anthocyanin and Malate Accumulation by Directly Facilitating Their Transport into Vacuoles in Apples.

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    Hu, Da-Gang; Sun, Cui-Hui; Ma, Qi-Jun; You, Chun-Xiang; Cheng, Lailiang; Hao, Yu-Jin

    2016-03-01

    Tonoplast transporters, including proton pumps and secondary transporters, are essential for plant cell function and for quality formation of fleshy fruits and ornamentals. Vacuolar transport of anthocyanins, malate, and other metabolites is directly or indirectly dependent on the H(+)-pumping activities of vacuolar H(+)-ATPase (VHA) and/or vacuolar H(+)-pyrophosphatase, but how these proton pumps are regulated in modulating vacuolar transport is largely unknown. Here, we report a transcription factor, MdMYB1, in apples that binds to the promoters of two genes encoding the B subunits of VHA, MdVHA-B1 and MdVHA-B2, to transcriptionally activate its expression, thereby enhancing VHA activity. A series of transgenic analyses in apples demonstrates that MdMYB1/10 controls cell pH and anthocyanin accumulation partially by regulating MdVHA-B1 and MdVHA-B2. Furthermore, several other direct target genes of MdMYB10 are identified, including MdVHA-E2, MdVHP1, MdMATE-LIKE1, and MdtDT, which are involved in H(+)-pumping or in the transport of anthocyanins and malates into vacuoles. Finally, we show that the mechanism by which MYB controls malate and anthocyanin accumulation in apples also operates in Arabidopsis (Arabidopsis thaliana). These findings provide novel insights into how MYB transcription factors directly modulate the vacuolar transport system in addition to anthocyanin biosynthesis, consequently controlling organ coloration and cell pH in plants.

  6. Isolation and characterization of an apple cytosolic malate dehydrogenase gene reveal its function in malate synthesis.

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    Yao, Yu-Xin; Li, Ming; Zhai, Heng; You, Chun-Xiang; Hao, Yu-Jin

    2011-03-15

    Cytosolic NAD-dependent malate dehydrogenase (cyMDH) is an enzyme crucial for malate synthesis in the cytosol. The apple MdcyMDH gene (GenBank Accession No. DQ221207) encoding the cyMDH enzyme in apple was cloned and functionally characterized. The protein was subcellularly localized to the cytoplasm and plasma membrane. Based on kinetic parameters, it mainly catalyzes the reaction from oxalacetic acid (OAA) to malate in vitro. The expression level of MdcyMDH was positively correlated with malate dehydrogenase (MDH) activity throughout fruit development, but not with malate content, especially in the ripening apple fruit. MdcyMDH overexpression contributed to malate accumulation in the apple callus and tomato. Taken together, our results support the involvement of MdcyMDH directly in malate synthesis and indirectly in malate accumulation through the regulation of genes/enzymes associated with malate degradation and transportation, gluconeogenesis and the tricarboxylic acid cycle.

  7. Implication of citrate, malate and histidine in the accumulation and transport of nickel in Mesembryanthemum crystallinum and Brassica juncea.

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    Amari, Taoufik; Lutts, Stanley; Taamali, Manel; Lucchini, Giorgio; Sacchi, Gian Attilio; Abdelly, Chedly; Ghnaya, Tahar

    2016-04-01

    Citrate, malate and histidine have been involved in many processes including metal tolerance and accumulation in plants. These molecules have been frequently reported to be the potential nickel chelators, which most likely facilitate metal transport through xylem. In this context, we assess here, the relationship between organics acids and histidine content and nickel accumulation in Mesembryanthemum crystallinum and Brassica juncea grown in hydroponic media added with 25, 50 and 100 µM NiCl2. Results showed that M. crystallinum is relatively more tolerant to Ni toxicity than B. juncea. For both species, xylem transport rate of Ni increased with increasing Ni supply. A positive correlation was established between nickel and citrate concentrations in the xylem sap. In the shoot of B. juncea, citric and malic acids concentrations were significantly higher than in the shoot of M. crystallinum. Also, the shoots and roots of B. juncea accumulated much more histidine. In contrast, a higher root citrate concentration was observed in M. crystallinum. These findings suggest a specific involvement of malic and citric acid in Ni translocation and accumulation in M. crystallinum and B. juncea. The high citrate and histidine accumulation especially at 100µM NiCl2, in the roots of M. crystallinum might be among the important factors associated with the tolerance of this halophyte to toxic Ni levels.

  8. The metabolism of malate by cultured rat brain astrocytes

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    McKenna, M.C.; Tildon, J.T.; Couto, R.; Stevenson, J.H.; Caprio, F.J. (Department of Pediatrics, University of Maryland School of Medicine, Baltimore (USA))

    1990-12-01

    Since malate is known to play an important role in a variety of functions in the brain including energy metabolism, the transfer of reducing equivalents and possibly metabolic trafficking between different cell types; a series of biochemical determinations were initiated to evaluate the rate of 14CO2 production from L-(U-14C)malate in rat brain astrocytes. The 14CO2 production from labeled malate was almost totally suppressed by the metabolic inhibitors rotenone and antimycin A suggesting that most of malate metabolism was coupled to the electron transport system. A double reciprocal plot of the 14CO2 production from the metabolism of labeled malate revealed biphasic kinetics with two apparent Km and Vmax values suggesting the presence of more than one mechanism of malate metabolism in these cells. Subsequent experiments were carried out using 0.01 mM and 0.5 mM malate to determine whether the addition of effectors would differentially alter the metabolism of high and low concentrations of malate. Effectors studied included compounds which could be endogenous regulators of malate metabolism and metabolic inhibitors which would provide information regarding the mechanisms regulating malate metabolism. Both lactate and aspartate decreased 14CO2 production from malate equally. However, a number of effectors were identified which selectively altered the metabolism of 0.01 mM malate including aminooxyacetate, furosemide, N-acetylaspartate, oxaloacetate, pyruvate and glucose, but had little or no effect on the metabolism of 0.5 mM malate. In addition, alpha-ketoglutarate and succinate decreased 14CO2 production from 0.01 mM malate much more than from 0.5 mM malate. In contrast, a number of effectors altered the metabolism of 0.5 mM malate more than 0.01 mM. These included methionine sulfoximine, glutamate, malonate, alpha-cyano-4-hydroxycinnamate and ouabain.

  9. Malate and fumarate extend lifespan in Caenorhabditis elegans.

    Directory of Open Access Journals (Sweden)

    Clare B Edwards

    Full Text Available Malate, the tricarboxylic acid (TCA cycle metabolite, increased lifespan and thermotolerance in the nematode C. elegans. Malate can be synthesized from fumarate by the enzyme fumarase and further oxidized to oxaloacetate by malate dehydrogenase with the accompanying reduction of NAD. Addition of fumarate also extended lifespan, but succinate addition did not, although all three intermediates activated nuclear translocation of the cytoprotective DAF-16/FOXO transcription factor and protected from paraquat-induced oxidative stress. The glyoxylate shunt, an anabolic pathway linked to lifespan extension in C. elegans, reversibly converts isocitrate and acetyl-CoA to succinate, malate, and CoA. The increased longevity provided by malate addition did not occur in fumarase (fum-1, glyoxylate shunt (gei-7, succinate dehydrogenase flavoprotein (sdha-2, or soluble fumarate reductase F48E8.3 RNAi knockdown worms. Therefore, to increase lifespan, malate must be first converted to fumarate, then fumarate must be reduced to succinate by soluble fumarate reductase and the mitochondrial electron transport chain complex II. Reduction of fumarate to succinate is coupled with the oxidation of FADH2 to FAD. Lifespan extension induced by malate depended upon the longevity regulators DAF-16 and SIR-2.1. Malate supplementation did not extend the lifespan of long-lived eat-2 mutant worms, a model of dietary restriction. Malate and fumarate addition increased oxygen consumption, but decreased ATP levels and mitochondrial membrane potential suggesting a mild uncoupling of oxidative phosphorylation. Malate also increased NADPH, NAD, and the NAD/NADH ratio. Fumarate reduction, glyoxylate shunt activity, and mild mitochondrial uncoupling likely contribute to the lifespan extension induced by malate and fumarate by increasing the amount of oxidized NAD and FAD cofactors.

  10. Malic acid production by Saccharomyces cerevisiae: engineering of pyruvate carboxylation, oxaloacetate reduction, and malate export.

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    Zelle, Rintze M; de Hulster, Erik; van Winden, Wouter A; de Waard, Pieter; Dijkema, Cor; Winkler, Aaron A; Geertman, Jan-Maarten A; van Dijken, Johannes P; Pronk, Jack T; van Maris, Antonius J A

    2008-05-01

    Malic acid is a potential biomass-derivable "building block" for chemical synthesis. Since wild-type Saccharomyces cerevisiae strains produce only low levels of malate, metabolic engineering is required to achieve efficient malate production with this yeast. A promising pathway for malate production from glucose proceeds via carboxylation of pyruvate, followed by reduction of oxaloacetate to malate. This redox- and ATP-neutral, CO(2)-fixing pathway has a theoretical maximum yield of 2 mol malate (mol glucose)(-1). A previously engineered glucose-tolerant, C(2)-independent pyruvate decarboxylase-negative S. cerevisiae strain was used as the platform to evaluate the impact of individual and combined introduction of three genetic modifications: (i) overexpression of the native pyruvate carboxylase encoded by PYC2, (ii) high-level expression of an allele of the MDH3 gene, of which the encoded malate dehydrogenase was retargeted to the cytosol by deletion of the C-terminal peroxisomal targeting sequence, and (iii) functional expression of the Schizosaccharomyces pombe malate transporter gene SpMAE1. While single or double modifications improved malate production, the highest malate yields and titers were obtained with the simultaneous introduction of all three modifications. In glucose-grown batch cultures, the resulting engineered strain produced malate at titers of up to 59 g liter(-1) at a malate yield of 0.42 mol (mol glucose)(-1). Metabolic flux analysis showed that metabolite labeling patterns observed upon nuclear magnetic resonance analyses of cultures grown on (13)C-labeled glucose were consistent with the envisaged nonoxidative, fermentative pathway for malate production. The engineered strains still produced substantial amounts of pyruvate, indicating that the pathway efficiency can be further improved.

  11. Advances in research of malate and citrate transporter genes in plants%植物苹果酸和柠檬酸通道蛋白基因的研究进展

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    梁锋; 罗义勇; 陈丽梅; 李昆志

    2011-01-01

    Aluminum is the major factor inhibiting plant growth and crop yield in acid soils.Recent researches show that Al is mainly detoxified by transporting small molecular anions of organic acids out of cells in the root with the organic acid channel protein in the plants.In this paper, two Al-resistant genes encoding aluminumactivated malate transporter and multidrug and toxic compound extrusion protein in plants are summarized from the aspects of gene cloning, protein homology comparison, gene expression regulation, function and application of gene as well as the predicted acting model of Al-tolerance genes.In addition, the prospect of these Al-resistant genes is also predicted.%铝毒是酸性土壤中抑制植物生长和减少作物产量的主要因素.近年来研究表明植物主要通过根部有机酸通道蛋白将小分子有机酸阴离子转运到细胞膜外来缓解铝毒.本文综述了植物中编码铝诱导的苹果酸转运蛋白和多药及毒性复合物的排出转运蛋白两种耐铝基因,并从基因克隆、蛋白质同源性比较、基因表达调控、基因的功能和应用以及预测耐铝基因作用模式等方面进行了阐述;同时对这些耐铝基因的应用前景进行了展望.

  12. Effects of L-malate on mitochondrial oxidoreductases in liver of aged rats.

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    Wu, J-L; Wu, Q-P; Peng, Y-P; Zhang, J-M

    2011-01-01

    Accumulation of oxidative damage has been implicated to be a major causative factor in the decline in physiological functions that occur during the aging process. The mitochondrial respiratory chain is a powerful source of reactive oxygen species (ROS), considered as the pathogenic agent of many diseases and aging. L-malate, a tricarboxylic acid cycle intermediate, plays an important role in transporting NADH from cytosol to mitochondria for energy production. Previous studies in our laboratory reported L-malate as a free radical scavenger in aged rats. In the present study we focused on the effect of L-malate on the activities of electron transport chain in young and aged rats. We found that mitochondrial membrane potential (MMP) and the activities of succinate dehydrogenase, NADH-cytochrome c oxidoreductase and cytochrome c oxidase in liver of aged rats were significantly decreased when compared to young control rats. Supplementation of L-malate to aged rats for 30 days slightly increased MMP and improved the activities of NADH-dehydrogenase, NADH-cytochrome c oxidoreductase and cytochrome c oxidase in liver of aged rats when compared with aged control rats. In young rats, L-malate administration increased only the activity of NADH-dehydrogenase. Our result suggested that L-malate could improve the activities of electron transport chain enzymes in aged rats.

  13. Identification and characterization of chemosensors for d-malate, unnatural enantiomer of malate, in Ralstonia pseudosolanacearum.

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    Tunchai, Mattana; Hida, Akiko; Oku, Shota; Nakashimada, Yutaka; Tajima, Takahisa; Kato, Junichi

    2017-02-01

    Ralstonia pseudosolanacearum Ps29 is attracted by nonmetabolizable d-malate, an unnatural enantiomer. Screening of a complete collection of single-mcp-gene deletion mutants of Ps29 revealed that the RSc1156 homologue is a chemosensor for d-malate. An RSc1156 homologue deletion mutant of Ps29 showed decreased but significant responses to d-malate, suggesting the existence of another d-malate chemosensor. McpM previously had been identified as a chemosensor for l-malate. We constructed an RSc1156 homologue mcpM double deletion mutant and noted that this mutant failed to respond to d-malate; thus, the RSc1156 homologue and McpM are the major chemosensors for d-malate in this organism. To further characterize the ligand specificities of the RSc1156 homologue and McpM, we constructed a Ps29 derivative (designated K18) harbouring deletions in 18 individual mcp genes, including mcpM and RSc1156. K18 harbouring the RSc1156 homologue responded strongly to l-tartrate and d-malate and moderately to d-tartrate, but not to l-malate or succinate. K18 harbouring mcpM responded strongly to l-malate and d-tartrate and moderately to succinate, fumarate and d-malate. Ps29 utilizes l-malate and l-tartrate, but not d-malate. We therefore concluded that l-tartrate and l-malate are natural ligands of the RSc1156 homologue and McpM, respectively, and that chemotaxis toward d-malate is a fortuitous response by the RSc1156 homologue and McpM in Ps29. We propose re-designation of the RSc1156 homologue as McpT. In tomato plant infection assays, the mcpT deletion mutant of highly virulent R. pseudosolanacearum MAFF106611 was as infectious as wild-type MAFF106611, suggesting that McpT-mediated chemotaxis does not play an important role in tomato plant infection.

  14. Malate metabolism in Bacillus subtilis: distinct roles for three classes of malate-oxidizing enzymes.

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    Meyer, Frederik M; Stülke, Jörg

    2013-02-01

    The Gram-positive soil bacterium Bacillus subtilis uses glucose and malate as the preferred carbon sources. In the presence of either glucose or malate, the expression of genes and operons for the utilization of secondary carbon sources is subject to carbon catabolite repression. While glucose is a preferred substrate in many organisms from bacteria to man, the factors that contribute to the preference for malate have so far remained elusive. In this work, we have studied the contribution of the different malate-metabolizing enzymes in B. subtilis, and we have elucidated their distinct functions. The malate dehydrogenase and the phosphoenolpyruvate carboxykinase are both essential for malate utilization; they introduce malate into gluconeogenesis. The NADPH-generating malic enzyme YtsJ is important to establish the cellular pools of NADPH for anabolic reactions. Finally, the NADH-generating malic enzymes MaeA, MalS, and MleA are involved in keeping the ATP levels high. Together, this unique array of distinct activities makes malate a preferred carbon source for B. subtilis.

  15. Streptococcus pyogenes malate degradation pathway links pH regulation and virulence.

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    Paluscio, Elyse; Caparon, Michael G

    2015-03-01

    The ability of Streptococcus pyogenes to infect different niches within its human host most likely relies on its ability to utilize alternative carbon sources. In examining this question, we discovered that all sequenced S. pyogenes strains possess the genes for the malic enzyme (ME) pathway, which allows malate to be used as a supplemental carbon source for growth. ME is comprised of four genes in two adjacent operons, with the regulatory two-component MaeKR required for expression of genes encoding a malate permease (maeP) and malic enzyme (maeE). Analysis of transcription indicated that expression of maeP and maeE is induced by both malate and low pH, and induction in response to both cues is dependent on the MaeK sensor kinase. Furthermore, both maePE and maeKR are repressed by glucose, which occurs via a CcpA-independent mechanism. Additionally, malate utilization requires the PTS transporter EI enzyme (PtsI), as a PtsI(-) mutant fails to express the ME genes and is unable to utilize malate. Virulence of selected ME mutants was assessed in a murine model of soft tissue infection. MaeP(-), MaeK(-), and MaeR(-) mutants were attenuated for virulence, whereas a MaeE(-) mutant showed enhanced virulence compared to that of the wild type. Taken together, these data show that ME contributes to S. pyogenes' carbon source repertory, that malate utilization is a highly regulated process, and that a single regulator controls ME expression in response to diverse signals. Furthermore, malate uptake and utilization contribute to the adaptive pH response, and ME can influence the outcome of infection.

  16. Plastidial NAD-dependent malate dehydrogenase is critical for embryo development and heterotrophic metabolism in Arabidopsis.

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    Beeler, Seraina; Liu, Hung-Chi; Stadler, Martha; Schreier, Tina; Eicke, Simona; Lue, Wei-Ling; Truernit, Elisabeth; Zeeman, Samuel C; Chen, Jychian; Kötting, Oliver

    2014-03-01

    In illuminated chloroplasts, one mechanism involved in reduction-oxidation (redox) homeostasis is the malate-oxaloacetate (OAA) shuttle. Excess electrons from photosynthetic electron transport in the form of nicotinamide adenine dinucleotide phosphate, reduced are used by NADP-dependent malate dehydrogenase (MDH) to reduce OAA to malate, thus regenerating the electron acceptor NADP. NADP-MDH is a strictly redox-regulated, light-activated enzyme that is inactive in the dark. In the dark or in nonphotosynthetic tissues, the malate-OAA shuttle was proposed to be mediated by the constitutively active plastidial NAD-specific MDH isoform (pdNAD-MDH), but evidence is scarce. Here, we reveal the critical role of pdNAD-MDH in Arabidopsis (Arabidopsis thaliana) plants. A pdnad-mdh null mutation is embryo lethal. Plants with reduced pdNAD-MDH levels by means of artificial microRNA (miR-mdh-1) are viable, but dark metabolism is altered as reflected by increased nighttime malate, starch, and glutathione levels and a reduced respiration rate. In addition, miR-mdh-1 plants exhibit strong pleiotropic effects, including dwarfism, reductions in chlorophyll levels, photosynthetic rate, and daytime carbohydrate levels, and disordered chloroplast ultrastructure, particularly in developing leaves, compared with the wild type. pdNAD-MDH deficiency in miR-mdh-1 can be functionally complemented by expression of a microRNA-insensitive pdNAD-MDH but not NADP-MDH, confirming distinct roles for NAD- and NADP-linked redox homeostasis.

  17. Kinetics of myoglobin redox form stabilization by malate dehydrogenase.

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    Mohan, Anand; Muthukrishnan, S; Hunt, Melvin C; Barstow, Thomas J; Houser, Terry A

    2010-06-09

    This study reports the reduction of metmyoglobin (MMb) via oxidation of malate to oxaloacetate and the regeneration of reduced nicotinamide adenine dinucleotide (NADH) via malate dehydrogenase (MDH). Two experiments were conducted to evaluate a malate-MDH-NADH system as a possible mechanism for MMb reduction. In experiment 1, kinetics of MDH and MMb reduction were determined, and the results showed that increasing concentrations of oxidized nicotinamide adenine dinucleotide (NAD(+)) and l-malate also increased (p malate and NAD(+) added. Reduction of MMb in the muscle extracts via MDH was NAD(+), malate, and extract concentration dependent (p malate can replenish NADH via MDH activity in post-mortem muscle, ultimately resulting in a more functional meat color.

  18. Metabolic engineering of Torulopsis glabrata for malate production.

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    Chen, Xiulai; Xu, Guoqiang; Xu, Nan; Zou, Wei; Zhu, Pan; Liu, Liming; Chen, Jian

    2013-09-01

    The yeast Torulopsis glabrata CCTCC M202019, which is used for industrial pyruvate production, was chosen to explore the suitability of engineering this multi-vitamin auxotrophic yeast for increased malate production. Various metabolic engineering strategies were used to manipulate carbon flux from pyruvate to malate: (i) overexpression of pyruvate carboxylase and malate dehydrogenase; (ii) identification of the bottleneck in malate production by model iNX804; (iii) simultaneous overexpression of genes RoPYC, RoMDH and SpMAE1. Using these strategies, 8.5gL(-1) malate was accumulated in the engineered strain T.G-PMS, which was about 10-fold greater than that of the control strain T.G-26. The results presented here suggest that T. glabrata CCTCC M202019 is a promising candidate for industrial malate production.

  19. Malate dehydrogenase: a model for structure, evolution, and catalysis.

    OpenAIRE

    1994-01-01

    Malate dehydrogenases are widely distributed and alignment of the amino acid sequences show that the enzyme has diverged into 2 main phylogenetic groups. Multiple amino acid sequence alignments of malate dehydrogenases also show that there is a low degree of primary structural similarity, apart from in several positions crucial for nucleotide binding, catalysis, and the subunit interface. The 3-dimensional structures of several malate dehydrogenases are similar, despite their low amino acid s...

  20. AcEST: BP913659 [AcEST

    Lifescience Database Archive (English)

    Full Text Available acterized protein OS=Oryza... 50 4e-05 tr|Q5Z6M5|Q5Z6M5_ORYSJ Aluminum-activated malate transporter-lik... 5...RLDHLVEAAERLATMARFK 519 >tr|Q5Z6M5|Q5Z6M5_ORYSJ Aluminum-activated malate transporter-like OS=Oryza sativa s

  1. Cell wall-associated malate dehydrogenase activity from maize roots.

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    Hadži-Tašković Šukalović, Vesna; Vuletić, Mirjana; Marković, Ksenija; Vučinić, Zeljko

    2011-10-01

    Isolated cell walls from maize (Zea mays L.) roots exhibited ionically and covalently bound NAD-specific malate dehydrogenase activity. The enzyme catalyses a rapid reduction of oxaloacetate and much slower oxidation of malate. The kinetic and regulatory properties of the cell wall enzyme solubilized with 1M NaCl were different from those published for soluble, mitochondrial or plasma membrane malate dehydrogenase with respect to their ATP, Pi, and pH dependence. Isoelectric focusing of ionically-bound proteins and specific staining for malate dehydrogenase revealed characteristic isoforms present in cell wall isolate, different from those present in plasma membranes and crude homogenate. Much greater activity of cell wall-associated malate dehydrogenase was detected in the intensively growing lateral roots compared to primary root with decreased growth rates. Presence of Zn(2+) and Cu(2+) in the assay medium inhibited the activity of the wall-associated malate dehydrogenase. Exposure of maize plants to excess concentrations of Zn(2+) and Cu(2+) in the hydroponic solution inhibited lateral root growth, decreased malate dehydrogenase activity and changed isoform profiles. The results presented show that cell wall malate dehydrogenase is truly a wall-bound enzyme, and not an artefact of cytoplasmic contamination, involved in the developmental processes, and detoxification of heavy metals.

  2. Low pH, aluminum, and phosphorus coordinately regulate malate exudation through GmALMT1 to improve soybean adaptation to acid soils.

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    Liang, Cuiyue; Piñeros, Miguel A; Tian, Jiang; Yao, Zhufang; Sun, Lili; Liu, Jiping; Shaff, Jon; Coluccio, Alison; Kochian, Leon V; Liao, Hong

    2013-03-01

    Low pH, aluminum (Al) toxicity, and low phosphorus (P) often coexist and are heterogeneously distributed in acid soils. To date, the underlying mechanisms of crop adaptation to these multiple factors on acid soils remain poorly understood. In this study, we found that P addition to acid soils could stimulate Al tolerance, especially for the P-efficient genotype HN89. Subsequent hydroponic studies demonstrated that solution pH, Al, and P levels coordinately altered soybean (Glycine max) root growth and malate exudation. Interestingly, HN89 released more malate under conditions mimicking acid soils (low pH, +P, and +Al), suggesting that root malate exudation might be critical for soybean adaptation to both Al toxicity and P deficiency on acid soils. GmALMT1, a soybean malate transporter gene, was cloned from the Al-treated root tips of HN89. Like root malate exudation, GmALMT1 expression was also pH dependent, being suppressed by low pH but enhanced by Al plus P addition in roots of HN89. Quantitative real-time PCR, transient expression of a GmALMT1-yellow fluorescent protein chimera in Arabidopsis protoplasts, and electrophysiological analysis of Xenopus laevis oocytes expressing GmALMT1 demonstrated that GmALMT1 encodes a root cell plasma membrane transporter that mediates malate efflux in an extracellular pH-dependent and Al-independent manner. Overexpression of GmALMT1 in transgenic Arabidopsis, as well as overexpression and knockdown of GmALMT1 in transgenic soybean hairy roots, indicated that GmALMT1-mediated root malate efflux does underlie soybean Al tolerance. Taken together, our results suggest that malate exudation is an important component of soybean adaptation to acid soils and is coordinately regulated by three factors, pH, Al, and P, through the regulation of GmALMT1 expression and GmALMT1 function.

  3. Malate dehydrogenases from actinomycetes: structural comparison of Thermoactinomyces enzyme with other actinomycete and Bacillus enzymes.

    OpenAIRE

    1984-01-01

    Malate dehydrogenases from bacteria belonging to the genus Thermoactinomyces are tetrameric, like those from Bacillus spp., and exhibit a high degree of structural homology to Bacillus malate dehydrogenase as judged by immunological cross-reactivity. Malate dehydrogenases from other actinomycetes are dimers and do not cross-react with antibodies to Bacillus malate dehydrogenase.

  4. Type 2 diabetic rats on diet supplemented with chromium malate show improved glycometabolism, glycometabolism-related enzyme levels and lipid metabolism.

    Directory of Open Access Journals (Sweden)

    Weiwei Feng

    Full Text Available Our previous study showed that chromium malate improved the regulation of blood glucose in mice with alloxan-induced diabetes. The present study was designed to evaluate the effect of chromium malate on glycometabolism, glycometabolism-related enzymes and lipid metabolism in type 2 diabetic rats. Our results showed that fasting blood glucose, serum insulin level, insulin resistance index and C-peptide level in the high dose group had a significant downward trend when compared with the model group, chromium picolinate group and chromium trichloride group. The hepatic glycogen, glucose-6-phosphate dehydrogenase, glucokinase, Glut4, phosphor-AMPKβ1 and Akt levels in the high dose group were significantly higher than those of the model, chromium picolinate and chromium trichloride groups. Chromium malate in a high dose group can significantly increase high density lipoprotein cholesterol level while decreasing the total cholesterol, low density lipoprotein cholesterol and triglyceride levels when compared with chromium picolinate and chromium trichloride. The serum chromium content in chromium malate and chromium picolinate group is significantly higher than that of the chromium trichloride group. The results indicated that the curative effects of chromium malate on glycometabolism, glycometabolism-related enzymes and lipid metabolism changes are better than those of chromium picolinate and chromium trichloride. Chromium malate contributes to glucose uptake and transport in order to improved glycometabolism and glycometabolism-related enzymes.

  5. Magnitude of malate-aspartate reduced nicotinamide adenine dinucleotide shuttle activity in intact respiring tumor cells.

    Science.gov (United States)

    Greenhouse, W V; Lehninger, A L

    1977-11-01

    Measurements of respiration, CO2 and lactate production, and changes in the levels of various key metabolites of the glycolytic sequence and tricarboxylic acid cycle were made on five lines of rodent ascites tumor cells (two strains of Ehrlich ascites tumor cells, Krebs II carcinoma, AS-30D carcinoma, and L1210 cells) incubated aerobically in the presence of uniformly labeled D-[14C]glucose. From these data, as well as earlier evidence demonstrating that the reduced nicotinamide adenine dinucleotide (NADH) shuttle in these cells requires a transaminase step and is thus identified as the malate-aspartate shuttle (W.V.V. Greenhouse and A.L. Lehninger, Cancer Res., 36: 1392-1396, 1976), metabolic flux diagrams were constructed for the five cell lines. These diagrams show the relative rates of glycolysis, the tricarboxylic acid cycle, electron transport, and the malate-aspartate shuttle in these tumors. Large amounts of cytosolic NADH were oxidized by the mitochondrial respiratory chain via the NADH shuttle, comprising anywhere from about 20 to 80% of the total flow of reducing equivalents to oxygen in these tumors. Calculations of the sources of energy for adenosine triphosphate synthesis indicated that on the average about one-third of the respiratory adenosine triphosphate is generated by electron flow originating from cytosolic NADH via the malate-aspartate shuttle.

  6. The vacuolar channel VvALMT9 mediates malate and tartrate accumulation in berries of Vitis vinifera.

    Science.gov (United States)

    De Angeli, Alexis; Baetz, Ulrike; Francisco, Rita; Zhang, Jingbo; Chaves, Maria Manuela; Regalado, Ana

    2013-08-01

    Vitis vinifera L. represents an economically important fruit species. Grape and wine flavour is made from a complex set of compounds. The acidity of berries is a major parameter in determining grape berry quality for wine making and fruit consumption. Despite the importance of malic and tartaric acid (TA) storage and transport for grape berry acidity, no vacuolar transporter for malate or tartrate has been identified so far. Some members of the aluminium-activated malate transporter (ALMT) anion channel family from Arabidopsis thaliana have been shown to be involved in mediating malate fluxes across the tonoplast. Therefore, we hypothesised that a homologue of these channels could have a similar role in V. vinifera grape berries. We identified homologues of the Arabidopsis vacuolar anion channel AtALMT9 through a TBLASTX search on the V. vinifera genome database. We cloned the closest homologue of AtALMT9 from grape berry cDNA and designated it VvALMT9. The expression profile revealed that VvALMT9 is constitutively expressed in berry mesocarp tissue and that its transcription level increases during fruit maturation. Moreover, we found that VvALMT9 is targeted to the vacuolar membrane. Using patch-clamp analysis, we could show that, besides malate, VvALMT9 mediates tartrate currents which are higher than in its Arabidopsis homologue. In summary, in the present study we provide evidence that VvALMT9 is a vacuolar malate channel expressed in grape berries. Interestingly, in V. vinifera, a tartrate-producing plant, the permeability of the channel is apparently adjusted to TA.

  7. Immobilization of malate dehydrogenase on carbon nanotubes for development of malate biosensor.

    Science.gov (United States)

    Ruhal, A; Rana, J S; Kumar, S; Kumar, A

    2012-12-22

    An amperometric malic acid biosensor was developed by immobilizing malate dehydrogenase on multi-walled carbon nanotubes (MWCNT) coated on screen printed carbon electrode. The screen printed carbon electrode is made up of three electrodes viz., carbon as working, platinum as counter and silver as reference electrode. Detection of L-malic acid concentration provides important information about the ripening and shelf life of the fruits. The NADP specific malate dehydrogenase was immobilized on carboxylated multiwalled carbon nanotubes using cross linker EDC [1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide] on screen printed carbon electrode. An amperometric current was measured by differential pulse voltammetry (DPV) which increases with increasing concentrations of malic acid at fixed concentration of NADP. Enzyme electrode was characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The detection limit of malic acid by the sensor was 60 - 120 μM and sensitivity of the sensor was 60 μM with a response time of 60s. The usual detection methods of malic acid are nonspecific, time consuming and less sensitive. However, an amperometric malic acid nanosensor is quick, specific and more sensitive for detection of malic acid in test samples.

  8. Malate synthesis and secretion mediated by a manganese-enhanced malate dehydrogenase confers superior manganese tolerance in Stylosanthes guianensis.

    Science.gov (United States)

    Chen, Zhijian; Sun, Lili; Liu, Pandao; Liu, Guodao; Tian, Jiang; Liao, Hong

    2015-01-01

    Manganese (Mn) toxicity is a major constraint limiting plant growth on acidic soils. Superior Mn tolerance in Stylosanthes spp. has been well documented, but its molecular mechanisms remain largely unknown. In this study, superior Mn tolerance in Stylosanthes guianensis was confirmed, as reflected by a high Mn toxicity threshold. Furthermore, genetic variation of Mn tolerance was evaluated using two S. guianensis genotypes, which revealed that the Fine-stem genotype had higher Mn tolerance than the TPRC2001-1 genotype, as exhibited through less reduction in dry weight under excess Mn, and accompanied by lower internal Mn concentrations. Interestingly, Mn-stimulated increases in malate concentrations and exudation rates were observed only in the Fine-stem genotype. Proteomic analysis of Fine-stem roots revealed that S. guianensis Malate Dehydrogenase1 (SgMDH1) accumulated in response to Mn toxicity. Western-blot and quantitative PCR analyses showed that Mn toxicity resulted in increased SgMDH1 accumulation only in Fine-stem roots, but not in TPRC2001-1. The function of SgMDH1-mediated malate synthesis was verified through in vitro biochemical analysis of SgMDH1 activities against oxaloacetate, as well as in vivo increased malate concentrations in yeast (Saccharomyces cerevisiae), soybean (Glycine max) hairy roots, and Arabidopsis (Arabidopsis thaliana) with SgMDH1 overexpression. Furthermore, SgMDH1 overexpression conferred Mn tolerance in Arabidopsis, which was accompanied by increased malate exudation and reduced plant Mn concentrations, suggesting that secreted malate could alleviate Mn toxicity in plants. Taken together, we conclude that the superior Mn tolerance of S. guianensis is achieved by coordination of internal and external Mn detoxification through malate synthesis and exudation, which is regulated by SgMDH1 at both transcription and protein levels.

  9. Malate dehydrogenase in phototrophic purple bacteria: purification, molecular weight, and quaternary structure.

    OpenAIRE

    1987-01-01

    The citric acid cycle enzyme malate dehydrogenase was purified to homogeneity from the nonsulfur purple bacteria Rhodobacter capsulatus, Rhodospirillum rubrum, Rhodomicrobium vannielii, and Rhodocyclus purpureus. Malate dehydrogenase was purified from each species by either a single- or a two-step protocol: triazine dye affinity chromatography was the key step in purification of malate dehydrogenase in all cases. Purification of malate dehydrogenase resulted in a 130- to 240-fold increase in ...

  10. Malic acid production by Saccharomyces cerevisiae: engineering of pyruvate carbosylation, oxaloacetate reduction and malate export

    NARCIS (Netherlands)

    Zelle, R.M.; Hulster, de E.; Winden, van W.A.; Waard, de P.; Dijkema, C.; Winkler, A.A.; Geertman, J.M.A.

    2008-01-01

    Malic acid is a potential biomass-derivable "building block" for chemical synthesis. Since wild-type Saccharomyces cerevisiae strains produce only low levels of malate, metabolic engineering is required to achieve efficient malate production with this yeast. A promising pathway for malate production

  11. Malic Acid Production by Saccharomyces cerevisiae: Engineering of Pyruvate Carboxylation, Oxaloacetate Reduction, and Malate Export

    NARCIS (Netherlands)

    Zelle, R.M.; De Hulster, E.; Van Winden, W.A.; De Waard, P.; Dijkema, C.; Winkler, A.A.; Geertman, J.M.; Van Dijken, J.P.; Pronk, J.T.; Van Maris, A.J.A.

    2008-01-01

    Malic acid is a potential biomass-derivable "building block" for chemical synthesis. Since wild-type Saccharomyces cerevisiae strains produce only low levels of malate, metabolic engineering is required to achieve efficient malate production with this yeast. A promising pathway for malate production

  12. Malate Synthesis by Dark Carbon Dioxide Fixation in Leaves 1

    Science.gov (United States)

    Levi, Carolyn; Perchorowicz, John T.; Gibbs, Martin

    1978-01-01

    The rates of dark CO2 fixation and the label distribution in malate following dark 14CO2 fixation in a C-4 plant (maize), a C-3 plant (sunflower), and two Crassulacean acid metabolism plants (Bryophyllum calycinum and Kalanchoë diagremontianum leaves and plantlets) are compared. Within the first 30 minutes of dark 14CO2 fixation, leaves of maize, B. calycinum, and sunflower, and K. diagremontianum plantlets fix CO2 at rates of 1.4, 3.4, 0.23, and 1.0 μmoles of CO2/mg of chlorophyll· hour, respectively. Net CO2 fixation stops within 3 hours in maize and sunflower, but Crassulaceans continue fixing CO2 for the duration of the 23-hour experiment. A bacterial procedure using Lactobacillus plantarum ATCC No. 8014 and one using malic enzyme to remove the β-carboxyl (C4) from malate are compared. It is reported that highly purified malic enzyme and the bacterial method provide equivalent results. Less purified malic enzyme may overestimate the label in C4 as much as 15 to 20%. The contribution of carbon atom 1 of malate is between 18 and 21% of the total carboxyl label after 1 minute of dark CO2 fixation. Isotopic labeling in the two carboxyls approached unity with time. The rate of increase is greatest in sunflower leaves and Kalanchoë plantlets. In addition, Kalanchoë leaves fix 14CO2 more rapidly than Kalanchoë plantlets and the equilibration of the malate carboxyls occurs more slowly. The rates of fixation and the randomization are tissue-specific. The rate of fixation does not correlate with the rate of randomization of isotope in the malate carboxyls. PMID:16660319

  13. Malate synthesis by dark carbon dioxide fixation in leaves.

    Science.gov (United States)

    Levi, C; Perchorowicz, J T; Gibbs, M

    1978-04-01

    The rates of dark CO(2) fixation and the label distribution in malate following dark (14)CO(2) fixation in a C-4 plant (maize), a C-3 plant (sunflower), and two Crassulacean acid metabolism plants (Bryophyllum calycinum and Kalanchoë diagremontianum leaves and plantlets) are compared. Within the first 30 minutes of dark (14)CO(2) fixation, leaves of maize, B. calycinum, and sunflower, and K. diagremontianum plantlets fix CO(2) at rates of 1.4, 3.4, 0.23, and 1.0 mumoles of CO(2)/mg of chlorophyll. hour, respectively. Net CO(2) fixation stops within 3 hours in maize and sunflower, but Crassulaceans continue fixing CO(2) for the duration of the 23-hour experiment.A bacterial procedure using Lactobacillus plantarum ATCC No. 8014 and one using malic enzyme to remove the beta-carboxyl (C(4)) from malate are compared. It is reported that highly purified malic enzyme and the bacterial method provide equivalent results. Less purified malic enzyme may overestimate the label in C(4) as much as 15 to 20%.The contribution of carbon atom 1 of malate is between 18 and 21% of the total carboxyl label after 1 minute of dark CO(2) fixation. Isotopic labeling in the two carboxyls approached unity with time. The rate of increase is greatest in sunflower leaves and Kalanchoë plantlets. In addition, Kalanchoë leaves fix (14)CO(2) more rapidly than Kalanchoë plantlets and the equilibration of the malate carboxyls occurs more slowly. The rates of fixation and the randomization are tissue-specific. The rate of fixation does not correlate with the rate of randomization of isotope in the malate carboxyls.

  14. Activity of the mitochondrial pyruvate dehydrogenase complex in plants is stimulated in the presence of malate.

    Science.gov (United States)

    Igamberdiev, Abir U; Lernmark, Ulrikа; Gardeström, Per

    2014-11-01

    The effect of malate on the steady-state activity of the pea (Pisum sativum L.) and barley (Hordeum vulgare L.) leaf pyruvate dehydrogenase complex (PDC) has been studied in isolated mitochondria. The addition of malate was found to be stimulatory for the mitochondrial PDC, however there was no stimulation of chloroplast PDC. The stimulation was saturated below 1mM malate and was apparently related to а partially activated complex, which activity increased in the presence of malate by about twofold. Malate also reversed the reduction of PDC activity in the presence of glycine. Based on the obtained kinetic data, we suggest that the effect of malate is rather not a direct activation of PDC but involves the establishment of NAD-malate dehydrogenase equilibrium, decreasing concentration of NADH and relieving its inhibitory effect of PDC.

  15. Relayed 13C magnetization transfer: Detection of malate dehydrogenase reaction in vivo

    Science.gov (United States)

    Yang, Jehoon; Shen, Jun

    2007-02-01

    Malate dehydrogenase catalyzes rapid interconversion between dilute metabolites oxaloacetate and malate. Both oxaloacetate and malate are below the detection threshold of in vivo MRS. Oxaloacetate is also in rapid exchange with aspartate catalyzed by aspartate aminotransferase, the latter metabolite is observable in vivo using 13C MRS. We hypothesized that the rapid turnover of oxaloacetate can effectively relay perturbation of magnetization between malate and aspartate. Here, we report indirect observation of the malate dehydrogenase reaction by saturating malate C2 resonance at 71.2 ppm and detecting a reduced aspartate C2 signal at 53.2 ppm due to relayed magnetization transfer via oxaloacetate C2 at 201.3 ppm. Using this strategy the rate of the cerebral malate dehydrogenase reaction was determined to be 9 ± 2 μmol/g wet weight/min (means ± SD, n = 5) at 11.7 Tesla in anesthetized adult rats infused with [1,6- 13C 2]glucose.

  16. Multiple strategies to prevent oxidative stress in Arabidopsis plants lacking the malate valve enzyme NADP-malate dehydrogenase.

    Science.gov (United States)

    Hebbelmann, Inga; Selinski, Jennifer; Wehmeyer, Corinna; Goss, Tatjana; Voss, Ingo; Mulo, Paula; Kangasjärvi, Saijaliisa; Aro, Eva-Mari; Oelze, Marie-Luise; Dietz, Karl-Josef; Nunes-Nesi, Adriano; Do, Phuc T; Fernie, Alisdair R; Talla, Sai K; Raghavendra, Agepati S; Linke, Vera; Scheibe, Renate

    2012-02-01

    The nuclear-encoded chloroplast NADP-dependent malate dehydrogenase (NADP-MDH) is a key enzyme controlling the malate valve, to allow the indirect export of reducing equivalents. Arabidopsis thaliana (L.) Heynh. T-DNA insertion mutants of NADP-MDH were used to assess the role of the light-activated NADP-MDH in a typical C(3) plant. Surprisingly, even when exposed to high-light conditions in short days, nadp-mdh knockout mutants were phenotypically indistinguishable from the wild type. The photosynthetic performance and typical antioxidative systems, such as the Beck-Halliwell-Asada pathway, were barely affected in the mutants in response to high-light treatment. The reactive oxygen species levels remained low, indicating the apparent absence of oxidative stress, in the mutants. Further analysis revealed a novel combination of compensatory mechanisms in order to maintain redox homeostasis in the nadp-mdh plants under high-light conditions, particularly an increase in the NTRC/2-Cys peroxiredoxin (Prx) system in chloroplasts. There were indications of adjustments in extra-chloroplastic components of photorespiration and proline levels, which all could dissipate excess reducing equivalents, sustain photosynthesis, and prevent photoinhibition in nadp-mdh knockout plants. Such metabolic flexibility suggests that the malate valve acts in concert with other NADPH-consuming reactions to maintain a balanced redox state during photosynthesis under high-light stress in wild-type plants.

  17. Reassessment of the transhydrogenase/malate shunt pathway in Clostridium thermocellum ATCC 27405 through kinetic characterization of malic enzyme and malate dehydrogenase.

    Science.gov (United States)

    Taillefer, M; Rydzak, T; Levin, D B; Oresnik, I J; Sparling, R

    2015-04-01

    Clostridium thermocellum produces ethanol as one of its major end products from direct fermentation of cellulosic biomass. Therefore, it is viewed as an attractive model for the production of biofuels via consolidated bioprocessing. However, a better understanding of the metabolic pathways, along with their putative regulation, could lead to improved strategies for increasing the production of ethanol. In the absence of an annotated pyruvate kinase in the genome, alternate means of generating pyruvate have been sought. Previous proteomic and transcriptomic work detected high levels of a malate dehydrogenase and malic enzyme, which may be used as part of a malate shunt for the generation of pyruvate from phosphoenolpyruvate. The purification and characterization of the malate dehydrogenase and malic enzyme are described in order to elucidate their putative roles in malate shunt and their potential role in C. thermocellum metabolism. The malate dehydrogenase catalyzed the reduction of oxaloacetate to malate utilizing NADH or NADPH with a kcat of 45.8 s(-1) or 14.9 s(-1), respectively, resulting in a 12-fold increase in catalytic efficiency when using NADH over NADPH. The malic enzyme displayed reversible malate decarboxylation activity with a kcat of 520.8 s(-1). The malic enzyme used NADP(+) as a cofactor along with NH4 (+) and Mn(2+) as activators. Pyrophosphate was found to be a potent inhibitor of malic enzyme activity, with a Ki of 0.036 mM. We propose a putative regulatory mechanism of the malate shunt by pyrophosphate and NH4 (+) based on the characterization of the malate dehydrogenase and malic enzyme.

  18. Safety Assessment of Dialkyl Malates as Used in Cosmetics.

    Science.gov (United States)

    Becker, Lillian C; Bergfeld, Wilma F; Belsito, Donald V; Hill, Ronald A; Klaassen, Curtis D; Liebler, Daniel C; Marks, James G; Shank, Ronald C; Slaga, Thomas J; Snyder, Paul W; Andersen, F Alan

    2015-01-01

    The Cosmetic Ingredient Review Expert Panel (Panel) reviewed the safety of 6 dialkyl malate compounds used in cosmetics. These ingredients function mostly as skin-conditioning agents-emollients. The Panel reviewed relevant animal and human data related to the ingredients along with a previous safety assessment of malic acid. The similar structure, properties, functions, and uses of these ingredients enabled grouping them and using the available toxicological data to assess the safety of the entire group. The Panel concluded that these dialkyl maleate compounds are safe in the present practices of use and concentration as given in this safety assessment.

  19. Structures of citrate synthase and malate dehydrogenase of Mycobacterium tuberculosis.

    Science.gov (United States)

    Ferraris, Davide M; Spallek, Ralf; Oehlmann, Wulf; Singh, Mahavir; Rizzi, Menico

    2015-02-01

    The tricarboxylic acid (TCA) cycle is a central metabolic pathway of all aerobic organisms and is responsible for the synthesis of many important precursors and molecules. TCA cycle plays a key role in the metabolism of Mycobacterium tuberculosis and is involved in the adaptation process of the bacteria to the host immune response. We present here the first crystal structures of M. tuberculosis malate dehydrogenase and citrate synthase, two consecutive enzymes of the TCA, at 2.6 Å and 1.5 Å resolution, respectively. General analogies and local differences with the previously reported homologous protein structures are described.

  20. Metabolic engineering of Escherichia coli W3110 to produce L-malate.

    Science.gov (United States)

    Dong, Xiaoxiang; Chen, Xiulai; Qian, Yuanyuan; Wang, Yuancai; Wang, Li; Qiao, Weihua; Liu, Liming

    2017-03-01

    A four-carbon dicarboxylic acid L-malate has recently attracted attention due to its potential applications in the fields of medicine and agriculture. In this study, Escherichia coli W3110 was engineered and optimized for L-malate production via one-step L-malate synthesis pathway. First, deletion of the genes encoding lactate dehydrogenase (ldhA), pyruvate oxidase (poxB), pyruvate formate lyase (pflB), phosphotransacetylase (pta), and acetate kinase A (ackA) in pta-ackA pathway led to accumulate 20.9 g/L pyruvate. Then, overexpression of NADP(+) -dependent malic enzyme C490S mutant in this multi-deletion mutant resulted in the direct conversion of pyruvate into L-malate (3.62 g/L). Next, deletion of the genes responsible for succinate biosynthesis further enhanced L-malate production up to 7.78 g/L. Finally, L-malate production was elevated to 21.65 g/L with the L-malate yield to 0.36 g/g in a 5 L bioreactor by overexpressing the pos5 gene encoding NADH kinase in the engineered E. coli F0931 strain. This study demonstrates the potential utility of one-step pathway for efficient L-malate production. Biotechnol. Bioeng. 2017;114: 656-664. © 2016 Wiley Periodicals, Inc.

  1. Characterization of malate dehydrogenase from the hyperthermophilic archaeon Pyrobaculum islandicum.

    Science.gov (United States)

    Yennaco, Lynda J; Hu, Yajing; Holden, James F

    2007-09-01

    Native and recombinant malate dehydrogenase (MDH) was characterized from the hyperthermophilic, facultatively autotrophic archaeon Pyrobaculum islandicum. The enzyme is a homotetramer with a subunit mass of 33 kDa. The activity kinetics of the native and recombinant proteins are the same. The apparent K ( m ) values of the recombinant protein for oxaloacetate (OAA) and NADH (at 80 degrees C and pH 8.0) were 15 and 86 microM, respectively, with specific activity as high as 470 U mg(-1). Activity decreased more than 90% when NADPH was used. The catalytic efficiency of OAA reduction by P. islandicum MDH using NADH was significantly higher than that reported for any other archaeal MDH. Unlike other archaeal MDHs, specific activity of the P. islandicum MDH back-reaction also decreased more than 90% when malate and NAD(+) were used as substrates and was not detected with NADP(+). A phylogenetic tree of 31 archaeal MDHs shows that they fall into 5 distinct groups separated largely along taxonomic lines suggesting minimal lateral mdh transfer between Archaea.

  2. Cytosolic malate dehydrogenase regulates senescence in human fibroblasts.

    Science.gov (United States)

    Lee, Seung-Min; Dho, So Hee; Ju, Sung-Kyu; Maeng, Jin-Soo; Kim, Jeong-Yoon; Kwon, Ki-Sun

    2012-10-01

    Carbohydrate metabolism changes during cellular senescence. Cytosolic malate dehydrogenase (MDH1) catalyzes the reversible reduction of oxaloacetate to malate at the expense of reduced nicotinamide adenine dinucleotide (NADH). Here, we show that MDH1 plays a critical role in the cellular senescence of human fibroblasts. We observed that the activity of MDH1 was reduced in old human dermal fibroblasts (HDFs) [population doublings (PD) 56], suggesting a link between decreased MDH1 protein levels and aging. Knockdown of MDH1 in young HDFs (PD 20) and the IMR90 human fibroblast cell line resulted in the appearance of significant cellular senescence features, including senescence-associated β-galactosidase staining, flattened and enlarged morphology, increased population doubling time, and elevated p16(INK4A) and p21(CIP1) protein levels. Cytosolic NAD/NADH ratios were decreased in old HDFs to the same extent as in MDH1 knockdown HDFs, suggesting that cytosolic NAD depletion is related to cellular senescence. We found that AMP-activated protein kinase, a sensor of cellular energy, was activated in MDH1 knockdown cells. We also found that sirtuin 1 (SIRT1) deacetylase, a controller of cellular senescence, was decreased in MDH1 knockdown cells. These results indicate that the decrease in MDH1 and subsequent reduction in NAD/NADH ratio, which causes SIRT1 inhibition, is a likely carbohydrate metabolism-controlled cellular senescence mechanism.

  3. Putative role of the malate valve enzyme NADP-malate dehydrogenase in H2O2 signalling in Arabidopsis.

    Science.gov (United States)

    Heyno, Eiri; Innocenti, Gilles; Lemaire, Stéphane D; Issakidis-Bourguet, Emmanuelle; Krieger-Liszkay, Anja

    2014-04-19

    In photosynthetic organisms, sudden changes in light intensity perturb the photosynthetic electron flow and lead to an increased production of reactive oxygen species. At the same time, thioredoxins can sense the redox state of the chloroplast. According to our hypothesis, thioredoxins and related thiol reactive molecules downregulate the activity of H2O2-detoxifying enzymes, and thereby allow a transient oxidative burst that triggers the expression of H2O2 responsive genes. It has been shown recently that upon light stress, catalase activity was reversibly inhibited in Chlamydomonas reinhardtii in correlation with a transient increase in the level of H2O2. Here, it is shown that Arabidopsis thaliana mutants lacking the NADP-malate dehydrogenase have lost the reversible inactivation of catalase activity and the increase in H2O2 levels when exposed to high light. The mutants were slightly affected in growth and accumulated higher levels of NADPH in the chloroplast than the wild-type. We propose that the malate valve plays an essential role in the regulation of catalase activity and the accumulation of a H2O2 signal by transmitting the redox state of the chloroplast to other cell compartments.

  4. Malate Oxidation and Cyanide-Insensitive Respiration in Avocado Mitochondria during the Climacteric Cycle.

    Science.gov (United States)

    Moreau, F; Romani, R

    1982-11-01

    After preparation on self-generated Percoll gradients, avocado (Persea americana Mill, var. Fuerte and Hass) mitochondria retain a high proportion of cyanide-insensitive respiration, especially with alpha-ketoglutarate and malate as substrates. Whereas alpha-ketoglutarate oxidation remains unchanged, the rate of malate oxidation increases as ripening advances through the climacteric. An enhancement of mitochondrial malic enzyme activity, measured by the accumulation of pyruvate, closely parallels the increase of malate oxidation. The capacity for cyanide-insensitive respiration is also considerably enhanced while respiratory control decreases (from 3.3 to 1.7), leading to high state 4 rates.Both malate dehydrogenase and malic enzyme are functional in state 3, but malic enzyme appears to predominate before the addition of ADP and after its depletion. In the presence of cyanide, a membrane potential is generated when the alterntive pathway is operating. Cyanide-insensitive malate oxidation can be either coupled to the first phosphorylation site, sensitive to rotenone, or by-pass this site. In the absence of phosphate acceptor, malate oxidation is mainly carried out via malic enzyme and the alternative pathway. Experimental modification of the external mitochondrial environment in vitro (pH, NAD(+), glutamade) results in changes in malate dehydrogenase and malic enzyme activities, which also modify cyanide resistance. It appears that a functional connection exists between malic enzyme and the alternative pathway via a rotenone-insensitive NADH dehydrogenase and that this pathway is responsible, in part, for nonphosphorylating respiratory activity during the climacteric.

  5. Guillain-Barré Syndrome following Treatment with Sunitinib Malate

    Directory of Open Access Journals (Sweden)

    Ziad Kanaan

    2014-01-01

    Full Text Available Sunitinib malate (Sutent, SU011248 is an oral multitargeted tyrosine kinase inhibitor (TKI used for the treatment of metastatic renal cell carcinoma and imatinib (Gleevec—resistant gastrointestinal stromal tumor (GIST with few reported side effects including asthenia, myelosuppression, diarrhea, and mucositis. Scarce literature exists regarding the rare but often serious toxicities of sunitinib. Autoimmune and neurological side effects have been linked to sunitinib’s inhibition of VEGF receptors with a corresponding increase in VEGF levels, which is associated with development of different neuropathies. We hereby report an interesting case of Guillain-Barré syndrome in a middle-aged patient with metastatic renal cell carcinoma following sunitinib treatment.

  6. Organic acid metabolism and root excretion of malate in wheat cultivars under aluminium stress.

    Science.gov (United States)

    de Andrade, Leide Rovênia Miranda; Ikeda, Motoki; do Amaral, Lourdes Isabel Velho; Ishizuka, Junji

    2011-01-01

    The effects of aluminium (Al) on the metabolism of organic acids synthesised via nonphotosynthetic carbon fixation in the roots and on malate exudation were investigated in Al-tolerant Shirosanjyaku (SH) and Al-sensitive Chikushikomugi (CK) wheat cultivars labelled with bicarbonate-(14)C. Aluminum triggered the excretion of (14)C into the solution, especially in the SH that excreted 2.5 times more (14)C than the CK. The loss of radioactivity (about 10%) into the solution represented a small drain in the (14)C reserve found in the roots. In the organic acid fraction within the roots, malate contained the greatest amount of (14)C, and this amount decreased rapidly with time in both cultivars. The disappearance of radioactivity in the malate resulted from metabolism and translocation rather than to root efflux. Aluminium decreased the malate concentrations in roots of both cultivars. The Al-sensitive cultivar had higher concentrations of malate regardless of the presence of Al. It was therefore assumed that the decrease of malate concentration in roots under Al stress did not result from the decline in malate synthesis but due to an increase in malate decomposition. This response was interpreted as the result of the Al-induced stress and not as the cause of a differential Al-tolerance between the wheat cultivars. An important component of the differential Al tolerance between SH and CK is the greater ability of the Al-tolerant cultivar to excrete malate from the roots, which is independent of its internal concentration in the roots.

  7. Vibrational, optical and microhardness studies of trimethoprim DL -malate

    Energy Technology Data Exchange (ETDEWEB)

    Franklin, S.; Bhuvana, K.P.; Balasubramanian, T. [Department of Physics, National Institute of Technology, Tiruchirappalli-620015, Tamilnadu (India)

    2009-12-15

    Trimethoprim malate, an organic crystal, has been synthesized using slow evaporation method from its aqueous solution. Structural, optical and the mechanical properties of the grown crystal have been investigated by various characterization techniques which include FTIR spectra, single crystal XRD, UV-Vis spectra and Vickers microhardness testing. The structure of the compound predicted by analysing the recorded FTIR spectrum compliments the structure determined using single crystal X-ray diffraction. Single crystal X-ray diffraction study reveals that the crystals are monoclinic[P2{sub 1}/c, a=12.9850A, b=9.3038A, c=15.6815A and {beta}=111.065 ]. The UV-Vis spectrum exhibits maximum transparency (98%) for a wide range suggesting the suitability of the title compound for optical applications. The optical constants have been calculated and illustrated graphically. Microhardness tests have been performed on the crystal under study and the Vicker hardness number has been calculated. The work hardening coefficient is found to be 2.85 which suggest that the crystal belongs to the family of soft materials. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Alternative splicing regulates targeting of malate dehydrogenase in Yarrowia lipolytica.

    Science.gov (United States)

    Kabran, Philomène; Rossignol, Tristan; Gaillardin, Claude; Nicaud, Jean-Marc; Neuvéglise, Cécile

    2012-06-01

    Alternative pre-mRNA splicing is a major mechanism contributing to the proteome complexity of most eukaryotes, especially mammals. In less complex organisms, such as yeasts, the numbers of genes that contain introns are low and cases of alternative splicing (AS) with functional implications are rare. We report the first case of AS with functional consequences in the yeast Yarrowia lipolytica. The splicing pattern was found to govern the cellular localization of malate dehydrogenase, an enzyme of the central carbon metabolism. This ubiquitous enzyme is involved in the tricarboxylic acid cycle in mitochondria and in the glyoxylate cycle, which takes place in peroxisomes and the cytosol. In Saccharomyces cerevisiae, three genes encode three compartment-specific enzymes. In contrast, only two genes exist in Y. lipolytica. One gene (YlMDH1, YALI0D16753g) encodes a predicted mitochondrial protein, whereas the second gene (YlMDH2, YALI0E14190g) generates the cytosolic and peroxisomal forms through the alternative use of two 3'-splice sites in the second intron. Both splicing variants were detected in cDNA libraries obtained from cells grown under different conditions. Mutants expressing the individual YlMdh2p isoforms tagged with fluorescent proteins confirmed that they localized to either the cytosolic or the peroxisomal compartment.

  9. Multiple soluble malate dehydrogenase of Geophagus brasiliensis (Cichlidae, Perciformes

    Directory of Open Access Journals (Sweden)

    Aquino-Silva Maria Regina de

    1998-01-01

    Full Text Available A recent locus duplication hypothesis for sMDH-B* was proposed to explain the complex electrophoretic pattern of six bands detected for the soluble form of malate dehydrogenase (MDH, EC 1.1.1.37 in 84% of the Geophagus brasiliensis (Cichlidae, Perciformes analyzed (AB1B2 individuals. Klebe's serial dilutions were carried out in skeletal muscle extracts. B1 and B2 subunits had the same visual end-points, reflecting a nondivergent pattern for these B-duplicated genes. Since there is no evidence of polyploidy in the Cichlidae family, MDH-B* loci must have evolved from regional gene duplication. Tissue specificities, thermostability and kinetic tests resulted in similar responses from both B-isoforms, in both sMDH phenotypes, suggesting that these more recently duplicated loci underwent the same regulatory gene action. Similar results obtained with the two sMDH phenotypes did not show any indication of a six-banded specimen adaptive advantage in subtropical regions.

  10. Engineered Bacillus subtilis 168 produces L-malate by heterologous biosynthesis pathway construction and lactate dehydrogenase deletion.

    Science.gov (United States)

    Mu, Li; Wen, Jianping

    2013-01-01

    In the present work, Bacillus subtilis was engineered to produce L-malate. Initially, the study revealed that the slight fumarase activity under anaerobic conditions is extremely favourable for L-malate one-step fermentation accumulation. Subsequently, an efficient heterologous biosynthesis pathway formed by Escherichia coli phosphoenolpyruvate carboxylase and Saccharomyces cerevisiae malate dehydrogenase was introduced into B. subtilis, which led to 6.04 ± 0.19 mM L-malate production. Finally, the L-malate production was increased 1.5-fold to 9.18 ± 0.22 mM by the deletion of lactate dehydrogenase. Under two-stage fermentation conditions, the engineered B. subtilis produced up to 15.65 ± 0.13 mM L-malate, which was 86.3 % higher than that under anaerobic fermentation conditions. Though the L-malate production by the recombinant was low, this is the first attempt to produce L-malate in engineered B. subtilis and paves the way for further improving L-malate production in B. subtilis.

  11. Function, kinetic properties, crystallization, and regulation of microbial malate dehydrogenase

    Institute of Scientific and Technical Information of China (English)

    Tóshiko TAKAHASHI-ÍÑIGUEZ; Nelly ABURTO-RODRÍGUEZ; Ana Laura VILCHIS-GONZÁLEZ; María Elena FLORES

    2016-01-01

    题目:微生物苹果酸脱氢酶的功能、动力学特征、晶体结构以及调控概苹果酸脱氢酶(MDH)广泛存在于动物、植物以及微生物体内,是生物体进行糖代谢的关键酶之一。在辅酶I(NAD+)或辅酶II(NADP+)的作用下,能够催化草酰乙酸和苹果酸之间相互转化。虽然目前真核微生物中MDH已被广泛研究,但是对原核生物中的这种酶却鲜有报道。因此,有必要对MDH的相关研究信息进行综述,以期更好地了解这种酶的功能。本文综述了细菌相关研究的各种数据信息,进一步挖掘MDH的分子多样性,包括分子量、低聚态、辅因子与底物的结合力,以及酶反应方向的差异等。通过对不同细菌来源的MDH的晶体结构的分析,可鉴别底物与辅因子结合的部位以及形成二聚体的重要残基。对这些结构信息的了解将有利于指导研究人员对酶的结构进行修饰从而提高其催化能力,比如增加酶的活性、辅助因子的结合能力、底物特异性和热稳定性等。另外,本文通过分析比较MDH 系统发生树的重建,将其蛋白超家族分成两个主分支,同时在古生菌、细菌和真核微生物等不同细胞的MDH之间建立联系。%Malate dehydrogenase (MDH) is an enzyme widely distributed among living organisms and is a key protein in the central oxidative pathway. It catalyzes the interconversion between malate and oxaloacetate using NAD+ or NADP+ as a cofactor. Surprisingly, this enzyme has been extensively studied in eukaryotes but there are few reports about this enzyme in prokaryotes. It is necessary to review the relevant information to gain a better understanding of the function of this enzyme. Our review of the data generated from studies in bacteria shows much diversity in their molecular properties, including weight, oligomeric states, cofactor and substrate binding affinities, as wel as differ-ences in the direction

  12. The efficacy of topical ivermectin versus malation 0.5% lotion for the treatment of scabies.

    Science.gov (United States)

    Goldust, Mohamad; Rezaee, Elham

    2013-05-06

    Objective: There are different medications for the treatment of scabies but the treatment of choice is still controversial. This study aimed at comparing the efficacy of topical ivermectin versus malation 0.5% lotion for the treatment of scabies. Methods: In total, 340 patients with scabies were enrolled, and randomized into two groups: the first group received 1% ivermectin applied topically to the affected skin and the second group received topical malation 0.5% lotion and were told to apply this twice with 1 week interval. Treatment was evaluated at intervals of 2 and 4 weeks, and if there was treatment failure at the 2-week follow-up, treatment was repeated. Results: Two application of topical ivermectin provided a cure rate of 67.6% at the 2-week follow-up, which increased to 85.2% at the 4-week follow-up after repeating the treatment. Treatment with two applications of malation 0.5% lotion was effective in 44.1% of patients at the 2-week follow-up, which increased to 67.6% at the 4-week follow-up after this treatment was repeated. Conclusion:Two application of ivermectin was as effective as single applications of malation 0.5% lotion at the 2-week follow-up. After repeating the treatment, ivermectin was superior to malation 0.5% lotion at the 4-week follow up.

  13. Day-night variations in malate concentration, osmotic pressure, and hydrostatic pressure in Cereus validus

    Energy Technology Data Exchange (ETDEWEB)

    Luettge, U.; Nobel, P.S.

    1984-07-01

    Malate concentration and stem osmotic pressure concomitantly increase during nighttime CO/sub 2/ fixation and then decrease during the daytime in the obligate Crassulacean acid metabolism (CAM) plant, Cereus validus (Cactaceae). Changes in malate osmotic pressure calculated using the Van't Hoff relation match the changes in stem osmotic pressure, indicating that changes in malate level affected the water relations of the succulent stems. In contrast to stem osmotic pressure, stem water potential showed little day-night changes, suggesting that changes in cellular hydrostatic pressure occurred. This was corroborated by direct measurements of hydrostatic pressure using the Juelich pressure probe where a small oil-filled micropipette is inserted directly into chlorenchyma cells, which indicated a 4-fold increase in hydrostatic pressure from dusk to dawn. A transient increase of hydrostatic pressure at the beginning of the dark period was correlated with a short period of stomatal closing between afternoon and nighttime CO/sub 2/ fixation, suggesting that the rather complex hydrostatic pressure patterns could be explained by an interplay between the effects of transpiration and malate levels. A second CAM plant, Agave deserti, showed similar day-night changes in hydrostatic pressure in its succulent leaves. It is concluded that, in addition to the inverted stomatal rhythm, the oscillations of malate markedly affect osmotic pressures and hence water relations of CAM plants. 13 references, 4 figures.

  14. Expression and identification of a thermostable malate dehydrogenase from multicellular prokaryote Streptomyces avermitilis MA-4680.

    Science.gov (United States)

    Wang, Zong-Da; Wang, Bao-Juan; Ge, Ya-Dong; Pan, Wei; Wang, Jie; Xu, Lei; Liu, Ai-Min; Zhu, Guo-Ping

    2011-03-01

    A malate dehydrogenase (MDH) from Streptomyces avermitilis MA-4680 (SaMDH) has been expressed and purified as a fusion protein. The molecular mass of SaMDH is about 35 kDa determined by SDS-PAGE. The recombinant SaMDH has a maximum activity at pH 8.0. The enzyme shows the optimal temperature around 42 °C and displays a half-life (t(1/2)) of 160 min at 50°C which is more thermostable than reported MDHs from most bacteria and fungi. The k(cat) value of SaMDH is about 240-fold of that for malate oxidation. In addition, the k(cat)/K(m) ratio shows that SaMDH has about 1,246-fold preference for oxaloacetate (OAA) reduction over L-malate oxidation. The recombinant SaMDH may also use NADPH as a cofactor although it is a highly NAD(H)-specific enzyme. There was no activity detected when malate and NADP(+) were used as substrates. Substrate inhibition studies show that SaMDH activity is strongly inhibited by excess OAA with NADH, but is not sensitive to excess L-malate. Enzymatic activity is enhanced by the addition of Na(+), NH(4)(+), Ca(2+), Cu(2+) and Mg(2+) and inhibited by addition of Hg(2+) and Zn(2+). MDH is widely used in coenzyme regeneration, antigen immunoassays and bioreactors. The enzymatic analysis could provide the important basic knowledge for its utilizations.

  15. Gain of interaction of ALS-linked G93A superoxide dismutase with cytosolic malate dehydrogenase.

    Science.gov (United States)

    Mali, Yael; Zisapels, Nava

    2008-10-01

    Protein interactions of the Amyotrophic Lateral Sclerosis (ALS)-linked copper-zinc superoxide dismutase (hSOD1) G93A mutation were studied using a fluorescence resonance energy transfer (FRET) based screening system. The FRET results confirmed by pull-down immunoprecipitation indicated "gain-of-interaction" of the G93A-hSOD1 mutant with cytosolic malate dehydrogenase (cytMDH)-a key enzyme in the malate-aspartate shuttle which is vital to neurons. Furthermore, cytMDH mRNA expression was upregulated in G93A-hSOD1 expressing cells but endogenous cytMDH enzymatic activity was not enhanced, not even with exogenously added-on enzyme. Consistent with inhibition of the malate-aspartate shuttle, G93A-hSOD1 had lower malate and higher lactate levels compared to non-induced or Wild-Type-hSOD1 expressing cells. Mitochondrial NADH/NAD+ ratio is also elevated. Malate-aspartate shuttle dysfunction may explain the damage to neurons and the vulnerability to impairments of glycolytic pathways in ALS and provide a new target for the development of potential therapies.

  16. [Isoformes of Malate Dehydrogenase from Rhodovulum Steppense A-20s Grown Chemotrophically under Aerobic Condtions].

    Science.gov (United States)

    Eprintsev, A T; Falaleeva, M I; Lyashchenko, M S; Gataullinaa, M O; Kompantseva, E I

    2016-01-01

    Three malate dehydrogenase isoforms (65-, 60-, and 71-fold purifications) with specific activities of 4.23, 3.88, and 4.56 U/mg protein were obtained in an electrophoretically homogenous state from Rhodovulum steppense bacteria strain A-20s chemotropically grown under aerobic conditions. The physicochemical and kinetic properties of malate dehydrogenase isoforms were determined. The molecular weight and the Michaelis constants were determined; the effect of hydrogen ions on the forward and reverse MDH reaction was studied. The results of the study demonstrated that the enzyme consists of subunits; the molecular weight of subunits was determined by SDS-PAGE.

  17. [Physicochemical, catalytic, and regulatory properties of malate dehydrogenase from Rhodovulum steppense bacteria, strain A-20s].

    Science.gov (United States)

    Eprintsev, A T; Falaleeva, M I; Parfenova, I V; Liashchenko, M S; Kompantseva, E I; Tret'iakova, A Iu

    2014-01-01

    The physicochemical, regulatory, and kinetic properties of malate dehydrogenase (EC 1.1.1.37) from haloalkaliphilic purple nonsulfur Rhodovulum steppense bacteria, strain A-20s, were studied. The malate dehydrogenase (MDH) preparation with a specific activity of 0.775 ± 0.113 U/mg protein was obtained in an electrophoretically homogeneous state using multistep purification. Using homogenous preparations, the molecular weight and the Michaelis constant of the enzyme were determined; the effects of metal ions, the temperature effect, and the thermal stability of the MDH were studied. The dimer structure of the enzyme was demonstrated by DS-Na-electrophoresis.

  18. Development and validation of HPTLC method for the estimation of almotriptan malate in tablet dosage form

    Directory of Open Access Journals (Sweden)

    Suneetha A

    2010-01-01

    Full Text Available A new, simple, precise and accurate high performance thin layer chromatographic method has been proposed for the determination of almotriptan malate in a tablet dosage form. The drug was separated on aluminum plates precoated with silica gel 60 GF 254 with butanol:acetic acid:water (3:1:1 was used as mobilephase. Quantitative analysis was performed by densitometric scanning at 300 nm. The method was validated for linearity, accuracy, precision and robustness. The calibration plot was linear over the range of 100-700 ng/band for almotriptan malate. The method was successfully applied to the analysis of drug in a pharmaceutical dosage form.

  19. Lack of malate valve capacities lead to improved N-assimilation and growth in transgenic A. thaliana plants.

    Science.gov (United States)

    Selinski, Jennifer; Scheibe, Renate

    2014-01-01

    In this study we analyzed the relationship between malate valve capacities, N-assimilation, and energy metabolism. We used transgenic plants either lacking the chloroplast NADP-dependent malate dehydrogenase or mutants with a decreased transcript level of the plastid-localized NAD-dependent malate dehydrogenase. Plants were grown on nitrate or ammonium, respectively, as the sole N-source and transcripts were analyzed by qRT-PCR. We could show that the lack of malate valve capacities enhances N-assimilation and plastidial glycolysis by increasing transcript levels of Fd-GOGATs or NADH-GOGAT and plastidic NAD-GAPDHs (GapCps), respectively. Based on our results, we conclude that the lack of malate valve capacities is balanced by an increase of the activity of plastid-localized glycolysis in order to cover the high demand for plastidial ATP, stressing the importance of the plastids for energy metabolism in plant cells.

  20. Leaf malate and succinate accumulation are out of phase throughout the development of the CAM plant Ananas comosus.

    Science.gov (United States)

    Rainha, N; Medeiros, V P; Ferreira, C; Raposo, A; Leite, J P; Cruz, C; Pacheco, C A; Ponte, D; Silva, A B

    2016-03-01

    In plants with Crassulacean Acid Metabolism (CAM), organic acids, mainly malate are crucial intermediates for carbon fixation. In this research we studied the circadian oscillations of three organic anions (malate, citrate, and succinate) in Ananas comosus, assessing the effect of season and plant development stage. Seasonal and plant development dependencies were observed. The circadian oscillations of malate and citrate were typical of CAM pathways reported in the literature. Citrate content was quite stable (25-30 μmol g(-1) FW) along the day, with a seasonal effect. Succinate was shown to have both diurnal and seasonal oscillations and also a correlation with malate, since it accumulated during the afternoon when malate content was normally at a minimum, suggesting a possible mechanistic effect between both anions in CAM and/or respiratory metabolisms.

  1. Phenotypes of gene disruptants in relation to a putative mitochondrial malate-citrate shuttle protein in citric acid-producing Aspergillus niger.

    Science.gov (United States)

    Kirimura, Kohtaro; Kobayashi, Keiichi; Ueda, Yuka; Hattori, Takasumi

    2016-09-01

    The mitochondrial citrate transport protein (CTP) functions as a malate-citrate shuttle catalyzing the exchange of citrate plus a proton for malate between mitochondria and cytosol across the inner mitochondrial membrane in higher eukaryotic organisms. In this study, for functional analysis, we cloned the gene encoding putative CTP (ctpA) of citric acid-producing Aspergillus niger WU-2223L. The gene ctpA encodes a polypeptide consisting 296 amino acids conserved active residues required for citrate transport function. Only in early-log phase, the ctpA disruptant DCTPA-1 showed growth delay, and the amount of citric acid produced by strain DCTPA-1 was smaller than that by parental strain WU-2223L. These results indicate that the CTPA affects growth and thereby citric acid metabolism of A. niger changes, especially in early-log phase, but not citric acid-producing period. This is the first report showing that disruption of ctpA causes changes of phenotypes in relation to citric acid production in A. niger.

  2. Long noncoding RNA MALAT1-regulated microRNA 506 modulates ovarian cancer growth by targeting iASPP

    Directory of Open Access Journals (Sweden)

    Lei R

    2016-12-01

    Full Text Available Ruilin Lei,1,2,* Min Xue,2,* Lan Zhang,1 ZhongQiu Lin1 1Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Department of Obstetrics and Gynecology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 2Department of Obstetrics and Gynecology, Third Xiangya Hospital, Central South University, Changsha, China *These authors contributed equally to this work Abstract: MALAT1, an important cancer-associated long noncoding RNA (lncRNA, contributes to the development and progression of several cancers. Disordered expression of MALAT1 has been observed in several cancers, including cervical cancer, breast cancer, and ovarian cancer. However, the exact effects and molecular mechanisms of MALAT1 in ovarian cancer progression are still unknown. Here, we investigated the role of MALAT1 in human ovarian cancer cell lines and clinical tumor samples, in order to determine the function of this molecule. In our research, lncRNA-MALAT1 was specifically upregulated in ovarian cancer cell lines and promoted ovarian cancer-cell growth through targeting microRNA (miR-506. Knockdown of MALAT1 inhibited the proliferation and DNA synthesis of human ovarian cancer cell in vitro. In addition, miR-506-dependent iASPP regulation was required in MALAT1-induced ovarian cancer-cell growth. These findings indicated that MALAT1 might suppress tumor growth via miR-506-dependent iASPP regulation. Taken together, our data indicated that MALAT1 might be an oncogenic lncRNA that promotes proliferation of ovarian cancer and could be regarded as a therapeutic target in human ovarian cancer. Keywords: lncRNA, MALAT1, miR-506, ovarian cancer, iASPP

  3. Respiratory properties and malate metabolism in Percoll-purified mitochondria isolated from pineapple, Ananas comosus (L.) Merr. cv. smooth cayenne.

    Science.gov (United States)

    Hong, Hoang Thi Kim; Nose, Akihiro; Agarie, Sakae

    2004-10-01

    An investigation was made of the respiratory properties and the role of the mitochondria isolated from one phosphoenolpyruvate carboxykinase (PCK)-CAM plant Ananas comosus (pineapple) in malate metabolism during CAM phase III. Pineapple mitochondria showed very high malate dehydrogenase (MDH), and low malic enzyme (ME) and glutamate-oxaloacetate transaminase (GOT) activities. The mitochondria readily oxidized succinate and NADH with high rates and coupling, while they only oxidized NADPH in the presence of Ca(2+). Pineapple mitochondria oxidized malate with low rates under most assay conditions, despite increasing malate concentrations, optimizing pH, providing cofactors such as coenzyme A, thiamine pyrophosphate, and NAD(+), and supplying individually external glutamate or GOT. However, providing glutamate and GOT simultaneously strongly increased the rates of malate oxidation. The OAA easily permeated the mitochondrial membranes to import into or export out of pineapple mitochondria during malate oxidation, but the mitochondria did not consume external Asp or alpha-KG. These results suggest that OAA played a significant role in the mitochondrial malate metabolism of pineapple, in which malate was mainly oxidized by active mMDH to produce OAA which could be exported outside the mitochondria via a malate-OAA shuttle. Cytosolic GOT then consumed OAA by transamination in the presence of glutamate, leading to a large increase in respiration rates. The malate-OAA shuttle might operate as a supporting system for decarboxylation in phase III of PCK-CAM pineapple. This shuttle system may be important in pineapple to provide a source of energy and substrate OAA for cytosolic PCK activity during the day when cytosolic OAA and ATP was limited for the overall decarboxylation process.

  4. L-malate enhances the gene expression of carried proteins and antioxidant enzymes in liver of aged rats.

    Science.gov (United States)

    Zeng, X; Wu, J; Wu, Q; Zhang, J

    2015-01-01

    Previous studies in our laboratory reported L-malate as a free radical scavenger in aged rats. To investigate the antioxidant mechanism of L-malate in the mitochondria, we analyzed the change in gene expression of two malate-aspartate shuttle (MAS)-related carried proteins (AGC, aspartate/glutamate carrier and OMC, oxoglutarate/malate carrier) in the inner mitochondrial membrane, and three antioxidant enzymes (CAT, SOD, and GSH-Px) in the mitochondria. The changes in gene expression of these proteins and enzymes were examined by real-time RT-PCR in the heart and liver of aged rats treated with L-malate. L-malate was orally administered in rats continuously for 30 days using a feeding atraumatic needle. We found that the gene expression of OMC and GSH-Px mRNA in the liver increased by 39 % and 38 %, respectively, in the 0.630 g/kg L-malate treatment group than that in the control group. The expression levels of SOD mRNA in the liver increased by 39 %, 56 %, and 78 % in the 0.105, 0.210, and 0.630 g/kg L-malate treatment groups, respectively. No difference were observed in the expression levels of AGC, OMC, CAT, SOD, and GSH-Px mRNAs in the heart of rats between the L-malate treatment and control groups. These results predicted that L-malate may increase the antioxidant capacity of mitochondria by enhancing the expression of mRNAs involved in the MAS and the antioxidant enzymes.

  5. Crystallization and preliminary X-ray diffraction of malate dehydrogenase from Plasmodium falciparum

    NARCIS (Netherlands)

    Wrenger, Carsten; Mueller, Ingrid B.; Butzloff, Sabine; Jordanova, Rositsa; Lunev, Sergey; Groves, Matthew R.

    2012-01-01

    The expression, purification, crystallization and preliminary X-ray diffraction characterization of malate dehydrogenase (MDH) from the malarial parasite Plasmodium falciparum (PfMDH) are reported. In order to gain a deeper understanding of the function and role of PfMDH, the protein was purified to

  6. Escherichia coli D-malate dehydrogenase, a generalist enzyme active in the leucine biosynthesis pathway.

    Science.gov (United States)

    Vorobieva, Anastassia A; Khan, Mohammad Shahneawz; Soumillion, Patrice

    2014-10-17

    The enzymes of the β-decarboxylating dehydrogenase superfamily catalyze the oxidative decarboxylation of D-malate-based substrates with various specificities. Here, we show that, in addition to its natural function affording bacterial growth on D-malate as a carbon source, the D-malate dehydrogenase of Escherichia coli (EcDmlA) naturally expressed from its chromosomal gene is capable of complementing leucine auxotrophy in a leuB(-) strain lacking the paralogous isopropylmalate dehydrogenase enzyme. To our knowledge, this is the first example of an enzyme that contributes with a physiologically relevant level of activity to two distinct pathways of the core metabolism while expressed from its chromosomal locus. EcDmlA features relatively high catalytic activity on at least three different substrates (L(+)-tartrate, D-malate, and 3-isopropylmalate). Because of these properties both in vivo and in vitro, EcDmlA may be defined as a generalist enzyme. Phylogenetic analysis highlights an ancient origin of DmlA, indicating that the enzyme has maintained its generalist character throughout evolution. We discuss the implication of these findings for protein evolution.

  7. The intracellular localization of malate dehydrogenase isoenzymes in Pisum arvense roots

    Directory of Open Access Journals (Sweden)

    Genowefa Kubik-Dorosz

    2014-02-01

    Full Text Available Mitochondria and plastids were isolated from Pisum arvense root cells by sucrose density gradient centrifugation. The individual subcellular fractions so obtained were subjected to isoelectric focusing on cellulose acetate strips. Mitochondria and plastids each contained one NAD -malate dehydrogenase, while three isoenzymes were associated with the supernatant.

  8. Homochiral Cu(II) and Ni(II) malates with tunable structural features

    Science.gov (United States)

    Zavakhina, Marina S.; Samsonenko, Denis G.; Virovets, Alexander V.; Dybtsev, Danil N.; Fedin, Vladimir P.

    2014-02-01

    Four new homochiral metal-organic frameworks (MOFs) based on S-malate anions and N-donor linkers of different length have been prepared under solvothermal conditions. [Cu(mal)(bpy)]·H2O (1), [Cu(mal)(bpe)]·2H2O (2), [Ni(mal)(bpy)]·1.3CH3OH (3) and [Ni(mal)(bpe)]·4H2O (4) (mal=S-malate, bpy=4,4‧-bipyridil, bpe=trans-1,2-bis(4-pyridyl)ethylene) were characterized by a number of analytical methods including powder X-ray diffraction, elemental, thermogravimetric analyses, IR spectroscopy. Compounds 1-3 were structurally characterized by X-ray crystallography. The absence of the chiral ligand racemization under synthetic conditions was unambiguously confirmed by polarimetry experiments. Compounds 1 and 2 contain metal-malate layered motives, connected by N-donor linkers and contribute to the family of isoreticular Cu(II) malates and tartrates [Cu(mal)L] and [Cu(tart)L], (tart=tartrate; L=ditopic rigid organic ligand). The Ni-based compounds 3 and 4 share 1D chiral {Ni(mal)} motives and possess novel type of the chiral framework, previously unknown for chiral carboxylates. The linear N-donor linkers connect these chiral chains, thus controlling the channel diameter and guest accessible volume of the homochiral structure, which exceeds 60 %.

  9. Occurrence of the malate-aspartate shuttle in various tumor types.

    Science.gov (United States)

    Greenhouse, W V; Lehninger, A L

    1976-04-01

    The activity of the malate-aspartate shuttle for the reoxidation of cytoplasmic reduced nicotinamide adenine dinucleotide (NADH) by mitochondria was assessed in six lines of rodent ascites tumor cells (two strains of Ehrlich ascites carcinoma, Krebs II carcinoma, Novikoff hepatoma, AS-30D hepatoma, and L1210 mouse leukemia). All the tumor cells examined showed mitochondrial reoxidation of cytoplasmic NADH, as evidenced by the accumulation of pyruvate when the cells were incubated aerobically with L-lactate. Reoxidation of cytoplasmic NADH thus generated was completely inhibited by the transaminase inhibitor aminooxyacetate. The involvement of the respiratory chain in the reoxidation of cytoplasmic NADH was demonstrated by the action of cyanide, rotenone, and antimycin A, which strongly inhibited the formation of pyruvate from added L-lactate. Compounds that inhibit the carrier-mediated entry of malate into mitochondria, such as butylmalonate, benzenetricarboxylate, and iodobenzylmalonate, also inhibited the accumulation of pyruvate from added L-lactate by the tumor cells. The maximal rate of the malate-aspartate shuttle was established by addtion of arsenite to inhibit the mitochondrial oxidation of the pyruvate formed from added lactate. The capacity of the various tumor lines for the reoxidation of cytoplasmic NADH via the malate-aspartate shuttle approaches 20% of the total respiratory rate of the cells and thus appears to be sufficient to account for the mitochondrial reoxidation of that fraction of glycolytic NADH not reoxidized by pyruvate and lactate dehydrognenase in the cytoplasm.

  10. Watermelon glyoxysomal malate dehydrogenase is sorted to peroxisomes of the methylotrophic yeast, Hansenula polymorpha

    NARCIS (Netherlands)

    Klei, I.J. van der; Faber, K.N.; Keizer-Gunnink, I.; Gietl, C.; Harder, W.; Veenhuis, M.

    1993-01-01

    We have studied the fate of the watermelon (Citrullus vulgaris Schrad.) glyoxysomal enzyme, malate dehydrogenase (gMDH), after synthesis in the methylotrophic yeast, Hansenula polymorpha. The gene encoding the precursor form of gMDH (pre-gMDH) was cloned in an H. polymorpha expression vector downstr

  11. Purification, properties, and kinetic studies of cytoplasmic malate dehydrogenase from Taenia solium cysticerci.

    Science.gov (United States)

    Plancarte, Agustín; Nava, Gabriela; Mendoza-Hernández, Guillermo

    2009-07-01

    Malate dehydrogenase (L: -malate: NAD oxidoreductase, EC 1.1.1.37) from the cytoplasm of Taenia solium cysticerci (cMDHTs) was purified 48-fold through a four-step procedure involving salt fractionation, ionic exchange, and dye affinity chromatography. cMDHTs had a native M (r) of 64,000, while the corresponding value per subunit, obtained under denaturing conditions, was 32,000. The enzyme is partially positive, with an isoelectric point of 8.7, and had a specific activity of 2,615 U mg(-1) in the reduction of oxaloacetate. The second to the 21st amino acids from cMDHTs N-terminal group were P G P L R V L I T G A A G Q I A Y N L S. This sequence is 100% identical to that of Echinococcus granulosus. Basic kinetic parameters were determined for this enzyme. The optimum pH for enzyme reaction was at 7.6 for oxaloacetate reduction and at 9.6 for malate oxidation. K (m) values for oxaloacetate, malate, NAD, and NADH were 2.4, 215, 50, and 48 microM, respectively. V (max) values for the substrates and cosubstrates as described above were 1,490, 87.8, 104, and 1,714 micromol min(-1) mg(-1). Several NAD analogs, structurally altered in either the pyridine or purine moiety, were observed to function as coenzymes in the reaction catalyzed by the purified malate dehydrogenase. cMDHTs activity was uncompetitive inhibited by arsenate for both the forward (Ki = 8.2 mM) and reverse (Ki = 77 mM) reactions. The mechanism of the cMDHTs reactivity was investigated kinetically by the product inhibition approach. The results of this study are qualitatively consistent with an Ordered Bi Bi reaction mechanism, in which only the coenzymes can react with the free enzyme.

  12. Expression of novel cytosolic malate dehydrogenases (cMDH) in Lupinus angustifolius nodules during phosphorus starvation.

    Science.gov (United States)

    Le Roux, Marcellous; Phiri, Ethel; Khan, Wesaal; Sakiroğlu, Muhammet; Valentine, Alex; Khan, Sehaam

    2014-11-01

    During P deficiency, the increased activity of malate dehydrogenase (MDH, EC 1.1.1.37) can lead to malate accumulation. Cytosolic- and nodule-enhanced MDH (cMDH and neMDH, respectively) are known isoforms, which contribute to MDH activity in root nodules. The aim of this study was to investigate the role of the cMDH isoforms in nodule malate supply under P deficiency. Nodulated lupins (Lupinus angustifolius var. Tanjil) were hydroponically grown at adequate P (+P) or low P (-P). Total P concentration in nodules decreased under P deficiency, which coincided with an increase in total MDH activity. A consequence of higher MDH activity was the enhanced accumulation of malate derived from dark CO2 fixation via PEPC and not from pyruvate. Although no measurable neMDH presence could be detected via PCR, gene-specific primers detected two 1kb amplicons of cMDH, designated LangMDH1 (corresponding to +P, HQ690186) and LangMDH2 (corresponding to -P, HQ690187), respectively. Sequencing analyses of these cMDH amplicons showed them to be 96% identical on an amino acid level. There was a high degree of diversification between proteins detected in this study and other known MDH proteins, particularly those from other leguminous plants. Enhanced malate synthesis in P-deficient nodules was achieved via increased anaplerotic CO2 fixation and subsequent higher MDH activities. Novel isoforms of cytosolic MDH may be involved, as shown by gene expression of specific genes under P deficiency.

  13. Protective Effects of L-Malate against Myocardial Ischemia/Reperfusion Injury in Rats

    Directory of Open Access Journals (Sweden)

    Shiao Ding

    2016-01-01

    Full Text Available Objective. To investigate the protective effects of L-malate against myocardial ischemia/reperfusion (I/R injury in rats. Methods. Male Sprague-Dawley rats were randomly assigned to the following groups: sham (sham, an ischemia/reperfusion (I/R model group (model, an DMF pretreated group (DMF, and 5 L-malate pretreated groups (15, 60, 120, 240, or 480 mg/kg, gavage before inducing myocardial ischemia. Plasma LDH, cTn-I, TNF-α, hs-CRP, SOD, and GSH-PX were measured 3 h later I/R. Areas of myocardial infarction were measured; hemodynamic parameters during I/R were recorded. Hearts were harvested and Western blot was used to quantify Nrf2, Keap1, HO-1, and NQO-1 expression in the myocardium. Results. L-malate significantly reduced LDH and cTn-I release, reduced myocardial infarct size, inhibited expression of inflammatory cytokines, and partially preserved heart function, as well as increasing antioxidant activity after myocardial I/R injury. Western blot confirmed that L-malate reduced Kelch-like ECH-associated protein 1 in ischemic myocardial tissue, upregulated expression of Nrf2 and Nrf2 nuclear translocation, and increased expression of heme oxygenase-1 and NAD(PH:quinone oxidoreductase 1, which are major targets of Nrf2. Conclusions. L-malate may protect against myocardial I/R injury in rats and this may be associated with activation of the Nrf2/Keap1 antioxidant pathway.

  14. Clinical Significance of Long Non-coding RNA MALAT1 Expression in Tissue and Serum of Breast Cancer.

    Science.gov (United States)

    Miao, Yufeng; Fan, Rengen; Chen, Lige; Qian, Haixin

    2016-07-01

    Long non-coding RNAs (lncRNAs) have been proven to serve a critical role in cancer development and progression. The aim of this study was to elucidate clinical significance of lncRNA MALAT1 expression in breast cancer (BC). A total of 78 BC patients treated with radical resection were enrolled in this study. Quantitative reverse transcription-polymerase chain reaction was used to detect MALAT1 expression in tissues and serum samples. The receiver operating characteristics (ROC) curve was constructed to describe diagnostic specificity and sensitivity. Lentivirus-mediated RNA interference was used to knockdown MALAT1 in the MDA-MB-231 cell line, and then cell proliferation and invasion were explored. Results showed that MALAT1 expression was significantly up-regulated in 85.9% (67/78) of cancerous tissues compared with normal counterparts (P<0.01). Further, an elevated MALAT1 expression in BC tissue was significantly associated with lymph metastasis (P=0.037) and adverse 5-year disease-free survival (mean 48.5 months vs 62.7 months, P=0.012). Suppression of lncRNA MALAT1 significantly inhibited BC cells proliferation, migration and invasion, induced apoptosis and cell cycle G1 arrest. In addition, serum MALAT1 levels in BC patients were much higher than levels in patients with benign breast disease (P<0.001), its diagnostic efficacy was satisfactory, area under the curve (AUC) was 0.833. In conclusion, MALAT1 upregulation plays an important rolein BC development, and serum MALAT1 level may be a potential tumor marker for BC diagnosis.

  15. Metabolomics-driven approach for the improvement of Chinese hamster ovary cell growth: overexpression of malate dehydrogenase II.

    Science.gov (United States)

    Chong, William P K; Reddy, Satty G; Yusufi, Faraaz N K; Lee, Dong-Yup; Wong, Niki S C; Heng, Chew Kiat; Yap, Miranda G S; Ho, Ying Swan

    2010-05-17

    We have established a liquid chromatography-mass spectrometry based metabolomics platform to identify extracellular metabolites in the medium of recombinant Chinese hamster ovary (CHO) fed-batch reactor cultures. Amongst the extracellular metabolites identified, malate accumulation was the most significant. The contributing factors to malate efflux were found to be the supply of aspartate from the medium, and an enzymatic bottleneck at malate dehydrogenase II (MDH II) in the tricarboxylic acid cycle. Subsequent metabolic engineering to overexpress MDH II in CHO resulted in increases in intracellular ATP and NADH, and up to 1.9-fold improvement in integral viable cell number.

  16. Prediction of MALAT1 Mediated Regulatory Network by Bioinformatics Analysis%生物信息学分析及预测长链非编码RNA MALAT1的分子调控网络

    Institute of Scientific and Technical Information of China (English)

    韩泽平; 何金花; 黎毓光; 杨晓燕; 李秋娴; 朱剑霞

    2013-01-01

    目的 运用在线数据库对长链非编码RNA MALAT1(metastasis-associated lung adenocarcinoma transcript 1,MALAT1)进行生物信息学分析,并进一步推测其分子调控网络.方法 运用多个在线数据库,预测并筛选MALAT1的上游转录因子、下游miRNA 及其靶基因,筛选出均与其相关的疾病,进一步研究在该疾病中MALAT1的核心调控网络.结果 通过预测及筛选,以乳腺癌为研究对象,MALAT1受上游转录因子snail、sox-5、FOXQ1和RUNX1的调控,同时又可调控下游hsa-miR-320a的表达;而hsa-miR-320a的预测靶基因为CCR7、PTEN和FADD,它们又可与MALAT1的转录因子相互作用,形成了一个调控环路.结论 对MALAT1分子调控网络生物信息学的分析可有助于理解其在乳腺癌发生与发展中的作用机制并为后续实验提供良好的指导依据.%Objective To analyze the bioinformatics of the long noncoding RNA MALAT1 ( metastasis-associated lung adenocarcinoma transcript 1 , MALAT1) through online database , and to predict the molecular control network of MALAT1. Methods Several online databases were used to predict and screen the upstream transcription factors , the downstream miRNAs , the target genes and the related diseases of MALAT1. The role of MALAT1-mediated regulatory network was further examined in the diseases. Results After prediction and screening , with the breast cancer as the object of study, it was found that MALAT1 was regulated by the upstream transcription factors snail , sox-5, FOXQ1 and RUNX1, and meanwhile, it could regulate the expression of its downstream miRNA has-miR-320a. The target genes of hsa-miR-320a were speculated to be CCR7, PTEN and FADD, which could interact with the transcription factors of MALAT 1 and form a control loop of MALAT1. Conclusion Analyzing the MALAT1 molecular regulation network by bioinformatics method helps understand the mechanism of occurrence and development of breast cancer , and provide valuable guideline

  17. Common catabolic enzyme patterns in a microplankton community of the Humboldt Current System off northern and central-south Chile: Malate dehydrogenase activity as an index of water-column metabolism in an oxygen minimum zone

    Science.gov (United States)

    González, R. R.; Quiñones, R. A.

    2009-07-01

    An extensive subsurface oxygen minimum zone off northern and central-south Chile, associated with the Peru-Chile undercurrent, has important effects on the metabolism of the organisms inhabiting therein. Planktonic species deal with the hypoxic and anoxic environments by relying on biochemical as well as physiological processes related to their anaerobic metabolisms. Here we characterize, for the first time, the potential enzymatic activities involved in the aerobic and anaerobic energy production pathways of microplanktonic organisms (catabolic pathways in the oxygen minimum zone. Malate dehydrogenase had the highest oxidizing activity of nicotinamide adenine dinucleotide (reduced form) in the batch of catabolic enzymatic activities assayed, including potential pyruvate oxidoreductases activity, the electron transport system, and dissimilatory nitrate reductase. Malate dehydrogenase correlated significantly with almost all the enzymes analyzed within and above the oxygen minimum zone, and also with the oxygen concentration and microplankton biomass in the water column of the Humboldt Current System, especially in the oxygen minimum zone off Iquique. These results suggest a possible specific pattern for the catabolic activity of the microplanktonic realm associated with the oxygen minimum zone spread along the Humboldt Current System off Chile. We hypothesize that malate dehydrogenase activity could be an appropriate indicator of microplankton catabolism in the oxygen minimum zone and adjacent areas.

  18. Effect of abscisic and gibberellic acids on malate synthase transcripts in germinating castor bean seeds.

    Science.gov (United States)

    Rodriguez, D; Dommes, J; Northcote, D H

    1987-05-01

    Several clones complementary to malate synthase mRNA have been identified in a complementary-DNA library to mRNA from castor bean endosperm. One of these clones has been used as a probe to measure levels of transcripts during seed germination and the effects of gibberellic acid and abscisic acid on these levels have been examined.Malate synthase transcripts increased during germination and GA3 advanced their appearance in the endosperm. Exogenously applied ABA inhibited the accumulation of transcripts over a time course of germination but the addition of GA3 counteracted its inhibitory effects. The data confirmed previous reports which indicated that the action of both growth regulators was on transcript accumulation and that there is a coordinated induction of the enzymes involved in the lipid metabolism in oil seeds.

  19. [Mechanism of malate dehydrogenase isoform formation in Sphaerotilus natans D-507 under different cultivation conditions].

    Science.gov (United States)

    Eprintsev, A T; Falaleeva, M I; Arabtseva, M A; Lavrinenko, I A; Parfenova, I V; Grechkina, M V; Abud, F S

    2011-01-01

    Electrophoretically homogenous preparations of malate dehydrogenase (MDH) isoforms of the bacteria Sphaerotilus natans D-507 with specific activity 7.46 U/mg and 5.74 U/mg with respect to protein concentration have been obtained. The dimeric isoform of the enzyme was shown to function under organotrophic growth conditions, whereas the tetrameric isoform was induced under mixotrophic cultivation conditions. PCR-analysis revealed a single gene encoding the malate dehydrogenase molecule. The topography of the MDH isoform surface was studied by atomic-force microscopy, and a 3D-structure of the enzyme was obtained. Spectraphotometric analysis data allowed us to suggest that stabilization of the tetrameric form of MDH is due to additional bounds implicated in the quaternary structure formation.

  20. Long non-coding RNA MALAT1 promotes gastric cancer tumorigenicity and metastasis by regulating vasculogenic mimicry and angiogenesis.

    Science.gov (United States)

    Li, Yue; Wu, Zhenzhen; Yuan, Jia; Sun, Li; Lin, Li; Huang, Na; Bin, Jianping; Liao, Yulin; Liao, Wangjun

    2017-06-01

    MALAT1 is an oncogenic long non-coding RNA that has been found to promote the proliferation of many malignant cell types and non-malignant human umbilical vein endothelial cells (HUVECs). However, the functions of MALAT1 in vasculogenic mimicry (VM) and angiogenesis and the potential mechanisms responsible have not yet been investigated in any malignancy. Here, in situ hybridization and CD31/periodic acid-Schiff double staining of 150 gastric cancer (GC) clinical specimens revealed that MALAT1 expression was tightly associated with densities of VM and endothelial vessels. MALAT1 knockdown markedly reduced GC cell migration, invasion, tumorigenicity, metastasis, and VM, while restricting HUVEC angiogenesis and increasing vascular permeability. Moreover, MALAT1 was found to regulate expression of VE-cadherin, β-catenin, MMPs 2 and 9, MT1-MMP, p-ERK, p-FAK, and p-paxillin, which have been established as classical markers of VM and angiogenesis and components of associated signaling pathways. Consistent with this, the p-ERK inhibitors U0126 and PD98059 both effectively blocked GC cell VM. In conclusion, MALAT1 can promote tumorigenicity and metastasis in GC by facilitating VM and angiogenesis via the VE-cadherin/β-catenin complex and ERK/MMP and FAK/paxillin signaling pathways.

  1. Arsenic mobilization by citrate and malate from a red mud-treated contaminated soil.

    Science.gov (United States)

    Castaldi, Paola; Silvetti, Margherita; Mele, Elena; Garau, Giovanni; Deiana, Salvatore

    2013-01-01

    The mobility and bioavailability of As in the soil-plant system can be affected by a number of organic acids that originate from the activity of plants and microorganisms. In this study we evaluated the ability of citrate and malate anions to mobilize As in a polluted subacidic soil (UP soil) treated with red mud (RM soil). Both anions promoted the mobilization of As from UP and RM soils, with citrate being more effective than malate. The RM treatment induced a greater mobility of As. The amounts of As released in RM and UP soils treated with 3.0 mmol L citric acid solution were 2.78 and 1.83 μmol g respectively, whereas an amount equal to 1.73 and 1.06 μmol g was found after the treatment with a 3.0 mmol L malic acid solution. The release of As in both soils increased with increasing concentration of organic acids, and the co-release of Al and Fe in solution also increased. The sequential extraction showed that Fe/Al (oxi)hydroxides in RM were the main phases involved in As binding in RM soil. Two possible mechanisms could be responsible for As solubilization: (i) competition of the organic anions for As adsorption sites and (ii) partial dissolution of the adsorbents (e.g., dissolution of iron and aluminum oxi-hydroxides) induced by citrate or malate and formation of complexes between dissolved Fe and Al and organic anions. This is the first report on the effect of malate and citrate on the As mobility in a polluted soil treated with RM.

  2. Synergistic Effect between Cisplatin and Sunitinib Malate on Human Urinary Bladder-Cancer Cell Lines

    Directory of Open Access Journals (Sweden)

    Regina Arantes-Rodrigues

    2013-01-01

    Full Text Available The aim of this paper is to analyse sunitinib malate in vitro ability to enhance cisplatin cytotoxicity in T24, 5637, and HT1376 human urinary bladder-cancer cell lines. Cells were treated with cisplatin (3, 6, 13, and 18 μM and sunitinib malate (1, 2, 4, 6, and 20 μM, either in isolation or combined, over the course of 72 hours. 3-(4,5-Dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide assay, acridine orange, and monodansylcadaverine staining and flow cytometry were performed. The combination index (CI was calculated based on the Chou and Talalay method. In isolation, cisplatin and sunitinib malate statistically (. Autophagy and apoptosis studies showed a greater incidence when the combined treatment was put into use. This hints at the possibility of a new combined therapeutic approach. If confirmed in vivo, this conjugation may provide a means of new perspectives in muscle-invasive urinary bladder cancer treatment.

  3. L-citrulline-malate influence over branched chain amino acid utilization during exercise.

    Science.gov (United States)

    Sureda, Antoni; Córdova, Alfredo; Ferrer, Miguel D; Pérez, Gerardo; Tur, Josep A; Pons, Antoni

    2010-09-01

    Exhaustive exercise induces disturbances in metabolic homeostasis which can result in amino acid catabolism and limited L-arginine availability. Oral L-citrulline supplementation raises plasma L-arginine concentration and augments NO-dependent signalling. Our aim was to evaluate the effects of diet supplementation with L-citrulline-malate prior to intense exercise on the metabolic handle of plasma amino acids and on the products of metabolism of arginine as creatinine, urea and nitrite and the possible effects on the hormonal levels. Seventeen voluntary male pre-professional cyclists were randomly assigned to one of two groups: control or supplemented (6 g L-citrulline-malate 2 h prior exercise) and participated in a 137-km cycling stage. Blood samples were taken in basal conditions, 15 min after the race and 3 h post race (recovery). Most essential amino acids significantly decreased their plasma concentration as a result of exercise; however, most non-essential amino acids tended to significantly increase their concentration. Citrulline-malate ingestion significantly increased the plasma concentration of citrulline, arginine, ornithine, urea, creatinine and nitrite (p urea.

  4. Gene clone,expression and enzyme activity assay of a cytosolic malate dehydrogenase from apple fruits

    Institute of Scientific and Technical Information of China (English)

    Yuxin YAO; Yujin HAO; Ming LI; Mingli PANG; Zhi LIU; Heng ZHAI

    2008-01-01

    Malate dehydrogenase (MDH) ubiquitously exists in animals,plants and microoganisms,and catalyzes the interconversion from oxaloacetate to malate.Cytosolic NAD-dependent MDH gene (cyMDH)encodes a key enzyme crucial for malic acid synthesis in the cytosol which has not been extensively characterized in plants.In this study,a full-length cDNA of cyMDH was isolated from apple fruits with RT-PCR as well as 3' and 5' rapid amplification of cDNA ends,and designated as Mal-cyMDH (GenBank accession No.DQ221207).It contained a 996-bp ORF and its sequence analysis shows a high similarity to other plant cyMDHs.Phylogenetic analysis indicated that almost all the cyMDHs could be clustered into the same group and it was likely to represent the original MDH.A roughly 37-kDa fused protein was obtained by the recombinant prokaryotic expression and its enzyme activity assay showed that it mainly catalyzed oxaloacetate to malate.It was also discovered that the enzyme activity of cyMDH exhibited remarkable difference between the high- and low-acid apple germplasm.

  5. Another unusual type of citric acid cycle enzyme in Helicobacter pylori: the malate:quinone oxidoreductase.

    Science.gov (United States)

    Kather, B; Stingl, K; van der Rest, M E; Altendorf, K; Molenaar, D

    2000-06-01

    The only enzyme of the citric acid cycle for which no open reading frame (ORF) was found in the Helicobacter pylori genome is the NAD-dependent malate dehydrogenase. Here, it is shown that in this organism the oxidation of malate to oxaloacetate is catalyzed by a malate:quinone oxidoreductase (MQO). This flavin adenine dinucleotide-dependent membrane-associated enzyme donates electrons to quinones of the electron transfer chain. Similar to succinate dehydrogenase, it is part of both the electron transfer chain and the citric acid cycle. MQO activity was demonstrated in isolated membranes of H. pylori. The enzyme is encoded by the ORF HP0086, which is shown by the fact that expression of the HP0086 sequence from a plasmid induces high MQO activity in mqo deletion mutants of Escherichia coli or Corynebacterium glutamicum. Furthermore, this plasmid was able to complement the phenotype of the C. glutamicum mqo deletion mutant. Interestingly, the protein predicted to be encoded by this ORF is only distantly related to known or postulated MQO sequences from other bacteria. The presence of an MQO shown here and the previously demonstrated presence of a 2-ketoglutarate:ferredoxin oxidoreductase and a succinyl-coenzyme A (CoA):acetoacetyl-CoA transferase indicate that H. pylori possesses a complete citric acid cycle, but one which deviates from the standard textbook example in three steps.

  6. Characterization of the immunogenicity and pathogenicity of malate dehydrogenase in Brucella abortus.

    Science.gov (United States)

    Han, Xiangan; Tong, Yongliang; Tian, Mingxing; Sun, Xiaoqing; Wang, Shaohui; Ding, Chan; Yu, Shengqing

    2014-07-01

    Brucella abortus is a gram-negative, facultative intracellular pathogen that causes brucellosis, a chronic zoonotic disease resulting in abortion in pregnant cattle and undulant fever in humans. Malate dehydrogenase (MDH), a key enzyme in the tricarboxylic acid cycle, plays important metabolic roles in aerobic energy producing pathways and in malate shuttle. In this study, the MDH-encoding gene for malate dehydrogenase mdh of B. abortus S2308 was cloned, sequenced and expressed. Western blot analysis demonstrated that MDH is an immunogenic membrane-associated protein. In addition, recombinant MDH showed sero-reactivity with 30 individual bovine B. abortus-positive sera by enzyme-linked immunosorbent assay, indicates that MDH may be used as a candidate marker for sero-diagnosis of brucellosis. Furthermore, MDH exhibits fibronectin and plasminogen-binding ability in immunoblotting assay. Inhibition assays on HeLa cells demonstrated that rabbit anti-serum against MDH significantly reduced both bacterial adherence and invasion abilities (p < 0.05), suggesting that MDH play a role in B. abortus colonization. Our results indicated that MDH is not only an immunogenic protein, but is also related to bacterial pathogenesis and may act as a new virulent factor, which will benefit for further understanding the MDH's roles in B. abortus metabolism, pathogenesis and immunity.

  7. Duplication of Locus Coding of Malate Dehydrogenase in Populus tomentosa Carr.

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Horizontal starch-gel electrophoresis was used to study crude enzyme extraction from young leaves of 234 clones of Populus tomentosa Carr. selected from nine provenances in North China. Ten enzyme systems were resolved. One hundred and fifty-six clones showing unusual allozyme band patterns at locus Mdh-1 were found. Three allozyme bands at locus Mdh-1 were 9:6:1 in concentration. Further studies on the electrophoretic patterns of ground mixed pollen extraction of 30 male clones selected at random from the 156 clones were conducted and it was found that allozyme bands at locus Mdh-1 were composed of two dark-stained bands and a weak band. Only one group of the malate dehydrogenase (MDH) zymogram composed of two bands was obtained from the electrophoretic segregation of pollen leachate of the same clones. A comparison of the electrophoretic patterns one another suggested that the locus Mdh-1 coding malate dehydrogenase in diploid species of P. tomentosa was duplicated. The duplicate gene locus possessed three same alleles and was located in mitochondria. The locus duplication of alleles coding malate dehydrogenase in P. tomentosa was discovered and reported for the first time.

  8. Pcal_1699, an extremely thermostable malate dehydrogenase from hyperthermophilic archaeon Pyrobaculum calidifontis.

    Science.gov (United States)

    Gharib, Ghazaleh; Rashid, Naeem; Bashir, Qamar; Gardner, Qura-Tul Ann Afza; Akhtar, Muhammad; Imanaka, Tadayuki

    2016-01-01

    Two malate dehydrogenase homologs, Pcal_0564 and Pcal_1699, have been found in the genome of Pyrobaculum calidifontis. The gene encoding Pcal_1699 consisted of 927 nucleotides corresponding to a polypeptide of 309 amino acids. To examine the properties of Pcal_1699, the structural gene was cloned, expressed in Escherichia coli and the purified gene product was characterized. Pcal_1699 was NADH specific enzyme exhibiting a high malate dehydrogenase activity (886 U/mg) at optimal pH (10) and temperature (90 °C). Unfolding studies suggested that urea could not induce complete unfolding and inactivation of Pcal_1699 even at a final concentration of 8 M; however, in the presence of 4 M guanidine hydrochloride enzyme structure was unfolded with complete loss of enzyme activity. Thermostability experiments revealed that Pcal_1699 is the most thermostable malate dehydrogenase, reported to date, retaining more than 90 % residual activity even after heating for 6 h in boiling water.

  9. Characterisation of the two malate dehydrogenases from Phytomonas sp. Purification of the glycosomal isoenzyme.

    Science.gov (United States)

    Uttaro, A D; Opperdoes, F R

    1997-10-01

    Two NAD(H)-dependent malate dehydrogenase (MDH) isoenzymes were detected in Phytomonas isolated from the lactiferous tubes of Euphorbia characias. The total specific activity in crude extracts using oxaloacetate as substrate was 3.3 U mg-1 of protein. The two isoenzymes had isoelectric points of 6.0 and 7.2, respectively. The acidic isoform represented 80% of the total activity in the cell and was present in the glycosome. It was purified to homogeneity by a method involving hydrophobic interaction chromatography on Phenyl-Sepharose followed by ionic exchange on CM-Sepharose and affinity chromatography on Blue-Sepharose. The purified glycosomal MDH is a homodimeric protein with a subunit molecular mass of 37 kDa and it has a low substrate specificity, since it was able to reduce both aromatic and aliphatic alpha-ketoacids as substrate including oxaloacetate, phenyl pyruvate, alpha-keto iso-caproate and pyruvate. The apparent K(m)s for oxaloacetate and NADH were 166 and 270 microM, respectively and for L-malate and NAD+, 3000 and 246 microM, respectively. The basic isoform was present in the mitochondrion. It has a high substrate specificity and an apparent K(m) of 132 and 63 microM for oxaloacetate and NADH, respectively, and of 450 and 91 microM, respectively, with L-malate and NAD+.

  10. Maize ZmALMT2 is a root anion transporter that mediates constitutive root malate efflux

    Science.gov (United States)

    Aluminum (Al) toxicity is a primary limitation to crop productivity on acid soils throughout the plant. Root efflux of organic acid anions constitutes a mechanism by which plants cope with toxic aluminum (Al) ions on acid soils. In this study, we have characterized ZmALMT2 (a member of aluminum-acti...

  11. Final report on the safety assessment of Malic Acid and Sodium Malate.

    Science.gov (United States)

    Fiume, Z

    2001-01-01

    Malic Acid functions in cosmetic formulations as a pH adjuster, and Sodium Malate functions as a skin conditioning agent-humectant. Malic Acid is reportedly used in almost 50 cosmetic formulations across a range of product types at low concentrations, whereas Sodium Malate is used in only one. As a pH adjuster, Malic Acid is used at low concentrations. One commercial method of preparing Malic Acid is hydration of fumaric acid or maleic acid, and then purified to limit the amount of the starting material present. Because Malic Acid is a component of the Kreb's cycle, another method is fermentation. Malic Acid was relatively nontoxic in acute toxicity studies using animals. In a chronic oral study, feeding Malic Acid to rats resulted only in weight gain changes and changes in feed consumption. Malic Acid did not cause reproductive toxicity in mice, rats, or rabbits. Malic Acid was a moderate to strong skin irritatant in animal tests, and was a strong ocular irritant. Malic Acid was not mutagenic across a range of genotoxicity tests. Malic Acid was irritating in clinical tests, with less irritation seen as pH of the applied material increased. Patients patch tested with Malic Acid, placed on a diet that avoided foods containing Malic or citric acid, and then challenged with a diet high in Malic and citric acid had both immediate urticarial and delayed contact dermatitis reactions. These data were considered sufficient to determine that Malic Acid and Sodium Malate would be safe at the low concentrations at which these ingredients would be used to adjust pH (even though Sodium Malate is not currently used for that purpose). The data, however, were insufficient to determine the safety of these ingredients when used in cosmetics as other than pH adjusters and specifically, the data are insufficient to determine the safety of Sodium Malate when used as a skin conditioning agent-humectant. The types of data required for the Expert Panel to determine the safety of Sodium

  12. Quercetin promotes the apoptosis of fibroblast-like synoviocytes in rheumatoid arthritis by upregulating lncRNA MALAT1.

    Science.gov (United States)

    Pan, Fang; Zhu, Lihua; Lv, Haozhe; Pei, Chunpeng

    2016-11-01

    Rheumatoid arthritis (RA) is a chronic autoimmune joint disease and fibroblast-like synoviocytes (FLS) are the resident mesenchymal cells of synovial joints. Quercetin is a dietary antioxidant. In this study, we aimed to explore the mechanisms responsible for the quercetin-induced apoptosis of FLS from patients with RA (termed RAFLS). RAFLS viability was determined following treatent of the cells with or without quercetin using the Cell Counting kit-8 (CCK-8) assay. The apoptosis of the RAFLS was analyzed using the Annexin V-fluorescein isothiocyanate (FITC) apoptosis detection kit I. The results revealed that RAFLS viability decreased and apoptosis increased in following treatment with quercetin. The differentially expressed long non-coding RNAs (lncRNAs) were screened and marked by PCR array following treatment with quercetin. The expression levels of the screened lncRNAs were then determined and compared in the cells treated with or without quercetin by quantitative PCR. The lncRNA metastasis associated lung adenocarcinoma transcript 1 (MALAT1) was finally selected. Small interfering RNA (siRNA) was then used to knock down the expression of MALAT1 in order to determine the role of MALAT1 in the quercetin-induced apoptosis of RAFLS. The results revealed that the knockdown of MALAT1 inhibited RAFLS apoptosis. At the same time, the expression of caspase-3 and caspase-9 was significantly decreased in the cells in which MALAT1 was knocked down. The phosphoinositide 3-kinase (PI3K)/AKT signaling pathway was activated; this activation is known to be associated with enhanced cell proliferation and decreased apoptosis. The findings of our study indicate that quercetin promotes RAFLS apoptosis by upregulating lncRNA MALAT1, and that MALAT1 induces apoptosis by inhibiting the activation of the PI3K/AKT pathway.

  13. Evaluation of the Reproductive Toxicity, Glycometabolism, Glycometabolism-Related Enzyme Levels and Lipid Metabolism of Chromium Malate Supplementation in Sprague-Dawley Rats.

    Science.gov (United States)

    Feng, Weiwei; Zhang, Weijie; Zhao, Ting; Mao, Guanghua; Wang, Wei; Wu, Xueshan; Zhou, Zhaoxiang; Huang, Jing; Bao, Yongtuan; Yang, Liuqing; Wu, Xiangyang

    2015-11-01

    Our previous study showed that chromium malate improved the regulation of blood glucose in mice with alloxan-induced diabetes. The present study was designed to evaluate the reproductive toxicity of chromium malate in Sprague-Dawley rats and then inspected the effect of chromium malate on glycometabolism, glycometabolism-related enzymes, and lipid metabolism. The results showed that no pathological, toxic feces and urine changes were observed in clinical signs of parental and fetal rats in chromium malate groups. The fasting blood glucose, serum insulin, insulin resistance index, C-peptide, hepatic glycogen, glucose-6-phosphate dehydrogenase, glucokinase, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels of chromium malate groups have no significant change compared with control group and chromium picolinate group. The serum and organ contents of Cr in chromium malate groups have no significant change when compared with control group. No measurable damage on liver, brain, kidney, and testis/uterus of chromium malate groups was found. No significant change in body mass, absolute and relative organ weights, and hematological and biochemical changes of rats were observed compared with the control and chromium picolinate groups. The results indicated that supplements with chromium malate does not cause obvious damage and has no obvious effect on glycometabolism, glycometabolism-related enzyme, and lipid metabolism on female and male rats. The results of this study suggested that chromium malate is safe for human consumption and has the potential for application as a functional food ingredient and dietary supplement.

  14. Long Non-Coding RNA MALAT1 Mediates Transforming Growth Factor Beta1-Induced Epithelial-Mesenchymal Transition of Retinal Pigment Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Shuai Yang

    Full Text Available To study the role of long non-coding RNA (lncRNA MALAT1 in transforming growth factor beta 1 (TGF-β1-induced epithelial-mesenchymal transition (EMT of retinal pigment epithelial (RPE cells.ARPE-19 cells were cultured and exposed to TGF-β1. The EMT of APRE-19 cells is confirmed by morphological change, as well as the increased expression of alpha-smooth muscle actin (αSMA and fibronectin, and the down-regulation of E-cadherin and Zona occludin-1(ZO-1 at both mRNA and protein levels. The expression of lncRNA MALAT1 in RPE cells were detected by quantitative real-time PCR. Knockdown of MALAT1 was achieved by transfecting a small interfering RNA (SiRNA. The effect of inhibition of MALAT1 on EMT, migration, proliferation, and TGFβ signalings were observed. MALAT1 expression was also detected in primary RPE cells incubated with proliferative vitreoretinopathy (PVR vitreous samples.The expression of MALAT1 is significantly increased in RPE cells incubated with TGFβ1. MALAT1 silencing attenuates TGFβ1-induced EMT, migration, and proliferation of RPE cells, at least partially through activating Smad2/3 signaling. MALAT1 is also significantly increased in primary RPE cells incubated with PVR vitreous samples.LncRNA MALAT1 is involved in TGFβ1-induced EMT of human RPE cells and provides new understandings for the pathogenesis of PVR.

  15. Long Non Coding RNA MALAT1 Promotes Tumor Growth and Metastasis by inducing Epithelial-Mesenchymal Transition in Oral Squamous Cell Carcinoma.

    Science.gov (United States)

    Zhou, Xuan; Liu, Su; Cai, Guoshuai; Kong, Lingping; Zhang, Tingting; Ren, Yu; Wu, Yansheng; Mei, Mei; Zhang, Lun; Wang, Xudong

    2015-11-02

    The prognosis of advanced oral squamous cell carcinoma (OSCC) patients remains dismal, and a better understanding of the underlying mechanisms is critical for identifying effective targets with therapeutic potential to improve the survival of patients with OSCC. This study aims to clarify the clinical and biological significance of metastasis-associated long non-coding RNA, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in OSCC. We found that MALAT1 is overexpressed in OSCC tissues compared to normal oral mucosa by real-time PCR. MALAT1 served as a new prognostic factor in OSCC patients. When knockdown by small interfering RNA (siRNA) in OSCC cell lines TSCCA and Tca8113, MALAT1 was shown to be required for maintaining epithelial-mesenchymal transition (EMT) mediated cell migration and invasion. Western blot and immunofluorescence staining showed that MALAT1 knockdown significantly suppressed N-cadherin and Vimentin expression but induced E-cadherin expression in vitro. Meanwhile, both nucleus and cytoplasm levels of β-catenin and NF-κB were attenuated, while elevated MALAT1 level triggered the expression of β-catenin and NF-κB. More importantly, targeting MALAT1 inhibited TSCCA cell-induced xenograft tumor growth in vivo. Therefore, these findings provide mechanistic insight into the role of MALAT1 in regulating OSCC metastasis, suggesting that MALAT1 is an important prognostic factor and therapeutic target for OSCC.

  16. Long non-coding RNA MALAT1 interacts with miR-124 and modulates tongue cancer growth by targeting JAG1.

    Science.gov (United States)

    Zhang, Tong-Han; Liang, Li-Zhong; Liu, Xiao-Ling; Wu, Ji-Nan; Su, Kui; Chen, Jue-Yao; Zheng, Qiao-Yi; Huang, Hong-Zhang; Liao, Gui-Qing

    2017-04-01

    Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long non-coding RNA (lncRNA), was the earliest discovered to be correlated with cancer and contributes to the initiation and development of several types of tumors. Dysregulation of MALAT1 expression is frequently observed in many types of cancer such as gastric cancer, esophageal squamous cell carcinoma and glioma. To date, the role of MALAT1 and the underlying mechanisms in tongue cancer development remain unclear. In the present study, we studied the influence of MALAT1 on tongue cancer cell lines and clinical tongue cancer samples so as to detect its function and the underlying mechanism. In the present study, lncRNA-MALAT1 was specifically upregulated in tongue cancer cell lines and overexpression promoted tongue cancer cell growth by targeting miR-124. Knockdown of MALAT1 suppressed the growth and invasion of human tongue cancer cells and inhibited metastasis in vitro and in vivo. In addition, miR-124-dependent jagged1 (JAG1) regulation was required for MALAT1-induced tongue cancer cell growth. Our data revealed that MALAT1 inhibited tongue cancer cell growth and metastasis through miR-124-dependent JAG1 regulation. In conclusion, we revealed that MALAT1 may play an oncogenic role by increasing proliferation and metastasis of tongue cancer and is a potential therapeutic target in human tongue cancer.

  17. Improved phosphorus acquisition by tobacco through transgenic expression of mitochondrial malate dehydrogenase from Penicillium oxalicum.

    Science.gov (United States)

    Lü, Jun; Gao, Xiaorong; Dong, Zhimin; Yi, Jun; An, Lijia

    2012-01-01

    Phosphorus (P) is an essential nutrient for plant growth and development, but is generally unavailable and inaccessible in soil, since applied P is mostly fixed to aluminium (Al) and ferrum (Fe) in acidic soils and to calcium (Ca) in alkaline soils. Increased organic acid excretion is thought to be one mechanism by which plants use to enhance P uptake. In this study, we overexpressed a mitochondrial malate dehydrogenase (MDH) gene from the mycorrhizal fungi Penicillium oxalicum in tobacco. The MDH activity of transgenic lines was significantly increased compared to that of wild type. Malate content in root exudation of transgenic lines induced in response to P deficiency was 1.3- to 2.9-fold greater than that of wild type under the same condition. Among the transgenic lines that were selected for analysis, one line (M1) showed the highest level of MDH activity and malate exudate. M1 showed a significant increase in growth over wild type, with 149.0, 128.5, and 127.9% increases in biomass, when grown in Al-phosphate, Fe-phosphate, and Ca-phosphate media, respectively. M1 also had better P uptake compared to wild type, with total P content increased by 287.3, 243.5, and 223.4% when grown in Al-phosphate, Fe-phosphate, and Ca-phosphate media, respectively. To our knowledge, this is the first study on improving the ability of a plant to utilize P from Al-phosphate, Fe-phosphate, and Ca-phosphate by manipulating the organic acid metabolism of the plant through genetic engineering.

  18. Long non-coding RNA MALAT-1 is downregulated in preeclampsia and regulates proliferation, apoptosis, migration and invasion of JEG-3 trophoblast cells.

    Science.gov (United States)

    Chen, Haiying; Meng, Tao; Liu, Xuemin; Sun, Manni; Tong, Chunxiao; Liu, Jing; Wang, He; Du, Juan

    2015-01-01

    Long non-coding RNA (lncRNA), as a newly identified subset of the transcriptome, has been implicated in a variety of physiological and pathological processes. Metastasis associated lung adenocarcinoma transcript-1 (MALAT-1), a lncRNA that was initially detected in the metastatic lung cancer, was reported to be overexpressed in placenta previa increta/percreta (I/P), which is caused by excessive trophoblast invasion. However, the role of MALAT-1 in the regulation of trophoblast behavior is not fully understood. In this study, we first examined the expression of MALAT-1 in the placentas from the patients with preeclampsia, the pathology of which is associated with inadequate trophoblast invasion, and found that the expression of MALAT-1 was downregulated in the preeclamptic placentas as compared to the normal placentas. We further investigated the function of MALAT-1 in JEG-3 trophoblast cell line using short interfering RNA (siRNA) against MALAT-1 transcripts. Silencing of MALAT-1 in JEG-3 cells suppressed proliferation and induced cell cycle arrest at G0/G1 phase. Reduced expression of MALAT-1 by RNA interference resulted in enhanced apoptosis in JEG-3 cells, accompanied with elevated levels of the pro-apoptotic proteins including cleaved caspase-3, cleaved caspase-9 and cleaved poly (ADP-ribose) polymerase-1 (PARP-1). Moreover, the migration rate and the invasiveness of JEG-3 cells were suppressed when MALAT-1 was downregulated. In summary, our results suggest that MALAT-1 may play an important role in the regulation of proliferation, cell cycle, apoptosis, migration and invasion of trophoblast cells, and under-expression of MALAT-1 during early placentation may be involved in the pathogenesis of preeclampsia.

  19. Molecular cloning, purification and immunogenicity of recombinant Brucella abortus 544 malate dehydrogenase protein.

    Science.gov (United States)

    Reyes, Alisha Wehdnesday Bernardo; Simborio, Hannah Leah Tadeja; Hop, Huynh Tan; Arayan, Lauren Togonon; Kim, Suk

    2016-03-01

    The Brucella mdh gene was successfully cloned and expressed in E. coli. The purified recombinant malate dehydrogenase protein (rMDH) was reactive to Brucella-positive bovine serum in the early stage, but not reactive in the middle or late stage, and was reactive to Brucella-positive mouse serum in the late stage, but not in the early or middle stage of infection. In addition, rMDH did not react with Brucella-negative bovine or mouse sera. These results suggest that rMDH has the potential for use as a specific antigen in serological diagnosis for early detection of bovine brucellosis.

  20. Peroxisomal malate dehydrogenase is not essential for photorespiration in Arabidopsis but its absence causes an increase in the stoichiometry of photorespiratory CO2 release.

    Science.gov (United States)

    Cousins, Asaph B; Pracharoenwattana, Itsara; Zhou, Wenxu; Smith, Steven M; Badger, Murray R

    2008-10-01

    Peroxisomes are important for recycling carbon and nitrogen that would otherwise be lost during photorespiration. The reduction of hydroxypyruvate to glycerate catalyzed by hydroxypyruvate reductase (HPR) in the peroxisomes is thought to be facilitated by the production of NADH by peroxisomal malate dehydrogenase (PMDH). PMDH, which is encoded by two genes in Arabidopsis (Arabidopsis thaliana), reduces NAD(+) to NADH via the oxidation of malate supplied from the cytoplasm to oxaloacetate. A double mutant lacking the expression of both PMDH genes was viable in air and had rates of photosynthesis only slightly lower than in the wild type. This is in contrast to other photorespiratory mutants, which have severely reduced rates of photosynthesis and require high CO(2) to grow. The pmdh mutant had a higher O(2)-dependent CO(2) compensation point than the wild type, implying that either Rubisco specificity had changed or that the rate of CO(2) released per Rubisco oxygenation was increased in the pmdh plants. Rates of gross O(2) evolution and uptake were similar in the pmdh and wild-type plants, indicating that chloroplast linear electron transport and photorespiratory O(2) uptake were similar between genotypes. The CO(2) postillumination burst and the rate of CO(2) released during photorespiration were both greater in the pmdh mutant compared with the wild type, suggesting that the ratio of photorespiratory CO(2) release to Rubisco oxygenation was altered in the pmdh mutant. Without PMDH in the peroxisome, the CO(2) released per Rubisco oxygenation reaction can be increased by over 50%. In summary, PMDH is essential for maintaining optimal rates of photorespiration in air; however, in its absence, significant rates of photorespiration are still possible, indicating that there are additional mechanisms for supplying reductant to the peroxisomal HPR reaction or that the HPR reaction is altogether circumvented.

  1. Inhibition of ruminal microbial methane production by beta-cyclodextrin iodopropane, malate and their combination in vitro.

    Science.gov (United States)

    Mohammed, N; Lila, Z A; Ajisaka, N; Hara, K; Mikuni, K; Hara, K; Kanda, S; Itabashi, H

    2004-06-01

    The objective of this study was to evaluate the effects of different concentrations of l-malate (0, 5, 10 and 20 mm), 2-iodopropane-beta-cyclodextrin complex (CD-IP) (0, 0.1, 0.2 and 0.4 mm) and a combination of malate (10 and 20 mm) plus CD-IP (0.2 and 0.4 mm) on methane production from corn starch. Ruminal fluid was collected from dairy cows, mixed with phosphate buffer (1 : 2) and incubated (30 ml) anaerobically at 38 degrees C for 6 h with or without additives. Fermentation of corn starch in the presence of malate resulted in an increase (p hydrogen production was increased (p Hydrogen production was also decreased (p inhibit methane production as well as to improve rumen fermentation and animal performance.

  2. Ab initio calculation of the Zn isotope effect in phosphates, citrates, and malates and applications to plants and soil.

    Science.gov (United States)

    Fujii, Toshiyuki; Albarède, Francis

    2012-01-01

    Stable Zn isotopes are fractionated in roots and leaves of plants. Analyses demonstrate that the heavy Zn isotopes are enriched in the root system of plants with respect to shoots and leaves as well as the host soil, but the fractionation mechanisms remain unclear. Here we show that the origin of this isotope fractionation is due to a chemical isotope effect upon complexation by Zn malates and citrates in the aerial parts and by phosphates in the roots. We calculated the Zn isotope effect in aqueous citrates, malates, and phosphates by ab initio methods. For pHphosphates, with respect to leaves, which concentrate malates and citrates, by about one permil. It is proposed that Zn isotope fractionation represents a useful tracer of Zn availability and mobility in soils.

  3. Domain structure and pore loops in the 2-hydroxycarboxylate transporter family

    NARCIS (Netherlands)

    Lolkema, Juke S.

    2006-01-01

    The 2-hydroxycarboxylate transporter (2HCT) family is a family of bacterial secondary transporters for substrates like citrate, malate and lactate. The family is in class ST[3] of the MemGen classification system that groups membrane proteins in structural classes based on hydropathy profile analysi

  4. Evaluation of 90-day Repeated Dose Oral Toxicity, Glycometabolism, Learning and Memory Ability, and Related Enzyme of Chromium Malate Supplementation in Sprague-Dawley Rats.

    Science.gov (United States)

    Feng, Weiwei; Wu, Huiyu; Li, Qian; Zhou, Zhaoxiang; Chen, Yao; Zhao, Ting; Feng, Yun; Mao, Guanghua; Li, Fang; Yang, Liuqing; Wu, Xiangyang

    2015-11-01

    Our previous study showed that chromium malate improved the regulation of blood glucose in mice with alloxan-induced diabetes. The present study was designed to evaluate the 90-day oral toxicity of chromium malate in Sprague-Dawley rats. The present study inspected the effect of chromium malate on glycometabolism, glycometabolism-related enzymes, lipid metabolism, and learning and memory ability in metabolically healthy Sprague-Dawley rats. The results showed that all rats survived and pathological, toxic, feces, and urine changes were not observed. Chromium malate did not cause measurable damage on liver, brain, and kidney. The fasting blood glucose, serum insulin, insulin resistance index, C-peptide, hepatic glycogen, glucose-6-phosphate dehydrogenase, glucokinase, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels of normal rats in chromium malate groups had no significant change when compared with control group and chromium picolinate group under physiologically relevant conditions. The serum and organ content of Cr in chromium malate groups had no significant change compared with control group. No significant changes were found in morris water maze test and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and true choline esterase (TChE) activity. The results indicated that supplementation with chromium malate did not cause measurable toxicity and has no obvious effect on glycometabolism and related enzymes, learning and memory ability, and related enzymes and lipid metabolism of female and male rats. The results of this study suggest that chromium malate is safe for human consumption.

  5. Enhancement of malate-production and increase in sensitivity to dimethyl succinate by mutation of the VID24 gene in Saccharomyces cerevisiae.

    Science.gov (United States)

    Negoro, Hiroaki; Kotaka, Atsushi; Matsumura, Kengo; Tsutsumi, Hiroko; Hata, Yoji

    2016-06-01

    Malate in sake (a Japanese alcoholic beverage) is an important component for taste that is produced by yeasts during alcoholic fermentation. To date, many researchers have developed methods for breeding high-malate-producing yeasts; however, genes responsible for the high-acidity phenotype are not known. We determined the mutated gene involved in high malate production in yeast, isolated as a sensitive mutant to dimethyl succinate. In the comparative whole genome analysis between high-malate-producing strain and its parent strain, one of the non-synonymous substitutions was identified in the VID24 gene. The mutation of VID24 resulted in enhancement of malate-productivity and sensitivity to dimethyl succinate. The mutation appeared to lead to a deficiency in Vid24p function. Furthermore, disruption of cytoplasmic malate dehydrogenase (Mdh2p) gene in the VID24 mutant inhibited the high-malate-producing phenotype. Vid24p is known as a component of the multisubunit ubiquitin ligase and participates in the degradation of gluconeogenic enzymes such as Mdh2p. We suggest that the enhancement of malate-productivity results from an accumulation of Mdh2p due to the loss of Vid24p function. These findings propose a novel mechanism for the regulation of organic acid production in yeast cells by the component of ubiquitin ligase, Vid24p.

  6. Structural insights into the stabilization of MALAT1 noncoding RNA by a bipartite triple helix.

    Science.gov (United States)

    Brown, Jessica A; Bulkley, David; Wang, Jimin; Valenstein, Max L; Yario, Therese A; Steitz, Thomas A; Steitz, Joan A

    2014-07-01

    Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a highly abundant nuclear long noncoding RNA that promotes malignancy. A 3'-stem-loop structure is predicted to confer stability by engaging a downstream A-rich tract in a triple helix, similar to the expression and nuclear retention element (ENE) from the KSHV polyadenylated nuclear RNA. The 3.1-Å-resolution crystal structure of the human MALAT1 ENE and A-rich tract reveals a bipartite triple helix containing stacks of five and four U•A-U triples separated by a C+•G-C triplet and C-G doublet, extended by two A-minor interactions. In vivo decay assays indicate that this blunt-ended triple helix, with the 3' nucleotide in a U•A-U triple, inhibits rapid nuclear RNA decay. Interruption of the triple helix by the C-G doublet induces a 'helical reset' that explains why triple-helical stacks longer than six do not occur in nature.

  7. Enzymatic Activity Analysis and Catalytic Essential Residues Identification of Brucella abortus Malate Dehydrogenase

    Directory of Open Access Journals (Sweden)

    Xiangan Han

    2014-01-01

    Full Text Available Malate dehydrogenase (MDH plays important metabolic roles in bacteria. In this study, the recombinant MDH protein (His-MDH of Brucella abortus was purified and its ability to catalyze the conversion of oxaloacetate (OAA to L-malate (hereon referred to as MDH activity was analyzed. Michaelis Constant (Km and Maximum Reaction Velocity (Vmax of the reaction were determined to be 6.45×10−3 M and 0.87 mM L−1 min−1, respectively. In vitro studies showed that His-MDH exhibited maximal MDH activity in pH 6.0 reaction buffer at 40°C. The enzymatic activity was 100%, 60%, and 40% inhibited by Cu2+, Zn2+, and Pb2+, respectively. In addition, six amino acids in the MDH were mutated to investigate their roles in the enzymatic activity. The results showed that the substitutions of amino acids Arg 89, Asp 149, Arg 152, His 176, or Thr 231 almost abolished the activity of His-MDH. The present study will help to understand MDH’s roles in B. abortus metabolism.

  8. Visnagin protects against doxorubicin-induced cardiomyopathy through modulation of mitochondrial malate dehydrogenase.

    Science.gov (United States)

    Liu, Yan; Asnani, Aarti; Zou, Lin; Bentley, Victoria L; Yu, Min; Wang, You; Dellaire, Graham; Sarkar, Kumar S; Dai, Matthew; Chen, Howard H; Sosnovik, David E; Shin, Jordan T; Haber, Daniel A; Berman, Jason N; Chao, Wei; Peterson, Randall T

    2014-12-10

    Doxorubicin is a highly effective anticancer chemotherapy agent, but its use is limited by its cardiotoxicity. To develop a drug that prevents this toxicity, we established a doxorubicin-induced cardiomyopathy model in zebrafish that recapitulates the cardiomyocyte apoptosis and contractility decline observed in patients. Using this model, we screened 3000 compounds and found that visnagin (VIS) and diphenylurea (DPU) rescue the cardiac performance and circulatory defects caused by doxorubicin in zebrafish. VIS and DPU reduced doxorubicin-induced apoptosis in cultured cardiomyocytes and in vivo in zebrafish and mouse hearts. VIS treatment improved cardiac contractility in doxorubicin-treated mice. Further, VIS and DPU did not reduce the chemotherapeutic efficacy of doxorubicin in several cultured tumor lines or in zebrafish and mouse xenograft models. Using affinity chromatography, we found that VIS binds to mitochondrial malate dehydrogenase (MDH2), a key enzyme in the tricarboxylic acid cycle. As with VIS, treatment with the MDH2 inhibitors mebendazole, thyroxine, and iodine prevented doxorubicin cardiotoxicity, as did treatment with malate itself, suggesting that modulation of MDH2 activity is responsible for VIS' cardioprotective effects. Thus, VIS and DPU are potent cardioprotective compounds, and MDH2 is a previously undescribed, druggable target for doxorubicin-induced cardiomyopathy.

  9. Enzymatic activity analysis and catalytic essential residues identification of Brucella abortus malate dehydrogenase.

    Science.gov (United States)

    Han, Xiangan; Tong, Yongliang; Tian, Mingxing; Zhang, Yuxi; Sun, Xiaoqing; Wang, Shaohui; Qiu, Xusheng; Ding, Chan; Yu, Shengqing

    2014-01-01

    Malate dehydrogenase (MDH) plays important metabolic roles in bacteria. In this study, the recombinant MDH protein (His-MDH) of Brucella abortus was purified and its ability to catalyze the conversion of oxaloacetate (OAA) to L-malate (hereon referred to as MDH activity) was analyzed. Michaelis Constant (Km) and Maximum Reaction Velocity (Vmax) of the reaction were determined to be 6.45 × 10(-3) M and 0.87 mM L(-1)min(-1), respectively. In vitro studies showed that His-MDH exhibited maximal MDH activity in pH 6.0 reaction buffer at 40°C. The enzymatic activity was 100%, 60%, and 40% inhibited by Cu(2+), Zn(2+), and Pb(2+), respectively. In addition, six amino acids in the MDH were mutated to investigate their roles in the enzymatic activity. The results showed that the substitutions of amino acids Arg 89, Asp 149, Arg 152, His 176, or Thr 231 almost abolished the activity of His-MDH. The present study will help to understand MDH's roles in B. abortus metabolism.

  10. Macromolecular crowding and the steady-state kinetics of malate dehydrogenase.

    Science.gov (United States)

    Poggi, Christopher G; Slade, Kristin M

    2015-01-20

    To understand how macromolecular crowding affects enzyme activity, we quantified the Michaelis-Menten kinetics of mitochondrial malate dehydrogenase (MDH) in the presence of hen egg white (HEW), lysozyme, bovine serum albumin (BSA), gum arabic, poly(vinylpyrrolidone) (PVP), and dextrans of various molecular weights. Although crowding tended to decrease Km and Vmax values, the magnitude depended on the crowding agent, reaction direction, and isozyme (mitochondrial porcine heart or thermophlic TaqMDH from Thermus flavus). Crowding slowed oxaloacetate reduction more significantly than malate oxidation, which may suggest that mitochondrial enzymes have evolved to function optimally under the crowded constraints in which they are immersed. Since direct comparisons of neutral to charged crowders are underrepresented in the literature, we performed these studies and found that neutral crowding agents lowered Vmax values more than charged crowders of similar size. The exception was hen egg white, a mixture of charged proteins that caused the largest observed decreases in both Km and Vmax. Finally, the data provide insight about the mechanism by corroborating MDH subunit dependence.

  11. A novel malate dehydrogenase from Ceratonia siliqua L. seeds with potential biotechnological applications.

    Science.gov (United States)

    Muccio, Clelia; Guida, Vincenzo; Di Petrillo, Amalia; Severino, Valeria; Di Maro, Antimo

    2012-12-01

    A novel malate dehydrogenase (MDH; EC 3.1.1.1.37), hereafter MDHCs, from Ceratonia siliqua seeds, commonly known as Carob tree, was purified by using ammonium sulphate precipitation, ion exchange chromatography on SteamLine SP and gel-filtration. The molecular mass of the native protein, obtained by analytical gel-filtration, was about 65 kDa, whereas, by using SDS-PAGE analysis, with and without reducing agent, was 34 kDa. The specific activity of purified MDHCs (0.25 mg/100 g seeds) was estimated to be 188 U/mg. The optimum activity of the enzyme is at pH 8.5, showing a decrease in the presence of Ca(2+), Mg(2+) and NaCl. The N-terminal sequence of the first 20 amino acids of MDHCs revealed 95 % identity with malate dehydrogenase from Medicago sativa L. Finally, the enzymatic activity of MDHCs was preserved even after absorption onto a PVDF membrane. To our knowledge, this is the first contribution to the characterization of an enzyme from Carob tree sources.

  12. Protein (Viridiplantae): 357521107 [PGDBj - Ortholog DB

    Lifescience Database Archive (English)

    Full Text Available 7 58024:8377 3398:8377 71240:7000 91827:7000 71275:1375 91835:4837 72025:7275 3803:7275 3814:7275 163742:587 3877:587 3880:587 Alumin...um activated malate transporter Medicago truncatula MAPKLAKSGSFRYTLAEKKERLLSMKGGDHI

  13. Analysis of Quaternary Structure of a [LDH-like] Malate Dehydrogenase of Plasmodium falciparum with Oligomeric Mutants

    Science.gov (United States)

    L-Malate dehydrogenase (PfMDH) from Plasmodium falciparum, the causative agent for the most severe form of malaria, has shown remarkable similarities to L-lactate dehydrogenase (PfLDH). PfMDH is more closely related to [LDH-like] MDHs characterized in archea and other prokaryotes. Initial sequence a...

  14. Structure and Function of Plasmodium falciparum malate dehydrogenase: Role of Critical Amino Acids in C-substrate Binding Procket

    Science.gov (United States)

    Malaria parasite thrives on anaerobic fermentation of glucose for energy. Earlier studies from our lab have demonstrated that a cytosolic malate dehydrogenase (PfMDH) with striking similarity to lactate dehydrogenase (PfLDH) might complement PfLDH function in Plasmodium falciparum. The N-terminal g...

  15. Resveratrol inhibits invasion and metastasis of colorectal cancer cells via MALAT1 mediated Wnt/β-catenin signal pathway.

    Directory of Open Access Journals (Sweden)

    Qing Ji

    Full Text Available Resveratrol, extracted from Chinese herbal medicine Polygonum cuspidatum, is known to inhibit invasion and metastasis of human colorectal cancer (CRC, in which long non-coding Metastasis Associated Lung Adenocarcinoma Transcript 1 (RNA-MALAT1 also plays an important role. Using MALAT1 lentiviral shRNA and over-expression constructs in CRC derived cell lines, LoVo and HCT116, we demonstrated that the anti-tumor effects of resveratrol on CRC are through inhibiting Wnt/β-catenin signaling, thus the expression of its target genes such as c-Myc, MMP-7, as well as the expression of MALAT1. In detail, resveratrol down-regulates MALAT1, resulting in decreased nuclear localization of β-catenin thus attenuated Wnt/β-catenin signaling, which leads to the inhibition of CRC invasion and metastasis. This finding of ours surely provides important pre-clinical evidence supporting future use of resveratrol in prevention and treatment of CRC.

  16. Purification, characterization, and overexpression of psychrophilic and thermolabile malate dehydrogenase of a novel antarctic psychrotolerant, Flavobacterium frigidimaris KUC-1.

    Science.gov (United States)

    Oikawa, Tadao; Yamamoto, Noriko; Shimoke, Koji; Uesato, Shinichi; Ikeuchi, Toshihiko; Fujioka, Toru

    2005-11-01

    We purified the psychrophilic and thermolabile malate dehydrogenase to homogeneity from a novel psychrotolerant, Flavobacterium frigidimaris KUC-1, isolated from Antarctic seawater. The enzyme was a homotetramer with a molecular weight of about 123 k and that of the subunit was about 32 k. The enzyme required NAD(P)(+) as a coenzyme and catalyzed the oxidation of L-malate and the reduction of oxalacetate specifically. The reaction proceeded through an ordered bi-bi mechanism. The enzyme was highly susceptible to heat treatment, and the half-life time at 40 degrees C was estimated to be 3.0 min. The k(cat)/K(m) (microM(-1).s(-1)) values for L-malate and NAD(+) at 30 degrees C were 289 and 2,790, respectively. The enzyme showed pro-R stereospecificity for hydrogen transfer at the C4 position of the nicotinamide moiety of the coenzyme. The enzyme contained 311 amino acid residues and much lower numbers of proline and arginine residues than other malate dehydrogenases.

  17. Identification and biochemical characterization of a thermostable malate dehydrogenase from the mesophile Streptomyces coelicolor A3(2).

    Science.gov (United States)

    Ge, Ya-Dong; Cao, Zheng-Yu; Wang, Zong-Da; Chen, Lu-Lu; Zhu, You-Ming; Zhu, Guo-Ping

    2010-01-01

    We identified and characterized a malate dehydrogenase from Streptomyces coelicolor A3(2) (ScMDH). The molecular mass of ScMDH was 73,353.5 Da with two 36,675.0 Da subunits as analyzed by matrix-assisted laser-desorption ionization-time-of-flight mass spectrometry (MALDI-TOF-MS). The detailed kinetic parameters of recombinant ScMDH are reported here. Heat inactivation studies showed that ScMDH was more thermostable than most MDHs from other organisms, except for a few extremely thermophile bacteria. Recombinant ScMDH was highly NAD(+)-specific and displayed about 400-fold (k(cat)) and 1,050-fold (k(cat)/K(m)) preferences for oxaloacetate reduction over malate oxidation. Substrate inhibition studies showed that ScMDH activity was inhibited by excess oxaloacetate (K(i)=5.8 mM) and excess L-malate (K(i)=12.8 mM). Moreover, ScMDH activity was not affected by most metal ions, but was strongly inhibited by Fe(2+) and Zn(2+). Taken together, our findings indicate that ScMDH is significantly thermostable and presents a remarkably high catalytic efficiency for malate synthesis.

  18. Solid and Solution Structural Studies of Dimeric and Tetrameric Molybdenum(Ⅵ) Malate Complexes

    Institute of Scientific and Technical Information of China (English)

    ZHANG Rong-Hua; ZHOU Zhao-Hui; WAN Hui-Lin

    2008-01-01

    Reactions of potassium molybdate with racemic malic acid (H3mal = C4H6O5) result in the isolation of two mesomeric molybdenum malate complexes Ks[(MoO2)2O(R-mal)2][(MoO2)2O(S- mal)2]·4H2O 1 and (Him)2K6[(MoO2)4O3(R-mal)2][(MoO2)4O3(S-mal)2]·8H2O 2. Complex 1 belongs to the monoclinic system, space group C2/c with a = 14.8637(3), b = 6.9544(1), c = 19.6783(5) A, β = 100.081(2)°, V= 2002.70(7)A3, Mr = 1452.88, Z= 2, F(000) = 1416, T= 173 K, Dc = 2.409 g/cm3, μ(MoKa) = 2.167, R = 0.0283 and wR = 0.0733.2 is of triclinic system, space group P1 with a = 8.7707(2), b = 9.3310(3), c = 17.9093(7) A, α = 83.781(3), β = 85.626(2), γ= 84.822(2)°, V = 1447.84(8) A3, Mr = 2160.68, Z = 1, F(000) = 1048, T= 173 K, Dc = 2.478 g/cm3, μ(MoKα) = 2.230, R = 0.0234 and wR = 0.0584.1 is the first isolated dinuclear molybdenum(Ⅵ) malato complex in 1:1 molar ratio. The molybdenum atoms in the two complexes are six-coordinated in an approximately octahedral geometry. Two malates coordinate tridentately with the Mo atom via their α-alkoxy, α-carboxy and α-carboxy groups in 1 and 2. β-Carboxy group in 2 further links with the other two Mo atoms to give a tetrameric unit. The solution 1H and 13C NMR spectra indicate that dimeric malate molybdenum in 1 dissociates partly in solution and exists in an equilibrium with tetrameric species, while 2 is stable and retains its tetrameric structure without any dissociation.

  19. Methyltransferase-like protein 16 binds the 3'-terminal triple helix of MALAT1 long noncoding RNA.

    Science.gov (United States)

    Brown, Jessica A; Kinzig, Charles G; DeGregorio, Suzanne J; Steitz, Joan A

    2016-12-06

    Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a cancer-promoting long noncoding RNA, accumulates in cells by using a 3'-triple-helical RNA stability element for nuclear expression (ENE). The ENE, a stem-loop structure containing a U-rich internal loop, interacts with a downstream A-rich tract (ENE+A) to form a blunt-ended triple helix composed of nine U•A-U triples interrupted by a C•G-C triple and C-G doublet. This unique structure prompted us to explore the possibility of protein binding. Native gel-shift assays revealed a shift in radiolabeled MALAT1 ENE+A RNA upon addition of HEK293T cell lysate. Competitive gel-shift assays suggested that protein binding depends not only on the triple-helical structure but also its nucleotide composition. Selection from the lysate using a biotinylated-RNA probe followed by mass spectrometry identified methyltransferase-like protein 16 (METTL16), a putative RNA methyltransferase, as an interacting protein of the MALAT1 ENE+A. Gel-shift assays confirmed the METTL16-MALAT1 ENE+A interaction in vitro: Binding was observed with recombinant METTL16, but diminished in lysate depleted of METTL16, and a supershift was detected after adding anti-METTL16 antibody. Importantly, RNA immunoprecipitation after in vivo UV cross-linking and an in situ proximity ligation assay for RNA-protein interactions confirmed an association between METTL16 and MALAT1 in cells. METTL16 is an abundant (∼5 × 10(5) molecules per cell) nuclear protein in HeLa cells. Its identification as a triple-stranded RNA binding protein supports the formation of RNA triple helices inside cells and suggests the existence of a class of triple-stranded RNA binding proteins, which may enable the discovery of additional cellular RNA triple helices.

  20. L-Malate dehydrogenase activity in the reductive arm of the incomplete citric acid cycle of Nitrosomonas europaea.

    Science.gov (United States)

    Deutch, Charles E

    2013-11-01

    The autotrophic nitrifying bacterium Nitrosomonas europaea does not synthesize 2-oxoglutarate (α-ketoglutarate) dehydrogenase under aerobic conditions and so has an incomplete citric acid cycle. L-malate (S-malate) dehydrogenase (MDH) from N. europaea was predicted to show similarity to the NADP(+)-dependent enzymes from chloroplasts and was separated from the NAD(+)-dependent proteins from most other bacteria or mitochondria. MDH activity in a soluble fraction from N. europaea ATCC 19718 was measured spectrophotometrically and exhibited simple Michaelis-Menten kinetics. In the reductive direction, activity with NADH increased from pH 6.0 to 8.5 but activity with NADPH was consistently lower and decreased with pH. At pH 7.0, the K m for oxaloacetate was 20 μM; the K m for NADH was 22 μM but that for NADPH was at least 10 times higher. In the oxidative direction, activity with NAD(+) increased with pH but there was very little activity with NADP(+). At pH 7.0, the K m for L-malate was 5 mM and the K m for NAD(+) was 24 μM. The reductive activity was quite insensitive to inhibition by L-malate but the oxidative activity was very sensitive to oxaloacetate. MDH activity was not strongly activated or inhibited by glycolytic or citric acid cycle metabolites, adenine nucleotides, NaCl concentrations, or most metal ions, but increased with temperature up to about 55 °C. The reductive activity was consistently 10-20 times higher than the oxidative activity. These results indicate that the L-malate dehydrogenase in N. europaea is similar to other NAD(+)-dependent MDHs (EC 1.1.1.37) but physiologically adapted for its role in a reductive biosynthetic sequence.

  1. Effects of Al(III) and nano-Al13 species on malate dehydrogenase activity.

    Science.gov (United States)

    Yang, Xiaodi; Cai, Ling; Peng, Yu; Li, Huihui; Chen, Rong Fu; Shen, Ren Fang

    2011-01-01

    The effects of different aluminum species on malate dehydrogenase (MDH) activity were investigated by monitoring amperometric i-t curves for the oxidation of NADH at low overpotential using a functionalized multi-wall nanotube (MWNT) modified glass carbon electrode (GCE). The results showed that Al(III) and Al(13) can activate the enzymatic activity of MDH, and the activation reaches maximum levels as the Al(III) and Al(13) concentration increase. Our study also found that the effects of Al(III) and Al(13) on the activity of MDH depended on the pH value and aluminum speciation. Electrochemical and circular dichroism spectra methods were applied to study the effects of nano-sized aluminum compounds on biomolecules.

  2. Effects of Al(III and Nano-Al13 Species on Malate Dehydrogenase Activity

    Directory of Open Access Journals (Sweden)

    Rong Fu Chen

    2011-05-01

    Full Text Available The effects of different aluminum species on malate dehydrogenase (MDH activity were investigated by monitoring amperometric i-t curves for the oxidation of NADH at low overpotential using a functionalized multi-wall nanotube (MWNT modified glass carbon electrode (GCE. The results showed that Al(III and Al13 can activate the enzymatic activity of MDH, and the activation reaches maximum levels as the Al(III and Al13 concentration increase. Our study also found that the effects of Al(III and Al13 on the activity of MDH depended on the pH value and aluminum speciation. Electrochemical and circular dichroism spectra methods were applied to study the effects of nano-sized aluminum compounds on biomolecules.

  3. Isoform expression in the multiple soluble malate dehydrogenase of Hoplias malabaricus (Erythrinidae, Characiformes

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    M. R. Aquino-Silva

    Full Text Available Kinetic properties and thermal stabilities of Hoplias malabaricus liver and skeletal muscle unfractionated malate dehydrogenase (MDH, EC 1.1.1.37 and its isolated isoforms were analyzed to further study the possible sMDH-A* locus duplication evolved from a recent tandem duplication. Both A (A1 and A2 and B isoforms had similar optima pH (7.5-8.0. While Hoplias A isoform could not be characterized as thermostable, B could as thermolabile. A isoforms differed from B isoform in having higher Km values for oxaloacetate. The possibly duplicated A2 isoform showed higher substrate affinity than the A1. Hoplias duplicated A isoforms may influence the direction of carbon flow between glycolisis and gluconeogenesis.

  4. Soluble malate dehydrogenase of Geophagus brasiliensis (Cichlidae, Perciformes: isolated isoforms and kinetics properties

    Directory of Open Access Journals (Sweden)

    Maria Regina de Aquino-Silva

    2008-01-01

    Full Text Available Kinetic properties and thermal stabilities of Geophagus brasiliensis skeletal muscle unfractionated malate dehydrogenase (MDH, EC 1.1.1.37 and its isolated isoforms were analyzed to examine a possible sMDH-B* locus duplication in a fixation process influenced by genetic drift. Two optimal pHs were detected: 7.5 for AB1 unfractionated muscle phenotype and its B1 isoform, and 8.0 for AB1B2 unfractionated muscle phenotype, A and B2 isoforms. While G. brasiliensis A isoform could be characterized as thermostable, the duplicated B isoform cannot be assumed as thermolabile. Km values for isolated B2 isoforms were 1.6 times lower than for B1. A duplication event in progress best explains the electrophoretic six-band pattern detected in G. brasiliensis, which would be caused by genetic drift.

  5. Hoogsteen-position pyrimidines promote the stability and function of the MALAT1 RNA triple helix.

    Science.gov (United States)

    Brown, Jessica A; Kinzig, Charles G; DeGregorio, Suzanne J; Steitz, Joan A

    2016-05-01

    Triple-stranded RNA was first deduced to form in vitro more than 50 years ago and has since been implicated in RNA catalysis, stability, and small molecule binding. Despite the emerging biological significance of RNA triple helices, it remains unclear how their nucleotide composition contributes to their thermodynamic stability and cellular function. To investigate these properties, we used in vitro RNA electrophoretic mobility shift assays (EMSAs) and in vivo intronless β-globin reporter assays to measure the relative contribution of 20 RNA base triples (N•A-U, N•G-C, N•C-G, N•U-A, and N•G-U) to triple-helical stability. These triples replaced a single internal U•A-U within the known structure of the triple-helical RNA stability element of human metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), which contains 10 major-groove base triples. In addition to the canonical C•G-C triple, the noncanonical base triples U•G-C, U•G-U, C•C-G, and U•C-G exhibited at least 30% stability relative to the wild-type U•A-U base triple in both assays. Of these triples, only U•A-U, C•G-C, and U•G-C, when tested as four successive triples, formed stabilizing structures that allowed accumulation of the intronless β-globin reporter. Overall, we find that Hoogsteen-position pyrimidines support triple helix stability and function and that thermodynamic stability, based on EMSA results, is necessary but not sufficient for stabilization activity of the MALAT1 triple helix in cells. These results suggest that additional RNA triple helices containing noncanonical triples likely exist in nature.

  6. Mitochondrial malate dehydrogenase lowers leaf respiration and alters photorespiration and plant growth in Arabidopsis.

    Science.gov (United States)

    Tomaz, Tiago; Bagard, Matthieu; Pracharoenwattana, Itsara; Lindén, Pernilla; Lee, Chun Pong; Carroll, Adam J; Ströher, Elke; Smith, Steven M; Gardeström, Per; Millar, A Harvey

    2010-11-01

    Malate dehydrogenase (MDH) catalyzes a reversible NAD(+)-dependent-dehydrogenase reaction involved in central metabolism and redox homeostasis between organelle compartments. To explore the role of mitochondrial MDH (mMDH) in Arabidopsis (Arabidopsis thaliana), knockout single and double mutants for the highly expressed mMDH1 and lower expressed mMDH2 isoforms were constructed and analyzed. A mmdh1mmdh2 mutant has no detectable mMDH activity but is viable, albeit small and slow growing. Quantitative proteome analysis of mitochondria shows changes in other mitochondrial NAD-linked dehydrogenases, indicating a reorganization of such enzymes in the mitochondrial matrix. The slow-growing mmdh1mmdh2 mutant has elevated leaf respiration rate in the dark and light, without loss of photosynthetic capacity, suggesting that mMDH normally uses NADH to reduce oxaloacetate to malate, which is then exported to the cytosol, rather than to drive mitochondrial respiration. Increased respiratory rate in leaves can account in part for the low net CO(2) assimilation and slow growth rate of mmdh1mmdh2. Loss of mMDH also affects photorespiration, as evidenced by a lower postillumination burst, alterations in CO(2) assimilation/intercellular CO(2) curves at low CO(2), and the light-dependent elevated concentration of photorespiratory metabolites. Complementation of mmdh1mmdh2 with an mMDH cDNA recovered mMDH activity, suppressed respiratory rate, ameliorated changes to photorespiration, and increased plant growth. A previously established inverse correlation between mMDH and ascorbate content in tomato (Solanum lycopersicum) has been consolidated in Arabidopsis and may potentially be linked to decreased galactonolactone dehydrogenase content in mitochondria in the mutant. Overall, a central yet complex role for mMDH emerges in the partitioning of carbon and energy in leaves, providing new directions for bioengineering of plant growth rate and a new insight into the molecular mechanisms

  7. Localization of the nucleic acid channel regulatory subunit, cytosolic malate dehydrogenase.

    Science.gov (United States)

    Hanss, Basil; Leal-Pinto, Edgar; Teixeira, Avelino; Tran, Baohuong; Lee, Chun-Hui; Henderson, Scott C; Klotman, Paul E

    2008-01-01

    NACh is a nucleic acid-conducting channel found in apical membrane of rat kidney proximal tubules. It is a heteromultimeric complex consisting of at least two proteins: a 45-kDa pore-forming subunit and a 36-kDa regulatory subunit. The regulatory subunit confers ion selectivity and influences gating kinetics. The regulatory subunit has been identified as cytosolic malate dehydrogenase (cMDH). cMDH is described in the literature as a soluble protein that is not associated with plasma membrane. Yet a role for cMDH as the regulatory subunit of NACh requires that it be present at the plasma membrane. To resolve this conflict, studies were initiated to determine whether cMDH could be found at the plasma membrane. Before performing localization studies, a suitable model system that expressed NACh was identified. A channel was identified in LLC-PK(1) cells, a line derived from pig proximal tubule, that is selective for nucleic acid and has a conductance of approximately 10 pS. It exhibits dose-dependent blockade by heparan sulfate or L-malate. These characteristics are similar to what has been reported for NACh from rat kidney and indicate that NACh is present in LLC-PK(1) cells. LLC-PK(1) cells were therefore used as a model system for immunolocalization of cMDH. Both immunofluorescence and immunoelectron microscopy demonstrated cMDH at the plasma membrane of LLC-PK(1) cells. This finding supports prior functional data that describe a role for cMDH as the regulatory subunit of NACh.

  8. Functional and prognostic significance of long non-coding RNA MALAT1 as a metastasis driver in ER negative lymph node negative breast cancer.

    Science.gov (United States)

    Jadaliha, Mahdieh; Zong, Xinying; Malakar, Pushkar; Ray, Tania; Singh, Deepak K; Freier, Susan M; Jensen, Tor; Prasanth, Supriya G; Karni, Rotem; Ray, Partha S; Prasanth, Kannanganattu V

    2016-06-28

    MALAT1 (metastasis associated lung adenocarcinoma transcript1) is a conserved long non-coding RNA, known to regulate gene expression by modulating transcription and post-transcriptional pre-mRNA processing of a large number of genes. MALAT1 expression is deregulated in various tumors, including breast cancer. However, the significance of such abnormal expression is yet to be fully understood. In this study, we demonstrate that regulation of aggressive breast cancer cell traits by MALAT1 is not predicted solely based on an elevated expression level but is context specific. By performing loss- and gain-of-function studies, both under in vitro and in vivo conditions, we demonstrate that MALAT1 facilitates cell proliferation, tumor progression and metastasis of triple-negative breast cancer (TNBC) cells despite having a comparatively lower expression level than ER or HER2-positive breast cancer cells. Furthermore, MALAT1 regulates the expression of several cancer metastasis-related genes, but displays molecular subtype specific correlations with such genes. Assessment of the prognostic significance of MALAT1 in human breast cancer (n=1992) revealed elevated MALAT1 expression was associated with decreased disease-specific survival in ER negative, lymph node negative patients of the HER2 and TNBC molecular subtypes. Multivariable analysis confirmed MALAT1 to have independent prognostic significance in the TNBC lymph node negative patient subset (HR=2.64, 95%CI 1.35- 5.16, p=0.005). We propose that the functional significance of MALAT1 as a metastasis driver and its potential use as a prognostic marker is most promising for those patients diagnosed with ER negative, lymph node negative breast cancer who might otherwise mistakenly be stratified to have low recurrence risk.

  9. The malate-aspartate NADH shuttle member Aralar1 determines glucose metabolic fate, mitochondrial activity, and insulin secretion in beta cells.

    Science.gov (United States)

    Rubi, Blanca; del Arco, Araceli; Bartley, Clarissa; Satrustegui, Jorgina; Maechler, Pierre

    2004-12-31

    The NADH shuttle system, which transports reducing equivalents from the cytosol to the mitochondria, is essential for the coupling of glucose metabolism to insulin secretion in pancreatic beta cells. Aralar1 and citrin are two isoforms of the mitochondrial aspartate/glutamate carrier, one key constituent of the malate-aspartate NADH shuttle. Here, the effects of Aralar1 overexpression in INS-1E beta cells and isolated rat islets were investigated for the first time. We prepared a recombinant adenovirus encoding for human Aralar1 (AdCA-Aralar1), tagged with the small FLAG epitope. Transduction of INS-1E cells and isolated rat islets with AdCA-Aralar1 increased aralar1 protein levels and immunostaining revealed mitochondrial localization. Compared with control INS-1E cells, overexpression of Aralar1 potentiated metabolism secretion coupling stimulated by 15 mm glucose. In particular, there was an increase of NAD(P)H generation, of mitochondrial membrane hyperpolarization, ATP levels, glucose oxidation, and insulin secretion (+45%, p < 0.01). Remarkably, this was accompanied by reduced lactate production. Rat islets overexpressing Aralar1 secreted more insulin at 16.7 mm glucose (+65%, p < 0.05) compared with controls. These results show that aspartate-glutamate carrier capacity limits glucose-stimulated insulin secretion and that Aralar1 overexpression enhances mitochondrial metabolism.

  10. Plants Possess a Cyclic Mitochondrial Metabolic Pathway similar to the Mammalian Metabolic Repair Mechanism Involving Malate Dehydrogenase and l-2-Hydroxyglutarate Dehydrogenase.

    Science.gov (United States)

    Hüdig, Meike; Maier, Alexander; Scherrers, Isabell; Seidel, Laura; Jansen, Erwin E W; Mettler-Altmann, Tabea; Engqvist, Martin K M; Maurino, Veronica G

    2015-09-01

    Enzymatic side reactions can give rise to the formation of wasteful and toxic products that are removed by metabolite repair pathways. In this work, we identify and characterize a mitochondrial metabolic repair mechanism in Arabidopsis thaliana involving malate dehydrogenase (mMDH) and l-2-hydroxyglutarate dehydrogenase (l-2HGDH). We analyze the kinetic properties of both A. thaliana mMDH isoforms, and show that they produce l-2-hydroxyglutarate (l-2HG) from 2-ketoglutarate (2-KG) at low rates in side reactions. We identify A. thaliana l-2HGDH as a mitochondrial FAD-containing oxidase that converts l-2HG back to 2-KG. Using loss-of-function mutants, we show that the electrons produced in the l-2HGDH reaction are transferred to the mitochondrial electron transport chain through the electron transfer protein (ETF). Thus, plants possess the biochemical components of an l-2HG metabolic repair system identical to that found in mammals. While deficiencies in the metabolism of l-2HG result in fatal disorders in mammals, accumulation of l-2HG in plants does not adversely affect their development under a range of tested conditions. However, orthologs of l-2HGDH are found in all examined genomes of viridiplantae, indicating that the repair reaction we identified makes an essential contribution to plant fitness in as yet unidentified conditions in the wild.

  11. The functions of an apple cytosolic malate dehydrogenase gene in growth and tolerance to cold and salt stresses.

    Science.gov (United States)

    Yao, Yu-Xin; Dong, Qing-Long; Zhai, Heng; You, Chun-Xiang; Hao, Yu-Jin

    2011-03-01

    It is well-known that cytosolic NAD-dependent malate dehydrogenase (cyMDH; l-malate:NAD-oxidoreductase; EC 1.1.1.37) is an enzyme crucial for malic acid synthesis in the cytosol. Nothing is known about cyMDH in growth and stress tolerance. Here we characterised the role of the apple cyMDH gene (MdcyMDH, GenBank ID: DQ221207) in growth and tolerance to cold and salt stresses. MdcyMDH transcripts were highly accumulated in vigorously growing apple tissues, organs and suspension cells. In addition, MdcyMDH was sensitive to cold and salt stresses. MdcyMDH overexpression favourably contributed to cell and plant growth and conferred stress tolerance both in the apple callus and tomato. Taken together, our results indicated that MdcyMDH is involved in plant and cell growth as well as the tolerance to cold and salt stresses.

  12. [The changes in complete blood count in patients treated with sunitinib malate for metastatic clear cell renal cell carcinoma].

    Science.gov (United States)

    Kucharz, Jakub; Michałowska-Kaczmarczyk, Anna; Streb, Joanna; Kuzniewski, Marek; Herman, Roman M; Krzemieniecki, Krzysztof

    2013-01-01

    Renal cell carcinoma (RCC) accounts for approximately 3% of adult malignancies. For stage I - III RCC surgery is the primary treatment. Systemic therapy is used in the patients with disseminated disease (stage IV). Sunitinib malate is commonly used in the patients with clear cell renal cell carcinoma (ccRCC) rated as 'low' or 'intermediate' risk according to the Motzer scale. Treatment with sunitinib malate is associated with myelotoxicity. To assess its clinical significance we conducted a pilot study in a group of 10 patients. We noticed a gradual decrease in the mean haemoglobin level during subsequent treatment cycles. Alternations in the platelet count were of no clinical significance. Episodes of the neutropenia were noticed in the study group. In some patients neutrophil count decreased to the level that put them at risk of the infectious complications.

  13. Long Non-Coding RNA Malat-1 Is Dispensable during Pressure Overload-Induced Cardiac Remodeling and Failure in Mice.

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    Tim Peters

    Full Text Available Long non-coding RNAs (lncRNAs are a class of RNA molecules with diverse regulatory functions during embryonic development, normal life, and disease in higher organisms. However, research on the role of lncRNAs in cardiovascular diseases and in particular heart failure is still in its infancy. The exceptionally well conserved nuclear lncRNA Metastasis associated in lung adenocarcinoma transcript 1 (Malat-1 is a regulator of mRNA splicing and highly expressed in the heart. Malat-1 modulates hypoxia-induced vessel growth, activates ERK/MAPK signaling, and scavenges the anti-hypertrophic microRNA-133. We therefore hypothesized that Malat-1 may act as regulator of cardiac hypertrophy and failure during cardiac pressure overload induced by thoracic aortic constriction (TAC in mice.Absence of Malat-1 did not affect cardiac hypertrophy upon pressure overload: Heart weight to tibia length ratio significantly increased in WT mice (sham: 5.78±0.55, TAC 9.79±1.82 g/mm; p<0.001 but to a similar extend also in Malat-1 knockout (KO mice (sham: 6.21±1.12, TAC 8.91±1.74 g/mm; p<0.01 with no significant difference between genotypes. As expected, TAC significantly reduced left ventricular fractional shortening in WT (sham: 38.81±6.53%, TAC: 23.14±11.99%; p<0.01 but to a comparable degree also in KO mice (sham: 37.01±4.19%, TAC: 25.98±9.75%; p<0.05. Histological hallmarks of myocardial remodeling, such as cardiomyocyte hypertrophy, increased interstitial fibrosis, reduced capillary density, and immune cell infiltration, did not differ significantly between WT and KO mice after TAC. In line, the absence of Malat-1 did not significantly affect angiotensin II-induced cardiac hypertrophy, dysfunction, and overall remodeling. Above that, pressure overload by TAC significantly induced mRNA levels of the hypertrophy marker genes Nppa, Nppb and Acta1, to a similar extend in both genotypes. Alternative splicing of Ndrg2 after TAC was apparent in WT (isoform ratio

  14. Role of NAD⁺-Dependent Malate Dehydrogenase in the Metabolism of Methylomicrobium alcaliphilum 20Z and Methylosinus trichosporium OB3b.

    Science.gov (United States)

    Rozova, Olga N; Khmelenina, Valentina N; Bocharova, Ksenia A; Mustakhimov, Ildar I; Trotsenko, Yuri A

    2015-02-27

    We have expressed the l-malate dehydrogenase (MDH) genes from aerobic methanotrophs Methylomicrobium alcaliphilum 20Z and Methylosinus trichosporium OB3b as his-tagged proteins in Escherichia coli. The substrate specificities, enzymatic kinetics and oligomeric states of the MDHs have been characterized. Both MDHs were NAD⁺-specific and thermostable enzymes not affected by metal ions or various organic metabolites. The MDH from M. alcaliphilum 20Z was a homodimeric (2 × 35 kDa) enzyme displaying nearly equal reductive (malate formation) and oxidative (oxaloacetate formation) activities and higher affinity to malate (Km = 0.11 mM) than to oxaloacetate (Km = 0.34 mM). The MDH from M. trichosporium OB3b was homotetrameric (4 × 35 kDa), two-fold more active in the reaction of oxaloacetate reduction compared to malate oxidation and exhibiting higher affinity to oxaloacetate (Km = 0.059 mM) than to malate (Km = 1.28 mM). The kcat/Km ratios indicated that the enzyme from M. alcaliphilum 20Z had a remarkably high catalytic efficiency for malate oxidation, while the MDH of M. trichosporium OB3b was preferable for oxaloacetate reduction. The metabolic roles of the enzymes in the specific metabolism of the two methanotrophs are discussed.

  15. Role of NAD+-Dependent Malate Dehydrogenase in the Metabolism of Methylomicrobium alcaliphilum 20Z and Methylosinus trichosporium OB3b

    Directory of Open Access Journals (Sweden)

    Olga N. Rozova

    2015-02-01

    Full Text Available We have expressed the l-malate dehydrogenase (MDH genes from aerobic methanotrophs Methylomicrobium alcaliphilum 20Z and Methylosinus trichosporium OB3b as his-tagged proteins in Escherichia coli. The substrate specificities, enzymatic kinetics and oligomeric states of the MDHs have been characterized. Both MDHs were NAD+-specific and thermostable enzymes not affected by metal ions or various organic metabolites. The MDH from M. alcaliphilum 20Z was a homodimeric (2 × 35 kDa enzyme displaying nearly equal reductive (malate formation and oxidative (oxaloacetate formation activities and higher affinity to malate (Km = 0.11 mM than to oxaloacetate (Km = 0.34 mM. The MDH from M. trichosporium OB3b was homotetrameric (4 × 35 kDa, two-fold more active in the reaction of oxaloacetate reduction compared to malate oxidation and exhibiting higher affinity to oxaloacetate (Km = 0.059 mM than to malate (Km = 1.28 mM. The kcat/Km ratios indicated that the enzyme from M. alcaliphilum 20Z had a remarkably high catalytic efficiency for malate oxidation, while the MDH of M. trichosporium OB3b was preferable for oxaloacetate reduction. The metabolic roles of the enzymes in the specific metabolism of the two methanotrophs are discussed.

  16. [Functional difference of malate-aspartate shuttle system in liver between plateau zokor (Myospalax baileyi) and plateau pika (Ochotona curzoniae)].

    Science.gov (United States)

    Zhu, Rui-Juan; Rao, Xin-Feng; Wei, Deng-Bang; Wang, Duo-Wei; Wei, Lian; Sun, Sheng-Zhen

    2012-04-25

    To explore the adaptive mechanisms of plateau zokor (Myospalax baileyi) to the enduring digging activity in the hypoxic environment and of plateau pika (Ochotona curzoniae) to the sprint running activity, the functional differences of malate-aspartate shuttle system (MA) in liver of plateau zokor and plateau pika were studied. The ratio of liver weight to body weight, the parameters of mitochondria in hepatocyte and the contents of lactic acid in serum were measured; the open reading frame of cytoplasmic malate dehydrogenase (MDH1), mitochondrial malate dehydrogenase (MDH2), and the partial sequence of aspartate glutamate carrier (AGC) and oxoglutarate malate carrier (OMC) genes were cloned and sequenced; MDH1, MDH2, AGC and OMC mRNA levels were determined by real-time PCR; the specific activities of MDH1 and MDH2 in liver of plateau zokor and plateau pika were measured using enzymatic methods. The results showed that, (1) the ratio of liver weight to body weight, the number and the specific surface of mitochondria in hepatocyte of plateau zokor were markedly higher than those of plateau pika (P 0.05); (3) mRNA level and enzymatic activity of MDH1 was significantly lower than those of MDH2 in the pika liver (P 0.05). These results indicate that the plateau zokor obtains ATP in the enduring digging activity by enhancing the function of MA, while plateau pika gets glycogen for their sprint running activity by increasing the process of gluconeogenesis. As a result, plateau pika converts the lactic acid quickly produced in their skeletal muscle by anaerobic glycolysis and reduces dependence on the oxygen.

  17. Cloning, sequencing and functional expression of cytosolic malate dehydrogenase from Taenia solium: Purification and characterization of the recombinant enzyme.

    Science.gov (United States)

    Nava, Gabriela; Laclette, Juan P; Bobes, Raúl; Carrero, Julio C; Reyes-Vivas, Horacio; Enriquez-Flores, Sergio; Mendoza-Hernández, Guillermo; Plancarte, Agustín

    2011-07-01

    We report herein the complete coding sequence of a Taenia solium cytosolic malate dehydrogenase (TscMDH). The cDNA fragment, identified from the T. solium genome project database, encodes a protein of 332 amino acid residues with an estimated molecular weight of 36517Da. For recombinant expression, the full length coding sequence was cloned into pET23a. After successful expression and enzyme purification, isoelectrofocusing gel electrophoresis allowed to confirm the calculated pI value at 8.1, as deduced from the amino acid sequence. The recombinant protein (r-TscMDH) showed MDH activity of 409U/mg in the reduction of oxaloacetate, with neither lactate dehydrogenase activity nor NADPH selectivity. Optimum pH for enzyme activity was 7.6 for oxaloacetate reduction and 9.6 for malate oxidation. K(cat) values for oxaloacetate, malate, NAD, and NADH were 665, 47, 385, and 962s(-1), respectively. Additionally, a partial characterization of TsMDH gene structure after analysis of a 1.56Kb genomic contig assembly is also reported.

  18. Ab initio calculation of the Zn isotope effect in phosphates, citrates, and malates and applications to plants and soil.

    Directory of Open Access Journals (Sweden)

    Toshiyuki Fujii

    Full Text Available Stable Zn isotopes are fractionated in roots and leaves of plants. Analyses demonstrate that the heavy Zn isotopes are enriched in the root system of plants with respect to shoots and leaves as well as the host soil, but the fractionation mechanisms remain unclear. Here we show that the origin of this isotope fractionation is due to a chemical isotope effect upon complexation by Zn malates and citrates in the aerial parts and by phosphates in the roots. We calculated the Zn isotope effect in aqueous citrates, malates, and phosphates by ab initio methods. For pH<5, the Zn isotopic compositions of the various parts of the plants are expected to be similar to those of groundwater. In the neutral to alkaline region, the calculations correctly predict that (66Zn is enriched over (64Zn in roots, which concentrate phosphates, with respect to leaves, which concentrate malates and citrates, by about one permil. It is proposed that Zn isotope fractionation represents a useful tracer of Zn availability and mobility in soils.

  19. High Performance Liquid Chromatographic Analysis of Almotriptan Malate in Bulk and Tablets

    Directory of Open Access Journals (Sweden)

    Chandra Bala Sekaran

    2013-02-01

    Full Text Available Purpose: A simple RP-HPLC method has been developed and validated for the determination of almotriptan malate (ATM in bulk and tablets. Methods: Chromatographic separation of ATM was achieved by using a Thermo Scientific C18 column. A Mobile phase containing a mixture of methanol, water and acetic acid (4:8:0.1 v/v was pumped at the flow rate of 1 mL/min. Detection was performed at 227 nm. According to ICH guidelines, the method was validated. Results: The calibration curve was linear in the concentration range 5–60 μg/mL for the ATM with regression coefficient 0.9999. The method was precise with RSD <1.2%. Excellent recoveries of 99.60 - 100.80% proved the accuracy of the method. The limits of detection and quantification were found to be 0.025 and 0.075 μg/mL, respectively. Conclusion: The method was successfully applied for the quantification of ATM in tablets with acceptable accuracy and precision.

  20. Lactate oxidation at the mitochondria: a lactate-malate-aspartate shuttle at work

    Directory of Open Access Journals (Sweden)

    Daniel A Kane

    2014-11-01

    Full Text Available Lactate, the conjugate base of lactic acid occurring in aqueous biological fluids, has been derided as a dead-end waste product of anaerobic metabolism. Catalyzed by the near-equilibrium enzyme lactate dehydrogenase (LDH, the reduction of pyruvate to lactate is thought to serve to regenerate the NAD+ necessary for continued glycolytic flux. Reaction kinetics for LDH imply that lactate oxidation is rarely favored in the tissues of its own production. However, a substantial body of research directly contradicts any notion that LDH invariably operates unidirectionally in vivo. In the current Perspective, a model is forwarded in which the continuous formation and oxidation of lactate serves as a mitochondrial electron shuttle, whereby lactate generated in the cytosol of the cell is oxidized at the mitochondria of the same cell. From this perspective, an intracellular lactate shuttle operates much like the malate-aspartate shuttle; it is also proposed that the two shuttles are necessarily interconnected. Among the requisite features of such a model, significant compartmentalization of LDH, much like the creatine kinase of the PCr shuttle, would facilitate net cellular lactate oxidation under a variety of conditions.

  1. Kinetic simulation of malate-aspartate and citrate-pyruvate shuttles in association with Krebs cycle.

    Science.gov (United States)

    Korla, Kalyani; Vadlakonda, Lakshmipathi; Mitra, Chanchal K

    2015-01-01

    In the present work, we have kinetically simulated two mitochondrial shuttles, malate-aspartate shuttle (used for transferring reducing equivalents) and citrate-pyruvate shuttle (used for transferring carbon skeletons). However, the functions of these shuttles are not limited to the points mentioned above, and they can be used in different arrangements to meet different cellular requirements. Both the shuttles are intricately associated with Krebs cycle through the metabolites involved. The study of this system of shuttles and Krebs cycle explores the response of the system in different metabolic environments. Here, we have simulated these subsets individually and then combined them to study the interactions among them and to bring out the dynamics of these pathways in focus. Four antiports and a pyruvate pump were modelled along with the metabolic reactions on both sides of the inner mitochondrial membrane. Michaelis-Menten approach was extended for deriving rate equations of every component of the system. Kinetic simulation was carried out using ordinary differential equation solver in GNU Octave. It was observed that all the components attained steady state, sooner or later, depending on the system conditions. Progress curves and phase plots were plotted to understand the steady state behaviour of the metabolites involved. A comparative analysis between experimental and simulated data show fair agreement thus validating the usefulness and applicability of the model.

  2. A Review on Molecular Physiology of Malate and Lactate Dehydrogenases in Fishes

    Institute of Scientific and Technical Information of China (English)

    G.TRIPATHI

    1993-01-01

    The malate(EC1.1.1.37)and lactate(EC1.1.1.27)dehydrogenases are the metaboliic enzymes directly or indirectly involved in energy production,gluconeogenesis and lipogenesis.Malate dehydrogenase(MDH)exists in two isoenzymic forms,cytoplasmic(cMDH)and mitochondrial(mMDH),composed of A and /or B subunits(dimeric molecule:MW 40,000-120,000).Lactate dehydrogenase(LDH)has tetrameric(W 35,000-110,000)structure made up of either A and/or B,or C(,C,E,F)subunits,They catalyze an ordered bisubstrate(substrate and coenzyme) reaction in cytosol(cMDH and LDH)and mitochondrion(mMDH)for specific purposes.The cMDH,mMDHand LDH generally exhibit the maxium velocity(Vmax)of 50-500,0.5-15,and 80-400 units/g wet wt.respectively at an optimum pH(6.5-8.0)and temperature(20-30℃).The several folds higher activity of cMDH as compared to mMDH is to carry out three different(energy production,gluconeogenesis,lipogenesis)metabolic functions rather catalysin only Krebs cycle as mMDH does.Kinetic constant(Km)of cMDH,mMDH and LDH for substrate and coenzyme varies within the rage of 0.06-0.30,0.04-0.20,and 0.04-0.50 mmol·L-1 respectively reflecting their affinities for the substrates.Activiities of these enzymes are inhibited by substrates and coenzymes both.A number of environmental and physiological signals considerably influence the enzyme activities.The extreme pH of the medium decreases the activities of cMDH,mMDH and LDH.Seasonal changes in environmental factors(temperature,photoperiod,rainfall,food availability etc.)alter enzyme activities and may affect the expression of subunits.Thermal acclimation exerts tissue and species-spectific changes in Km,activity and subunit expression of cMDH,mMDH and LDH.Activities of these enzymes substantially deline duuring starvation periods.Enzyme scaling shows a decrease in cMDH and an increase in mMDH and LDH activities as a function of increasing body-size.Metabolic hormones may either decrease or increase the activities of enzymes or they do not

  3. Interface matters: the stiffness route to stability of a thermophilic tetrameric malate dehydrogenase.

    Science.gov (United States)

    Kalimeri, Maria; Girard, Eric; Madern, Dominique; Sterpone, Fabio

    2014-01-01

    In this work we investigate by computational means the behavior of two orthologous bacterial proteins, a mesophilic and a thermophilic tetrameric malate dehydrogenase (MalDH), at different temperatures. Namely, we quantify how protein mechanical rigidity at different length- and time-scales correlates to protein thermophilicity as commonly believed. In particular by using a clustering analysis strategy to explore the conformational space of the folded proteins, we show that at ambient conditions and at the molecular length-scale the thermophilic variant is indeed more rigid that the mesophilic one. This rigidification is the result of more efficient inter-domain interactions, the strength of which is further quantified via ad hoc free energy calculations. When considered isolated, the thermophilic domain is indeed more flexible than the respective mesophilic one. Upon oligomerization, the induced stiffening of the thermophilic protein propagates from the interface to the active site where the loop, controlling the access to the catalytic pocket, anchors down via an extended network of ion-pairs. On the contrary in the mesophilic tetramer the loop is highly mobile. Simulations at high temperature, could not re-activate the mobility of the loop in the thermophile. This finding opens questions on the similarities of the binding processes for these two homologues at their optimal working temperature and suggests for the thermophilic variant a possible cooperative role of cofactor/substrate.

  4. [Effect of overexpression of malate dehydrogenase on succinic acid production in Escherichia coli NZN111].

    Science.gov (United States)

    Liang, Liya; Ma, Jiangfeng; Liu, Rongming; Wang, Guangming; Xu, Bing; Zhang, Min; Jiang, Min

    2011-07-01

    Escherichia coli NZN111 is a double mutant with lactate dehydrogenase (ldhA) and pyruvate formate-lyase (pflB) inactivated. Under anaerobic conditions, disequilibrium of coenzyme NADH and NAD+ causes Escherichia coli NZN111 losing the glucose utilizing capability. In this study, we constructed a recombinant strain E. coli NZN111/pTrc99a-mdh and overexpressed the mdh gene with 0.3 mmol/L of IPTG under anaerobic fermentation condition in sealed bottles. The specific malate dehydrogenase (MDH) activity in the recombinant strain was 14.8-fold higher than that in E. coli NZN111. The NADH/ NAD+ ratio decreased from 0.64 to 0.26 and the concentration of NAD+ and NADH increased 1.5-fold and 0.2-fold respectively. Under anaerobic conditions, the recombinant strain possessed the capability of growth and glucose absorption. We took dual-phase fermentation for succinate production. After the dry cell weight (DCW) reached 6.4 g/L under aerobic conditions, the cell culture was changed to anaerobic conditions. After 15 h, 14.75 g/L glucose was consumed and succinic acid reached 15.18 g/L. The yield of succinic acid was 1.03 g/g Glu and the productivity of succinic acid was 1.012 g/(L x h).

  5. Analysis of lactate and malate dehydrogenase enzyme profiles of selected major carps of wetland of Calcutta.

    Science.gov (United States)

    Manna, Madhumita; Chakraborty, Priyanka

    2012-07-01

    The East Calcutta Wetland (ECW), a Ramsar site in India, acts as the only sink for both city sewages as well as effluents from the surrounding small-scale industries and is alarmingly polluted with heavy metals. The three best edible major carp species rohu (Labeo rohita,), catla (Catla catla,) and mrigala (Cirrhinus mrigala) were undertaken to monitor lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) by cellulose acetate electrophoresis (CAE) to assess the effects of pollutants, if any. Crude tissue extracts were prepared from brain, eye, heart, skeletal muscle and kidney tissue respectively from each type of fish. No differences were not found in MDH of catla from both sites for all tissues analyzed in this study. Rohu also showed similar mobility for all tissues except for heart tissue which was distinctly different in fishes from ECW site than that of its counterpart from non ECW site. On the other hand, MDH of two tissues of mrigala, eye and muscle respectively showed different migration patterns. LDH profiles for all tissues of three fish species from both the sites were consistently similar, only the expression levels of muscle LDH of mrigala and kidney LDH of rohu varied little.

  6. Purification and Properties of Malate Dehydrogenase from the Extreme Thermophile Bacillus Caldolyticus

    Science.gov (United States)

    Kristjansson, Hordur; Ponnamperuma, Cyril

    1980-06-01

    The enzyme malate dehydrogenase (EC 1.1.1.37) from an extreme thermophileB. Caldolyticus was purified to about 91% homogeneity. The molar mass of the enzyme was determined as 73 000 daltons and it is composed of two subunits, each with a molar mass of 37 000. Initial velocity studies with oxaloacetic acid and NADH as substrates at pH 8.1, over a range of temperatures, indicate that the enzyme operates via a sequential type mechanism. Van't Hoff plots of the kinetic parameters displayed sharp changes in slope at characteristic temperatures, whereas the Arrhenius plot exhibited no such breaks over the temperature interval investigated. The enzyme was found to be stable at 41°C and lower temperatures. At 51°C and 59°C an almost immediate 20% reduction in activity was obtained, but no further inactivation occurred during the 60 min of incubation. At 59°C the enzyme lost 50% of its initial activity in about 38 s. High concentration of NADH was observed to greatly stabilize the enzyme at that temperature. It is suggested that the slope changes in the Van't Hoff plots and the stability profies at 51°C and 59°C are representative of a temperature induced conformational change in the enzyme.

  7. Immunological response and protection of mice immunized with plasmid encoding Toxoplasma gondii glycolytic enzyme malate dehydrogenase.

    Science.gov (United States)

    Hassan, I A; Wang, S; Xu, L; Yan, R; Song, X; XiangRui, L

    2014-12-01

    Toxoplasma gondii Malate dehydrogenase (TgMDH) plays an important role as part of the energy production cycle. In this investigation, immunological changes and protection efficiency of this protein delivered as a DNA vaccine have been evaluated. Mice were intramuscularly immunized with pTgMDH, followed by challenge with virulent T. gondii RH strain, 2 weeks after the booster immunization. Compared to the control groups, the results showed that pTgMDH has stimulated specific humoral response as demonstrated by significant high titers of total IgG and subclasses IgG1 and IgG2a , beside IgA and IgM, but not IgE. Analysis of cytokine profiles revealed significant increases of IFN-γ, IL-4 and IL-17, while no significant changes were detected in TGF-β1. In cell-mediated response, both T lymphocytes subpopulations CD4(+) and CD8(+) were positively recruited as significant percentages were recorded in response to immunization with TgMDH. Significant long survival rate, 17 days, has been observed in the TgMDH vaccinated group, in contrast with control groups which died within 8-9 days after challenge. These results demonstrated that TgMDH could induce significant immunological responses leading to a considerable level of protection against acute toxoplasmosis infection.

  8. Acetylation of malate dehydrogenase 1 promotes adipogenic differentiation via activating its enzymatic activity.

    Science.gov (United States)

    Kim, Eun Young; Kim, Won Kon; Kang, Hyo Jin; Kim, Jeong-Hoon; Chung, Sang J; Seo, Yeon Soo; Park, Sung Goo; Lee, Sang Chul; Bae, Kwang-Hee

    2012-09-01

    Acetylation is one of the most crucial post-translational modifications that affect protein function. Protein lysine acetylation is catalyzed by acetyltransferases, and acetyl-CoA functions as the source of the acetyl group. Additionally, acetyl-CoA plays critical roles in maintaining the balance between carbohydrate metabolism and fatty acid synthesis. Here, we sought to determine whether lysine acetylation is an important process for adipocyte differentiation. Based on an analysis of the acetylome during adipogenesis, various proteins displaying significant quantitative changes were identified by LC-MS/MS. Of these identified proteins, we focused on malate dehydrogenase 1 (MDH1). The acetylation level of MDH1 was increased up to 6-fold at the late stage of adipogenesis. Moreover, overexpression of MDH1 in 3T3-L1 preadipocytes induced a significant increase in the number of cells undergoing adipogenesis. The introduction of mutations to putative lysine acetylation sites showed a significant loss of the ability of cells to undergo adipogenic differentiation. Furthermore, the acetylation of MDH1 dramatically enhanced its enzymatic activity and subsequently increased the intracellular levels of NADPH. These results clearly suggest that adipogenic differentiation may be regulated by the acetylation of MDH1 and that the acetylation of MDH1 is one of the cross-talk mechanisms between adipogenesis and the intracellular energy level.

  9. Protein solvent and weak protein protein interactions in halophilic malate dehydrogenase

    Science.gov (United States)

    Ebel, Christine; Faou, Pierre; Zaccai, Giuseppe

    1999-01-01

    With the aim to correlate the solvation, stability and solubility properties of halophilic malate dehydrogenase, we characterized its weak interparticle interactions by small-angle neutron scattering in various solvents. The protein concentration dependence of the apparent radius of gyration and forward scattered intensity extrapolated from Guinier plots, and thus the second virial coefficient, A2, were determined for each solvent condition. In NaCl 1M+2-methylpentane-2,4-diol 30%, a solvent that promotes protein crystallization, A2 is negative, -0.4×10 -4 ml mol g -2 and indicating attractive interactions; in ammonium sulfate 3M, in which the protein precipitates at high concentrations, A2˜0. In 2-5M NaCl, 1-3.5M NaOAc, 1-4.5M KF or 1-2M (NH 4) 2SO 4, in which the protein is very soluble, A2 is positive with a value of the order of 0.4×10 -4 ml mol g -2 which decreases with increasing salt concentration. In MgCl 2 however, A2 increases with increasing salt concentration from 0.2 to 1.3M.

  10. Interface matters: the stiffness route to stability of a thermophilic tetrameric malate dehydrogenase.

    Directory of Open Access Journals (Sweden)

    Maria Kalimeri

    Full Text Available In this work we investigate by computational means the behavior of two orthologous bacterial proteins, a mesophilic and a thermophilic tetrameric malate dehydrogenase (MalDH, at different temperatures. Namely, we quantify how protein mechanical rigidity at different length- and time-scales correlates to protein thermophilicity as commonly believed. In particular by using a clustering analysis strategy to explore the conformational space of the folded proteins, we show that at ambient conditions and at the molecular length-scale the thermophilic variant is indeed more rigid that the mesophilic one. This rigidification is the result of more efficient inter-domain interactions, the strength of which is further quantified via ad hoc free energy calculations. When considered isolated, the thermophilic domain is indeed more flexible than the respective mesophilic one. Upon oligomerization, the induced stiffening of the thermophilic protein propagates from the interface to the active site where the loop, controlling the access to the catalytic pocket, anchors down via an extended network of ion-pairs. On the contrary in the mesophilic tetramer the loop is highly mobile. Simulations at high temperature, could not re-activate the mobility of the loop in the thermophile. This finding opens questions on the similarities of the binding processes for these two homologues at their optimal working temperature and suggests for the thermophilic variant a possible cooperative role of cofactor/substrate.

  11. Partial protective immunity against toxoplasmosis in mice elicited by recombinant Toxoplasma gondii malate dehydrogenase.

    Science.gov (United States)

    Liu, Zhuanzhuan; Yuan, Fei; Yang, Yanping; Yin, Litian; Liu, Yisheng; Wang, Yanjuan; Zheng, Kuiyang; Cao, Jianping

    2016-02-10

    Toxoplasma gondii can infect humans and wildlife, sometimes causing serious clinical presentations. Currently, no viable vaccine or effective drug strategies exist to prevent and control toxoplasmosis. T. gondii malate dehydrogenase (TgMDH) is a crucial enzyme in cellular redox reactions and has been shown to be an immunogenic compound that could be a potential vaccine candidate. Here, we investigate the protective efficacy of recombinant TgMDH (rTgMDH) against T. gondii infection in BALB/c mice. All mice were vaccinated via the nasal route. We determined the optimal vaccination dose by monitoring systemic and mucosal immune responses. The results showed that mice vaccinated with 30 μg of rTgMDH produced the highest antibody titers in serum, a strong lymphoproliferative response, marked increases in their levels of IL-2 and IFN-γ, and significantly greater levels of specific secretory IgA (sIgA) in mucosal washes. In addition, the vaccinated mice were orally challenged with tachyzoites of the virulent T. gondii RH strain 2 weeks after the final vaccination. Compared to the control group, we found that vaccination with rTgMDH increased the survival rate of infected mice by 47% and also significantly reduced the tachyzoite loads in their liver (by 58%) and brain (by 41%). Therefore, the rTgMDH protein triggers a strong systemic and mucosal immune response and provides partial protection against T. gondii infection.

  12. Regulation of human cerebrospinal fluid malate dehydrogenase 1 in sporadic Creutzfeldt-Jakob disease patients

    Science.gov (United States)

    Schmitz, Matthias; Llorens, Franc; Pracht, Alexander; Thom, Tobias; Correia, Ângela; Zafar, Saima; Ferrer, Isidre; Zerr, Inga

    2016-01-01

    The identification of reliable diagnostic biomarkers in differential diagnosis of neurodegenerative diseases is an ongoing topic. A previous two-dimensional proteomic study on cerebrospinal fluid (CSF) revealed an elevated level of an enzyme, mitochondrial malate dehydrogenase 1 (MDH1), in sporadic Creutzfeldt-Jakob disease (sCJD) patients. Here, we could demonstrate the expression of MDH1 in neurons as well as in the neuropil. Its levels are lower in sCJD brains than in control brains. An examination of CSF-MDH1 in sCJD patients by ELISA revealed a significant elevation of CSF-MDH1 levels in sCJD patients (independently from the PRNP codon 129 MV genotype or the prion protein scrapie (PrPSc) type) in comparison to controls. In combination with total tau (tau), CSF-MDH1 detection exhibited a high diagnostic accuracy for sCJD diagnosis with a sensitivity of 97.5% and a specificity of 95.6%. A correlation study of MDH1 level in CSF with other neurodegenerative marker proteins revealed a significant positive correlation between MDH1 concentration with tau, 14-3-3 and neuron specific enolase level. In conclusion, our study indicated the potential of MDH1 in combination with tau as an additional biomarker in sCJD improving diagnostic accuracy of tau markedly. PMID:27852982

  13. Mechanical and thermal properties of biodegradable hydroxyapatite/poly(sorbitol sebacate malate composites

    Directory of Open Access Journals (Sweden)

    Weng Hong Tham

    2013-02-01

    Full Text Available In this project, novel hydroxyapatite (HAp/poly(sorbitol sebacate malate (PSSM composites for potential application in soft tissue engineering were developed. The composites consist of the biodegradable polyester prepared from sorbitol,sebacic acid, malic acid and various amount of HAp (5, 10, and 15 wt%. Effects of different weight percents of HAp on theproperties of the composites were studied. Fourier transform infrared spectroscopy was performed to analyze chemical interactions between HAp/PSSM. Tensile tests and differential scanning calorimetry were conducted to evaluate the mechanicaland thermal properties of HAp/PSSM composites. Tensile testing on HAp/PSSM composites showed that their mechanicalproperties improved with increasing concentration of HAp. The Young’s modulus and tensile strength of the compositesranged from 16.20±1.73 to 23.96±2.56 MPa and 626.96±81.04 to 1,026.46±105.12 MPa, respectively. The glass transition temperature of all samples was slightly higher than room temperature.

  14. Characterization of a bifunctional glyoxylate cycle enzyme, malate synthase/isocitrate lyase, of Euglena gracilis.

    Science.gov (United States)

    Nakazawa, Masami; Nishimura, Masaaki; Inoue, Kengo; Ueda, Mitsuhiro; Inui, Hiroshi; Nakano, Yoshihisa; Miyatake, Kazutaka

    2011-01-01

    The glyoxylate cycle is a modified form of the tricarboxylic acid cycle, which enables organisms to synthesize carbohydrates from C2 compounds. In the protozoan Euglena gracilis, the key enzyme activities of the glyoxylate cycle, isocitrate lyase (ICL) and malate synthase (MS), are conferred by a single bifunctional protein named glyoxylate cycle enzyme (Euglena gracilis glyoxylate cycle enzyme [EgGCE]). We analyzed the enzymatic properties of recombinant EgGCE to determine the functions of its different domains. The 62-kDa N-terminal domain of EgGCE was sufficient to provide the MS activity as expected from an analysis of the deduced amino acid sequence. In contrast, expression of the 67-kDa C-terminal domain of EgGCE failed to yield ICL activity even though this domain was structurally similar to ICL family enzymes. Analyses of truncation mutants suggested that the N-terminal residues of EgGCE are critical for both the ICL and MS activities. The ICL activity of EgGCE increased in the presence of micro-molar concentrations of acetyl-coenzyme A (CoA). Acetyl-CoA also increased the activity in a mutant type EgGCE with a mutation at the acetyl-CoA binding site in the MS domain of EgGCE. This suggests that acetyl-CoA regulates the ICL reaction by binding to a site other than the catalytic center of the MS reaction.

  15. Alternative oxidase pathway optimizes photosynthesis during osmotic and temperature stress by regulating cellular ROS, malate valve and antioxidative systems

    Directory of Open Access Journals (Sweden)

    DINAKAR eCHALLABATHULA

    2016-02-01

    Full Text Available The present study reveals the importance of alternative oxidase (AOX pathway in optimizing photosynthesis under osmotic and temperature stress conditions in the mesophyll protoplasts of Pisum sativum. The responses of photosynthesis and respiration were monitored at saturating light intensity of 1000 µmoles m-2 s-1 at 25 oC under a range of sorbitol concentrations from 0.4 M to 1.0M to induce hyper-osmotic stress and by varying the temperature of the thermo-jacketed pre-incubation chamber from 25 oC to 10 oC to impose sub-optimal temperature stress. Compared to controls (0.4 M sorbitol and 25 OC, the mesophyll protoplasts showed remarkable decrease in NaHCO3-dependent O2 evolution (indicator of photosynthetic carbon assimilation, under both hyper-osmotic (1.0 M sorbitol and sub-optimal temperature stress conditions (10 OC, while the decrease in rates of respiratory O2 uptake were marginal. The capacity of AOX pathway increased significantly in parallel to increase in intracellular pyruvate and reactive oxygen species (ROS levels under both hyper-osmotic stress and sub-optimal temperature stress under the background of saturating light. The ratio of redox couple (Malate/OAA related to malate valve increased in contrast to the ratio of redox couple (GSH/GSSG related to antioxidative system during hyper-osmotic stress. Nevertheless, the ratio of GSH/GSSG decreased in the presence of sub-optimal temperature, while the ratio of Malate/OAA showed no visible changes. Also, the redox ratios of pyridine nucleotides increased under hyper-osmotic (NADH/NAD and sub-optimal temperature (NADPH/NADP stresses, respectively. However, upon restriction of AOX pathway by using salicylhydroxamic acid (SHAM, the observed changes in NaHCO3 dependent O2 evolution, cellular ROS, redox ratios of Malate/OAA, NAD(PH/NAD(P and GSH/GSSG were further aggravated under stress conditions with concomitant modulations in NADP-MDH and antioxidant enzymes. Taken together, the

  16. Effect of Nitric Oxide on the Interaction Between Mitochondrial Malate Dehydrogenase and Citrate Synthase

    Institute of Scientific and Technical Information of China (English)

    LIU Yu-chen; WANG Juan; SU Pei-ying; MA Chun-mei; ZHU Shu-hua

    2014-01-01

    Mitochondrial malate dehydrogenase (mMDH) and citrate synthase (CS) are sequential enzymes in Krebs cycle. mMDH, CS and the complex between mMDH and CS (mMDH+CS) were treated with nitric oxide solution. The roles of notric oxide (NO) on the secondary structures and the interactions between mMDH and CS were studied using circular diehroism (CD) and Fourier transform surface plasmon resonance (FT-SPR), respectivley. The effects of NO on the activities of mMDH, CS and mMDH+CS were also studied. And the regulations by NO on mMDH and CS were simulated by PyMOL software. The results of SPR conifrmed that strong interaction between mMDH and CS existed and NO could signiifcantly regulate the interaction between the two enzymes. NO reduced the mass percents ofα-helix and increased that of random in mMDH, CS and mMDH+CS. NO increased the activities of CS and mMDH+CS, and inhibited the activity of mMDH. Graphic simulation indicated that covalent bond was formed between NO and Asn242 in active site of CS. However, there was no direct bond between NO and mMDH. The increase in activity of mMDH+CS complex depended mostly on the interaction between NO and CS. All the results suggested that the regulations by NO on the activity and interaction between mMDH and CS were accord with the changes in mMDH, CS and mMDH+CS caused by NO.

  17. Evaluation of Tear Malate Dehydrogenase 2 in Mild Dry Eye Disease

    Institute of Scientific and Technical Information of China (English)

    Qing Guo; Houbin Huang; Yuli Pi; Hancheng Zhang

    2014-01-01

    Purpose: To evaluate the effect of tear malate dehydrogenase 2 on monitoring ocular surface injury in mild dry eye (DE) disease. Methods: A total of 15 DE patients (30 eyes) with mild sub-jective symptoms but no ocular surface fluorescein staining signs were enrolled in this study. (DE group)..The control group was 15 healthy age- and sex-matched volunteers (30 eyes)..All subjects were asked to fill out a DE symptoms questionnaire and take different tests including tear MDH and MDH2 activities evaluation,..tear breakup time. (TBUT), Schirmer I,.and slit-lamp examination of the ocular surface. We investigated different changes in tear MDH and MDH2 ac-tivities in the DE group and control group,.discussed the as-sociation between tear MDH2 activity and DE symptoms, and the relationship between tear MDH2 activity and diagnostic tests (Schirmer I and TBUT). We also analyzed the changes in tear MDH2 activities after the treatment with artificial tears. Results:.Tear MDH activities in the DE group and control group were 288 ±102 U/L and 259 ±112 U/L,.respectively, and this difference was not statistically significant (P>0.05). The tear MDH2 activities in DE group were significantly in-creased compared with control group. Tear MDH2 was signif-icantly and negatively correlated with the Schirmer’s value (r=-0.733,P Conclusion: Tear MDH2 activity can indicate ocular surface injury in mild DE patients and may be used to monitor the re-sponse to therapy.

  18. Cloning, overexpression, purification and crystallization of malate dehydrogenase from Thermus thermophilus.

    Science.gov (United States)

    Chang, Yu-Yung; Hung, Chih-Hung; Hwang, Tzann-Shun; Hsu, Chun-Hua

    2013-11-01

    Malate dehydrogenase (MDH) has been used as a conjugate for enzyme immunoassay of a wide variety of compounds, such as drugs of abuse, drugs used in repetitive therapeutic application and hormones. In consideration of the various biotechnological applications of MDH, investigations of MDH from Thermus thermophilus were carried out to further understand the properties of this enzyme. The DNA fragment containing the open reading frame of mdh was amplified from the genomic DNA of T. thermophilus and cloned into the expression vector pET21b(+). The protein was expressed in a soluble form in Escherichia coli strain BL21(DE3). Homogeneous protein was obtained using a three-step procedure consisting of thermal treatment, Ni(2+)-chelating chromatography and size-exclusion chromatography. The purified MDH was crystallized and the crystals diffracted to a resolution of 1.80 Å on the BL13C1 beamline of the National Synchrotron Radiation Research Center (NSRRC), Taiwan. The crystals belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 71.3, b = 86.1, c = 118.2 Å. The unit-cell volume of the crystal is compatible with the presence of two monomers in the asymmetric unit, with a corresponding Matthews coefficient VM of 2.52 Å(3) Da(-1) and a solvent content of 51.2%. The crystal structure of MDH has been solved by molecular replacement and is currently under refinement.

  19. Validation and application of reversed phase high-performance liquid chromatographic method for quantification of pizotifen malate in pharmaceutical solid dosage formulations.

    Science.gov (United States)

    Rahman, Shaikh Mukidur; Lutfulkabir, Abulkalam; Jahan, M D Arshad; Momen, A Z M Ruhul; Rouf, Abushara Shamsur

    2010-10-01

    The aim of this study was to develop and validate an isocratic reversed phase high-performance liquid chromatographic method for quantification of pizotifen malate in pharmaceutical solid dosage formulations. Good chromatographic separation of pizotifen malate was achieved by using an analytical column, C(18) ODS column. The system was operated at 40°C oven temperature using a mobile phase consisting of acetonitrile and acetate buffer pH 7.0 (60:40) at a flow rate of 2 ml/min. The method showed high sensitivity with good linearity (r(2)= 0.99997) over the tested concentration range of 0.0020-0.0300 mg/ml for pizotifen malate. Detection was carried out at 231 nm and retention time was 2.838 min. Placebo and blank studies were performed and no peak was observed at the retention time of pizotifen malate. The intermediate precision and accuracy results (mean ± RSD, n=3) were (99.11±0.21) % and (99.19±0.55) % respectively with tailing factor (1.26±0.19). The proposed method was validated in terms of selectivity, linearity, accuracy, precision, range, detection and quantitation limit, system suitability and solution stability.This method can be successfully employed for simultaneous quantitative analysis of pizotifen malate in pharmaceutical solid dosage formulations.

  20. Pengaruh Pengasapan (Thermal Fogging Insektisida Piretroid (Malation 95% Terhadap Nyamuk Aedes aegypti dan Culex quinquefasciatus di Pemukiman

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    Hasan Boesri

    2009-12-01

    Full Text Available The evaluation of piretroid insecticide (active ingredient Malation 95% was con-ducted in Sub district Tengarang, Semarang Segency, Central Java Province. The insecti-cide was applied using thermal fogging method for dosages of 125, 250, 375, 500 and 625 ml/ha (diluted in diesel to 10 litters. The evaluation of the efficacy was conducted against two mosquito species, Aedes aegypti (the main dengue haemorrhagic fever and Culex quinquefasciatus (the urban lymphatic fil-ariasis vector. Result of the evaluation was revealed that dosages of 500 and 625 ml/ha were effective against both tested mosquito species indoor and outdoor.

  1. Phosphofructokinase and malate dehydrogenase participate in the in vitro maturation of porcine oocytes.

    Science.gov (United States)

    Breininger, E; Vecchi Galenda, B E; Alvarez, G M; Gutnisky, C; Cetica, P D

    2014-12-01

    Oocyte maturation depends on the metabolic activity of cumulus-oocyte complex (COC) that performs nutritive and regulatory functions during this process. In this work, the enzymes [phosphofructokinase (PFK) and malate dehydrogenase (MDH)] were tested to elucidate the metabolic profile of porcine COCs during the in vitro maturation (IVM). Enzymatic activity was expressed in U/COC and U/mg protein (specific activity) as mean ± SEM. In vitro maturation was performed with 2-oxoglutarate (5, 10 and 20 mm) or hydroxymalonate (30, 60 and 100 mm) inhibitors of PFK and MDH, respectively. The PFK and MDH activities (U) remained constant during maturation. For PFK, the U were (2.48 ± 0.23) 10(-5) and (2.54 ± 0.32) 10(-5) , and for MDH, the U were (4.72 ± 0.42) 10(-5) and (4.38 ± 0.25) 10(-5) for immature and in vitro matured COCs, respectively. The specific activities were significantly lower after IVM, for PFK (4.29 ± 0.48) 10(-3) and (0.94 ± 0.12) 10(-3) , and for MDH (9.08 ± 0.93) 10(-3) and (1.89 ± 0.10) 10(-3) for immature and in vitro matured COCs, respectively. In vitro maturation percentages and enzymatic activity diminished with 20 mm 2-oxoglutarate or 60 mm hydroxymalonate (p < 0.05). Viability was not affected by any concentration of the inhibitors evaluated. The U remained unchanged during IVM; however, the increase in the total protein content per COC provoked a decrease in the specific activity of both enzymes. Phosphofructokinase and MDH necessary for oocyte IVM would be already present in the immature oocyte. The presence of inhibitors of these enzymes impairs the meiotic maturation. Therefore, the participation of these enzymes in the energy metabolism of the porcine oocyte during IVM is confirmed in this study.

  2. QUANTITATIVE ASSAY OF ALMOTRIPTAN MALATE IN PURE DRUG AND PHARMACEUTICAL PREPARATIONS USING SIMPLE AND CONVENIENT VISIBLE SPECTROPHOTOMETRIC METHODS

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    U. VIPLOVA PRASAD

    2012-05-01

    Full Text Available Two direct, simple and sensitive visible spectrophotometric methods (M1&M2 are described for the assay of almotripan malate in pure and solid dosage forms. The method M1 involves oxidative coupling of drug with brucine in presence of sodium meta periodate and purple red colored species is formed and exhibits absorption maxima at 520nm. The method M2 is based on the formation of yellowish brown colored species by the drug with Folin reagent and exhibits absorption maxima at 450nm. Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges (8.0-24 μg/ml for method M1, (16-48 μg/ml for method M2 respectively. The proposed methods are applied to commercial available tablets and the results are statistically compared with those obtained by the reported UV reference method and validated by recovery studies. The results are found satisfactory and reproducible. These methods are applied successfully for the estimation of the almotriptan malate in the presence of other ingredients that are usually present in dosageforms. These methods offer the advantages of rapidity, simplicity and sensitivity and normal cost and can be easily applied to resource-poor settings without the need for expensive instrumentation and reagents.

  3. Crystal structures and molecular dynamics simulations of thermophilic malate dehydrogenase reveal critical loop motion for co-substrate binding.

    Science.gov (United States)

    Hung, Chih-Hung; Hwang, Tzann-Shun; Chang, Yu-Yung; Luo, Huei-Ru; Wu, Szu-Pei; Hsu, Chun-Hua

    2013-01-01

    Malate dehydrogenase (MDH) catalyzes the conversion of oxaloacetate and malate by using the NAD/NADH coenzyme system. The system is used as a conjugate for enzyme immunoassays of a wide variety of compounds, such as illegal drugs, drugs used in therapeutic applications and hormones. We elucidated the biochemical and structural features of MDH from Thermus thermophilus (TtMDH) for use in various biotechnological applications. The biochemical characterization of recombinant TtMDH revealed greatly increased activity above 60 °C and specific activity of about 2,600 U/mg with optimal temperature of 90 °C. Analysis of crystal structures of apo and NAD-bound forms of TtMDH revealed a slight movement of the binding loop and few structural elements around the co-substrate binding packet in the presence of NAD. The overall structures did not change much and retained all related positions, which agrees with the CD analyses. Further molecular dynamics (MD) simulation at higher temperatures were used to reconstruct structures from the crystal structure of TtMDH. Interestingly, at the simulated structure of 353 K, a large change occurred around the active site such that with increasing temperature, a mobile loop was closed to co-substrate binding region. From biochemical characterization, structural comparison and MD simulations, the thermal-induced conformational change of the co-substrate binding loop of TtMDH may contribute to the essential movement of the enzyme for admitting NAD and may benefit the enzyme's activity.

  4. Inhibition of corneal neovascularization with new Tyrosine Kinase Inhibitors targeting vascular endothelial growth factor receptors: Sunitinib malate and Sorafenib

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    Delnia Arshadi

    2007-06-01

    Full Text Available Corneal neovascularization (NV is a significant, sight-threatening, complication of many ocular surface disorders. Presence of new vessels in cornea can compromise clarity and thus vision. The data supporting a causal role for vascular endothelial growth factor (VEGF in corneal NV are extensive. Inhibition of VEGF remains as a main strategy for treating corneal NV. There is a growing body of evidence that corneal NV can be reduced by using anti-VEGF agents. Sunitinib malate and Sorafenib are new orally bio-available anti-angiogenic agents undergoing tests of efficacy in the treatment of various types of cancers. The main mechanism of these drugs is inhibiting angiogenesis by diminishing signaling through VEGF receptor1 (VEGFR1, VEGFR2, and platelet-derived growth factor receptors. Since VEGF exerts its angiogenic effects through tyrosine kinase receptors in cornea, any mechanisms which reduce VEGF signaling may inhibit corneal NV or at least attenuate it. Based on this fact we herein hypothesize that Sunitinib malate and Sorafenib can be prepared in topical form and be used in corneal neovascularization states. These approaches offer new hope for the successful treatment of corneal NV. Further investigations in animal models are needed to place these two drugs alongside corneal NV therapeutics.

  5. Independent fluctuations of malate and citrate in the CAM species Clusia hilariana Schltdl. under low light and high light in relation to photoprotection.

    Science.gov (United States)

    Miszalski, Zbigniew; Kornas, Andrzej; Rozpądek, Piotr; Fischer-Schliebs, Elke; Lüttge, Ulrich

    2013-03-15

    Clusia hilariana Schltdl. is described in literature as an obligate Crassulacean acid metabolism (CAM) species. In the present study we assessed the effect of irradiance with low light (LL, 200μmolm(-2)s(-1)) and high light (HL, 650-740μmolm(-2)s(-1)), on the interdependency of citrate and malate diurnal fluctuations. In plants grown at HL CAM-type oscillations of concentration of citrate and malate were obvious. However, at LL daily courses of both acids do not seem to indicate efficient utilization of these compounds as CO2 and NADPH sources. One week after transferring plants from LL to HL decarboxylation of malate was accelerated. Thus, in the CAM plant C. hilariana two independent rhythms of accumulation and decarboxylation of malate and citrate take place, which appear to be related to photosynthesis and respiration, respectively. Non photochemical quenching (NPQ) of photosystem II, especially well expressed during the evening hours was enhanced. Exposure to HL for 7 d activated oxidative stress protection mechanisms such as the interconversion of violaxanthin (V), antheraxanthin (A) and zeaxanthin (Z) (epoxydation/de-epoxydation) measured as epoxydation state (EPS). This was accompanied by a slight increase in the total amount of these pigments. However, all these changes were not observed in plants exposed to HL for only 2 d. Besides violaxanthin cycle components also lutein, which shows a small, but not significant increase, may be involved in dissipating excess light energy in C. hilariana.

  6. Crystal structures of a halophilic archaeal malate synthase from Haloferax volcanii and comparisons with isoforms A and G

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    Thomas Geoffrey C

    2011-05-01

    Full Text Available Abstract Background Malate synthase, one of the two enzymes unique to the glyoxylate cycle, is found in all three domains of life, and is crucial to the utilization of two-carbon compounds for net biosynthetic pathways such as gluconeogenesis. In addition to the main isoforms A and G, so named because of their differential expression in E. coli grown on either acetate or glycolate respectively, a third distinct isoform has been identified. These three isoforms differ considerably in size and sequence conservation. The A isoform (MSA comprises ~530 residues, the G isoform (MSG is ~730 residues, and this third isoform (MSH-halophilic is ~430 residues in length. Both isoforms A and G have been structurally characterized in detail, but no structures have been reported for the H isoform which has been found thus far only in members of the halophilic Archaea. Results We have solved the structure of a malate synthase H (MSH isoform member from Haloferax volcanii in complex with glyoxylate at 2.51 Å resolution, and also as a ternary complex with acetyl-coenzyme A and pyruvate at 1.95 Å. Like the A and G isoforms, MSH is based on a β8/α8 (TIM barrel. Unlike previously solved malate synthase structures which are all monomeric, this enzyme is found in the native state as a trimer/hexamer equilibrium. Compared to isoforms A and G, MSH displays deletion of an N-terminal domain and a smaller deletion at the C-terminus. The MSH active site is closely superimposable with those of MSA and MSG, with the ternary complex indicating a nucleophilic attack on pyruvate by the enolate intermediate of acetyl-coenzyme A. Conclusions The reported structures of MSH from Haloferax volcanii allow a detailed analysis and comparison with previously solved structures of isoforms A and G. These structural comparisons provide insight into evolutionary relationships among these isoforms, and also indicate that despite the size and sequence variation, and the truncated C

  7. Alteration of coenzyme specificity of malate dehydrogenase from Streptomyces coelicolor A3(2) by site-directed mutagenesis.

    Science.gov (United States)

    Ge, Y D; Song, P; Cao, Z Y; Wang, P; Zhu, G P

    2014-07-29

    We describe here for the first time the alteration of coenzyme specificity of malate dehydrogenase (MDH) from Streptomyces coelicolor A3(2) (ScMDH). In the present study, we replaced four amino acid residues in the Rossmann fold (βB-αC) region of NADH-dependent ScMDH by site-directed mutagenesis with those of NADPH-dependent MDH (Glu42Gly, Ile43Ser, Pro45Arg, and Ala46Ser). The coenzyme specificity of the mutant enzyme (ScMDH-T4) was examined. Coenzyme specificity of ScMDH-T4 was shifted 2231.3-fold toward NADPH using kcat/Km(coenzyme) as the measurement of coenzyme specificity. Accordingly, the effect of the replacements on coenzyme specificity is discussed. Our work provides further insight into the coenzyme specificity of ScMDH.

  8. Effects of Supplemental Citrulline-Malate Ingestion on Blood Lactate, Cardiovascular Dynamics, and Resistance Exercise Performance in Trained Males.

    Science.gov (United States)

    Wax, Benjamin; Kavazis, Andreas N; Luckett, William

    2016-01-01

    Citrulline-malate (CM) has been proposed to provide an ergogenic effect during resistance exercise; however, there is a paucity of research investigating these claims. Therefore, we investigated the impact that CM supplementation would have on repeated bouts of resistance exercise. Fourteen resistance-trained males participated in a randomized, counterbalanced, double-blind study. Subjects were randomly assigned to placebo (PL) or CM (8 g) and performed three sets each of chin-ups, reverse chin-ups, and push-ups to failure. One week later, subjects ingested the other supplement and performed the same protocol. Blood lactate (BLa), heart rate (HR), and blood pressure (BP) were measured preexercise, with BLa measured a second time immediately following the last set, while HR and BP were measured 5 and 10 min postexercise. Citrulline-malate ingestion significantly increased the amount of repetitions performed for each exercise (chin-ups: PL = 28.4 ± 7.1, CM = 32.2 ± 5.6, p = .003; reverse chin-ups: PL = 26.6 ± 5.6, CM = 32.1 ± 7.1, p = .017; push-ups: PL = 89.1 ± 37.4, CM = 97.7 ± 36.1, p < .001). Blood lactate data indicated a time effect (p < .001), but no treatment differences (p = .935). Systolic BP data did not show differences for time (p = .078) or treatment (p = .119). Diastolic BP data did not show differences for time (p = .069), but indicated treatment differences (p = .014) for subjects ingesting CM. Collectively, these findings suggests that CM increased upper-body resistance performance in trained college-age males.

  9. Reduced mitochondrial malate dehydrogenase activity has a strong effect on photorespiratory metabolism as revealed by 13C labelling.

    Science.gov (United States)

    Lindén, Pernilla; Keech, Olivier; Stenlund, Hans; Gardeström, Per; Moritz, Thomas

    2016-05-01

    Mitochondrial malate dehydrogenase (mMDH) catalyses the interconversion of malate and oxaloacetate (OAA) in the tricarboxylic acid (TCA) cycle. Its activity is important for redox control of the mitochondrial matrix, through which it may participate in regulation of TCA cycle turnover. In Arabidopsis, there are two isoforms of mMDH. Here, we investigated to which extent the lack of the major isoform, mMDH1 accounting for about 60% of the activity, affected leaf metabolism. In air, rosettes of mmdh1 plants were only slightly smaller than wild type plants although the fresh weight was decreased by about 50%. In low CO2 the difference was much bigger, with mutant plants accumulating only 14% of fresh weight as compared to wild type. To investigate the metabolic background to the differences in growth, we developed a (13)CO2 labelling method, using a custom-built chamber that enabled simultaneous treatment of sets of plants under controlled conditions. The metabolic profiles were analysed by gas- and liquid- chromatography coupled to mass spectrometry to investigate the metabolic adjustments between wild type and mmdh1 The genotypes responded similarly to high CO2 treatment both with respect to metabolite pools and (13)C incorporation during a 2-h treatment. However, under low CO2 several metabolites differed between the two genotypes and, interestingly most of these were closely associated with photorespiration. We found that while the glycine/serine ratio increased, a concomitant altered glutamine/glutamate/α-ketoglutarate relation occurred. Taken together, our results indicate that adequate mMDH activity is essential to shuttle reductants out from the mitochondria to support the photorespiratory flux, and strengthen the idea that photorespiration is tightly intertwined with peripheral metabolic reactions.

  10. On the consequences of aluminium stress in rye: repression of two mitochondrial malate dehydrogenase mRNAs.

    Science.gov (United States)

    Abd El-Moneim, D; Contreras, R; Silva-Navas, J; Gallego, F J; Figueiras, A M; Benito, C

    2015-01-01

    Plants have developed several external and internal aluminium (Al) tolerance mechanisms. The external mechanism best characterised is the exudation of organic acids induced by Al. Rye (Secale cereale L.), one of the most Al-tolerant cereal crops, secretes both citrate and malate from its roots in response to Al. However, the role of malate dehydrogenase (MDH) genes in Al-induced stress has not been studied in rye. We have isolated the ScMDH1 and ScMDH2 genes, encoding two different mitochondrial MDH isozymes, in three Al-tolerant rye cultivars (Ailés, Imperial and Petkus) and one sensitive inbred rye line (Riodeva). These genes, which have seven exons and six introns, were located on the 1R (ScMDH1) and 3RL (ScMDH2) chromosomes. Exon 1 of ScMDH1 and exon 7 of ScMDH2 were the most variable among the different ryes. The hypothetical proteins encoded by these genes were classified as putative mitochondrial MDH isoforms. The phylogenetic relationships obtained using both cDNA and protein sequences indicated that the ScMDH1 and ScMDH2 proteins are orthologous to mitochondrial MDH1 and MDH2 proteins of different Poaceae species. The expression studies of the ScMDH1 and ScMDH2 genes indicate that it is more intense in roots than in leaves. Moreover, the amount of their corresponding mRNAs in roots from plants treated and not treated with Al was higher in the tolerant cultivar Petkus than in the sensitive inbred line Riodeva. In addition, ScMDH1 and ScMDH2 mRNA levels decreased in response to Al stress (repressive behaviour) in the roots of both the tolerant Petkus and the sensitive line Riodeva.

  11. l-Lactate metabolism in HEP G2 cell mitochondria due to the l-lactate dehydrogenase determines the occurrence of the lactate/pyruvate shuttle and the appearance of oxaloacetate, malate and citrate outside mitochondria.

    Science.gov (United States)

    Pizzuto, Roberto; Paventi, Gianluca; Porcile, Carola; Sarnataro, Daniela; Daniele, Aurora; Passarella, Salvatore

    2012-09-01

    As part of an ongoing study of l-lactate metabolism both in normal and in cancer cells, we investigated whether and how l-lactate metabolism occurs in mitochondria of human hepatocellular carcinoma (Hep G2) cells. We found that Hep G2 cell mitochondria (Hep G2-M) possess an l-lactate dehydrogenase (ml-LDH) restricted to the inner mitochondrial compartments as shown by immunological analysis, confocal microscopy and by assaying ml-LDH activity in solubilized mitochondria. Cytosolic and mitochondrial l-LDHs were found to differ from one another in their saturation kinetics. Having shown that l-lactate itself can enter Hep G2 cells, we found that Hep G2-M swell in ammonium l-lactate, but not in ammonium pyruvate solutions, in a manner inhibited by mersalyl, this showing the occurrence of a carrier-mediated l-lactate transport in these mitochondria. Occurrence of the l-lactate/pyruvate shuttle and the appearance outside mitochondria of oxaloacetate, malate and citrate arising from l-lactate uptake and metabolism together with the low oxygen consumption and membrane potential generation are in favor of an anaplerotic role for l-LAC in Hep G2-M.

  12. Crystallization and preliminary X-ray diffraction studies of tetrameric malate dehydrogenase from the novel Antarctic psychrophile Flavobacterium frigidimaris KUC-1

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Tomomi [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Oikawa, Tadao; Muraoka, Ikuo [Department of Life Science and Biotechnology, Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita, Osaka 564-8680 (Japan); Soda, Kenji [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Department of Life Science and Biotechnology, Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita, Osaka 564-8680 (Japan); Hata, Yasuo, E-mail: hata@scl.kyoto-u.ac.jp [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2007-11-01

    A psychrophilic malate dehydrogenase from the novel Antarctic bacterium F. frigidimaris KUC-1 was crystallized using the hanging-drop vapour-diffusion method. The crystals contained one tetrameric molecule per asymmetric unit. The best crystal diffracted to 1.8 Å resolution. Flavobacterium frigidimaris KUC-1 is a novel psychrotolerant bacterium isolated from Antarctic seawater. Malate dehydrogenase (MDH) is an essential metabolic enzyme in the citric acid cycle and has been cloned, overexpressed and purified from F. frigidimaris KUC-1. In contrast to the already known dimeric form of MDH from the psychrophile Aquaspirillium arcticum, F. frigidimaris MDH exists as a tetramer. It was crystallized at 288 K by the hanging-drop vapour-diffusion method using ammonium sulfate as the precipitating agent. The crystal diffracted to a maximum resolution of 1.80 Å. It contains one tetrameric molecule in the asymmetric unit.

  13. Brucine salts of L-alpha-hydroxy acids: brucinium hydrogen (S)-malate pentahydrate and anhydrous brucinium hydrogen (2R,3R)-tartrate at 130 K.

    Science.gov (United States)

    Smith, Graham; Wermuth, Urs D; White, Jonathan M

    2006-06-01

    The structures of two brucinium (2,3-dimethoxy-10-oxostrychnidinium) salts of the alpha-hydroxy acids L-malic acid and L-tartaric acid, namely brucinium hydrogen (S)-malate pentahydrate, C23H27N2O4+.C4H5O5-.5H2O, (I), and anhydrous brucinium hydrogen (2R,3R)-tartrate, C23H27N2O4+.C4H5O6-,(II), have been determined at 130 K. Compound (I) has two brucinium cations, two hydrogen malate anions and ten water molecules of solvation in the asymmetric unit, and forms an extensively hydrogen-bonded three-dimensional framework structure. In compound (II), the brucinium cations form the common undulating brucine sheet substructures, which accommodate parallel chains of head-to-tail hydrogen-bonded tartrate anion species in the interstitial cavities.

  14. Structure and function of Plasmodium falciparum malate dehydrogenase: role of critical amino acids in co-substrate binding pocket.

    Science.gov (United States)

    Pradhan, Anupam; Tripathi, Abhai K; Desai, Prashant V; Mukherjee, Prasenjit K; Avery, Mitchell A; Walker, Larry A; Tekwani, Babu L

    2009-01-01

    The malaria parasite thrives on anaerobic fermentation of glucose for energy. Earlier studies from our laboratory have demonstrated that a cytosolic malate dehydrogenase (PfMDH) with striking similarity to lactate dehydrogenase (PfLDH) might complement PfLDH function in Plasmodium falciparum. The N-terminal glycine motif, which forms a characteristic Rossman dinucleotide-binding fold in the co-substrate binding pocket, differentiates PfMDH (GlyXGlyXXGly) from other eukaryotic and prokaryotic malate dehydrogenases (GlyXXGlyXXGly). The amino acids lining the co-substrate binding pocket are completely conserved in MDHs from different species of human, primate and rodent malaria parasites. Based on this knowledge and conserved domains among prokaryotic and eukaryotic MDH, the role of critical amino acids lining the co-substrate binding pocket was analyzed in catalytic functions of PfMDH using site-directed mutagenesis. Insertion of Ala at the 9th or 10th position, which converts the N-terminal GlyXGlyXXGly motif (characteristic of malarial MDH and LDH) to GlyXXGlyXXGly (as in bacterial and eukaryotic MDH), uncoupled regulation of the enzyme through substrate inhibition. The dinucleotide fold GlyXGlyXXGly motif seems not to be responsible for the distinct affinity of PfMDH to 3-acetylpyridine-adenine dinucleotide (APAD, a synthetic analog of NAD), since Ala9 and Ala10 insertion mutants still utilized APADH. The Gln11Met mutation, which converts the signature glycine motif in PfMDH to that of PfLDH, did not change the enzyme function. However, the Gln11Gly mutant showed approximately a 5-fold increase in catalytic activity, and higher susceptibility to inhibition with gossypol. Asn119 and His174 participate in binding of both co-substrate and substrate. The Asn119Gly mutant exhibited approximately a 3-fold decrease in catalytic efficiency, while mutation of His174 to Asn or Ala resulted in an inactive enzyme. These studies provide critical insights into the co

  15. Cyanide degradation by Pseudomonas pseudoalcaligenes CECT5344 involves a malate:quinone oxidoreductase and an associated cyanide-insensitive electron transfer chain.

    Science.gov (United States)

    Luque-Almagro, Victor M; Merchán, Faustino; Blasco, Rafael; Igeño, M Isabel; Martínez-Luque, Manuel; Moreno-Vivián, Conrado; Castillo, Francisco; Roldán, M Dolores

    2011-03-01

    The alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344 is able to grow with cyanide as the sole nitrogen source. Membrane fractions from cells grown under cyanotrophic conditions catalysed the production of oxaloacetate from L-malate. Several enzymic activities of the tricarboxylic acid and glyoxylate cycles in association with the cyanide-insensitive respiratory pathway seem to be responsible for the oxaloacetate formation in vivo. Thus, in cyanide-grown cells, citrate synthase and isocitrate lyase activities were significantly higher than those observed with other nitrogen sources. Malate dehydrogenase activity was undetectable, but a malate:quinone oxidoreductase activity coupled to the cyanide-insensitive alternative oxidase was found in membrane fractions from cyanide-grown cells. Therefore, oxaloacetate production was linked to the cyanide-insensitive respiration in P. pseudoalcaligenes CECT5344. Cyanide and oxaloacetate reacted chemically inside the cells to produce a cyanohydrin (2-hydroxynitrile), which was further converted to ammonium. In addition to cyanide, strain CECT5344 was able to grow with several cyano derivatives, such as 2- and 3-hydroxynitriles. The specific system required for uptake and metabolization of cyanohydrins was induced by cyanide and by 2-hydroxynitriles, such as the cyanohydrins of oxaloacetate and 2-oxoglutarate.

  16. The mitochondrial malate dehydrogenase 1 gene GhmMDH1 is involved in plant and root growth under phosphorus deficiency conditions in cotton.

    Science.gov (United States)

    Wang, Zhi-An; Li, Qing; Ge, Xiao-Yang; Yang, Chun-Lin; Luo, Xiao-Li; Zhang, An-Hong; Xiao, Juan-Li; Tian, Ying-Chuan; Xia, Gui-Xian; Chen, Xiao-Ying; Li, Fu-Guang; Wu, Jia-He

    2015-07-16

    Cotton, an important commercial crop, is cultivated for its natural fibers, and requires an adequate supply of soil nutrients, including phosphorus, for its growth. Soil phosporus exists primarily in insoluble forms. We isolated a mitochondrial malate dehydrogenase (MDH) gene, designated as GhmMDH1, from Gossypium hirsutum L. to assess its effect in enhancing P availability and absorption. An enzyme kinetic assay showed that the recombinant GhmMDH1 possesses the capacity to catalyze the interconversion of oxaloacetate and malate. The malate contents in the roots, leaves and root exudates was significantly higher in GhmMDH1-overexpressing plants and lower in knockdown plants compared with the wild-type control. Knockdown of GhmMDH1 gene resulted in increased respiration rate and reduced biomass whilst overexpression of GhmMDH1 gave rise to decreased respiration rate and higher biomass in the transgenic plants. When cultured in medium containing only insoluble phosphorus, Al-phosphorus, Fe-phosphorus, or Ca-phosphorus, GhmMDH1-overexpressing plants produced significantly longer roots and had a higher biomass and P content than WT plants, however, knockdown plants showed the opposite results for these traits. Collectively, our results show that GhmMDH1 is involved in plant and root growth under phosphorus deficiency conditions in cotton, owing to its functions in leaf respiration and P acquisition.

  17. Late onset of dietary restriction reverses age-related decline of malate-aspartate shuttle enzymes in the liver and kidney of mice.

    Science.gov (United States)

    Goyary, Danswrang; Sharma, Ramesh

    2008-02-01

    Dietary restriction (DR) influences several physiological processes, retards the incidences and severity of various age-related diseases and extends lifespan of various animal species. The effect of DR on the activities of malate-aspartate shuttle enzymes, viz. cytosolic and mitochondrial aspartate aminotransferase (c- and m-AsAT) and malate dehydrogenase (c- and m-MDH) was investigated in the liver and kidney of adult (5-months) and old (21-months) male mice. The results show that the activity (U/mg protein) of both c- and m-MDH and AsAT is decreased significantly in the liver and kidney of old mice compared to adult ones. However, DR in old mice reverses significantly the enzyme activities to a level closer to adult animals. Polyacrylamide gel electrophoresis (PAGE) and specific staining of c-AsAT, one of the selected isoenzymes of the shuttle, showed a similar pattern of activity expression as observed by activity measurements in both the tissues studied. Slot blot analysis of c-AsAT confirmed the lower protein content of this isoenzyme in old mice compared to adult ones and a higher level in old-dietary restricted mice. Thus, our results suggest that the late onset of DR in older mice reverses decline in malate-aspartate shuttle enzymes and that it may allow a better metabolic regulation in older animals.

  18. MALAT1 and HOTAIR Long Non-Coding RNAs Play Opposite Role in Estrogen-Mediated Transcriptional Regulation in Prostate Cancer Cells

    Science.gov (United States)

    Aiello, Aurora; Bacci, Lorenza; Re, Agnese; Ripoli, Cristian; Pierconti, Francesco; Pinto, Francesco; Masetti, Riccardo; Grassi, Claudio; Gaetano, Carlo; Bassi, Pier Francesco; Pontecorvi, Alfredo; Nanni, Simona; Farsetti, Antonella

    2016-01-01

    In the complex network of nuclear hormone receptors, the long non-coding RNAs (lncRNAs) are emerging as critical determinants of hormone action. Here we investigated the involvement of selected cancer-associated lncRNAs in Estrogen Receptor (ER) signaling. Prior studies by Chromatin Immunoprecipitation (ChIP) Sequencing showed that in prostate cancer cells ERs form a complex with the endothelial nitric oxide synthase (eNOS) and that in turn these complexes associate with chromatin in an estrogen-dependent fashion. Among these associations (peaks) we focused our attention on those proximal to the regulatory region of HOTAIR and MALAT1. These transcripts appeared regulated by estrogens and able to control ERs function by interacting with ERα/ERβ as indicated by RNA-ChIP. Further studies performed by ChIRP revealed that in unstimulated condition, HOTAIR and MALAT1 were present on pS2, hTERT and HOTAIR promoters at the ERE/eNOS peaks. Interestingly, upon treatment with17β-estradiol HOTAIR recruitment to chromatin increased significantly while that of MALAT1 was reduced, suggesting an opposite regulation and function for these lncRNAs. Similar results were obtained in cells and in an ex vivo prostate organotypic slice cultures. Overall, our data provide evidence of a crosstalk between lncRNAs, estrogens and estrogen receptors in prostate cancer with important consequences on gene expression regulation. PMID:27922078

  19. NADP-malate Dehydrogenase Isoforms of Wheat Leaves under Drought: Their Localization, and Some physicochemical and Kinetic Properties

    Directory of Open Access Journals (Sweden)

    H.G. Babayev

    2015-09-01

    Full Text Available Changes in sub-cellular localization, isoenzyme spectrum and kinetic characteristics of NADP-malate dehydrogenase (NADP-MDH, EC 1.1.1.82 in Triticum durum Desf. genotypes with contrasting drought tolerance have been studied. In chloroplast and cytosol fractions of mesophyll cells of wheat flag leaves 70-75% and 25-30% of the total NADP-MDH activity were found to be localized, respectively. Three isoforms of NADP-MDH with molecular weights of 66, 74 and 86 kDa were revealed in the chloroplast fraction, whereas in the cytosolic fraction molecular weights of the isoenzymes were found to be 42, 66 and 74 kDa. Drought caused the formation of a new 90 kDa isoform of the enzyme in the chloroplast fraction in anthesis phase of ontogenesis. In the drought-tolerant genotype the appearance of the new isoform in the chloroplast fraction was accompanied by a more rapid increase in Km and Vmax contrary to the chloroplast fraction of the drought-sensitive genotype manifesting a slight decrease in these parameters, suggesting one of the adaptive traits in forming drought tolerance in C3 plants.

  20. The malate synthase of Paracoccidioides brasiliensis is a linked surface protein that behaves as an anchorless adhesin

    Directory of Open Access Journals (Sweden)

    Pereira Maristela

    2009-12-01

    Full Text Available Abstract Background The pathogenic fungus Paracoccidioides brasiliensis is the agent of paracoccidioidomycosis (PCM. This is a pulmonary mycosis acquired by inhalation of fungal airborne propagules that can disseminate to several organs and tissues leading to a severe form of the disease. Adhesion and invasion to host cells are essential steps involved in the internalization and dissemination of pathogens. Inside the host, P. brasiliensis may use the glyoxylate cycle for intracellular survival. Results Here, we provide evidence that the malate synthase of P. brasiliensis (PbMLS is located on the fungal cell surface, and is secreted. PbMLS was overexpressed in Escherichia coli, and polyclonal antibody was obtained against this protein. By using Confocal Laser Scanning Microscopy, PbMLS was detected in the cytoplasm and in the cell wall of the mother, but mainly of budding cells of the P. brasiliensis yeast phase. PbMLSr and its respective polyclonal antibody produced against this protein inhibited the interaction of P. brasiliensis with in vitro cultured epithelial cells A549. Conclusion These observations indicated that cell wall-associated PbMLS could be mediating the binding of fungal cells to the host, thus contributing to the adhesion of fungus to host tissues and to the dissemination of infection, behaving as an anchorless adhesin.

  1. Rhizobium meliloti genes required for C4-dicarboxylate transport and symbiotic nitrogen fixation are located on a megaplasmid.

    OpenAIRE

    Watson, R J; Chan, Y K; Wheatcroft, R; Yang, A. F.; Han, S. H.

    1988-01-01

    A mutant of Rhizobium meliloti unable to transport C4 dicarboxylates (dct) was isolated after Tn5 mutagenesis. The mutant, 4F6, could not grow on aspartate or the tricarboxylic acid cycle intermediates succinate, fumarate, or malate. It produced symbiotically ineffective nodules on Medicago sativa in which bacteroids appeared normal, but the symbiotic zone was reduced and the plant cells contained numerous starch granules at their peripheries. Cosmids containing the dct region were obtained b...

  2. Enhancing the aluminium tolerance of barley by expressing the citrate transporter genes SbMATE and FRD3

    OpenAIRE

    Zhou, Gaofeng; Pereira, Jorge F.; Delhaize, Emmanuel; Zhou, Meixue; Magalhaes, Jurandir V.; Ryan, Peter R.

    2014-01-01

    Malate and citrate efflux from root apices is a mechanism of Al3+ tolerance in many plant species. Citrate efflux is facilitated by members of the MATE (multidrug and toxic compound exudation) family localized to the plasma membrane of root cells. Barley (Hordeum vulgare) is among the most Al3+-sensitive cereal species but the small genotypic variation in tolerance that is present is correlated with citrate efflux via a MATE transporter named HvAACT1. This study used a biotechnological approa...

  3. Combined inactivation of the Clostridium cellulolyticum lactate and malate dehydrogenase genes substantially increases ethanol yield from cellulose and switchgrass fermentations

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yongchao [ORNL; Tschaplinski, Timothy J [ORNL; Engle, Nancy L [ORNL; Hamilton, Choo Yieng [ORNL; Rodriguez, Jr., Miguel [ORNL; Liao, James C [ORNL; Schadt, Christopher Warren [ORNL; Guss, Adam M [ORNL; Yang, Yunfeng [ORNL; Graham, David E [ORNL

    2012-01-01

    Background: The model bacterium Clostridium cellulolyticum efficiently hydrolyzes crystalline cellulose and hemicellulose, using cellulosomes to degrade lignocellulosic biomass. Although it imports and ferments both pentose and hexose sugars to produce a mixture of ethanol, acetate, lactate, H2 and CO2, the proportion of ethanol is low, which impedes its use in consolidated bioprocessing for biofuels. Therefore genetic engineering will likely be required to improve the ethanol yield. Random mutagenesis, plasmid transformation, and heterologous expression systems have previously been developed for C. cellulolyticum, but targeted mutagenesis has not been reported for this organism. Results: The first targeted gene inactivation system was developed for C. cellulolyticum, based on a mobile group II intron originating from the Lactococcus lactis L1.LtrB intron. This markerless mutagenesis system was used to disrupt both the paralogous L-lactate dehydrogenase (Ccel_2485; ldh) and L-malate dehydrogenase (Ccel_0137; mdh) genes, distinguishing the overlapping substrate specificities of these enzymes. Both mutations were then combined in a single strain. This double mutant produced 8.5-times more ethanol than wild-type cells growing on crystalline cellulose. Ethanol constituted 93% of the major fermentation products (by molarity), corresponding to a molar ratio of ethanol to organic acids of 15, versus 0.18 in wild-type cells. During growth on acid-pretreated switchgrass, the double mutant also produced four-times as much ethanol as wild-type cells. Detailed metabolomic analyses identified increased flux through the oxidative branch of the mutant s TCA pathway. Conclusions: The efficient intron-based gene inactivation system produced the first gene-targeted mutations in C. cellulolyticum. As a key component of the genetic toolbox for this bacterium, markerless targeted mutagenesis enables functional genomic research in C. cellulolyticum and rapid genetic engineering to

  4. Tear Malate Dehydrogenase,Lactate Dehydrogenase and Their Isoenzymes in Normal Chinese Subjects and Patients of Ocular Surface Disorders

    Institute of Scientific and Technical Information of China (English)

    QingGuo; HanchengZhang

    1995-01-01

    Purose:To determine levels of malate dehydrogenase(MDH),lactate dehydroge-nase(LDH)and their isoenzymes in tears of normal Chinese subjects and patients with ocular surface disorders.Methods:The age range of normal subjects was10-88,with136mal and 128fe-male subjects.123patients suffered from ocular surface disorders.Tears were col-lected from lower fornix on Xinghua filter disc(0.1mm thick,5mm in diameter).The values of tearMDHand LDHwere determined by MONARCH-2000Ana-lyzer(U.S.A)Their isoenzymes were separated by acetate cellulose elec-trophoresis and were determined by Model CDS-200light densitometer.Results:The normal values of tear LDH and MDH were 45.51+23.00-81.35+37.84umol·s-1/Land11.00+5.33-19.50+9.17umol·s-1/Lrespectively,dis-regarding sex or eye distriction(P>0.05).The values of tear LDHandMDH in the group aged10-19were significantly lower than in another groups(P<0.05),95%normal ranges of tearMDHaged below19and above20were3.63-19.90umol·s-1/L.THe MDH isoenzymes comprised MDHs and MDHm,the former accounting for80.0-89.1%.The LDH isoenzymes comprised 5varieties.of which the ratioH/Mof subunit H tosubunit Mwas0.196+0.02.Levels of tear LDH,MDHand their isoenzymes in different diseases were various.Conclusions;Tear LDH/MDHratio reflected sensitively the matabolism of corneae and conjunetival epithelium.The changes in LDH isoenzymes were hel-ful to the differential diagnosis of external eye diseases,and the increase of MDHm reflected sensitively the degree of injury to the corneal epithelium.

  5. Thermal adaptation of cytoplasmic malate dehydrogenases of eastern Pacific barracuda (Sphyraena spp): the role of differential isoenzyme expression

    Science.gov (United States)

    Lin; Somero

    1995-01-01

    Kinetic properties, electrophoretic patterns and thermal stabilities of cytoplasmic malate dehydrogenases (cMDHs) were compared in Eastern Pacific barracuda (Sphyraena spp) from different latitudes. All tissues of the tropical species S. ensis contained only a single, thermostable form of cMDH. Subtropical (S. lucasana) as well as north (S. argentea) and south (S. idiastes) temperate barracuda contained both thermostable and thermolabile cMDHs, the pattern characteristic of most teleosts. Kinetic studies using unfractioned cMDHs showed that the apparent Michaelis­Menten constant (Km) of cofactor (NADH) increased with temperature, but at the physiological temperatures of the four species, Km of NADH was conserved within a narrow range (20­23 µmol l-1). Thermostable and thermolabile cMDHs were chromatographically separated and compared. Thermolabile cMDHs had higher Km values for NADH at all measurement temperatures than did thermostable cMDHs. Thermolabile cMDHs isolated from congeneric barracuda exhibited similar kinetic properties (Km versus temperature, optimal pH, optimal substrate and cofactor concentrations). Thermostable cMDHs, likewise, were similar among the barracuda. Conservation of Km in the differently thermally adapted barracudas is, therefore, apparently due to adjustments in the ratio of expression of the thermostable and thermolabile isoforms, rather than to temperature-adaptive differences among orthologous homologues, as is commonly found for enzymes encoded by a single gene locus. The effects of temperature on the Km of NADH for isolated thermostable and thermolabile cMDHs of a eurythermal goby, Gillichthys mirabilis, however, were consistent with adaptive change in orthologous homologues of cMDH. The selective basis for the absence of thermolabile cMDH in warm-adapted ectotherms, mammals and birds is discussed.

  6. Thermal stability of soluble malate dehydrogenase isozymes of subtropical fish belonging to the orders Characiformes, Siluriformes and Perciformes

    Directory of Open Access Journals (Sweden)

    Monteiro Maria do Carmo

    1998-01-01

    Full Text Available Electrophoretic thermostability tests of soluble malate dehydrogenases (sMDH isozymes in tissue extracts of 21 subtropical fish belonging to the orders Characiformes, Siluriformes and Perciformes showed three distinct results. The first, characterized by thermal stability of the slowest-migrating band or A-isoform, was detected in 52% of all species. The second, exhibited in 29% of the species analyzed, had a bidirectionally divergent pattern of their sMDH locus expression, and was characterized by a nondivergent thermostability pattern of both sMDH-A* and B*. In the third category, obtained in 19% of the species studied (the four Siluriformes species, thermostability of the fastest-migrating bands, or B-isoforms, was observed. Comparison of the effects of habitat temperature on the activity of paralogous and orthologous isoforms in tissue extracts of two of these species with different thermostability properties (Leporinus friderici - thermostable sMDH-A*, and Pimelodus maculatus - reverse thermostability properties or reverse electrophoretic pattern, collected during winter and summer months, showed that A and B subunits were present at different quantitative levels and their activities were nearly season independent. Differences in susceptibility to temperature (50°C of both sMDH loci from tissue extracts of these species were found. In P. maculatus, these susceptibilities helped strengthen one of the hypotheses: the reverse thermostability pattern, where the fastest-migrating band or the B-isoform was the thermostable sMDH. Thus, temperature differences among orthologous homologues of sMDH seem to have occurred in these acclimatized species, where the fastest-migrating band, usually muscle specific and thermolabile in most teleosts, appeared in P. maculatus as the thermostable isoform.

  7. Adenine nucleotide-dependent and redox-independent control of mitochondrial malate dehydrogenase activity in Arabidopsis thaliana.

    Science.gov (United States)

    Yoshida, Keisuke; Hisabori, Toru

    2016-06-01

    Mitochondrial metabolism is important for sustaining cellular growth and maintenance; however, the regulatory mechanisms underlying individual processes in plant mitochondria remain largely uncharacterized. Previous redox-proteomics studies have suggested that mitochondrial malate dehydrogenase (mMDH), a key enzyme in the tricarboxylic acid (TCA) cycle and redox shuttling, is under thiol-based redox regulation as a target candidate of thioredoxin (Trx). In addition, the adenine nucleotide status may be another factor controlling mitochondrial metabolism, as respiratory ATP production in mitochondria is believed to be influenced by several environmental stimuli. Using biochemical and reverse-genetic approaches, we addressed the redox- and adenine nucleotide-dependent regulation of mMDH in Arabidopsis thaliana. Recombinant mMDH protein formed intramolecular disulfide bonds under oxidative conditions, but these bonds did not have a considerable effect on mMDH activity. Mitochondria-localized o-type Trx (Trx-o) did not facilitate re-reduction of oxidized mMDH. Determination of the in vivo redox state revealed that mMDH was stably present in the reduced form even in Trx-o-deficient plants. Accordingly, we concluded that mMDH is not in the class of redox-regulated enzymes. By contrast, mMDH activity was lowered by adenine nucleotides (AMP, ADP, and ATP). Each adenine nucleotide suppressed mMDH activity with different potencies and ATP exerted the largest inhibitory effect with a significantly lower K(I). Correspondingly, mMDH activity was inhibited by the increase in ATP/ADP ratio within the physiological range. These results suggest that mMDH activity is finely controlled in response to variations in mitochondrial adenine nucleotide balance.

  8. Improved production of propionic acid in Propionibacterium jensenii via combinational overexpression of glycerol dehydrogenase and malate dehydrogenase from Klebsiella pneumoniae.

    Science.gov (United States)

    Liu, Long; Zhuge, Xin; Shin, Hyun-Dong; Chen, Rachel R; Li, Jianghua; Du, Guocheng; Chen, Jian

    2015-04-01

    Microbial production of propionic acid (PA), an important chemical building block used as a preservative and chemical intermediate, has gained increasing attention for its environmental friendliness over traditional petrochemical processes. In previous studies, we constructed a shuttle vector as a useful tool for engineering Propionibacterium jensenii, a potential candidate for efficient PA synthesis. In this study, we identified the key metabolites for PA synthesis in P. jensenii by examining the influence of metabolic intermediate addition on PA synthesis with glycerol as a carbon source under anaerobic conditions. We also further improved PA production via the overexpression of the identified corresponding enzymes, namely, glycerol dehydrogenase (GDH), malate dehydrogenase (MDH), and fumarate hydratase (FUM). Compared to those in wild-type P. jensenii, the activities of these enzymes in the engineered strains were 2.91- ± 0.17- to 8.12- ± 0.37-fold higher. The transcription levels of the corresponding enzymes in the engineered strains were 2.85- ± 0.19- to 8.07- ± 0.63-fold higher than those in the wild type. The coexpression of GDH and MDH increased the PA titer from 26.95 ± 1.21 g/liter in wild-type P. jensenii to 39.43 ± 1.90 g/liter in the engineered strains. This study identified the key metabolic nodes limiting PA overproduction in P. jensenii and further improved PA titers via the coexpression of GDH and MDH, making the engineered P. jensenii strain a potential industrial producer of PA.

  9. An alpha-proteobacterial type malate dehydrogenase may complement LDH function in Plasmodium falciparum. Cloning and biochemical characterization of the enzyme.

    Science.gov (United States)

    Tripathi, Abhai K; Desai, Prashant V; Pradhan, Anupam; Khan, Shabana I; Avery, Mitchell A; Walker, Larry A; Tekwani, Babu L

    2004-09-01

    Malate dehydrogenase (MDH) may be important in carbohydrate and energy metabolism in malarial parasites. The cDNA corresponding to the MDH gene, identified on chromosome 6 of the Plasmodium falciparum genome, was amplified by RT-PCR, cloned and overexpressed in Escherichia coli. The recombinant Pf MDH was purified to homogeneity and biochemically characterized as an NAD(+)(H)-specific MDH, which catalysed reversible interconversion of malate to oxaloacetate. Pf MDH could not use NADP/NADPH as a cofactor, but used acetylpyridine adenine dinucleoide, an analogue of NAD. The enzyme exhibited strict substrate and cofactor specificity. The highest levels of Pf MDH transcripts were detected in trophozoites while the Pf MDH protein level remained high in trophozoites as well as schizonts. A highly refined model of Pf MDH revealed distinct structural characteristics of substrate and cofactor binding sites and important amino acid residues lining these pockets. The active site amino acid residues involved in substrate binding were conserved in Pf MDH but the N-terminal glycine motif, which is involved in nucleotide binding, was similar to the GXGXXG signature sequence found in Pf LDH and also in alpha-proteobacterial MDHs. Oxamic acid did not inhibit Pf MDH, while gossypol, which interacts at the nucleotide binding site of oxidoreductases and shows antimalarial activity, inhibited Pf MDH also. Treatment of a synchronized culture of P. falciparum trophozoites with gossypol caused induction in expression of Pf MDH, while expression of Pf LDH was reduced and expression of malate:quinone oxidoreductase remained unchanged. Pf MDH may complement Pf LDH function of NAD/NADH coupling in malaria parasites. Thus, dual inhibitors of Pf MDH and Pf LDH may be required to target this pathway and to develop potential new antimalarial drugs.

  10. Determination of malic Acid using a malate dehydrogenase reactor after purification and immobilization in non-denaturing conditions and staining with ponceau S.

    Science.gov (United States)

    Shimazaki, Youji; Sakikawa, Takahiro

    2010-08-01

    Mouse liver cytosolic malate dehydrogenase was separated by non-denaturing two-dimensional electrophoresis and identified. Furthermore, the activity of the enzyme was preserved even after separation, electroblotting onto a membrane and staining with Ponceau S in acidic buffer solution (pH 5.1). Using the membrane-immobilized enzyme, the malic acid content was estimated by measuring absorbance changes due to the conversion of nicotinamide adenine dinucleotide (NAD) to NADH. These results indicate that enzyme reactors can be systematically produced after purification, immobilization and staining with Ponceau S.

  11. Comparative analysis of malate synthase G from Mycobacterium tuberculosis and E. coli: role of ionic interaction in modulation of structural and functional properties.

    Science.gov (United States)

    Kumar, Ranjeet; Bhakuni, Vinod

    2011-12-01

    Metabolic plasticity of Mycobacterium renders high degree of adaptive advantages in the persistence through the upregulation of glyoxylate shunt. The malate synthase (MS), an important enzyme of the shunt belongs to the G isoform and expressed predominantly as monomer. Here we did a comparative unfolding studies of two homologous MS from Mycobacterium tuberculosis (MtbMS) and Escherichia coli (ecMS) using various biophysical techniques. Despite having high sequence identities, they show different structural, stability and functional properties. The study suggests that the differences in the stability and unfolding of the two enzymes are by virtue of differential electrostatic modulation unique to their respective molecular assembly.

  12. Identification and Functional Characterization of a Tonoplast Dicarboxylate Transporter in Tomato (Solanum lycopersicum)

    Science.gov (United States)

    Liu, Ruiling; Li, Boqiang; Qin, Guozheng; Zhang, Zhanquan; Tian, Shiping

    2017-01-01

    Acidity plays an important role in flavor and overall organoleptic quality of fruit and is mainly due to the presence of organic acids. Understanding the molecular basis of organic acid metabolism is thus of primary importance for fruit quality improvement. Here, we cloned a putative tonoplast dicarboxylate transporter gene (SlTDT) from tomato, and submitted it to the NCBI database (GenBank accession number: KC733165). SlTDT protein contained 13 putative transmembrane domains in silico analysis. Confocal microscopic study using green fluorescent fusion proteins revealed that SlTDT was localized on tonoplast. The expression patterns of SlTDT in tomato were analyzed by RT-qPCR. The results indicated that SlTDT expressed in leaves, roots, flowers and fruits at different ripening stages, suggesting SlTDT may be associated with the development of different tissues. To further explore the function of SlTDT, we constructed both overexpression and RNAi vectors and obtained transgenic tomato plants by agrobacterium-mediated method. Gas chromatography-mass spectrometer (GC-MS) analysis showed that overexpression of SlTDT significantly increased malate content, and reduced citrate content in tomato fruit. By contrast, repression of SlTDT in tomato reduced malate content of and increased citrate content. These results indicated that SlTDT played an important role in remobilization of malate and citrate in fruit vacuoles. PMID:28261242

  13. Combined inactivation of the Clostridium cellulolyticum lactate and malate dehydrogenase genes substantially increases ethanol yield from cellulose and switchgrass fermentations

    Directory of Open Access Journals (Sweden)

    Li Yongchao

    2012-01-01

    Full Text Available Abstract Background The model bacterium Clostridium cellulolyticum efficiently degrades crystalline cellulose and hemicellulose, using cellulosomes to degrade lignocellulosic biomass. Although it imports and ferments both pentose and hexose sugars to produce a mixture of ethanol, acetate, lactate, H2 and CO2, the proportion of ethanol is low, which impedes its use in consolidated bioprocessing for biofuels production. Therefore genetic engineering will likely be required to improve the ethanol yield. Plasmid transformation, random mutagenesis and heterologous expression systems have previously been developed for C. cellulolyticum, but targeted mutagenesis has not been reported for this organism, hindering genetic engineering. Results The first targeted gene inactivation system was developed for C. cellulolyticum, based on a mobile group II intron originating from the Lactococcus lactis L1.LtrB intron. This markerless mutagenesis system was used to disrupt both the paralogous L-lactate dehydrogenase (Ccel_2485; ldh and L-malate dehydrogenase (Ccel_0137; mdh genes, distinguishing the overlapping substrate specificities of these enzymes. Both mutations were then combined in a single strain, resulting in a substantial shift in fermentation toward ethanol production. This double mutant produced 8.5-times more ethanol than wild-type cells growing on crystalline cellulose. Ethanol constituted 93% of the major fermentation products, corresponding to a molar ratio of ethanol to organic acids of 15, versus 0.18 in wild-type cells. During growth on acid-pretreated switchgrass, the double mutant also produced four times as much ethanol as wild-type cells. Detailed metabolomic analyses identified increased flux through the oxidative branch of the mutant's tricarboxylic acid pathway. Conclusions The efficient intron-based gene inactivation system produced the first non-random, targeted mutations in C. cellulolyticum. As a key component of the genetic toolbox

  14. Complex formation between malate dehydrogenase and isocitrate dehydrogenase from Bacillus subtilis is regulated by tricarboxylic acid cycle metabolites.

    Science.gov (United States)

    Bartholomae, Maike; Meyer, Frederik M; Commichau, Fabian M; Burkovski, Andreas; Hillen, Wolfgang; Seidel, Gerald

    2014-02-01

    In Bacillus subtilis, recent in vivo studies revealed that particular enzymes of the tricarboxylic acid cycle form complexes that allow an efficient transfer of metabolites. Remarkably, a complex of the malate dehydrogenase (Mdh) (EC 1.1.1.37) with isocitrate dehydrogenase (Icd) (EC 1.1.1.42) was identified, although both enzymes do not catalyze subsequent reactions. In the present study, the interactions between these enzymes were characterized in vitro by surface plasmon resonance in the absence and presence of their substrates and cofactors. These analyses revealed a weak but specific interaction between Mdh and Icd, which was specifically stimulated by a mixture of substrates and cofactors of Icd: isocitrate, NADP(+) and Mg(2+). Wild-type Icd converted these substrates too fast, preventing any valid quantitative analysis of the interaction with Mdh. Therefore, binding of the IcdS104P mutant to Mdh was quantified because the mutation reduced the enzymatic activity by 174-fold but did not affect the stimulatory effect of substrates and cofactors on Icd-Mdh complex formation. The analysis of the unstimulated Mdh-IcdS104P interaction revealed kinetic constants of k(a) = 2.0 ± 0.2 × 10(2) m(-1) ·s(-1) and k(d) = 1.0 ± 0.1 × 10(-3) ·s(-1) and a K(D) value of 5.0 ± 0.1 μm. Addition of isocitrate, NADP(+) and Mg(2+) stimulated the affinity of IcdS104P to Mdh by 33-fold (K(D) = 0.15 ± 0.01 μm, k(a) = 1.7 ± 0.7 × 10(3) m(-1) ·s(-1), k(d) = 2.6 ± 0.6 × 10(-4) ·s(-1)). Analyses of the enzymatic activities of wild-type Icd and Mdh showed that Icd activity doubles in the presence of Mdh, whereas Mdh activity was slightly reduced by Icd. In summary, these data indicate substrate control of complex formation in the tricarboxylic acid cycle metabolon assembly and maintenance of the α-ketoglutarate supply for amino acid anabolism in vivo.

  15. Inheritance of malate dehydrogenase in wild pepper Herança da malato desidrogenase em pimenta-silvestre

    Directory of Open Access Journals (Sweden)

    ADILSON RICKEN SCHUELTER

    1999-01-01

    Full Text Available Leaf extracts from wild pepper (Capsicum flexuosum Sendt were analysed for the presence of malate dehydrogenase (E.C. 1.1.1.37; MDH isozymes using starch gel electrophoresis. Seven phenotypes for MDH isozymes were observed in the genitors. Genetic analysis in F1 progenies revealed five loci coding for MDH. Isozyme banding patterns of hybrids indicated that MDH-3 and MDH-4 genes code for monomeric enzymes, while MDH-5 for a dimeric isoform. In MDH-2 loci, one particular F1 progeny showed a significant deviation from the expected isozyme pattern. It is possible that other genes are controlling the expression of MDH-2 in pepper. Also, there are two alleles coding for MDH-2 isozyme. On the other hand, MDH-1 was monomorphic for all genotypes used in the experiment.Extratos de folhas de pimenta silvestre (Capsicum flexuosum Sendt foram analisados para a presença do sistema isoenzimático malato desidrogenase (E.C. 1.1.1.37; MDH, usando a técnica eletroforese em gel de amido hidrolisado. Sete fenótipos de malato desidrogenase foram observados entre os genitores. As análises de segregação em progênies F1 revelaram que cinco locos gênicos estavam envolvidos na codificação de MDH. Os padrões de bandeamento dos híbridos indicaram que os genes MDH-3 e MDH-4 codificavam para enzimas monoméricas, enquanto o MDH-5, para uma isoforma dimérica. Para o loco MDH-2, detectou-se desvio significativo para proporção de segregação esperada. Outros genes podem estar controlando a expressão de MDH-2 em pimenta. Como nos outros locos MDH, detectaram-se dois alelos codificando para MDH-2. Por outro lado, o MDH-1 foi monomórfico para todos os genótipos avaliados no experimento.

  16. HvALMT1 from barley is involved in the transport of organic anions.

    Science.gov (United States)

    Gruber, Benjamin D; Ryan, Peter R; Richardson, Alan E; Tyerman, Stephen D; Ramesh, Sunita; Hebb, Diane M; Howitt, Susan M; Delhaize, Emmanuel

    2010-03-01

    Members of the ALMT gene family contribute to the Al(3+) resistance of several plant species by facilitating malate efflux from root cells. The first member of this family to be cloned and characterized, TaALMT1, is responsible for most of the natural variation of Al(3+) resistance in wheat. The current study describes the isolation and characterization of HvALMT1, the barley gene with the greatest sequence similarity to TaALMT1. HvALMT1 is located on chromosome 2H which has not been associated with Al(3+) resistance in barley. The relatively low levels of HvALMT1 expression detected in root and shoot tissues were independent of external aluminium or phosphorus supply. Transgenic barley plants transformed with the HvALMT1 promoter fused to the green fluorescent protein (GFP) indicated that expression of HvALMT1 was relatively high in stomatal guard cells and in root tissues containing expanding cells. GFP fused to the C-terminus of the full HvALMT1 protein localized to the plasma membrane and motile vesicles within the cytoplasm. HvALMT1 conferred both inward and outward currents when expressed in Xenopus laevis oocytes that were bathed in a range of anions including malate. Both malate uptake and efflux were confirmed in oocyte assays using [(14)C]malate as a radiotracer. It is suggested that HvALMT1 functions as an anion channel to facilitate organic anion transport in stomatal function and expanding cells.

  17. 17β-Estradiol regulates cell proliferation, colony formation, migration, invasion and promotes apoptosis by upregulating miR-9 and thus degrades MALAT-1 in osteosarcoma cell MG-63 in an estrogen receptor-independent manner

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Dengfeng; Yang, Hui; Lin, Jing; Teng, Yi; Jiang, Yingying; Chen, Jiao; Li, Yu, E-mail: yuli_scu@163.com

    2015-02-20

    In bone, different concentration of estrogen leads to various of physiological processes in osteoblast, such as the proliferation, migration, and apoptosis in an estrogen receptor-dependent manner. But little was known about the estrogen effects on osteosarcoma (OS). In this study, OS cell MG-63 was treated with low (1 nM) or high (100 nM) dose of 17β-Estradiol (E2) with the presence or absence of estrogen receptor α (ERα), for evaluating the E2 effects on proliferation, migration, invasion, colony formation and apoptosis. Consistent with a previous study, high dose of E2 treatment dramatically downregulated expressing level of long non-coding RNA metastasis associated lung adenocarcinoma transcript 1 (MALAT-1). The observation of upregulation of miR-9 after a high dose of E2 treatment indicated the cause of MALAT-1 reduction. Downregulation of MALAT-1 promoted the combination of SFPQ/PTBP2 complex. It was also observed that the proliferation, migration, invasion, colony formation and apoptosis of OS cells were remarkably affected by high dose of E2 treatment, but not by low dose, in an ERα independent manner. Furthermore, the abolishment of the effects on these physiological processes caused by ectopic expression of miR-9 ASOs suggested the necessity of miR-9 in MALAT-1 regulation. Here we found that the high dose of E2 treatment upregulated miR-9 thus posttranscriptionally regulated MALAT-1 RNA level in OS cells, and then the downregulation of MALAT-1 inhibited cell proliferation, migration, invasion and epithelial–mesenchymal transition (EMT) processes in the E2-dose dependent and ER-independent ways. - Highlights: • E2 affects osteosarcoma cell MG-63 in an Estrogen receptor-independent way. • High dose of E2 treatment upregulates miR-9 which target to MALAT-1 RNA. • Upregulated miR-9 degrades MALAT-1 and thus affects combination of SFPQ/PTBP2. • E2 treatment block cell proliferation, colony formation, mobility, and enhance apoptosis.

  18. Biochemical analysis of the NAD+-dependent malate dehydrogenase, a substrate of several serine/threonine protein kinases of Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Xiao Ming Wang

    Full Text Available PknD is one of the eleven eukaryotic-like serine/threonine protein kinases (STPKs of Mycobacterium tuberculosis (Mtb. In vitro phosphorylation assays with the active recombinant PknD showed that the intracellular protein NAD+-dependent malate dehydrogenase (MDH is a substrate of this kinase. MDH, an energy-supplying enzyme, catalyzes the interconversion of malate and oxaloacetate and plays crucial roles in several metabolic pathways including the citric acid cycle. The phosphorylation site was identified on threonine residues and the phosphorylation inhibited the MDH activity. In vitro, the recombinant MDH could also be phosphorylated by at least five other STPKs, PknA, PknE, PknH, PknJ, and PknG. Immunoprecipitation analysis revealed that MDH was hyperphosphorylated in the bacteria at the beginning of the stationary and under oxygen-limited conditions by STPKs other than PknD. On the contrary, when PknD-deficient mutant mycobacteria were grown in a phosphate-depleted medium, MDH was not detectably phosphorylated. These results suggest that although the MDH is a substrate of several mycobacterial STPKs, the activity of these kinases can depend on the environment, as we identified PknD as a key element in the MDH phosphorylation assay under phosphate-poor conditions.

  19. Decreasing the mitochondrial synthesis of malate in potato tubers does not affect plastidial starch synthesis, suggesting that the physiological regulation of ADPglucose pyrophosphorylase is context dependent.

    Science.gov (United States)

    Szecowka, Marek; Osorio, Sonia; Obata, Toshihiro; Araújo, Wagner L; Rohrmann, Johannes; Nunes-Nesi, Adriano; Fernie, Alisdair R

    2012-12-01

    Modulation of the malate content of tomato (Solanum lycopersicum) fruit by altering the expression of mitochondrially localized enzymes of the tricarboxylic acid cycle resulted in enhanced transitory starch accumulation and subsequent effects on postharvest fruit physiology. In this study, we assessed whether such a manipulation would similarly affect starch biosynthesis in an organ that displays a linear, as opposed to a transient, kinetic of starch accumulation. For this purpose, we used RNA interference to down-regulate the expression of fumarase in potato (Solanum tuberosum) under the control of the tuber-specific B33 promoter. Despite displaying similar reductions in both fumarase activity and malate content as observed in tomato fruit expressing the same construct, the resultant transformants were neither characterized by an increased flux to, or accumulation of, starch, nor by alteration in yield parameters. Since the effect in tomato was mechanistically linked to derepression of the reaction catalyzed by ADP-glucose pyrophosphorylase, we evaluated whether the lack of effect on starch biosynthesis was due to differences in enzymatic properties of the enzyme from potato and tomato or rather due to differential subcellular compartmentation of reductant in the different organs. The results are discussed in the context both of current models of metabolic compartmentation and engineering.

  20. Biochemical analysis of the NAD+-dependent malate dehydrogenase, a substrate of several serine/threonine protein kinases of Mycobacterium tuberculosis.

    Science.gov (United States)

    Wang, Xiao Ming; Soetaert, Karine; Peirs, Priska; Kalai, Michaël; Fontaine, Véronique; Dehaye, Jean Paul; Lefèvre, Philippe

    2015-01-01

    PknD is one of the eleven eukaryotic-like serine/threonine protein kinases (STPKs) of Mycobacterium tuberculosis (Mtb). In vitro phosphorylation assays with the active recombinant PknD showed that the intracellular protein NAD+-dependent malate dehydrogenase (MDH) is a substrate of this kinase. MDH, an energy-supplying enzyme, catalyzes the interconversion of malate and oxaloacetate and plays crucial roles in several metabolic pathways including the citric acid cycle. The phosphorylation site was identified on threonine residues and the phosphorylation inhibited the MDH activity. In vitro, the recombinant MDH could also be phosphorylated by at least five other STPKs, PknA, PknE, PknH, PknJ, and PknG. Immunoprecipitation analysis revealed that MDH was hyperphosphorylated in the bacteria at the beginning of the stationary and under oxygen-limited conditions by STPKs other than PknD. On the contrary, when PknD-deficient mutant mycobacteria were grown in a phosphate-depleted medium, MDH was not detectably phosphorylated. These results suggest that although the MDH is a substrate of several mycobacterial STPKs, the activity of these kinases can depend on the environment, as we identified PknD as a key element in the MDH phosphorylation assay under phosphate-poor conditions.

  1. Polymyxin B identified as an inhibitor of alternative NADH dehydrogenase and malate: quinone oxidoreductase from the Gram-positive bacterium Mycobacterium smegmatis.

    Science.gov (United States)

    Mogi, Tatsushi; Murase, Yoshiro; Mori, Mihoko; Shiomi, Kazuro; Omura, Satoshi; Paranagama, Madhavi P; Kita, Kiyoshi

    2009-10-01

    Tuberculosis is the leading cause of death due to a single infectious agent in the world and the emergence of multidrug-resistant strains prompted us to develop new drugs with novel targets and mechanism. Here, we screened a natural antibiotics library with Mycobacterium smegmatis membrane-bound dehydrogenases and identified polymyxin B (cationic decapeptide) and nanaomycin A (naphtoquinone derivative) as inhibitors of alternative NADH dehydrogenase [50% inhibitory concentration (IC(50)) values of 1.6 and 31 microg/ml, respectively] and malate: quinone oxidoreductase (IC(50) values of 4.2 and 49 microg/ml, respectively). Kinetic analysis on inhibition by polymyxin B showed that the primary site of action was the quinone-binding site. Because of the similarity in K(m) value for ubiquinone-1 and inhibitor sensitivity, we examined amino acid sequences of actinobacterial enzymes and found possible binding sites for L-malate and quinones. Proposed mechanisms of polymyxin B and nanaomycin A for the bacteriocidal activity were the destruction of bacterial membranes and production of reactive oxygen species, respectively, while this study revealed their inhibitory activity on bacterial membrane-bound dehydrogenases. Screening of the library with bacterial respiratory enzymes resulted in unprecedented findings, so we are hoping that continuing efforts could identify lead compounds for new drugs targeting to mycobacterial respiratory enzymes.

  2. Organohalogen compounds in human breast milk from mothers living in Payatas and Malate, the Philippines: levels, accumulation kinetics and infant health risk.

    Science.gov (United States)

    Malarvannan, Govindan; Kunisue, Tatsuya; Isobe, Tomohiko; Sudaryanto, Agus; Takahashi, Shin; Prudente, Maricar; Subramanian, Annamalai; Tanabe, Shinsuke

    2009-06-01

    Human breast milk samples (n=33) from primipara and multipara mothers from Payatas a waste dump site, and Malate a reference site in the Phillipines were collected in 2004 and analyzed for eight organohalogen compounds, viz., PCBs, DDTs, CHLs, HCHs, HCB, TCPMe, PBDEs and HBCDs. DDTs and PCBs were predominant in all the samples. Overall mean concentrations of PBDEs found in our study were higher (7.5 ng/g lipid wt.) than those reported for Japan and many other Asian countries. Primipara mothers had significantly higher levels of DDTs, CHLs and HCHs than multipara mothers, but not PBDEs and HBCDs. A few individuals accumulated CHLs close to or even higher than the tolerable daily intake guidelines proposed by Health Canada.

  3. Organohalogen compounds in human breast milk from mothers living in Payatas and Malate, the Philippines: Levels, accumulation kinetics and infant health risk

    Energy Technology Data Exchange (ETDEWEB)

    Malarvannan, Govindan; Kunisue, Tatsuya; Isobe, Tomohiko; Sudaryanto, Agus; Takahashi, Shin [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Ehime Prefecture (Japan); Prudente, Maricar [Science Education Department, De La Salle University, Manila (Philippines); Subramanian, Annamalai [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Ehime Prefecture (Japan); Tanabe, Shinsuke, E-mail: shinsuke@agr.ehime-u.ac.j [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577, Ehime Prefecture (Japan)

    2009-06-15

    Human breast milk samples (n = 33) from primipara and multipara mothers from Payatas a waste dump site, and Malate a reference site in the Phillipines were collected in 2004 and analyzed for eight organohalogen compounds, viz., PCBs, DDTs, CHLs, HCHs, HCB, TCPMe, PBDEs and HBCDs. DDTs and PCBs were predominant in all the samples. Overall mean concentrations of PBDEs found in our study were higher (7.5 ng/g lipid wt.) than those reported for Japan and many other Asian countries. Primipara mothers had significantly higher levels of DDTs, CHLs and HCHs than multipara mothers, but not PBDEs and HBCDs. A few individuals accumulated CHLs close to or even higher than the tolerable daily intake guidelines proposed by Health Canada. - First comprehensive study on organohalogen contaminants in human breast milk from the Philippines.

  4. Direct evidence that genetic variation in glycerol-3-phosphate and malate dehydrogenase genes (Gpdh and Mdh1) affects adult ethanol tolerance in Drosophila melanogaster.

    Science.gov (United States)

    Eanes, Walter F; Merritt, Thomas J S; Flowers, Jonathan M; Kumagai, Seiji; Zhu, Chen-Tseh

    2009-02-01

    Many studies of alcohol adaptation in Drosophila melanogaster have focused on the Adh polymorphism, yet the metabolic elimination of alcohol should involve many enzymes and pathways. Here we evaluate the effects of glycerol-3-phosphate dehydrogenase (Gpdh) and cytosolic malate dehydrogenase (Mdh1) genotype activity on adult tolerance to ethanol. We have created a set of P-element-excision-derived Gpdh, Mdh1, and Adh alleles that generate a range of activity phenotypes from full to zero activity. Comparisons of paired Gpdh genotypes possessing 10 and 60% normal activity and 66 and 100% normal activity show significant effects where higher activity increases tolerance. Mdh1 null allele homozygotes show reductions in tolerance. We use piggyBac FLP-FRT site-specific recombination to create deletions and duplications of Gpdh. Duplications show an increase of 50% in activity and an increase of adult tolerance to ethanol exposure. These studies show that the molecular polymorphism associated with GPDH activity could be maintained in natural populations by selection related to adaptation to alcohols. Finally, we examine the interactions between activity genotypes for Gpdh, Mdh1, and Adh. We find no significant interlocus interactions. Observations on Mdh1 in both Gpdh and Adh backgrounds demonstrate significant increases in ethanol tolerance with partial reductions (50%) in cytosolic MDH activity. This observation strongly suggests the operation of pyruvate-malate and, in particular, pyruvate-citrate cycling in adaptation to alcohol exposure. We propose that an understanding of the evolution of tolerance to alcohols will require a system-level approach, rather than a focus on single enzymes.

  5. 几种泥炭藓属植物苹果酸脱氢酶同工酶研究%Study on Malate Dehydrogenase lsozyme of Several Sphagnum

    Institute of Scientific and Technical Information of China (English)

    张春; 张以忠

    2012-01-01

    The malate dehydrogenase isozymes of ten populations belonging to five species of Sphag- num were studied by means of polyacrylamide gel eletrophoresis (PAGE) . The results showed that there were six different hands of malate dehydrogenase isozyme. Among them, MDH-5 and MDH-6 were common and characteristic bands. Sphagnum palustre L. had two bands, Sphagnum ovatum Hamp. had five bands, Sphagnum khasiaum Mitt. had six bands , Sphagnum multifibrosum Li at Zang. and Sphagnum nemoreum Scop. had four bands. Spss systems clustering showed that there were genetic differences among five different species of Sphagnum.%采用聚丙烯酰胺凝胶电泳对泥炭藓属植物5个种10个居群的苹果酸脱氢酶同工酶进行分析,结果表明:苹果酸脱氢酶同工酶带共6条,MDH-5和MDH-6在5个种中均可见,其酶带明显,染色较深,说明酶活性较强,可以判断MDH-5和MDH-6为共有特征带。泥炭藓有酶带2条,卵叶泥炭藓有酶带5条,加萨泥炭藓有酶带6条,多纹泥炭藓有酶带4条,尖叶泥炭藓有酶带4条,通过SPSS系统聚类表明:泥炭藓属5泥炭藓植物种间存在遗传差异。

  6. Radiation Transport

    Energy Technology Data Exchange (ETDEWEB)

    Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  7. [Effect of electric fields on the living organism. III. Activity of fructose-1,6-diphosphate aldolase and malate dehydrogenase in whole liver homogenate and in subcellular liver fractions in guinea pigs].

    Science.gov (United States)

    Kula, B; Wardas, M

    1990-01-01

    Guinea pigs were exposed to electric field of 50 Hz in different times of day. Activity of aldolase and malate dehydrogenase in whole liver homogenate as well as in nuclear, mitochondrial and supernatant liver fractions of guinea pigs was examined. A remarkable increase in enzyme activity in all studied groups was observed which may prove that a relevant electric stimulus can result in certain disorders in carbohydrate changes in liver cells.

  8. Chamber transport

    Energy Technology Data Exchange (ETDEWEB)

    OLSON,CRAIG L.

    2000-05-17

    Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system.

  9. Hypersensitivity of Arabidopsis TAXIMIN1 overexpression lines to light stress is correlated with decreased sinapoyl malate abundance and countered by the antibiotic cefotaxime.

    Science.gov (United States)

    Colling, Janine; Pollier, Jacob; Vanden Bossche, Robin; Makunga, Nokwanda Pearl; Pauwels, Laurens; Goossens, Alain

    2016-01-01

    Peptide signaling in plants is involved in regulating development, (1,2) ensuring cross pollination through initiation of self-incompatibility (4) and assisting with recognition of beneficial (nitrogen fixing bacteria (5)) or unfavorable organisms (pathogens (6) or herbivores (7)). Peptides function to help plants to respond to a changing environment and improve their chances of survival. Constitutive expression of the gene encoding a novel cysteine rich peptide TAXIMIN1 (TAX1) resulted in fusion of lateral organs and in abnormal fruit morphology. TAX1 signaling functions independently from transcription factors known to play a role in this process such as LATERAL ORGAN FUSION1 (LOF1). Here, we report that the TAX1 promoter is not induced by the LOF1 transcription factor and that the TAX1 peptide neither interferes with transcriptional activation by LOF1.1 or transcriptional repression by LOF1.2. Furthermore, we found that TAX1 overexpressing lines were hypersensitive to continuous light, which may be reflected by a decreased accumulation of the UV-B protecting compound sinapoyl-malate. Finally, adding the antibiotic cefotaxime to the medium surprisingly countered the light hypersensitivity phenotype of TAX1 overexpressing seedlings.

  10. Renal cell carcinoma with t(6 ;11)(p21.2;q13)/MALAT1-TFEB fusion: a clinical and pathological analysis%t(6;11)(p21.2;q13)/MALAT1-TFEB基因易位相关性肾癌的临床病理分析

    Institute of Scientific and Technical Information of China (English)

    夏秋媛; 时姗姗; 沈勤; 魏雪; 王璇; 马恒辉; 陆珍凤; 周晓军; 饶秋

    2015-01-01

    目的 探讨t (6; 11)(p21.2; q13)/MALAT1-TFEB基因易位相关性肾癌的临床病理特征、免疫表型、鉴别诊断及预后.方法 对9例TFEB基因易位相关性肾癌进行光镜观察、免疫组织化学EnVision法、荧光原位杂交、MALAT1-TFEB融合基因扩增研究及随访,并复习相关文献.结果 9例肿瘤中女性4例,男性5例.患者年龄21~42岁,平均31.3岁,平均随访31个月,均无病生存.镜下观察4例具特征性“假菊形团”结构,其余5例形态不典型,分别与血管周上皮样细胞肿瘤、肾透明细胞癌、嫌色细胞癌、乳头状肾细胞癌形态学有交叉.肿瘤内时常可见到基底膜样物质,色素及沙砾体.9例TFEB均呈弥漫细胞核表达,E-cadherin、波形蛋白一致强阳性,Ksp-cadherin、CD117阳性比例分别为7/9和6/9,色素性标志物Cathepsin K、HMB45和Melan A的阳性比例分别为8/9、6/9和6/9,广谱细胞角蛋白仅在1例中阳性,TFE3、CD10和CK7均阴性.荧光原位杂交9例均存在异常TFEB分离信号及MALAT1-TFEB融合信号.2例扩增出MALAT1-TFEB融合基因.结论 TFEB基因易位相关性肾癌是一种罕见肿瘤,好发于青壮年,预后较好.诊断可依据患者的年龄、病理学形态和免疫表型,荧光原位杂交检测TFEB基因易位是诊断该肿瘤的金标准.%Objective To study the clinicopathologic features,immunophenotype,differential diagnosis and prognosis of renal cell carcinoma (RCC) associated with t (6 ; 11) (p21.2 ; q13)/MALAT1-TFEB gene fusion.Methods A total of 9 cases of such rare tumor were selected for clinicopathologic,immunohistochemical and molecular analysis,with review of literature.Results The age of the patients ranged from 21 to 42 years (mean =31.3 years).The patients included four men and five women.Histologically,4 of the 9 cases studied showed classic morphologic features of TFEB RCC,with hyaline material,pigments and psammoma bodies frequently identified.The remaining 5 cases demonstrated

  11. The plastid-localized NAD-dependent malate dehydrogenase is crucial for energy homeostasis in developing Arabidopsis thaliana seeds.

    Science.gov (United States)

    Selinski, Jennifer; König, Nicolas; Wellmeyer, Benedikt; Hanke, Guy T; Linke, Vera; Neuhaus, H Ekkehard; Scheibe, Renate

    2014-01-01

    In the absence of photosynthesis, ATP is imported into chloroplasts and non-green plastids by ATP/ADP transporters or formed during glycolysis, the latter requiring continuous regeneration of NAD(+), supplied by the plastidial isoform of NAD-MDH. During screening for T-DNA insertion mutants in the plNAD-MDH gene of Arabidopsis, only heterozygous plants could be isolated and homozygous knockout mutants grew only after complementation. These heterozygous plants show higher transcript levels of an alternative NAD(+)-regenerating enzyme, NADH-GOGAT, and, remarkably, improved growth when ammonium is the sole N-source. In situ hybridization and GUS-histochemical staining revealed that plNAD-MDH was particularly abundant in male and female gametophytes. Knockout plNAD-MDH pollen exhibit impaired tube growth in vitro, which can be overcome by adding the substrates of NADH-GOGAT. In vivo, knockout pollen is able to fertilize the egg cell. Young siliques of selfed heterozygous plants contain both green and white seeds corresponding to wild-type/heterozygous (green) and homozygous knockout mutants (white) in a (1:2):1 ratio. Embryos of the homozygous knockout seeds only reached the globular stage, did not green, and developed to tiny wrinkled seeds. Complementation with the gene under the native promoter rescued this defect, and all seeds developed as wild-type. This suggests that a blocked major physiological process in plNAD-MDH mutants stops both embryo and endosperm development, thus avoiding assimilate investment in compromised offspring.

  12. Neurotransmitter transporters

    DEFF Research Database (Denmark)

    Gether, Ulrik; Andersen, Peter H; Larsson, Orla M

    2006-01-01

    The concentration of neurotransmitters in the extracellular space is tightly controlled by distinct classes of membrane transport proteins. This review focuses on the molecular function of two major classes of neurotransmitter transporter that are present in the cell membrane of neurons and....../or glial cells: the solute carrier (SLC)1 transporter family, which includes the transporters that mediate the Na(+)-dependent uptake of glutamate, and the SLC6 transporter family, which includes the transporters that mediate the Na(+)-dependent uptake of dopamine, 5-HT, norepinephrine, glycine and GABA....... Recent research has provided substantial insight into the structure and function of these transporters. In particular, the recent crystallizations of bacterial homologs are of the utmost importance, enabling the first reliable structural models of the mammalian neurotransmitter transporters...

  13. School Transportation.

    Science.gov (United States)

    Executive Educator, 1990

    1990-01-01

    This special section on student transportation offers a case study of a school system that recycles buses for safety drills; articles on fuel-saving strategies, the pros and cons of contracting for transportation services or operating a publicly owned bus fleet, and advice on full cost accounting for transportation costs; and a transportation…

  14. Scientific Opinion on the safety and efficacy of malic acid and a mixture of sodium and calcium malate when used as technological additives for all animal species

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP

    2014-02-01

    Full Text Available An application has been made for the re-authorisation of malic acid as a preservative in feed and an acidity regulator in feed for cats and dogs and for the authorisation of a mixture of sodium and calcium salts of malic acid to be used as an acidity regulator in feed for all animal species. Evidence from feeding studies with dogs, poultry, piglets, veal calves and ruminants showed that the highest typical use level of 1 600 mg malic acid/kg complete feedingstuffs (supplied as acid or salts is safe for all animal species. Setting a maximum content was not considered as necessary. Malic acid and its sodium and calcium salts are permitted food additives without limit in the EU. The use of malic acid and its sodium and calcium salts in animal nutrition is safe for the consumer. Malic acid and its salts are considered as strongly irritant to the skin and mucosa and as a particular risk to the eyes. Exposure via inhalation for those handling the additives is also considered to present a risk. Malates are components of the diet of humans and animals and are rapidly and completely metabolised to CO2. Consequently, their use in animal production would not pose a risk to the environment. Malic acid is used in food as a preservative. It is reasonable to expect that the effect seen in food will be observed in feed when it is used at comparable concentrations and under similar conditions. However, the FEEDAP Panel has reservations about the effectiveness of malic acid as a preservative in complete feedingstuffs with a moisture content of ≤ 12 %. The ability of malic acid and its salts to act as acidity regulators in feed has not been demonstrated.

  15. Cloning and Expression Analysis of Malate Dehydrogenase Gene from Cassava%木薯苹果酸脱氢酶基因克隆和表达分析

    Institute of Scientific and Technical Information of China (English)

    尹奇; 仝征; 贺庭琪; 王力敏; 黄启星; 郭运玲; 孔华; 王旭初; 郭安平

    2013-01-01

    为从木薯块根中获得苹果酸脱氢酶(MDH)基因,并研究其在转录水平的表达变化规律,利用RACE技术从木薯“华南8号”块根中克隆得到了苹果酸脱氢酶基因,其cDNA全长1 175 bp,包含999 bp的开放阅读框,共编码332个氨基酸.从木薯“华南8号”中获得的MDH氨基酸序列,与其它物种的该序列相似度达84%~94%,包含细胞质苹果酸脱氢酶中高度保守的NAD结合基元“TGAAGQI”和催化基元“IWGNH”.木薯MDH基因与块根淀粉合成相关,在块根发育前期表达量较低,膨大期表达量较高,膨大后期表达量逐渐降低.%A 1 175 bp cDNA sequence of MDH with a 999 bp open reading frame,encoding a protein with 332 amino acids,was obtained from cassava SC8 roots by RACE (rapid-amplification of cDNA ends) to study the expressional pattern of malate dehydrogenase (MDH) mRNA.The MDH shared 84%~94% of amino acid sequence identities with MDH from other species,and contained a typical NAD+ binding motif (TGAAGQI) and a catalytic motif (IWGNH),suggesting it was a cytosolic molate dehydrogenase (cyMDH) gene.MDH was perhaps involved in the process of starch accumulation in cassava,the expression of cassava MDH was up regulated during storage root thinckening.

  16. Long term intensive exercise training leads to a higher plasma malate/lactate dehydrogenase (M/L) ratio and increased level of lipid mobilization in horses.

    Science.gov (United States)

    Li, Gebin; Lee, Peter; Mori, Nobuko; Yamamoto, Ichiro; Arai, Toshiro

    2012-06-01

    Continuous high intensity training may induce alterations to enzyme activities related to glucose and lipid metabolism in horses. In our study, five Thoroughbred race horses (3 male and 2 female, avg age=5 yrs old) were compared against five riding horses (1 male, 1 female, 3 gelding, avg age=13 yrs old) in terms of energy metabolism, by examining plasma malate (MDH) and lactate (LDH) dehydrogenase activities and M/L ratio. MDH is involved in NADH and ATP generation, whereas LDH can convert NADH back into NAD(+) for ATP generation. An increase in plasma M/L ratio can reflect heightened energy metabolism in the liver and skeletal muscle of horses adapted to continuous intensive exercise. Moreover, plasma lipid metabolism analytes (adiponectin, NEFA, total cholesterol (T-Cho), and triglycerides (TG)) can reflect changes to lipolysis rate, which can also indicate a change in energy metabolism. Overall, race horses demonstrated increased MDH and LDH activity in plasma (4x and 2x greater, respectively), in addition to a plasma M/L ratio twice as high as that of riding horses (2.0 vs 1.0). In addition, race horses also demonstrated significantly higher levels of plasma NEFA (50% greater), TG (2x greater), and T-Cho (20% greater) as compared to riding horses. Therefore, race horse muscles may have adapted to prolonged high intensity endurance exercise by gaining a higher oxidative capacity and an increased capacity for fat utilization as an energy source, resulting in heightened energy metabolism and increased rate of lipid mobilization.

  17. Sustainable Transportation

    DEFF Research Database (Denmark)

    Hall, Ralph P.; Gudmundsson, Henrik; Marsden, Greg

    2014-01-01

    The transportation system is the backbone of economic and social progress and the means by which humans access goods and services and connect with one another. Yet, as the scale of transportation activities has grown worldwide, so too have the negative environmental, social, and economic impacts...... that relate to the construction and maintenance of transportation infrastructure and the operation or use of the different transportation modes. The concept of sustainable transportation emerged in response to these concerns as part of the broader notion of sustainable development. Given the transportation...... sector’s significant contribution to global challenges such as climate change, it is often said that sustainable development cannot be achieved without sustainable transportation....

  18. Sediment Transport

    DEFF Research Database (Denmark)

    Liu, Zhou

    Flow and sediment transport are important in relation to several engineering topics, e.g. erosion around structures, backfilling of dredged channels and nearshore morphological change. The purpose of the present book is to describe both the basic hydrodynamics and the basic sediment transport...... mechanics. Chapter 1 deals with fundamentals in fluid mechanics with emphasis on bed shear stress by currents, while chapter 3 discusses wave boundary layer theory. They are both written with a view to sediment transport. Sediment transport in rivers, cross-shore and longshore are dealt with in chapters 2...

  19. EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA); Scientific Opinion on the substantiation of a health claim related to citrulline-malate and faster recovery from muscle fatigue after exercise pursuant to Article 13(5) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    to citrulline-malate and faster recovery from muscle fatigue after exercise. Citrulline-malate is sufficiently characterised. The claimed effect is “maintenance of ATP levels through reduction of lactates in excess for an improved recovery from muscle fatigue”. The target population proposed by the applicant...... is healthy children above six years of age and adults. The Panel considers that faster recovery from muscle fatigue after exercise contributing to the restoration of muscle function is a beneficial physiological effect. A total of 33 references were considered as pertinent to the claim by the applicant...... to the methodological limitations of the study. A number of mechanistic, animal and in vitro studies were submitted. In the absence of evidence for an effect of consumption of citrulline-malate on a faster recovery from muscle fatigue after exercise in humans, these studies cannot be used as a source of data...

  20. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2014. Scientific Opinion on the substantiation of a health claim related to citrulline-malate and faster recovery from muscle fatigue after exercise pursuant to Article 13(5) of Regulation (EC) No 1924/2006

    DEFF Research Database (Denmark)

    Tetens, Inge

    the human study for the scientific substantiation of the claim. A health claim on citrulline-malate and faster recovery from muscle fatigue after exercise has already been assessed by the Panel with an unfavourable outcome. The additional information submitted by the applicant did not provide evidence...... on the scientific substantiation of a health claim related to citrulline-malate and faster recovery from muscle fatigue after exercise. The Panel considers that citrulline-malate is sufficiently characterised. The claimed effect proposed by the applicant is “improved recovery from muscle fatigue”. Faster recovery...... function. The evidence provided by the applicant did not establish that a faster reduction of blood lactate concentrations through a dietary intervention leads to faster recovery from muscle fatigue by contributing to the restoration of muscle function after exercise. No conclusions could be drawn from...

  1. Analysis of carbon source-regulated gene expression by the upstream region of the Candida tropicalis malate synthase gene in Saccharomyces cerevisiae.

    Science.gov (United States)

    Umemura, K; Atomi, H; Izuta, M; Kanai, T; Takeshita, S; Ueda, M; Tanaka, A

    1997-01-03

    We investigated the regulation of expression of a gene encoding malate synthase (MS) of an n-alkane-utilizable yeast Candida tropicalis in the yeast Saccharomyces cerevisiae, where its expression is highly induced by acetate. By comparing levels of gene expression in cells grown on glucose, acetate, lactate, and oleic acid, we found that the increase in gene expression was due to a glucose repression-derepression mechanism. In order to obtain information concerning the regulation of the gene expression, a fusion gene which consists of the 5'-upstream region of MS-2 (UPR-MS-2) and the lacZ gene (encoding Escherichia coli beta-galactosidase), was introduced into S. cerevisiae, and beta-galactosidase activities were measured with cells grown on glucose or acetate. Deletion analysis of UPR-MS-2 revealed that the region between -777 and -448 (against the translation initiation codon) enhanced the level of gene expression in both glucose- and acetate-grown cells. In this region, sequences which resemble binding sites of Rap1p/Grf1p/Tufp, a global transcription activator, were found at seven locations and one was found for another pleiotropic activator Abf1p. The result also suggested the presence of multiple upstream repression sequences (URSs), which function specifically in glucose-grown cells, in the region between -368 and -126. In the repressing region, there were three tandem C(A/T)CTCCC sequences and also a putative binding site of Mig1p, a transcriptional repressor which mediates glucose repression of several other genes. When MIG1 gene of S. cerevisiae was disrupted, the expression of the UPR-MS-2-lacZ gene in glucose-grown cells increased approx. 10-fold. Furthermore, the effect of deletion of a putative Mig1p binding site was abolished in the MIG1-disrupted strain, suggesting Mig1p binds to this site and brings about glucose repression. When the SNF1 gene was disrupted, the high level gene expression observed in acetate-grown cells bearing UPR-MS-2 was

  2. Temperature sensitivities of cytosolic malate dehydrogenases from native and invasive species of marine mussels (genus Mytilus): sequence-function linkages and correlations with biogeographic distribution.

    Science.gov (United States)

    Fields, Peter A; Rudomin, Emily L; Somero, George N

    2006-02-01

    The blue mussel Mytilus galloprovincialis, a native of the Mediterranean Sea, has invaded the west coast of North America in the past century, displacing the native blue mussel, Mytilus trossulus, from most of its former habitats in central and southern California. The invasive success of M. galloprovincialis is conjectured to be due, in part, to physiological adaptations that enable it to outperform M. trossulus at high temperatures. We have examined the structure and function of the enzyme cytosolic malate dehydrogenase (cMDH) from these species, as well as from the more distantly related ribbed mussel, Mytilus californianus, to characterize the effects of temperature on kinetic properties thought to exhibit thermal adaptation. The M. trossulus cMDH ortholog differs from the other cMDHs in a direction consistent with cold adaptation, as evidenced by a higher and more temperature-sensitive Michaelis-Menten constant for the cofactor NADH (Km(NADH)). This difference results from minor changes in sequence: the M. trossulus ortholog differs from the M. galloprovincialis ortholog by only two substitutions in the 334 amino acid monomer, and the M. californianus and M. trossulus orthologs differ by five substitutions. In each case, only one of these substitutions is non-conservative. To test the effects of individual substitutions on kinetic properties, we used site-directed mutagenesis to create recombinant cMDHs. Recombinant wild-type M. trossulus cMDH (rWT) has high Km(NADH) compared with mutants incorporating the non-conservative substitutions found in M. californianus and M. galloprovincialis - V114H and V114N, respectively - demonstrating that these mutations are responsible for the differences found in substrate affinity. Turnover number (kcat) is also higher in rWT compared with the two mutants, consistent with cold adaptation in the M. trossulus ortholog. Conversely, rWT and V114H appear more thermostable than V114N. Based on a comparison of Km(NADH) and kcat

  3. Transport Phenomena.

    Science.gov (United States)

    McCready, Mark J.; Leighton, David T.

    1987-01-01

    Discusses the problems created in graduate chemical engineering programs when students enter with a wide diversity of understandings of transport phenomena. Describes a two-semester graduate transport course sequence at the University of Notre Dame which focuses on fluid mechanics and heat and mass transfer. (TW)

  4. [{Cu(phen)2}(mu-malato){Cu(phen)(NO3)}](NO3).4H2O: malate acting as a tetradentate and dibridging ligand in a dinuclear copper complex.

    Science.gov (United States)

    Zhang, Xiang Dong; Sun, Jin Yu; Zhao, Zhen; Ma, Yong Chao; Zhu, Miao Li

    2006-01-01

    The crystal structure of the title compound, mu-2-hydroxybutanedioato-1kappa2O4,O4':2kappa3O1,O2,O4-nitrato-2kappaO-tris(1,10-phenanthroline)-1kappa(4)N,N';2kappa(2)N,N'-dicopper(II) nitrate tetrahydrate, [Cu2(C4H3O5)(NO3)(C12H8N2)3](NO3).4H2O, contains an unsymmetrical dinuclear copper complex with Cu(phen)2 and Cu(phen)(NO3) moieties (phen is 1,10-phenanthroline) bridged by a malate (2-hydroxybutanedioate) ligand, which acts as a double-bridging and tetradentate ligand. As a result of this double-bridging action, especially the direct coordination of the O atom of one carboxylate group of malate to the two Cu atoms, the Cu...Cu distance is only 4.199 (1) Angstrom and the two phen planes are roughly parallel [the shortest interplanar distance is 3.28 (1) Angstrom], exhibiting an obvious intramolecular pi-pi stacking interaction.

  5. Transport Phenomena.

    Science.gov (United States)

    Shah, D. B.

    1984-01-01

    Describes a course designed to achieve a balance between exposing students to (1) advanced topics in transport phenomena, pointing out similarities and differences between three transfer processes and (2) common methods of solving differential equations. (JN)

  6. Nicaragua - Transportation

    Data.gov (United States)

    Millennium Challenge Corporation — The evaluation examines impacts of the Transportation Project in three ways. First, we calculate economic rates of return associated with reduced user costs for each...

  7. L-苹果酸对苹果酸天冬氨酸穿梭转运蛋白及酶基因表达的作用研究%Effect of L-malate on Gene Expression of Proteins and Enzymes Related to the Malate-aspartate Shuttle

    Institute of Scientific and Technical Information of China (English)

    吴军林; 吴清平; 韦明肯; 吴慧清; 周小燕

    2006-01-01

    采用半定量RT-PCR方法,对小鼠给予L-苹果酸后肝线粒体苹果酸天冬氨酸穿梭相关的两种线粒体酶:线粒体天冬氨酸氨基转移酶(mitochondrial aspartate aminotransferase,mAST)及线粒体苹果酸脱氢酶(mitochondrial malate dehydrogenase,mMDH)及线粒体内膜上的天冬氨酸谷氨酸转运蛋白(AGC)与α-酮戊二酸苹果酸转运蛋白(OMC)的基因表达进行检测,探讨了L-苹果酸对肝线粒体苹果酸天冬氨酸穿梭的关键酶及转运蛋白mRNA表达规律.半定量RT-PCR结果表明:剂量组小鼠肝线粒体转运蛋白AGC mRNA的表达显著高于空白对照组,而mAST、mMDH及转运蛋白OMC mRNA的表达无显著性差异.由此可知,L-苹果酸能促进TCA循环及苹果酸天冬氨酸穿梭,其分子生物学机理与L-苹果酸提高AGC的基因表达水平有关.

  8. Action of the antitumor and antispermatogenic agent lonidamine on electron transport in Ehrlich ascites tumor mitochondria.

    Science.gov (United States)

    Floridi, A; Lehninger, A L

    1983-10-01

    The effect of lonidamine, an antispermatogenic and antitumor drug, on the oxygen consumption, ATPase activity, and redox state of the electron carriers of Ehrlich ascites tumor mitochondria has been studied. Lonidamine inhibits ADP- and uncoupler-stimulated respiration on various NAD- and FAD-linked substrates, but does not affect state 4 respiration. Experiments to determine its site of action showed that lonidamine does not significantly inhibit electron flow through cytochrome oxidase. Electron flow through site 2, the ubiquinone-cytochrome b-cytochrome c1 complex, also was unaffected by lonidamine, which failed to inhibit the oxidation of duroquinol. Moreover, inhibition of electron flow through site 2 was also excluded because of the inability of the N,N,N',N'-tetramethyl-p-phenylenediamine bypass to relieve the lonidamine inhibition of the oxidation of pyruvate + malate. The F0F1ATPase activity and vectorial H+ ejection are also unaffected by lonidamine. The inhibition of succinate oxidation by lonidamine was found to take place at a point between succinate and iron-sulfur center S3. Spectroscopic experiments demonstrated that lonidamine inhibits the reduction of mitochondrial NAD+ by pyruvate + malate and other NAD-linked substrates in the transition from state 1 to state 4. However, lonidamine does not inhibit reduction of added NAD+ by submitochondrial vesicles or by soluble purified NAD-linked dehydrogenases. These observations, together with other evidence, suggest that electron transport in tumor mitochondria is inhibited by lonidamine at the dehydrogenase-coenzyme level, particularly when the electron carriers are in a relatively oxidized state and/or when the inner membrane-matrix compartment is in the condensed state. The action of lonidamine in several respects resembles the selective inhibition of electron transport in tumor cells produced by cytotoxic macrophages (D. L. Granger and A. L. Lehninger (1982) J. Cell Biol. 95, 527).

  9. Functional characterization of a Na(+)-coupled dicarboxylate transporter from Bacillus licheniformis.

    Science.gov (United States)

    Strickler, Melodie A; Hall, Jason A; Gaiko, Olga; Pajor, Ana M

    2009-12-01

    The Na(+)-coupled dicarboxylate transporter, SdcL, from Bacillus licheniformis is a member of the divalent anion/Na(+) symporter (DASS) family that includes the bacterial Na(+)/dicarboxylate cotransporter SdcS (from Staphyloccocus aureus) and the mammalian Na(+)/dicarboxylate cotransporters, NaDC1 and NaDC3. The transport properties of SdcL produced in Escherichia coli are similar to those of its prokaryotic and eukaryotic counterparts, involving the Na(+)-dependent transport of dicarboxylates such as succinate or malate across the cytoplasmic membrane with a K(m) of approximately 6 microM. SdcL may also transport aspartate, alpha-ketoglutarate and oxaloacetate with low affinity. The cotransport of Na(+) and dicarboxylate by SdcL has an apparent stoichiometry of 2:1, and a K(0.5) for Na(+) of 0.9 mM. Our findings represent the characterization of another prokaryotic protein of the DASS family with transport properties similar to its eukaryotic counterparts, but with a broader substrate specificity than other prokaryotic DASS family members. The broader range of substrates carried by SdcL may provide insight into domains of the protein that allow a more flexible or larger substrate binding pocket.

  10. 大肠杆菌苹果酸合酶A的酶学和生理功能研究%Characterization and physiological role of malate synthase A in Escherichia coil

    Institute of Scientific and Technical Information of China (English)

    王程; 王敖; 赵旵军; 朱国萍

    2011-01-01

    Malate synthase is one of the key enzymes in glyoxylate cycle. The aceB gene, encoding malate synthase A ( MSA) , was amplified from the genomic DNA of Escherichia coli MC1655 using PCR with primers designed according to the sequence of E. coli genome. The PCR product was cloned into pET-29b( + ) , resulting the recombinant plasmid pET-MSA. The target protein ( MSA) was overexpressed in E. coli Rosetta ( DE3) under IPTG induction, and then the enzyme was purified to homogeneity. The molecular weight ( MW) of MSA was about 60 kDa. The optimal pH and temperature of MSA were pH 8. 0 and 30 C, respectively. The maximum activity of purified MSA was observed in the presence of Mg2+ . The Km and Vmax values for acetyl-CoA of MSA were 8. 07 μM and 3. 6 μM/min, respectively. Furthermore, the mutant strains, MG: : ΔaceB with MSA deletion and MG: : ΔaceBΔglcB with MSA and malate synthase G ( MSG) deletion, were constructed, respectively. It was observed that the growth rate of the mutant E. coli strain with MSA deletion was remarkably lower than that of the wild-type strain, indicating that MSA was essential for E. coli growth on acetate. Although MSG was able to partially recover the function of MSA , the glyoxylate bypass containing MSA was the much more effective metabolic pathway of glyoxylate.%苹果酸合酶是乙醛酸循环的关键酶之一.E.coli中苹果酸合酶A(malate synthase A,MSA)由aceB基因编码.根据E.coli基因组序列设计引物,利用PCR技术扩增aceB基因,并将其克隆入pET-29t,(+),构建了重组表达质粒pET-MSA.经IPTG诱导,MSA在E.coli Rosetta(DE3)中获得高效表达.纯化的MSA蛋白的分子量大小约为60 kDa,最适反应pH值和最适温度分别是pH值8.0、30℃.纯化的蛋白质在Mg2+存在时才能发挥最大的活性,其对乙酰辅酶A的Km和Vmax分别是8.07μM和3.6μM/min.此外构建了MSA和苹果酸合酶G(MSG)基因敲除菌株MG::AaceB和MG::AaceBAglcB.研究发现缺少MSA的E.coli突变菌株在乙

  11. Travel and transport

    DEFF Research Database (Denmark)

    Bill, Jan; Roesdahl, Else

    2007-01-01

    On the interrelationship between travel, transport and society; on land transport, sea and river transport, and on winter transport;  on the related technologies and their developments......On the interrelationship between travel, transport and society; on land transport, sea and river transport, and on winter transport;  on the related technologies and their developments...

  12. Transport modeling

    Institute of Scientific and Technical Information of China (English)

    R.E. Waltz

    2007-01-01

    @@ There has been remarkable progress during the past decade in understanding and modeling turbulent transport in tokamaks. With some exceptions the progress is derived from the huge increases in computational power and the ability to simulate tokamak turbulence with ever more fundamental and physically realistic dynamical equations, e.g.

  13. Optimal transport

    CERN Document Server

    Eckmann, B

    2008-01-01

    At the close of the 1980s, the independent contributions of Yann Brenier, Mike Cullen and John Mather launched a revolution in the venerable field of optimal transport founded by G Monge in the 18th century, which has made breathtaking forays into various other domains of mathematics ever since. The author presents a broad overview of this area.

  14. Transport fuel

    DEFF Research Database (Denmark)

    Ronsse, Frederik; Jørgensen, Henning; Schüßler, Ingmar

    2014-01-01

    Worldwide, the use of transport fuel derived from biomass increased four-fold between 2003 and 2012. Mainly based on food resources, these conventional biofuels did not achieve the expected emission savings and contributed to higher prices for food commod - ities, especially maize and oilseeds...

  15. Transport system

    NARCIS (Netherlands)

    Drenth, K.F.

    1999-01-01

    The transport system comprises at least one road surface (2) and at least one vehicle (4) on wheels (6). The road surface (2) has a substantially bowl-shaped cross section and the vehicle (4) is designed so that the wheels (6) run directly on the road surface (2) while the road surface (2) acts as a

  16. Anomalous transport

    Science.gov (United States)

    Cheverry, Christophe

    2017-02-01

    This article is concerned with the relativistic Vlasov equation, for collisionless axisymmetric plasmas immersed in a strong magnetic field, like in tokamaks. It provides a consistent kinetic treatment of the microscopic particle phase-space dynamics. It shows that the turbulent transport can be completely described through WKB expansions.

  17. Copper transport.

    Science.gov (United States)

    Linder, M C; Wooten, L; Cerveza, P; Cotton, S; Shulze, R; Lomeli, N

    1998-05-01

    In adult humans, the net absorption of dietary copper is approximately 1 mg/d. Dietary copper joins some 4-5 mg of endogenous copper flowing into the gastrointestinal tract through various digestive juices. Most of this copper returns to the circulation and to the tissues (including liver) that formed them. Much lower amounts of copper flow into and out of other major parts of the body (including heart, skeletal muscle, and brain). Newly absorbed copper is transported to body tissues in two phases, borne primarily by plasma protein carriers (albumin, transcuprein, and ceruloplasmin). In the first phase, copper goes from the intestine to the liver and kidney; in the second phase, copper usually goes from the liver (and perhaps also the kidney) to other organs. Ceruloplasmin plays a role in this second phase. Alternatively, liver copper can also exit via the bile, and in a form that is less easily reabsorbed. Copper is also present in and transported by other body fluids, including those bathing the brain and central nervous system and surrounding the fetus in the amniotic sac. Ceruloplasmin is present in these fluids and may also be involved in copper transport there. The concentrations of copper and ceruloplasmin in milk vary with lactational stage. Parallel changes occur in ceruloplasmin messenger RNA expression in the mammary gland (as determined in pigs). Copper in milk ceruloplasmin appears to be particularly available for absorption, at least in rats.

  18. Transporter Classification Database (TCDB)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Transporter Classification Database details a comprehensive classification system for membrane transport proteins known as the Transporter Classification (TC)...

  19. Mobile Transporter

    Science.gov (United States)

    2001-01-01

    The Space Shuttle Atlantis, STS-110 mission, deployed this railcar, called the Mobile Transporter, and an initial 43-foot section of track, the S0 (S-zero) truss, preparing the International Space Station (ISS) for future spacewalks. The first railroad in space, the Mobile Transporter will allow the Station's robotic arm to travel up and down the finished truss for future assembly and maintenance. The 27,000-pound S0 truss is the first of 9 segments that will make up the Station's external framework that will eventually stretch 356 feet (109 meters), or approximately the length of a football field. The completed truss structure will hold solar arrays and radiators to provide power and cooling for additional international research laboratories from Japan and Europe that will be attached to the Station. The Space Shuttle Orbiter Atlantis, STS-110 mission, was launched April 8, 2002 and returned to Earth April 19, 2002. STS-110's Extravehicular Activity (EVA) marked the first use of the Station's robotic arm to maneuver spacewalkers around the Station.

  20. Doubling the CO{sub 2} concentration enhanced the activity of carbohydrate-metabolism enzymes, source carbohydrate production, photoassimilate transport, and sink strength for Opuntia ficus-indica

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ning; Nobel, P.S. [Univ. of California, Los Angeles, CA (United States)

    1996-03-01

    After exposure to a doubled CO{sub 2} concentration of 750 {mu}mol mol{sup -1} air for about 3 months, glucose and starch in the chlorenchyma of basal cladodes of Opuntia ficus-indica increased 175 and 57%, respectively, compared with the current CO{sub 2} concentration of 370 {mu}mol mol{sup -1}, but sucrose content was virtually unaffected. Doubling the CO{sub 2} concentration increased the noncturnal malate production in basal cladodes by 75%, inorganic phosphate (Pi) by 32% soluble starch synthase activity by 30%, and sucrose-Pi synthase activity by 146%, but did not affect the activity of hexokinase. Doubling CO{sub 2} accelerated phloem transport of sucrose out of the basal cladodes, resulting in a 73% higher dry weight for the daughter cladodes. Doubling CO{sub 2} increased the glucose content in 14-d-old daughter cladodes by 167%, increased nocturnal malate production by 22%, decreased total amino acid content by 61%, and increased soluble starch synthase activity by 30% and sucrose synthase activity by 62%. No downward acclimation of photosynthesis during long-term exposure to elevated CO{sub 2} concentrations occurs for O. ficus-indica, consistent with its higher source capacity and sink strength than under current CO{sub 2}. These changes apparently do not result in Pi limitation of photosynthesis or suppression of genes governing photosynthesis for this perennial Crassulacean acid metabolism species, as occur for some annual crops.

  1. Engineering rTCA pathway and C4-dicarboxylate transporter for L-malic acid production.

    Science.gov (United States)

    Chen, Xiulai; Wang, Yuancai; Dong, Xiaoxiang; Hu, Guipeng; Liu, Liming

    2017-02-22

    L-Malic acid is an important component of a vast array of food additives, antioxidants, disincrustants, pharmaceuticals, and cosmetics. Here, we presented a pathway optimization strategy and a transporter modification approach to reconstruct the L-malic acid biosynthesis pathway and transport system, respectively. First, pyruvate carboxylase (pyc) and malate dehydrogenase (mdh) from Aspergillus flavus and Rhizopus oryzae were combinatorially overexpressed to construct the reductive tricarboxylic acid (rTCA) pathway for L-malic acid biosynthesis. Second, the L-malic acid transporter (Spmae) from Schizosaccharomyces pombe was engineered by removing the ubiquitination motification to enhance the L-malic acid efflux system. Finally, the L-malic acid pathway was optimized by controlling gene expression levels, and the final L-malic acid concentration, yield, and productivity were up to 30.25 g L(-1), 0.30 g g(-1), and 0.32 g L(-1) h(-1) in the resulting strain W4209 with CaCO3 as a neutralizing agent, respectively. In addition, these corresponding parameters of pyruvic acid remained at 30.75 g L(-1), 0.31 g g(-1), and 0.32 g L(-1) h(-1), respectively. The metabolic engineering strategy used here will be useful for efficient production of L-malic acid and other chemicals.

  2. Robotic transportation.

    Science.gov (United States)

    Lob, W S

    1990-09-01

    Mobile robots perform fetch-and-carry tasks autonomously. An intelligent, sensor-equipped mobile robot does not require dedicated pathways or extensive facility modification. In the hospital, mobile robots can be used to carry specimens, pharmaceuticals, meals, etc. between supply centers, patient areas, and laboratories. The HelpMate (Transitions Research Corp.) mobile robot was developed specifically for hospital environments. To reach a desired destination, Help-Mate navigates with an on-board computer that continuously polls a suite of sensors, matches the sensor data against a pre-programmed map of the environment, and issues drive commands and path corrections. A sender operates the robot with a user-friendly menu that prompts for payload insertion and desired destination(s). Upon arrival at its selected destination, the robot prompts the recipient for a security code or physical key and awaits acknowledgement of payload removal. In the future, the integration of HelpMate with robot manipulators, test equipment, and central institutional information systems will open new applications in more localized areas and should help overcome difficulties in filling transport staff positions.

  3. Chemical transport reactions

    CERN Document Server

    Schäfer, Harald

    2013-01-01

    Chemical Transport Reactions focuses on the processes and reactions involved in the transport of solid or liquid substances to form vapor phase reaction products. The publication first offers information on experimental and theoretical principles and the transport of solid substances and its special applications. Discussions focus on calculation of the transport effect of heterogeneous equilibria for a gas motion between equilibrium spaces; transport effect and the thermodynamic quantities of the transport reaction; separation and purification of substances by means of material transport; and

  4. 苹果酸法米替尼Ⅰ期临床人体耐受性研究初步总结%Tolerability of famitinib malate:the preliminary results from phase Ⅰ clinical trial

    Institute of Scientific and Technical Information of China (English)

    周爱萍; 张雯; 常春晓; 迟·依荷巴丽; 王金万

    2011-01-01

    Objective: To establish the safety profile and recommended dose of famitinib malate for phase Ⅱ clinical trials, and to evaluate the antitumor activity of famitinib malate. Methods: Totally 52 patients with advanced solid maliganancies received famitinib malate, once a day, at the dose ranging from 4 to 27 mg. One cycle consisted of 28 days. The antitumor efficacy was evaluated every 2 cycles. Results: Fifty-one patients were evalu-able for safety. For those patients without a history of hypertension, both 27 mg and 25 mg were safe. The dose limiting toxicities for these patients were grade Ⅲ hypertension, grade Ⅳ thrombocytopenia, grade Ⅲ proteinuria and grade Ⅲ hypertriglyceridemia if defined to occur during the first 8 weeks, and only included grade Ⅲ hypertension and grade IV thrombocytopenia if defined to occur during the first 4 weeks. At the dose of 25 mg, other common side effects included hematological toxicity, hand-foot skin reaction, fatigue, oral mucositis, pain, anorexia, nausea, elevation of transaminase, hypercholesterolemia, peripheral neuropathy, hypothyroidism and edema. Forty-eight patients were evaluable for efficacy. Six patients with renal cell carcinoma, 1 with alveolar soft part sarcoma and 1 with GIST achieved PR at the dose of 25 mg and 27 mg. Additional 1 patient with hepatocellular carcinoma, 1 with liposarcoma and 1 with thymic carcinoma achieved a PFS of 12 months or more. The response rate for renal cell carcinoma was 6/11 (54.5% ). Conclusion: Famitinib malate has a broad antitumor activity with manageable toxicity. The dose of 25 mg is the recommended dose for those patients without a history of hypertension in phase II clinical trials.%目的:考察苹果酸法米替尼在人体的耐受性、最大耐受剂量并初步考察其抗肿瘤活性.方法:52例经细胞病理学证实的晚期肿瘤患者接受法米替尼治疗,每日一次口服.剂量范围:4~27 mg.28d为一周期,每2周

  5. Alteration of the interconversion of pyruvate and malate in the plastid or cytosol of ripening tomato fruit invokes diverse consequences on sugar but similar effects on cellular organic acid, metabolism, and transitory starch accumulation.

    Science.gov (United States)

    Osorio, Sonia; Vallarino, José G; Szecowka, Marek; Ufaz, Shai; Tzin, Vered; Angelovici, Ruthie; Galili, Gad; Fernie, Alisdair R

    2013-02-01

    The aim of this work was to investigate the effect of decreased cytosolic phosphoenolpyruvate carboxykinase (PEPCK) and plastidic NADP-dependent malic enzyme (ME) on tomato (Solanum lycopersicum) ripening. Transgenic tomato plants with strongly reduced levels of PEPCK and plastidic NADP-ME were generated by RNA interference gene silencing under the control of a ripening-specific E8 promoter. While these genetic modifications had relatively little effect on the total fruit yield and size, they had strong effects on fruit metabolism. Both transformants were characterized by lower levels of starch at breaker stage. Analysis of the activation state of ADP-glucose pyrophosphorylase correlated with the decrease of starch in both transformants, which suggests that it is due to an altered cellular redox status. Moreover, metabolic profiling and feeding experiments involving positionally labeled glucoses of fruits lacking in plastidic NADP-ME and cytosolic PEPCK activities revealed differential changes in overall respiration rates and tricarboxylic acid (TCA) cycle flux. Inactivation of cytosolic PEPCK affected the respiration rate, which suggests that an excess of oxaloacetate is converted to aspartate and reintroduced in the TCA cycle via 2-oxoglutarate/glutamate. On the other hand, the plastidic NADP-ME antisense lines were characterized by no changes in respiration rates and TCA cycle flux, which together with increases of pyruvate kinase and phosphoenolpyruvate carboxylase activities indicate that pyruvate is supplied through these enzymes to the TCA cycle. These results are discussed in the context of current models of the importance of malate during tomato fruit ripening.

  6. 不同产地、不同年限人参中3种同工酶活力比较%Comparison of the activities of peroxidase, catalase, malate dehydrogenase isozymes in Radix Ginseng from different sources

    Institute of Scientific and Technical Information of China (English)

    刘宏; 赵雨; 邢楠楠; 张惠; 李红艳

    2011-01-01

    目的:对不同产地,不同生长年限(4年、5年)的人参中过氧化物酶(Peroxidase POD)、过氧化氢酶(Catalase CAT)、苹果酸脱氢酶(Malate Dehydrogenase MDH)活力进行比较.方法:采用中性缓冲液提取总蛋白,应用愈创木酚比色法测定过氧化物酶活力,过氧化氢比色法测定过氧化氢酶活力,草酰乙酸比色法测定苹果酸脱氢酶活力.结果:不同产地人参的同工酶活力存在一定差异,4年、5年生人参同工酶活力具有相似性,差异较小.结论:POD、CAT、MDH的活力可以作为人参品种鉴定及药材优选的评价指标.

  7. Sequence analysis of a 13.4 kbp fragment from the left arm of chromosome XV reveals a malate dehydrogenase gene, a putative Ser/Thr protein kinase, the ribosomal L25 gene and four new open reading frames.

    Science.gov (United States)

    Casamayor, A; Khalid, H; Balcells, L; Aldea, M; Casas, C; Herrero, E; Ariño, J

    1996-09-01

    A 13421 bp fragment located near the left telomere of chromosome XV (cosmid pEOA461) has been sequenced. Seven non-overlapping open reading frames (ORFs) encoding polypeptides longer than 100 residues have been found (AOB859, AOC184, AOE375, AOX142i, AOE423, AOA476 and AOE433). An additional ORF (AOE131) is found within AOA476. Three of them (AOC184, AOA476 and AOE433) show no remarkable identity with proteins deposited in the data banks. ORF AOB859 is quite similar to a hypothetical yeast protein of similar size located in chromosome VI, particularly within the C-terminal half. AOE375 encodes a new member of the glycogen synthase kinase-3 subfamily of Ser/Thr protein kinases. AOX142i is the gene encoding the previously described ribosomal protein L25. AOE423 codes for a protein virtually identical to the MDH2 malate dehydrogenase isozyme. However, our DNA sequence shows a single one-base insertion upstream of the reported initiating codon. This would produce a larger ORF by extending 46 residues the N-terminus of the protein. The existence of this insertion has been confirmed in three different yeast strains, including FY1679.

  8. Plant Transporter Identification

    DEFF Research Database (Denmark)

    Larsen, Bo

    Membrane transport proteins (transporters) play a critical role for numerous biological processes, by controlling the movements of ions and molecules in and out of cells. In plants, transporters thus function as gatekeepers between the plant and its surrounding environment and between organs......, tissues, cells and intracellular compartments. Since plants are highly compartmentalized organisms with complex transportation infrastructures, they consequently have many transporters. However, the vast majority of predicted transporters have not yet been experimentally verified to have transport...... activity. This project contains a review of the implemented methods, which have led to plant transporter identification, and present our progress on creating a high-throughput functional genomics transporter identification platform....

  9. Saxton Transportation Operations Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Saxton Transportation Operations Laboratory (Saxton Laboratory) is a state-of-the-art facility for conducting transportation operations research. The laboratory...

  10. The proton stoichiometry of electron transport in Ehrlich ascites tumor mitochondria.

    Science.gov (United States)

    Villalobo, A; Lehninger, A L

    1979-06-10

    Initial rate measurements of the stoichiometric relationships between H+ ejection, K+ and Ca2+ uptake, and electron transport were carried out on mitochondria from Ehrlich ascites tumor cells grown in mice. With succinate as substrate and N-ethylmaleimide to prevent interfering H+ reuptake via the phosphate carrier, close to 8 H+ were ejected per oxygen atom reduced (H+/O ejection ratio = 8.0); with the NAD-linked substrates pyruvate or pyruvate + malate, the H+/O ejection ratio was close to 12. The average H+/site ratio (H+ ejected/2e-/energy-conserving site) was thus close to 4. The simultaneous uptake of charge-compensating cations, either K+ (in the presence of valinomycin) or Ca2+, was also measured, yielding average K+/site uptake ratios of very close to 4 and Ca2+/site ratios close to 2. It was also demonstrated that each calcium ion enters the respiring tumor mitochondria carrying two positive electric charges. These stoichiometric data observed in mitochondria from Ehrlich ascites tumor cells thus are in complete agreement with similar data on normal rat liver and rat heart mitochondria and suggest that the H+/site ratio of mitochondrial electron transport may be 4 generally. It was also observed that the rate of deltaH+ back-decay in anaerobic tumor mitochondria following oxygen pulses is some 6- to 8-fold greater than in rat liver mitochondria tested at equal amounts of mitochondrial protein.

  11. The interaction between malate dehydrogenase and p53 protein contribute to tumor progression%苹果酸脱氢酶与p53蛋白相互调控对肿瘤进程的影响

    Institute of Scientific and Technical Information of China (English)

    伍科; 刘志宏

    2016-01-01

    p53基因是一种重要的抑癌基因,其肿瘤抑制机制十分复杂,p53基因编码的p53蛋白能通过多种途径抑制肿瘤的进程.苹果酸脱氢酶(MDH)是一种重要的代谢酶,但是MDH作用并不局限于代谢调节.p53蛋白与苹果酸脱氢酶的相互调控作用能影响肿瘤细胞的细胞周期、衰老和凋亡.同时,也对肿瘤细胞中葡萄糖、谷氨酸盐、烟酰胺腺嘌呤二核苷酸磷酸(NADPH)、脂质等物质代谢有重要影响.文章拟对MDH与p53蛋白相互调控作用对肿瘤细胞进程的影响及其相关机制做一综述.%p53 gene is a important cancer suppressor gene,tumor suppressor mechanism of p53 gene is very complex,p53 protein coded by p53 gene can inhibit the progression of tumor through a variety of ways.Malate dehydrogenase (MDH) is a important metabolic enzyme,but the function of MDH is not confined to metabolism regulation.Mutual regulation between p53 protein and MDH can influence the cell cycle,senescence and apoptosis of tumor cells.Meanwhile,the regulation also has great influence in material metabolism such as glucose,glutamate,nicotinamide adenine dinucleotide phosphate (NADPH) and lipid.This article will review the influence and related mechanism by mutual regulation between MDH and p53 protein.

  12. 四膜虫omc基因的克隆及在滴滴涕(DDT)暴露下的表达分析%Cloning and Expression Analysis of Tetrahymena 2-oxoglutarate/Malate Carrier Gene (omc) Exposed to Dichlorodiphenyltrichloroethane (DDT)

    Institute of Scientific and Technical Information of China (English)

    郭利娜; 俞婷; 冯立芳; 缪炜

    2010-01-01

    针对环境激素类污染物滴滴涕(DDT)危害大和分子机理复杂等问题,以之前筛选出的一个DDT暴露下差异表达的基因--酮戊二酸/苹果酸载体蛋白基因(2-oxoglutarate/malate carrier,omc)为研究对象,克隆得到该基因转录mRNA的全长为1 060 bp,其中5'、3'非翻译区分别为46 bp和99 bp;实时定量PCR方法测定不同浓度DDT暴露下该基因的表达水平下降了20%~50%.四膜虫omc基因上游数个AP-1和NF-kappaB位点的存在,提示该基因表达受DDT调控的模式可能是与高等动物类似的雌激素受体间接调控途径;同时根据omc基因存在多个与三羧酸循环和电子传递链相关的共表达基因的结果推测,DDT可能通过调控omc等基因来影响线粒体正常功能,进而对细胞产生毒害作用.

  13. Molecular characterization of the citrate transporter gene TaMATE1 and expression analysis of upstream genes involved in organic acid transport under Al stress in bread wheat (Triticum aestivum).

    Science.gov (United States)

    Garcia-Oliveira, Ana Luísa; Martins-Lopes, Paula; Tolrá, Roser; Poschenrieder, Charlotte; Tarquis, Marta; Guedes-Pinto, Henrique; Benito, César

    2014-11-01

    In bread wheat, besides malate, the importance of citrate efflux for Al tolerance has also been reported. For better understanding the Al tolerance mechanism in bread wheat, here, we performed both a molecular characterization of the citrate transporter gene TaMATE1 and an investigation on the upstream variations in citrate and malate transporter genes. TaMATE1 belong to multidrug transporter protein family, which are located on the long arm of homoeologous group 4 chromosomes (TaMATE1-4A, TaMATE1-4B TaMATE1-4D). TaMATE1 homoeologues transcript expression study exhibited the preponderance of homoeologue TaMATE1-4B followed by TaMATE1-4D whereas homoeologue TaMATE1-4A seemed to be silenced. TaMATE1, particularly homoeologue TaMATE1-4B and TaALMT1 transcripts were much more expressed in the root apices than in shoots of Al tolerant genotype Barbela 7/72/92 under both control and Al stress conditions. In addition, in both tissues of Barbela 7/72/92, higher basal levels of these gene transcripts were observed than in Anahuac (Al sensitive). Noticeably, the presence of a transposon in the upstream of TaMATE1-4B in Barbela 7/72/92 seems to be responsible for its higher transcript expression where it may confer citrate efflux. Thus, promoter variations (transposon in TaMATE1-4B upstream and type VI promoter in TaALMT1) associated with higher basal transcript expression of TaMATE1-4B and TaALMT1 clearly show how different mechanisms for Al tolerance operate simultaneously in a single genotype. In conclusion, our results demonstrate that Barbela 7/72/92 has favorable alleles for these organic acids transporter genes which could be utilized through genomic assisted selection to develop improved cultivars for acidic soils.

  14. Identification of the mcpA and mcpM Genes, Encoding Methyl-Accepting Proteins Involved in Amino Acid and l-Malate Chemotaxis, and Involvement of McpM-Mediated Chemotaxis in Plant Infection by Ralstonia pseudosolanacearum (Formerly Ralstonia solanacearum Phylotypes I and III)

    Science.gov (United States)

    Hida, Akiko; Oku, Shota; Kawasaki, Takeru; Tajima, Takahisa

    2015-01-01

    Sequence analysis has revealed the presence of 22 putative methyl-accepting chemotaxis protein (mcp) genes in the Ralstonia pseudosolanacearum GMI1000 genome. PCR analysis and DNA sequencing showed that the highly motile R. pseudosolanacearum strain Ps29 possesses homologs of all 22 R. pseudosolanacearum GMI1000 mcp genes. We constructed a complete collection of single mcp gene deletion mutants of R. pseudosolanacearum Ps29 by unmarked gene deletion. Screening of the mutant collection revealed that R. pseudosolanacearum Ps29 mutants of RSp0507 and RSc0606 homologs were defective in chemotaxis to l-malate and amino acids, respectively. RSp0507 and RSc0606 homologs were designated mcpM and mcpA. While wild-type R. pseudosolanacearum strain Ps29 displayed attraction to 16 amino acids, the mcpA mutant showed no response to 12 of these amino acids and decreased responses to 4 amino acids. We constructed mcpA and mcpM deletion mutants of highly virulent R. pseudosolanacearum strain MAFF106611 to investigate the contribution of chemotaxis to l-malate and amino acids to tomato plant infection. Neither single mutant exhibited altered virulence for tomato plants when tested by root dip inoculation assays. In contrast, the mcpM mutant (but not the mcpA mutant) was significantly less infectious than the wild type when tested by a sand soak inoculation assay, which requires bacteria to locate and invade host roots from sand. Thus, McpM-mediated chemotaxis, possibly reflecting chemotaxis to l-malate, facilitates R. pseudosolanacearum motility to tomato roots in sand. PMID:26276117

  15. Enhancing the aluminium tolerance of barley by expressing the citrate transporter genes SbMATE and FRD3.

    Science.gov (United States)

    Zhou, Gaofeng; Pereira, Jorge F; Delhaize, Emmanuel; Zhou, Meixue; Magalhaes, Jurandir V; Ryan, Peter R

    2014-06-01

    Malate and citrate efflux from root apices is a mechanism of Al(3+) tolerance in many plant species. Citrate efflux is facilitated by members of the MATE (multidrug and toxic compound exudation) family localized to the plasma membrane of root cells. Barley (Hordeum vulgare) is among the most Al(3+)-sensitive cereal species but the small genotypic variation in tolerance that is present is correlated with citrate efflux via a MATE transporter named HvAACT1. This study used a biotechnological approach to increase the Al(3+) tolerance of barley by transforming it with two MATE genes that encode citrate transporters: SbMATE is the major Al(3+)-tolerance gene from sorghum whereas FRD3 is involved with Fe nutrition in Arabidopsis. Independent transgenic and null T3 lines were generated for both transgenes. Lines expressing SbMATE showed Al(3+)-activated citrate efflux from root apices and greater tolerance to Al(3+) toxicity than nulls in hydroponic and short-term soil trials. Transgenic lines expressing FRD3 exhibited similar phenotypes except citrate release from roots occurred constitutively. The Al(3+) tolerance of these lines was compared with previously generated transgenic barley lines overexpressing the endogenous HvAACT1 gene and the TaALMT1 gene from wheat. Barley lines expressing TaALMT1 showed significantly greater Al(3+) tolerance than all lines expressing MATE genes. This study highlights the relative efficacy of different organic anion transport proteins for increasing the Al(3+) tolerance of an important crop species.

  16. Water-transporting proteins.

    Science.gov (United States)

    Zeuthen, Thomas

    2010-04-01

    Transport through lipids and aquaporins is osmotic and entirely driven by the difference in osmotic pressure. Water transport in cotransporters and uniporters is different: Water can be cotransported, energized by coupling to the substrate flux by a mechanism closely associated with protein. In the K(+)/Cl(-) and the Na(+)/K(+)/2Cl(-) cotransporters, water is entirely cotransported, while water transport in glucose uniporters and Na(+)-coupled transporters of nutrients and neurotransmitters takes place by both osmosis and cotransport. The molecular mechanism behind cotransport of water is not clear. It is associated with the substrate movements in aqueous pathways within the protein; a conventional unstirred layer mechanism can be ruled out, due to high rates of diffusion in the cytoplasm. The physiological roles of the various modes of water transport are reviewed in relation to epithelial transport. Epithelial water transport is energized by the movements of ions, but how the coupling takes place is uncertain. All epithelia can transport water uphill against an osmotic gradient, which is hard to explain by simple osmosis. Furthermore, genetic removal of aquaporins has not given support to osmosis as the exclusive mode of transport. Water cotransport can explain the coupling between ion and water transport, a major fraction of transepithelial water transport and uphill water transport. Aquaporins enhance water transport by utilizing osmotic gradients and cause the osmolarity of the transportate to approach isotonicity.

  17. Transportation Technology: Rail Transport and Logistics

    Science.gov (United States)

    Lang, Aaron B.

    2011-01-01

    Transportation can simply be defined as the movement of goods, services, and people from one location to another. Without an efficient means to transport goods from place to place, the economy would be nothing like it is today. Throughout the history of the United States, American railroads have paved the way toward creating a nation of great…

  18. Oxygen transport membrane

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof.......The present invention relates to a novel composite oxygen transport membrane as well as its preparation and uses thereof....

  19. Speeding up Transportation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ 2007 was an excellent year for the transportation industry, marked by high speed railway transportation, development of the national expressway network and launch of the Chang'e lunar probe satellite.

  20. Transportation Management Workshop: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-01

    This report is a compilation of discussions presented at the Transportation Management Workshop held in Gaithersburg, Maryland. Topics include waste packaging, personnel training, robotics, transportation routing, certification, containers, and waste classification.

  1. FREIGHT TRANSPORT IN EUROPE

    Directory of Open Access Journals (Sweden)

    A. REGGIANI

    2000-01-01

    Full Text Available This paper presents an overview of European policy on the interconnected cross-border transport networks as well as severe problems in estimating empirically the avalanche of goods movements in the European Union (EU. In particular, it deals with the Transalpine freight transport case, which represents one of the most challenging operational and policy issues of the present and future – both international (EU and national (the Alpine countries – freight transport development. The paper is organised to briefly describe the main objectives of EU transport policy, to generally introduce the concept of intermodal transport with particular emphasis on intermodal freight transport and to describe past, present and future development of Trans-Alpine intermodal transport. The scenarios of future development of Trans-Alpine intermodal transport have been particularly analysed.

  2. Small Satellite Transporter Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The primary objective is to determine whether this small satellite transporter is capable of transporting at least four 6U CubeSats is possible for a given set of...

  3. Reverse cholesterol transport revisited

    Institute of Scientific and Technical Information of China (English)

    Astrid; E; van; der; Velde

    2010-01-01

    Reverse cholesterol transport was originally described as the high-density lipoprotein-mediated cholesterol flux from the periphery via the hepatobiliary tract to the intestinal lumen, leading to fecal excretion. Since the introduction of reverse cholesterol transport in the 1970s, this pathway has been intensively investigated. In this topic highlight, the classical reverse cholesterol transport concepts are discussed and the subject reverse cholesterol transport is revisited.

  4. How stressful is transportation?

    Science.gov (United States)

    It is common for cattle to be transported multiple times during their production life cycle. Transportation events may include calves shipped to backgrounding facilities and feed yards, as well as pregnant cows that may be transported to sale barns or relocated due to drought to access a pasture or ...

  5. NATURAL GAS TRANSPORTATION

    OpenAIRE

    Stanis³aw Brzeziñski

    2007-01-01

    In the paper, Author presents chosen aspects of natural gas transportation within global market. Natural gas transportation is a technicaly complicated and economicly expensive process; in infrastructure construction and activities costs. The paper also considers last and proposed initiatives in natural gas transportation.

  6. Transportation in African Development.

    Science.gov (United States)

    Altschul, Robert D.

    1980-01-01

    Examines the structure, role, and needs of Africa's national and intracontinental transportation system. Characteristics of rail, water, road, and air transportation are examined. The conclusion is that high investment in transportation systems is essential to the development process. (Author/KC)

  7. Functional difference of malate-aspartate shuttle system in liver between plateau zokor (Myospalax baileyi) and plateau pika (Ochotona curzoniae)%高原鼢鼠和高原鼠兔肝脏苹果酸天冬氨酸穿梭系统的功能差异

    Institute of Scientific and Technical Information of China (English)

    朱瑞娟; 饶鑫峰; 魏登邦; 王多伟; 魏莲; 孙生祯

    2012-01-01

    To explore the adaptive mechanisms of plateau zokor (Myospalax baileyi) to the enduring digging activity in the hypoxic environment and of plateau pika (Ochotona curzoniae) to the sprint running activity, the functional differences of malate-aspartate shuttle system (MA) in liver of plateau zokor and plateau pika were studied. The ratio of liver weight to body weight, the parameters of mitochondria in hepatocyte and the contents of lactic acid in serum were measured; the open reading frame of cytoplasmic malate dehydrogenase (MDH1), mitochondrial malate dehydrogenase (MDH2), and the partial sequence of aspartate glutamate carrier (AGC) and oxoglutarate malate carrier (OMC) genes were cloned and sequenced; MDH1, MDH2, AGC and OMC mRNA levels were determined by real-time PCR; the specific activities of MDHI and MDH2 in liver of plateau zokor and plateau pika were measured using enzymatic methods. The results showed that, (1) the ratio of liver weight to body weight, the number and the specific surface of mitochondria in hepatocyte of plateau zokor were markedly higher than those of plateau pika (P 0.05); (3) mRNA level and enzymatic activity of MDHl was significantly lower than those of MDH2 in the pika liver (P 0.05). These results indicate that the plateau zokor obtains ATP in the enduring digging activity by enhancing the function of MA, while plateau pika gets glycogen for their sprint running activity by increasing the process of gluconeogenesis. As a result, plateau pika converts the lactic acid quickly produced in their skeletal muscle by anaerobic glycolysis and reduces dependence on the oxygen.%为了探讨高原鼢鼠(Myospalax baileyi)和高原鼠兔(Ochotona curzoniae)在低氧环境下适应耐力性挖掘活动和快速奔跑的生理机制,本文比较研究了这两种高原动物肝脏中苹果酸天冬氨酸穿梭系统(malate-spartate shuttle system,MA)的功能差异.测定高原鼢鼠和高原鼠兔的肝脏体重比、肝细胞中线粒体参

  8. Does Citrulline Malate Enhance Physical Performance

    Science.gov (United States)

    2010-10-01

    then returned for their second VO2 max test. After the second test, subjects ingested 6 g/d of the other condition’s capsules for 14 days, and then...returned for their third and final VO2 max test. VO2max, lactate threshold, maximum watts reached, ratings of perceived exertion and pre- and post...ingested 6 g/d of either CM or a placebo for 14 days. Subjects then returned for their second VO2 max test. After the second test, subjects

  9. Intelligent Freigth Transport Systems

    DEFF Research Database (Denmark)

    Overø, Helene Martine; Larsen, Allan; Røpke, Stefan

    2009-01-01

    The Danish innovation project entitled “Intelligent Freight Transport Systems” aims at developing prototype systems integrating public intelligent transport systems (ITS) with the technology in vehicles and equipment as well as the IT-systems at various transport companies. The objective is to en......The Danish innovation project entitled “Intelligent Freight Transport Systems” aims at developing prototype systems integrating public intelligent transport systems (ITS) with the technology in vehicles and equipment as well as the IT-systems at various transport companies. The objective...... is to enhance the efficiency and lower the environmental impact in freight transport. In this paper, a pilot project involving real-time waste collection at a Danish waste collection company is described, and a solution approach is proposed. The problem corresponds to the dynamic version of the waste collection...

  10. Transportation safety training

    Energy Technology Data Exchange (ETDEWEB)

    Jones, E.

    1990-01-01

    Over the past 25 years extensive federal legislation involving the handling and transport of hazardous materials/waste has been passed that has resulted in numerous overlapping regulations administered and enforced by different federal agencies. The handling and transport of hazardous materials/waste involves a significant number of workers who are subject to a varying degree of risk should an accident occur during handling or transport. Effective transportation training can help workers address these risks and mitigate them, and at the same time enable ORNL to comply with the federal regulations concerning the transport of hazardous materials/waste. This presentation will outline how the Environmental and Health Protection Division's Technical Resources and Training Section at the Oak Ridge National Laboratory, working with transportation and waste disposal personnel, have developed and implemented a comprehensive transportation safety training program to meet the needs of our workers while satisfying appropriate federal regulations. 8 refs., 3 tabs.

  11. [Fructose transporter in yeasts].

    Science.gov (United States)

    Lazar, Zbigniew; Dobrowolski, Adam; Robak, Małgorzata

    2014-01-01

    Study of hexoses transporter started with discovery of galactose permease in Saccharomyces cerevisiae. Glucose, fructose and mannose assimilation is assumed by numerous proteins encoded by different genes. To date over 20 hexoses transporters, belonging to Sugar Porter family and to Major Facilitator Superfamily, were known. Genome sequence analysis of Candida glabrata, Kluyveromyces lactis, Yarrowia lipolytica, S. cerevisaie and Debaryomyces hansenii reveled potential presence of 17-48 sugar porter proteins. Glucose transporters in S. cerevisiae have been already characterized. In this paper, hexoses transporters, responsible for assimilation of fructose by cells, are presented and compared. Fructose specific transporter are described for yeasts: Zygosaccharomyces rouxii, Zygosaccharomyces bailli, K. lactis, Saccharomyces pastorianus, S. cerevisiae winemaking strain and for fungus Botritys cinerea and human (Glut5p). Among six yeasts transporters, five are fructose specific, acting by facilitated diffusion or proton symport. Yeasts monosaccharides transporter studies allow understanding of sugars uptake and metabolism important aspects, even in higher eukaryotes cells.

  12. TRANSPORT/HANDLING REQUESTS

    CERN Multimedia

    Groupe ST/HM

    2002-01-01

    A new EDH document entitled 'Transport/Handling Request' will be in operation as of Monday, 11th February 2002, when the corresponding icon will be accessible from the EDH desktop, together with the application instructions. This EDH form will replace the paper-format transport/handling request form for all activities involving the transport of equipment and materials. However, the paper form will still be used for all vehicle-hire requests. The introduction of the EDH transport/handling request form is accompanied by the establishment of the following time limits for the various services concerned: 24 hours for the removal of office items, 48 hours for the transport of heavy items (of up to 6 metric tons and of standard road width), 5 working days for a crane operation, extra-heavy transport operation or complete removal, 5 working days for all transport operations relating to LHC installation. ST/HM Group, Logistics Section Tel: 72672 - 72202

  13. Transportation System Requirements Document

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    This Transportation System Requirements Document (Trans-SRD) describes the functions to be performed by and the technical requirements for the Transportation System to transport spent nuclear fuel (SNF) and high-level radioactive waste (HLW) from Purchaser and Producer sites to a Civilian Radioactive Waste Management System (CRWMS) site, and between CRWMS sites. The purpose of this document is to define the system-level requirements for Transportation consistent with the CRWMS Requirement Document (CRD). These requirements include design and operations requirements to the extent they impact on the development of the physical segments of Transportation. The document also presents an overall description of Transportation, its functions, its segments, and the requirements allocated to the segments and the system-level interfaces with Transportation. The interface identification and description are published in the CRWMS Interface Specification.

  14. Doubling the CO2 Concentration Enhanced the Activity of Carbohydrate-Metabolism Enzymes, Source Carbohydrate Production, Photoassimilate Transport, and Sink Strength for Opuntia ficus-indica.

    Science.gov (United States)

    Wang, N.; Nobel, P. S.

    1996-01-01

    After exposure to a doubled CO2 concentration of 750 [mu]mol mol-1 air for about 3 months glucose and starch in the chlorenchyma of basal cladodes of Opuntia ficus-indica increased 175 and 57%, respectively, compared with the current CO2 concentration of 370 [mu]mol mol-1, but sucrose content was virtually unaffected. Doubling the CO2 concentration increased the nocturnal malate production in basal cladodes by 75%, inorganic phosphate (Pi) by 32%, soluble starch synthase activity by 30%, and sucrose-Pi synthase activity by 146%, but did not affect the activity of hexokinase. Doubling CO2 accelerated phloem transport of sucrose out of the basal cladodes, resulting in a 73% higher dry weight for the daughter cladodes. Doubling CO2 increased the glucose content in 14-d-old daughter cladodes by 167%, increased nocturnal malate production by 22%, decreased total amino acid content by 61%, and increased soluble starch synthase activity by 30% and sucrose synthase activity by 62%. No downward acclimation of photosynthesis during long-term exposure to elevated CO2 concentrations occurs for O. ficus-indica (M. Cui, P.M. Miller, P.S. Nobel [1993] Plant Physiol 103: 519-524; P.S. Nobel, A.A. Israel [1994] J Exp Bot 45: 295-303), consistent with its higher source capacity and sink strength than under current CO2. These changes apparently do not result in Pi limitation of photosynthesis or suppression of genes governing photosynthesis for this perennial Crassulacean acid metabolism species, as occur for some annual crops. PMID:12226228

  15. Doubling the CO2 Concentration Enhanced the Activity of Carbohydrate-Metabolism Enzymes, Source Carbohydrate Production, Photoassimilate Transport, and Sink Strength for Opuntia ficus-indica.

    Science.gov (United States)

    Wang, N.; Nobel, P. S.

    1996-03-01

    After exposure to a doubled CO2 concentration of 750 [mu]mol mol-1 air for about 3 months glucose and starch in the chlorenchyma of basal cladodes of Opuntia ficus-indica increased 175 and 57%, respectively, compared with the current CO2 concentration of 370 [mu]mol mol-1, but sucrose content was virtually unaffected. Doubling the CO2 concentration increased the nocturnal malate production in basal cladodes by 75%, inorganic phosphate (Pi) by 32%, soluble starch synthase activity by 30%, and sucrose-Pi synthase activity by 146%, but did not affect the activity of hexokinase. Doubling CO2 accelerated phloem transport of sucrose out of the basal cladodes, resulting in a 73% higher dry weight for the daughter cladodes. Doubling CO2 increased the glucose content in 14-d-old daughter cladodes by 167%, increased nocturnal malate production by 22%, decreased total amino acid content by 61%, and increased soluble starch synthase activity by 30% and sucrose synthase activity by 62%. No downward acclimation of photosynthesis during long-term exposure to elevated CO2 concentrations occurs for O. ficus-indica (M. Cui, P.M. Miller, P.S. Nobel [1993] Plant Physiol 103: 519-524; P.S. Nobel, A.A. Israel [1994] J Exp Bot 45: 295-303), consistent with its higher source capacity and sink strength than under current CO2. These changes apparently do not result in Pi limitation of photosynthesis or suppression of genes governing photosynthesis for this perennial Crassulacean acid metabolism species, as occur for some annual crops.

  16. Transport of radioactive substances; Der Transport radioaktiver Stoffe

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-12-15

    The report on the transport of radioactive substances covers the following topics: facts on radioactive materials transport, safety of the transport of radioactive substances, legal regulations and guidelines: a multiform but consistent system, transport of nuclear fuels, safety during the transport of nuclear fuel, future transport of spent fuel elements and high-level radioactive wastes in Germany.

  17. Transport, energy and environment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    Transportation demands a large and increasing share of total energy consumption in Europe. At the same time many European countries are facing difficult decisions in achieving their long term environmental goals. Therefore energy policy, environmental policy and transport policy should be seen and discussed in a common perspective. In particular the relative contribution from the transport sector and the energy sector involves a number of important and difficult issues. The aim of the conference was to bring together economists, scientists, manufactures, energy planners, transport planners, and decision makers in order to discuss the importance of the transport sector in relation to energy demand and long term environmental goals. General conference sessions covered. Trends in Transport Energy Demand and Environmental constraints, Technological Development and New Transport Systems, Lifestyle Changes and the Transport Sector, Megacities: Solutions to the Transport and Air Pollution Problems, Effectiveness of Public Policies, Transport and Energy sector, and Methods, Models and Data. The conference took place at Hotel Marienlyst, Elsinore, Denmark and attracted wide interest. The participants represented 14 different countries covering international organisations, ministries, universities, research centres, consulting firms, industry etc. (EG)

  18. Energy and transport.

    Science.gov (United States)

    Woodcock, James; Banister, David; Edwards, Phil; Prentice, Andrew M; Roberts, Ian

    2007-09-22

    We examine the links between fossil-fuel-based transportation, greenhouse-gas emissions, and health. Transport-related carbon emissions are rising and there is increasing consensus that the growth in motorised land vehicles and aviation is incompatible with averting serious climate change. The energy intensity of land transport correlates with its adverse health effects. Adverse health effects occur through climate change, road-traffic injuries, physical inactivity, urban air pollution, energy-related conflict, and environmental degradation. For the world's poor people, walking is the main mode of transport, but such populations often experience the most from the harms of energy-intensive transport. New energy sources and improvements in vehicle design and in information technology are necessary but not sufficient to reduce transport-related carbon emissions without accompanying behavioural change. By contrast, active transport has the potential to improve health and equity, and reduce emissions. Cities require safe and pleasant environments for active transport with destinations in easy reach and, for longer journeys, public transport that is powered by renewable energy, thus providing high levels of accessibility without car use. Much investment in major road projects does not meet the transport needs of poor people, especially women whose trips are primarily local and off road. Sustainable development is better promoted through improving walking and cycling infrastructures, increasing access to cycles, and investment in transport services for essential needs. Our model of London shows how increased active transport could help achieve substantial reductions in emissions by 2030 while improving population health. There exists the potential for a global contraction and convergence in use of fossil-fuel energy for transport to benefit health and achieve sustainability.

  19. EBS Radionuclide Transport Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    J. Prouty

    2006-07-14

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport

  20. Liver iron transport

    Institute of Scientific and Technical Information of China (English)

    Ross M Graham; Anita CG Chua; Carly E Herbison; John K Olynyk; Debbie Trinder

    2007-01-01

    The liver plays a central role in iron metabolism. It is the major storage site for iron and also expresses a complex range of molecules which are involved in iron transport and regulation of iron homeostasis. An increasing number of genes associated with hepatic iron transport or regulation have been identified. These include transferrin receptors (TFR1 and 2), a ferrireductase (STEAP3), the transporters divalent metal transporter-1 (DMT1) and ferroportin (FPN) as well as the haemochromatosis protein, HFE and haemojuvelin (HJV),which are signalling molecules. Many of these genes also participate in iron regulatory pathways which focus on the hepatic peptide hepcidin. However, we are still only beginning to understand the complex interactions between liver iron transport and iron homeostasis. This review outlines our current knowledge of molecules of iron metabolism and their roles in iron transport and regulation of iron homeostasis.

  1. Transport Energy Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Transport is the sector with the highest final energy consumption and, without any significant policy changes, is forecast to remain so. In 2008, the IEA published 25 energy efficiency recommendations, among which four are for the transport sector. The recommendations focus on road transport and include policies on improving tyre energy efficiency, fuel economy standards for both light-duty vehicles and heavy-duty vehicles, and eco-driving. Implementation of the recommendations has been weaker in the transport sector than others. This paper updates the progress that has been made in implementing the transport energy efficiency recommendations in IEA countries since March 2009. Many countries have in the last year moved from 'planning to implement' to 'implementation underway', but none have fully implemented all transport energy efficiency recommendations. The IEA calls therefore for full and immediate implementation of the recommendations.

  2. Means of Transport

    DEFF Research Database (Denmark)

    Balle, Søren Hattesen

    2004-01-01

    improved means of fast physical movement from one place to another. Yet, the impact that the technology of automobility came to have was not of a limited materialistic nature. As many literary and cultural critics have noted, car technology extended its influence into the field of imaginative transport....... According to film theorist Julian Smith, the automobile has been just as much “embraced … as a form of emotional transport, the state or condition of being transported by ecstasy” as “perceived as a mode of transportation in the primary and ordinary sense of the word.” This paper analyses the ways in which...... William Carlos Williams negotiates the relationship between these two kinds of automotive transport in some of his poetic and poetic prose writings from the period when the car was introduced on a more general scale in America. Intense moments of emotional and imaginative transport in Williams are often...

  3. Affinity partitioning of malate dehydrogenase with triton X-100modified by cibacron blue F3G-A%三嗪染料修饰曲通X-100亲和分离苹果酸脱氢酶

    Institute of Scientific and Technical Information of China (English)

    杨梅; 唐江涛; 李步海; 唐尹萍

    2011-01-01

    三嗪染料(Cibacmn blue F3G-A)的蒽醌部分结构类似于腺嘌呤,可以用于亲和分离以NAD+(NADP+)和FAD为辅酶的脱氢酶.三嗪染料通过亲核取代反应修饰曲通X-100,形成的三嗪染料-曲通X-100与成相聚合物吐温80、磷酸钾盐构成液-固亲和萃取体系.从猪心肌匀浆液纯化苹果酸脱氢酶的条件:三嗪染料-曲通X-100浓度为1.2%(W/V),吐温舳浓度9%(V/V),猪心肌匀浆液0.25 mL(2.5%),pH8.0,加入成相磷酸钾终浓度1.6 mol/L,形成液固两相,固相酶活力平均收得率为81.01%,纯化倍数为4.93.固相30℃保温溶解,加入成相盐磷酸钾,终浓度为0.7mol/L,二次成相.低盐浓度条件下,近80%的酶反萃回液相,简化了苹果酸脱氢酶后续加工工艺.%Due to the structure of anthraquinone of triazine-dye( Cibacron blue F3G-A,short as Cb)similar as adenine.Cb could be used to purify enzymes whose coenzyme was NAD+( NADP+)or FAD with affinity partitioning method. Triton X-100 modified by Cb through nucleophilic substitution reaction,Tween 80 and potassium phosphate constituted the liquid-solid affinity partitioning system. The optimal malate dehydrogenase( short as MDH) purification system from porcine cardiac muscle homogenate condition consists of triton X-100 modified by Cb 1.2% ( W/V) .phase-forming polymer Tween 80 9% ( V/V) .porcine cardiac muscle homogenate 0.25 mL(2.5% ) .and the final concentration of phase-forming potassium phosphate 1.6 mol/L.pH 8.0. The enzyme recovery in solid-state(Tween 80 phase)was 81.01% .and the purification fold was 4.93. After the solid-state dissolved by incubation at 30℃ ,and then the concentration of potassium phosphate adjusted to 0.7 mol/L, the dissolved solid-state re-forms the liquid-solid two phase system with the enzyme recovery of near 80%in salt aqueous phase,which simplified the following processing of MDH.

  4. Study on activity of serum malate dehydrogenase in patients with liver cirrhosis.%肝硬化患者血清苹果酸脱氢酶的活性检测

    Institute of Scientific and Technical Information of China (English)

    陈芊伊; 吕星; 张志杰; 代洪

    2011-01-01

    目的 探讨肝硬化患者血清苹果酸脱氢酶(MDH)的活性变化及其临床意义.方法 95例血清分为肝硬化组48例、肝炎组20例和正常对照组27例.采用终点法测定肝硬化患者血清MDH活性,计算MDH对诊断肝硬化的阳性率、灵敏度和特异性,并分析血清MDH与白蛋白(ALB)、丙氨酸氨基转移酶(ALT)、总胆红素(TB)的相关性.结果 肝硬化组血清MDH活性为(72.60±7.90)U/L,肝炎组患者血清MDH活性(77.47±7.03)U/L,正常组血清MDH活性为(38.58±3.54)U/L.肝硬化组、肝炎组均显著高于正常对照组,有显著性差异(P0.05).MDH活性与ALB、ALT、TB均无相关性.阳性判断以MDH>50 U/L为标准,其敏感度为100%,特异性为96.3%.结论 肝硬化患者有MDH活性增高,可为辅助诊断肝硬化提供有价值的信息.%Objective To evaluate the activity and clinical significance of serum malate dehydrogenase ( MDH ) in patients with liver cirthosis. Methods 95 cases were divided into 48 cases of liver cirrhosis. 20 cases of hepatitis and 27 cases of normal control group. The serum activity of MDH was detected hy endpoint method. The positive rate, negative rate, sensitivity and specificity of serum MDH in diagnosis of patients with liver cirrhosis were evaluated. The correlation among MDH and ALB ,ALT and TB was studied and analyzefl. Results The activity of serum MDH in cirrhosis group was 72. 60 ±7. 90 U/L, hepatitis group was 77. 47 ±7. 03 U/L,and it was 38. 58 ±3. 54 U/L in normal control group. Cirrhosis , hepatitis group was significantly higher than the control group , the difference was significant( P < 0. 001 ) ; but no significant difference between Cirrhosis and hepatitis groups( P >0. 05 ). The activity of serum MDH had no correlation with serum levels of ALB, ALT and TB. Positive judgments to MDH > 50 U / L as the standard. the sensitivitv was 1OO% and specificity of 96. 3% . Conclusion The serum activity of MDH in patients with liver cirrhosis

  5. 大肠杆菌苹果酸脱氢酶基因mdh的克隆、高效表达及酶学性质%Cloning,Expression,and Characterization of a Malate Dehydrogenase Gene from Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    李倩; 徐美娟; 夏海锋; 饶志明

    2011-01-01

    Malate dehydrogenase (MDH) gene was amplified via PCR from the chromosome of Escherichia coli in this manuscript.The PCR product was cloned into the expression vector pET28a (+).The resulted recombinant plasmid was transformed into E.coli BL21 (DE3).Induced by 0.5 mmol/L IPTG, MDH, a 36KDa protein, was successfully expressed in E.coli BL21 (DE3).An active MDH was purified by Ni-NTA column affinity Chromatography, with the specific activity of 112.5 U/mg,the purification multiple of 2.62, and the recovery rate of 59%.In a preliminary study, the enzymatic properties of the purified His-tagged enzyme were characterized.It was found to have pH and temperature optima of 37 ℃ and 6.0, respectively.The enzyme was stable when pH and temperature kept in the range of 2.0 to 6.0 and blow 42 ℃, respectively.Its activity was activated by K+ dramatically, inhibited by Cu2+ , seriously inhibited by Zn2+ and Hg2+.Although alcohols have little effect on this enzyme, glycerol could dramatically improve the thermal stability of MDH.When oxaloacetic acid was used as substrate, the enzyme kinetic constants of Km and Vmax was 0.235 mmol/L and 0.47 μmol/(L · min), respectively.%以大肠杆菌基因组DNA为模板,扩增得到苹果酸脱氢酶(mdh)编码基因mdh,构建了重组菌pET-28a-mdh/BL21并成功表达了mdh,大小约36 000.选用Ni柱亲和层析法纯化具有活性的苹果酸脱氢酶(mdh),纯化后比酶活达到112.5 U/mg,纯化倍数达2.62倍,回收率为59%.并对该酶的酶学性质进行了初步研究,其中反应最适PH值为6.0,在PH值2.0~6.0范围内稳定;反应最适温度为37℃,在42℃以下酶的稳定性较好.K+对酶有明显的激活作用,Cu2+对酶有抑制作用,Hg2+和Zn2+对酶有很强的抑制作用.醇类对酶的活力影响不大,丙三醇可显著提高酶的热稳定性.酶动力学参数以草酰乙酸为底物的Km为0.235 mmol/L,Vmax为0.47 μmol/(L·min).

  6. Bioinformatics Analysis on the Structure and Function of Malate Dehydrogenase Gene of Taenia solium%生物信息学法分析猪带绦虫苹果酸脱氢酶结构与功能

    Institute of Scientific and Technical Information of China (English)

    蓝磊; 廖兴江; 黄江; 戴佳琳

    2012-01-01

    目的:分析和预测猪带绦虫苹果酸脱氢酶的结构和特性,用于指导其生物学功能的实验研究.方法:利用美国国家生物技术信息中心和瑞士生物信息学研究所的蛋白分析专家系统中有关基因和蛋白的序列和结构信息分析的工具,结合Pcgene和Vector NTI suite生物信息学分析软件包,从猪带绦虫全长cDNA质粒文库中识别苹果酸脱氢酶基因及其编码区,分析、预测该基因编码的蛋白质的理化特性、翻译后的修饰位点、功能域、亚细胞定位、拓扑结构、二级结构、三维空间构象等.结果:该基因编码332个氨基酸,为全长基因.GenBank中与细粒棘球绦虫苹果酸脱氢酶序列同源性最高,理论分子量为36459.2 Da.预测编码蛋白无跨膜区,无二硫键,稳定性较好.与吸虫属的苹果酸脱氢酶进化关系最近.结论:应用生物信息方法从猪带绦虫成虫Cd-NA文库中筛选出了猪带绦虫核糖体Cdna全长序列并预测得到其结构与功能方面信息.%Objective: To analyze and predict the structure and characteristics of Taenia solium mal-ate dehydrogenase ( MDH) , and so as to guide the experimental research on biological function of MDH. Methods: Tools about informatics analyis on sequences and structures of gene and protein in protein analysis expert system of bioinformatic institute of Switzerland, and those of state biological and technology information center of USA, combined with Pcgene and Vector NTI suite bioinformatics soft-ware pakege were employed to screen Taenia solium MDH gene and encoding region from cDNA plas-mid library to analyze and predict physicochemical properties of its encoding protein, modification site after translation, function domains, subcelluar location, topological structure, secondary structure, and 3D conformation and so on. Results: This gene encoded 332 amino acids, and was a full length gene. It was the most homologues to Taenia echinococcus MDH in Gen

  7. Thermodynamics of ABC transporters.

    Science.gov (United States)

    Zhang, Xuejun C; Han, Lei; Zhao, Yan

    2016-01-01

    ABC transporters form the largest of all transporter families, and their structural study has made tremendous progress over recent years. However, despite such advances, the precise mechanisms that determine the energy-coupling between ATP hydrolysis and the conformational changes following substrate binding remain to be elucidated. Here, we present our thermodynamic analysis for both ABC importers and exporters, and introduce the two new concepts of differential-binding energy and elastic conformational energy into the discussion. We hope that the structural analysis of ABC transporters will henceforth take thermodynamic aspects of transport mechanisms into account as well.

  8. UZ Colloid Transport Model

    Energy Technology Data Exchange (ETDEWEB)

    M. McGraw

    2000-04-13

    The UZ Colloid Transport model development plan states that the objective of this Analysis/Model Report (AMR) is to document the development of a model for simulating unsaturated colloid transport. This objective includes the following: (1) use of a process level model to evaluate the potential mechanisms for colloid transport at Yucca Mountain; (2) Provide ranges of parameters for significant colloid transport processes to Performance Assessment (PA) for the unsaturated zone (UZ); (3) Provide a basis for development of an abstracted model for use in PA calculations.

  9. WASTE PACKAGE TRANSPORTER DESIGN

    Energy Technology Data Exchange (ETDEWEB)

    D.C. Weddle; R. Novotny; J. Cron

    1998-09-23

    The purpose of this Design Analysis is to develop preliminary design of the waste package transporter used for waste package (WP) transport and related functions in the subsurface repository. This analysis refines the conceptual design that was started in Phase I of the Viability Assessment. This analysis supports the development of a reliable emplacement concept and a retrieval concept for license application design. The scope of this analysis includes the following activities: (1) Assess features of the transporter design and evaluate alternative design solutions for mechanical components. (2) Develop mechanical equipment details for the transporter. (3) Prepare a preliminary structural evaluation for the transporter. (4) Identify and recommend the equipment design for waste package transport and related functions. (5) Investigate transport equipment interface tolerances. This analysis supports the development of the waste package transporter for the transport, emplacement, and retrieval of packaged radioactive waste forms in the subsurface repository. Once the waste containers are closed and accepted, the packaged radioactive waste forms are termed waste packages (WP). This terminology was finalized as this analysis neared completion; therefore, the term disposal container is used in several references (i.e., the System Description Document (SDD)) (Ref. 5.6). In this analysis and the applicable reference documents, the term ''disposal container'' is synonymous with ''waste package''.

  10. RELATIVISTIC TRANSPORT-THEORY

    NARCIS (Netherlands)

    MALFLIET, R

    1993-01-01

    We discuss the present status of relativistic transport theory. Special emphasis is put on problems of topical interest: hadronic features, thermodynamical consistent approximations and spectral properties.

  11. Transportation Outreach Program Plan

    Energy Technology Data Exchange (ETDEWEB)

    1991-08-01

    The Department of Energy (DOE) Transportation Management Program (TMP) is committed to providing opportunities for public interaction, working cooperatively with groups interested in or affected by DOE transportation, and providing information through the development and implementation of its Outreach Program. This Plan describes how the DOE plans to involve the public in its transportation programs. This Transportation Outreach Program Plan will assist the Secretary of Energy is carrying out his vision of the good neighbor'' policy. The Department of Energy encourages face to face interaction and welcomes comments from everyone. Outreach means to go beyond,'' and the TMP, through its Outreach Program, will hear and address the public's concerns and recommendations about transportation of hazardous and radioactive materials. The TMP Outreach Program is based on a commitment to two-way communication. The TMP coordinates transportation policy for all DOE programs to ensure consistent approaches issues and operations. The TMP conducts outreach by interacting with many groups interested in DOE transportation, facilitating resolution of issues and information exchange, and coordinating the DOE's transportation emergency preparedness capabilities. Many of the specific activities in transportation outreach are usually carried out by field and area offices. 4 figs., 2 tabs.

  12. EUROPEAN MARITIME TRANSPORT POLICY

    Directory of Open Access Journals (Sweden)

    Jerzy Kujawa

    2014-03-01

    Full Text Available The article describes the common EU policy on maritime transport, which comprises almost 80% of the volume of external trade of the Union and about 40% of internal transport needs. The first part of the paper presents the origins of the common maritime transport policy and the difficulties encountered during its initial formation. Subsequently, the evolution of the concepts of the policy and its current shape is discussed. The final, substantial part of the article describes the main aims and directions of the EU maritime transport policy and includes an evaluation of the effects of the policy.

  13. Hopping transport in solids

    CERN Document Server

    Pollak, M

    1991-01-01

    The hopping process, which differs substantially from conventional transport processes in crystals, is the central process in the transport phenomena discussed in this book. Throughout the book the term ``hopping'' is defined as the inelastic tunneling transfer of an electron between two localized electronic states centered at different locations. Such processes do not occur in conventional electronic transport in solids, since localized states are not compatible with the translational symmetry of crystals.The rapid growth of interest in hopping transport has followed in the footsteps of the

  14. Moisture Transport in Wood

    DEFF Research Database (Denmark)

    Astrup, T.; Hansen, K. K.; Hoffmeyer, P.;

    2005-01-01

    Modelling of moisture transport in wood is of great importance as most mechanical and physical properties of wood depend on moisture content. Moisture transport in porous materials is often described by Ficks second law, but several observations indicate that this does not apply very well to wood....... Recently at the Technical University of Denmark, Department of Civil Engineering, a new model for moisture transport in wood has been developed. The model divides the transport into two phases, namely water vapour in the cell lumens and bound water in the cell walls....

  15. Human peptide transporters

    DEFF Research Database (Denmark)

    Nielsen, Carsten Uhd; Brodin, Birger; Jørgensen, Flemming Steen;

    2002-01-01

    Peptide transporters are epithelial solute carriers. Their functional role has been characterised in the small intestine and proximal tubules, where they are involved in absorption of dietary peptides and peptide reabsorption, respectively. Currently, two peptide transporters, PepT1 and PepT2...

  16. Bronchial mucus transport

    NARCIS (Netherlands)

    van der Schans, Cees P.

    2007-01-01

    Effective clearance of inhaled particles requires mucus production and continuous mucus transport from the lower airways to the oropharynx. Mucus production takes place mainly in the peripheral airways. Mucus transport is achieved by the action of the ciliated cells that cover the inner surface of t

  17. Energy technology for transport

    Energy Technology Data Exchange (ETDEWEB)

    Sloth, M. [H2 Logic (Denmark); Schroeder Pedersen, A. [Risoe National Lab. - DTU (Denmark)

    2007-11-15

    World energy demand for transport has increased significantly for many years. This trend is projected to continue in the years to come, one reason being that large and rapidly developing economies bring increasing demand for the transport of goods and people, including rising transport demand due to greater integration of developing countries in the international trade. Transport not only account for approximately 20 % of the total world energy consumption, but is almost entirely based on limited and expensive fossil energy resources. Technology development and economic incentives are key areas in bringing clean energy to the transportation sector. This chapter recommends that technology development must aim to make each link of the energy conversion chain cheaper, cleaner and more efficient. It should be driven by public-private partnerships, with a funding basis balance that reflects the nearness of each technology to commercial application. Onboard storage, for instance, still needs basic research, whereas fuel cells are already competitive in certain markets. For consumers, fossil fuels are certain to remain the cheapest option for transport as long as energy prices do not reflect the cost of environmental damage. To reduce CO{sub 2} emissions from transport, governments are recommended to set up strong economic or other incentives to encourage consumers to opt for low-carbon vehicles or public transport. As well as reducing environmental damage, such measures could generate money to support research and development in clean energy technologies. (BA)

  18. Transport and Sustainability

    DEFF Research Database (Denmark)

    Jørgensen, Kaj

    1997-01-01

    Ph.D. study of the scope for sustainable transport in Denmark, and particularly of the role of the motor vehicle in this context. The distribution of groceries is used as case study of the introduction of the motor vehicle in Denmark, concluding that this has resulted in increases of the transport...

  19. Transport of sugars.

    Science.gov (United States)

    Chen, Li-Qing; Cheung, Lily S; Feng, Liang; Tanner, Widmar; Frommer, Wolf B

    2015-01-01

    Soluble sugars serve five main purposes in multicellular organisms: as sources of carbon skeletons, osmolytes, signals, and transient energy storage and as transport molecules. Most sugars are derived from photosynthetic organisms, particularly plants. In multicellular organisms, some cells specialize in providing sugars to other cells (e.g., intestinal and liver cells in animals, photosynthetic cells in plants), whereas others depend completely on an external supply (e.g., brain cells, roots and seeds). This cellular exchange of sugars requires transport proteins to mediate uptake or release from cells or subcellular compartments. Thus, not surprisingly, sugar transport is critical for plants, animals, and humans. At present, three classes of eukaryotic sugar transporters have been characterized, namely the glucose transporters (GLUTs), sodium-glucose symporters (SGLTs), and SWEETs. This review presents the history and state of the art of sugar transporter research, covering genetics, biochemistry, and physiology-from their identification and characterization to their structure, function, and physiology. In humans, understanding sugar transport has therapeutic importance (e.g., addressing diabetes or limiting access of cancer cells to sugars), and in plants, these transporters are critical for crop yield and pathogen susceptibility.

  20. Transport, environment and sustainability

    DEFF Research Database (Denmark)

    Joumard, Robert; Gudmundsson, Henrik; Kehagia, Fotini

    2010-01-01

    This report is the final report of the action COST 356 'EST - Towards the definition of a measurable environmentally sustainable transport'. It tries to answer the following questions: How can environmental impacts of transport be measured? How can measurements be transformed into operational ind...

  1. Conservation in transportation

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-05-30

    A nationwide examination was made of grassroots energy conservation programs related to transportation. Information compiled from civic groups, trade associations, and corporations is included on driver awareness/mass transit; travel; and ride sharing. It is concluded that a willingness by the public to cooperate in transportation energy conservation exists and should be exploited. (LCL)

  2. Transportation: Topic Paper E.

    Science.gov (United States)

    National Council on the Handicapped, Washington, DC.

    As one of a series of topic papers assessing federal laws and programs affecting persons with disabilities, this paper reviews the issue of transportation services. In the area of urban mass transit, four relevant pieces of legislation and public transportation accessibility regulations are cited, and cost issues are explored. Paratransit systems,…

  3. Sustainable Inland Transportation

    NARCIS (Netherlands)

    Bloemhof, J.M.; Laan, van der E.A.; Beijer, C.

    2011-01-01

    Inland navigation is often mentioned as a ‘green’ alternative for the two other main inland transport modes: rail and road transport. In order to investigate the opportunities for inland navigation we first analyze the competitive position of inland navigation vis-à-vis the other main inland transpo

  4. New prospects of transportation mobility

    OpenAIRE

    Cheng-Min Feng

    2014-01-01

    The demand for improving the quality and efficiency of transportation service has been growing, and new technologies have been entering the market at a rapid pace. Creative thinking and approaches are increasingly important for governments in shaping their transportation policy and actions. This paper aims to discuss several challenges pertaining to the topic, including instant transportation, sharing transportation, fast transportation, resilient transportation, affordable transportation, an...

  5. Urban transportation projects conceptualised:

    DEFF Research Database (Denmark)

    Pineda, Andres Felipe Valderrama

    During the last ten years two innovations in urban transportation have been accomplished in two different parts of the planet: in the city of Bogotá, in Colombia, the first mass bus rapid transit system was designed, built and put into operation becoming the most visible icon of a great urban...... is straightforward: transportation projects transform cities. The paradoxical reality thus is that a problem that has been traditionally conceptualized in technical terms (transportation engineering, transportation economics, planning theory, traffic engineering, urban planning, etc.), has tremendous consequences...... operation when discussing transportation projects in big cities. The tradition of Science and Technology Studies might have provided some clues. In the following paper we discuss the most prominent aspects of some theories in STS in order to understand and conceptualize the cases of Bogotá and Copenhagen...

  6. Water-transporting proteins

    DEFF Research Database (Denmark)

    Zeuthen, Thomas

    2010-01-01

    . In the K(+)/Cl(-) and the Na(+)/K(+)/2Cl(-) cotransporters, water is entirely cotransported, while water transport in glucose uniporters and Na(+)-coupled transporters of nutrients and neurotransmitters takes place by both osmosis and cotransport. The molecular mechanism behind cotransport of water......Transport through lipids and aquaporins is osmotic and entirely driven by the difference in osmotic pressure. Water transport in cotransporters and uniporters is different: Water can be cotransported, energized by coupling to the substrate flux by a mechanism closely associated with protein...... is not clear. It is associated with the substrate movements in aqueous pathways within the protein; a conventional unstirred layer mechanism can be ruled out, due to high rates of diffusion in the cytoplasm. The physiological roles of the various modes of water transport are reviewed in relation to epithelial...

  7. Logistic innovations in transport

    Directory of Open Access Journals (Sweden)

    Mirosław Antonowicz

    2014-03-01

    Full Text Available Introduction: The article discusses the issue of logistic innovations in transport. The essentials of logistic innovations in transport together with some examples of specific innovations are presented. The role of the client's needs in transport innovations is indicated. The most vital postulates affecting the innovativeness of shipping companies and derived from the author's experience as well as scholarly publications, are time, safety, reliability as well as comprehensiveness of service offer. Following the analysis of the issue, and on the grounds of Kaizen's and Lean's method, the concept of continuous innovations is suggested as very useful for the development of transport. The potential of clusters as the source of logistic innovations in transport is emphasised. Methods: The discussion of the issue was preceded by the author's analysis of written sources on innovativeness, the evaluation of ratings of innovativeness as well as the analysis of rewarded innovative solutions in transport subsequent to the businesses participation in the programme of innovative solutions in transport. The role of innovation practical business operations is argued following the analysis of some strategic documents such as: 2011 White Paper and the Strategy for the Development of Transport by 2020 adopted by the Polish government in 2013. Aim: The aim of the article is to present the role and significance of the issue of logistic innovations in transport and to cite instances of practical solutions implemented by shipping companies, the solutions which resulted in measurable effects. Following the author's observation of the instances of innovative solutions as well as his analysis of the ratings of innovativeness, the article aims to present the conclusions as for the specific kinds of activities which are indispensable to foster innovativeness in transport. Conclusions: The conclusions derived from the author's analyses and observations show that logistic

  8. 小麦中一类依赖于NAD的细胞质型苹果酸脱氢酶cDNA的克隆和进化树分析%Cloning and Evolutionary Analysis of a Partial Cytosolic Malate Dehydrogenase cDNA from Wheat

    Institute of Scientific and Technical Information of China (English)

    蔺占兵; 徐洋; 马庆虎; 丁郁

    2004-01-01

    Malate dehydrogenase (MDH) is ubiquitous in nature, which catalyzes the interconversion of oxaloacetate and malate.Higher plants contain multiple forms of MDHs that differ in co-enzyme specificity, subcellular localization and physiological functions. Cytosolic NAD-dependent MDH (cyMDH) is one class of MDH that is still less investigated. Here we report the isolation and characterization of a partial cDNA clone encoding cyMDH from wheat, namely W-MDH1. The phylogenetic relationships among MDHs from different organisms showed that multiple forms of MDHs might be evolved through gene duplication of the pre-existing nuclear gene. Expression studies demonstrated that W-MDH1 gene was constitutively transcribed in the leaf, stem and root tissues.%苹果酸脱氢酶普遍存在于各种生物中,它负责催化草酰乙酸和苹果酸之间的相互转换.根据其辅酶的特异性和在细胞内的分布和生理功能的不同,苹果酸脱氢酶在高等植物中可以区分出不同的类型.依赖于NAD的细胞质型苹果酸脱氢酶(cyMDH)是其中研究较少的一类.报道了从小麦(Tritium aestivum L.)中克隆的一种cyMDH的部分cDNA序列,并命名为W-MDH1.进化树分析表明来自不同生物的MDH可能是通过基因复制形成的.W-MDH1在小麦的根、茎、叶中呈组成型表达.

  9. Globalisation and transport

    Energy Technology Data Exchange (ETDEWEB)

    Ubbels, B.; Rodenburg, C.; Nijkamp, P. [Department of Spatial Economics, Vrije Universiteit, Amsterdam (Netherlands)

    2001-02-01

    The relationship between globalisation and traffic volume is a complex one for many reasons. The transport sector is influenced by a variety of developments at different scales. Increasing incomes, more leisure time, new technology and a greying population are only a few examples of trends that are influencing future developments in transport and traffic. The future of transport is thus very uncertain. The project GITAGE (Globalisation, International Transport and the Global Environment) is being conducted by the Vrije Universteit Amsterdam, TRAIL (Delft University), the Netherlands Central Planning Bureau (CPB) and IVM (Institute for Environmental Studies). It was within this context that a layered assessment model was used to attempt to chart the possible influence of globalisation on the transport sector in terms of transport flows: and CO2 emissions. Four future scenarios at different scales (Global, European and Netherlands) produced virtually everywhere a (steep) rise in transport and emissions. The introduction of focused policy can change this picture. In fact, however, in most cases only a combination of stringent environmental policy and an environmentally conscious vision of the future can lead to a decline in CO2 emissions between 1995 and 2020.

  10. Transports and environment; Transports et environnements

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2004-07-01

    In the framework of the greenhouse gases reduction, this study proposes many advices to control the fuel consumption of the vehicles and to change habits in the transportation sector. It presents also the alternatives to the pollutant today vehicles in the domain of the vehicles and buses fuels but also the new motors. Many Internet addresses are provided to complete the presentation. (A.L.B.)

  11. Quantum Transport in Semiconductors

    Science.gov (United States)

    1991-10-01

    SRS i 91 4. TITLE AND SUBTITLE Quantum Transport in Semiconductors 5. FUNDING NUMBER söMtos-rizk-ooss 6. AUTHOR(S) D. K. Ferry ©fte ELECTE...OF ABSTRACT UL NSN 7540-01-280-5500 O 1 9 Standard Form 298 (Rev. 2-89) Presented by ANSI Std «9-18 298-102 Final Report Quantum Transport in... Quantum Transport in Semiconductor Devices This final report describes a program of research investigating quantum effects which become important in

  12. Inositol transport proteins.

    Science.gov (United States)

    Schneider, Sabine

    2015-04-28

    The cyclic polyol myo-inositol is a key molecule in many different metabolic pathways among all organisms; in addition, it is fundamental for osmotic balance in the mammalian brain. This review sums up inositol transporters from eukaryotic organisms, elucidating their vital role in regulating the intracellular distribution and uptake of inositol. They can be divided into two groups according to their transport mechanisms: (1) sodium ion coupled inositol transporters that belong to the Solute Carrier Families 5 and 6-like Superfamily and, (2) proton coupled inositol symporters that are members of the Major Facilitator Superfamily. Intriguingly members of both families offer promising targets for medical treatment of a variety of diseases.

  13. Transporte del paciente politraumatizado

    OpenAIRE

    J. López Bayón; A. Medina Villanueva; A. Concha Torre

    2008-01-01

    Tal como se ha explicado en otros capítulos, en el paciente pediátrico politraumatizado es fundamental una buena evaluación y reanimación inicial. Pero tan importante como estos puntos son la categorización y el transporte al centro más adecuado para un tratamiento definitivo. Por otra parte, el niño tiene unas características físicas y fisiológicas muy diferentes que hacen que el transporte pediátrico y la ventilación mecánica (VM) durante dicho transporte tengan una serie de particulari...

  14. Transport Coefficients of Fluids

    CERN Document Server

    Eu, Byung Chan

    2006-01-01

    Until recently the formal statistical mechanical approach offered no practicable method for computing the transport coefficients of liquids, and so most practitioners had to resort to empirical fitting formulas. This has now changed, as demonstrated in this innovative monograph. The author presents and applies new methods based on statistical mechanics for calculating the transport coefficients of simple and complex liquids over wide ranges of density and temperature. These molecular theories enable the transport coefficients to be calculated in terms of equilibrium thermodynamic properties, and the results are shown to account satisfactorily for experimental observations, including even the non-Newtonian behavior of fluids far from equilibrium.

  15. EBS Radionuclide Transport Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    J.D. Schreiber

    2005-08-25

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration'' (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment for the license application (TSPA-LA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA-LA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport

  16. Economical Logistics Transportation planning Case

    Institute of Scientific and Technical Information of China (English)

    王蓉

    2014-01-01

    Transportation is one of the most important nodes of supply chain. Economical transportation planning enables enterprises to reduce cost and perhaps optimize supply chain. This report clarifies the optimization of the transport node with a door-door project.

  17. Crew Transportation Operations Standards

    Science.gov (United States)

    Mango, Edward J.; Pearson, Don J. (Compiler)

    2013-01-01

    The Crew Transportation Operations Standards contains descriptions of ground and flight operations processes and specifications and the criteria which will be used to evaluate the acceptability of Commercial Providers' proposed processes and specifications.

  18. Transport Research Needs

    DEFF Research Database (Denmark)

    Ortúzar, Juan de Dios; Cherchi, Elisabetta; Rizzi, Luis

    2014-01-01

    Transport is a large, multidisciplinary and fascinating field, encompassing vastly different areas of research. In fact transport interests span from not very well understood (in fieldwork) issues related with survey methods to highly complex questions associated with the dynamic equilibration...... of supply and demand in strategic planning contexts; the latter involving large zoning systems, huge multimodal networks and highly complex dynamic modelling approaches (Mahmassani, 2001). But questions also arise at a more macro level (and in a different time span) regarding the interaction of transport...... and land use, and also at the more micro level with the dynamics of road traffic and public transport modelling, an area which is particularly interesting due to its high complexity in less developed nations (de Cea et al., 2005). We do not have the expertise or the space to dwell on all these issues...

  19. Planning Public Transport

    DEFF Research Database (Denmark)

    Andersen, Jonas Lohmann Elkjær; Landex, Alex

    2009-01-01

    This good practice guide is composed for the master course 13120 Public Transport Planning held at the Department of Transport, Technical University of Denmark. It is intended to use as guide in the different planning aspects and assignments of the course. Since the course is about the planning...... of new public transport infrastructure this guide also focuses on the planning of new infrastructure. Furthermore, the new infrastructure in the course is expected to be a light rail and even though this guide aims at being general for public transport some of the issues evidently become more relevant...... for light rail. A light rail system is chosen as focus because light rail systems generally have higher impacts in the traffic modeling than busses and are more challenging in the planning than urban rail and metro. This is emanated by the assumption that a capability for planning light rail inevitable...

  20. Animal transportation networks.

    Science.gov (United States)

    Perna, Andrea; Latty, Tanya

    2014-11-01

    Many group-living animals construct transportation networks of trails, galleries and burrows by modifying the environment to facilitate faster, safer or more efficient movement. Animal transportation networks can have direct influences on the fitness of individuals, whereas the shape and structure of transportation networks can influence community dynamics by facilitating contacts between different individuals and species. In this review, we discuss three key areas in the study of animal transportation networks: the topological properties of networks, network morphogenesis and growth, and the behaviour of network users. We present a brief primer on elements of network theory, and then discuss the different ways in which animal groups deal with the fundamental trade-off between the competing network properties of travel efficiency, robustness and infrastructure cost. We consider how the behaviour of network users can impact network efficiency, and call for studies that integrate both network topology and user behaviour. We finish with a prospectus for future research.

  1. Accident resistant transport container

    Science.gov (United States)

    Andersen, John A.; Cole, James K.

    1980-01-01

    The invention relates to a container for the safe air transport of plutonium having several intermediate wood layers and a load spreader intermediate an inner container and an outer shell for mitigation of shock during a hypothetical accident.

  2. MANAGEMENT OF TOURISM TRANSPORT

    Directory of Open Access Journals (Sweden)

    Gabriela Cecilia STĂNCIULESCU

    2016-06-01

    Full Text Available Undoubtedly, the relevance of transport activities in relation to tourism activities is essential, because it is extremely important and necessary to offer feasible information about tourism services to help consumer to choose the mode of travel to destinations ideal holiday. The methods used in the development of this hypothesis were explanation, exemplification (brief presentation of each mode of transport comparison etc. Analyzing the current situation of national, European and World Wide tourism transportation, the paper proposes practical applications able to explain that the conduct of economic activities as an integral part of the sector of trade and services within a national economy, would not be possible without the involvement of transport, whether by road, rail and air and naval. The results of the analysis are perfectly applicable offering guests the opportunity to reach the most remote corners of the world in a short time, high degree of comfort and affordable price.

  3. Improved electron transport layer

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention provides: a method of preparing a coating ink for forming a zinc oxide electron transport layer, comprising mixing zinc acetate and a wetting agent in water or methanol; a coating ink comprising zinc acetate and a wetting agent in aqueous solution or methanolic solution......; a method of preparing a zinc oxide electron transporting layer, which method comprises: i) coating a substrate with the coating ink of the present invention to form a film; ii) drying the film; and iii) heating the dry film to convert the zinc acetate substantially to ZnO; a method of preparing an organic...... photovoltaic device or an organic LED having a zinc oxide electron transport layer, the method comprising, in this order: a) providing a substrate bearing a first electrode layer; b) forming an electron transport layer according to the following method: i) coating a coating ink comprising an ink according...

  4. Appraisal of Transport Projects

    DEFF Research Database (Denmark)

    Jensen, Anders Vestergaard

    The evaluation of transport projects has traditionally been based on quantitative descriptions of selected impacts by the use of cost-benefit analysis (CBA). However, environmental impacts are now taking into consideration when decisions have to be made, regarding which large transport projects...... complexity. Optimisation has been replaced with satisficing, where satisficing is defined as finding an acceptable or satisfactory solution to a problem instead of a socio-economical optimal solution. This calls for new approaches of appraising transport projects that goes beyond what the classical CBA......, seems suitable for. As a result of the above mentioned issues regarding conflict of interests, multiple impacts, participation of stakeholders, and sustainability, additional approaches for appraisal have been suggested. Multi-criteria decision analysis (MCDA) has been introduced in the transport...

  5. Energy and transportation(*

    Directory of Open Access Journals (Sweden)

    Hermans J.

    2015-01-01

    Full Text Available Transportation takes a considerable and increasing fraction of the energy use worldwide, and more than half the oil consumption. By far the largest part is used by cars powered by internal combustion engines. The advantage of using internal combustion engines is that the energy density of liquid fuels is extremely high. The disadvantage is that gasoline and diesel engines have a poor performance: 20 to 25% only. How does this compare with electric cars? What are the alternative transportation systems and their efficiencies anyway? In this lecture we analyse the efficiency of various transport systems, using elementary physics principles. We will look at cars, buses, trains and TGVs, ships and aircraft. In addition, the efficiency of human powered vehicles will be considered. New and promising developments in the field of Intelligent Transportation Systems, like Cooperative Adaptive Cruise Control, are also discussed.

  6. Modelling Ballast Water Transport

    Digital Repository Service at National Institute of Oceanography (India)

    Jayakumar, S.; Babu, M.T.; Vethamony, P.

    Ballast water discharges in the coastal environs have caused a great concern over the recent periods as they account for transporting marine organisms from one part of the world to the other. The movement of discharged ballast water as well...

  7. Molecular electronic junction transport

    DEFF Research Database (Denmark)

    Solomon, Gemma C.; Herrmann, Carmen; Ratner, Mark

    2012-01-01

    Whenasinglemolecule,oracollectionofmolecules,isplacedbetween two electrodes and voltage is applied, one has a molecular transport junction. We discuss such junctions, their properties, their description, and some of their applications. The discussion is qualitative rather than quantitative, and f...

  8. Cooperative Transport Planning

    NARCIS (Netherlands)

    Zutt, J.; De Weerdt, M.M.

    2000-01-01

    To test and compare different forms of cooperative planning algorithms developed in the CABS project we use a generic simulator called MARS. Examples in the transportation sector are implemented in this simulator.

  9. Transportation Security Administration

    Science.gov (United States)

    ... content Official website of the Department of Homeland Security Transportation Security Administration A - Z Index What Can I Bring? ... form Search the Site Main menu Administrator Travel Security Screening Special Procedures TSA Pre✓® Passenger Support Travel ...

  10. Transportation Network Topologies

    Science.gov (United States)

    Holmes, Bruce J.; Scott, John

    2004-01-01

    A discomforting reality has materialized on the transportation scene: our existing air and ground infrastructures will not scale to meet our nation's 21st century demands and expectations for mobility, commerce, safety, and security. The consequence of inaction is diminished quality of life and economic opportunity in the 21st century. Clearly, new thinking is required for transportation that can scale to meet to the realities of a networked, knowledge-based economy in which the value of time is a new coin of the realm. This paper proposes a framework, or topology, for thinking about the problem of scalability of the system of networks that comprise the aviation system. This framework highlights the role of integrated communication-navigation-surveillance systems in enabling scalability of future air transportation networks. Scalability, in this vein, is a goal of the recently formed Joint Planning and Development Office for the Next Generation Air Transportation System. New foundations for 21st thinking about air transportation are underpinned by several technological developments in the traditional aircraft disciplines as well as in communication, navigation, surveillance and information systems. Complexity science and modern network theory give rise to one of the technological developments of importance. Scale-free (i.e., scalable) networks represent a promising concept space for modeling airspace system architectures, and for assessing network performance in terms of scalability, efficiency, robustness, resilience, and other metrics. The paper offers an air transportation system topology as framework for transportation system innovation. Successful outcomes of innovation in air transportation could lay the foundations for new paradigms for aircraft and their operating capabilities, air transportation system architectures, and airspace architectures and procedural concepts. The topology proposed considers air transportation as a system of networks, within which

  11. Transporte forestal con cables

    OpenAIRE

    Anaya L. Héctor J.

    2012-01-01

    La explotación forestal es un problema fundamentalmente de transporte. El apeo y la preparación de las trozas, aunque a veces presentan algunas dificultades, son operaciones fáciles de resolver comparadas con la operación de transporte la cual absorbe del 60% al 70% o más del costo total del aprovechamiento del bosque. El 30% o 40% restante es absorbido por las faenas previas de apeo y troceo.

  12. Membrane Transport Phenomena (MTP)

    Science.gov (United States)

    Mason, Larry W.

    1997-01-01

    The third semi-annual period of the MTP project has been involved with performing experiments using the Membrane Transport Apparatus (MTA), development of analysis techniques for the experiment results, analytical modeling of the osmotic transport phenomena, and completion of a DC-9 microgravity flight to test candidate fluid cell geometries. Preparations were also made for the MTP Science Concept Review (SCR), held on 13 June 1997 at Lockheed Martin Astronautics in Denver. These activities are detailed in the report.

  13. Sustainability - and sustainable transport

    Energy Technology Data Exchange (ETDEWEB)

    Thisgaard, P.

    1996-12-31

    To gain the fulfillment of basic sustainable objectives in a medium- and long-term perspective for transport. The necessary activities must be genuinely complementary i.e. it must solve problems within at least two sectors and at the same time this activity must be sustainable in a Brundtland report perspective. The transport sector must take steps to develop an `ECO-NOMY`. The principle here is a `fusion` of economy and ecology, and the first place this can take place is in the transport sector. This can only take place in a close cooperation between the transport sector and the other sectors of society. Methods to carry out cross-sectional priorities and allocation of resources must be developed in order to avoid societal sub-optimization of single issue solutions. Besides, a development of public administration must take place through a very heavy limitation of the principles of `sector thinking` as well as the carrying through of totally new principles in the selection of personnel as well as the principles of promotion and control. `Management by objectives` combined with an emphasis of certain moral codes - may contribute substantially to such a development. The principles are to economize with resources and as far as possible adjust the supply to a given demand with reasonable regard to comfort and transport considerations. Besides, the transport sector must try to solve other sector`s sociological problems and actively try to point out where other sectors create problems for the transport sector which prevent this in becoming `sustainable`. The transport sector must also continually try to forward its ability to change by avoiding capital investment or other forms of bindings which might hinder a different development if or when important technological changes occur. In a number of ways you can point to different concrete possibilities with the following headlines: diversification, integration, development of vehicles, information and concrete project areas

  14. [Recommendations for neonatal transport].

    Science.gov (United States)

    Moreno Hernando, J; Thió Lluch, M; Salguero García, E; Rite Gracia, S; Fernández Lorenzo, J R; Echaniz Urcelay, I; Botet Mussons, F; Herranz Carrillo, G; Sánchez Luna, M

    2013-08-01

    During pregnancy, it is not always possible to identify maternal or foetal risk factors. Infants requiring specialised medical care are not always born in centres providing intensive care and will need to be transferred to a referral centre where intensive care can be provided. Therefore Neonatal Transport needs to be considered as part of the organisation of perinatal health care. The aim of Neonatal Transport is to transfer a newborn infant requiring intensive care to a centre where specialised resources and experience can be provided for the appropriate assessment and continuing treatment of a sick newborn infant. Intrauterine transfer is the ideal mode of transport when the birth of an infant with risk factors is diagnosed. Unfortunately, not all problems can be detected in advance with enough time to safely transfer a pregnant woman. Around 30- 50% of risk factors will be diagnosed during labour or soon after birth. Therefore, it is important to have the knowledge and resources to resuscitate and stabilise a newborn infant, as well as a specialised neonatal transport system. With this specialised transport it is possible to transfer newly born infants with the same level of care that they would receive if they had been born in a referral hospital, without increasing their risks or affecting the wellbeing of the newborn. The Standards Committee of the Spanish Society of Neonatology reviewed and updated recommendations for intrauterine transport and indications for neonatal transfer. They also reviewed organisational and logistic factors involved with performing neonatal transport. The Committee review included the type of personnel who should be involved; communication between referral and receiving hospitals; documentation; mode of transport; equipment to stabilise newly born infants; management during transfer, and admission at the referral hospital.

  15. Bæredygtig transport

    DEFF Research Database (Denmark)

    Haas, Henning de; Søndergaard, Mads

    2009-01-01

    I denne artikel sættes fokus på bæredygtighed og transport. Baggrunden for artiklen er en undersøgelse af status for bæredygtig transport i et antal danske virksomheder i samarbejde med DHL. Indledningen giver en baggrund for fokus på bæredygtighed, efterfølgende sættes der fokus på "Green SCM...

  16. Transport of reservoir fines

    DEFF Research Database (Denmark)

    Yuan, Hao; Shapiro, Alexander; Stenby, Erling Halfdan

    Modeling transport of reservoir fines is of great importance for evaluating the damage of production wells and infectivity decline. The conventional methodology accounts for neither the formation heterogeneity around the wells nor the reservoir fines’ heterogeneity. We have developed an integral...... dispersion equation in modeling the transport and the deposition of reservoir fines. It successfully predicts the unsymmetrical concentration profiles and the hyperexponential deposition in experiments....

  17. Complexity of Public Transport Networks

    Institute of Scientific and Technical Information of China (English)

    LU Huapu; SHI Ye

    2007-01-01

    The theory of complex networks was used to classify public transport networks into public transportation route networks, public transportation transfer networks, and bus station networks. The practical significance of the network parameters was then analyzed. The public transport networks in Langfang, Jining, and Dalian were then chosen as specific research cases. The results show that the public transportation networks have the characteristics of complex networks. In addition, the urban transportation network parameters all significantly affect the accessibility, convenience, and terrorist security capability of the urban public transportation network. The results link the findings with the actual situations to explore means to solve transportation system problems.

  18. Bioreactor Mass Transport Studies

    Science.gov (United States)

    Kleis, Stanley J.; Begley, Cynthia M.

    1997-01-01

    The objectives of the proposed research efforts were to develop both a simulation tool and a series of experiments to provide a quantitative assessment of mass transport in the NASA rotating wall perfused vessel (RWPV) bioreactor to be flown on EDU#2. This effort consisted of a literature review of bioreactor mass transport studies, the extension of an existing scalar transport computer simulation to include production and utilization of the scalar, and the evaluation of experimental techniques for determining mass transport in these vessels. Since mass transport at the cell surface is determined primarily by the relative motion of the cell assemblage and the surrounding fluid, a detailed assessment of the relative motion was conducted. Results of the simulations of the motion of spheres in the RWPV under microgravity conditions are compared with flight data from EDU#1 flown on STS-70. The mass transport across the cell membrane depends upon the environment, the cell type, and the biological state of the cell. Results from a literature review of cell requirements of several scalars are presented. As a first approximation, a model with a uniform spatial distribution of utilization or production was developed and results from these simulations are presented. There were two candidate processes considered for the experimental mass transport evaluations. The first was to measure the dissolution rate of solid or gel beads. The second was to measure the induced fluorescence of beads as a stimulant (for example hydrogen peroxide) is infused into the vessel. Either technique would use video taped images of the process for recording the quantitative results. Results of preliminary tests of these techniques are discussed.

  19. Transport in gyrokinetic tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Mynick, H.E.; Parker, S.E.

    1995-01-01

    A comprehensive study of transport in full-volume gyrokinetic (gk) simulations of ion temperature gradient driven turbulence in core tokamak plasmas is presented. Though this ``gyrokinetic tokamak`` is much simpler than experimental tokamaks, such simplicity is an asset, because a dependable nonlinear transport theory for such systems should be more attainable. Toward this end, we pursue two related lines of inquiry. (1) We study the scalings of gk tokamaks with respect to important system parameters. In contrast to real machines, the scalings of larger gk systems (a/{rho}{sub s} {approx_gt} 64) with minor radius, with current, and with a/{rho}{sub s} are roughly consistent with the approximate theoretical expectations for electrostatic turbulent transport which exist as yet. Smaller systems manifest quite different scalings, which aids in interpreting differing mass-scaling results in other work. (2) With the goal of developing a first-principles theory of gk transport, we use the gk data to infer the underlying transport physics. The data indicate that, of the many modes k present in the simulation, only a modest number (N{sub k} {approximately} 10) of k dominate the transport, and for each, only a handful (N{sub p} {approximately} 5) of couplings to other modes p appear to be significant, implying that the essential transport physics may be described by a far simpler system than would have been expected on the basis of earlier nonlinear theory alone. Part of this analysis is the inference of the coupling coefficients M{sub kpq} governing the nonlinear mode interactions, whose measurement from tokamak simulation data is presented here for the first time.

  20. Paleoclassical transport explains electron transport barriers in RTP and TEXTOR

    NARCIS (Netherlands)

    Hogeweij, G. M. D.; Callen, J.D.

    2008-01-01

    The recently developed paleoclassical transport model sets the minimum level of electron thermal transport in a tokamak. This transport level has proven to be in good agreement with experimental observations in many cases when fluctuation-induced anomalous transport is small, i.e. in (near-) ohmic p

  1. Transport of radioactive materials; Transporte de materiais radioativos

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-11-15

    This ninth chapter presents de CNEN-NE--5.01 norm 'Transport of radioactive material'; the specifications of the radioactive materials for transport; the tests of the packages; the requests for controlling the transport and the responsibilities during the transport of radioactive material.

  2. ANALYISIS OF TRANSPORTATION SYSTEMS AND TRANSPORTATION POLICIES IN TURKEY

    Directory of Open Access Journals (Sweden)

    Ali Payıdar AKGÜNGÖR

    2004-03-01

    Full Text Available Transportation systems have to be considered and analysed as a whole while transportation demand, becoming as a natural outcome of socioeconomic and socio-cultural structure, is being evaluated. It is desired that transportation system, which will be selected for both passenger and freight transport, should be rapid, economic, safe, causing least harm to environment and appropriate for the conditions of a country. However, it is difficult for a transportation system to have all these properties. Every transportation system has advantages and disadvantages over each other. Therefore, comprehensive plans for future periods have to be prepared and how the sources of the country should be reasonably distributed among transportation systems must be investigated. Also, transportation plans have to be prepared to get coordinated operations among transportation systems while great investments are instituted in the entire country. There is no doubt that it is possible with combined transportation instead of concentration on one transportation system. Transportation policies in Turkey should be questioned since the level of highway transportation usage reaches to 95 % and level of sea transportation usage drops to less than 1 % in spite of being surrounded with sea in three sides of our land. In this paper, transportation systems and transportation policies in Turkey are evaluated in general and problems are analysed. Proposals are presented for the solutions of these problems.

  3. Intelligent Transport Systems in the Management of Road Transportation

    Science.gov (United States)

    Kalupová, Blanka; Hlavoň, Ivan

    2016-11-01

    Extension of European Union causes increase of free transfer of people and goods. At the same time they raised the problems associated with the transport, e.g. congestion and related accidents on roads, air traffic delays and more. To increase the efficiency and safety of transport, the European Commission supports the introduction of intelligent transport systems and services in all transport sectors. Implementation of intelligent transport systems and services in the road transport reduces accident frequency, increases the capacity of existing infrastructure and reduces congestions. Use of toll systems provides resources needed for the construction and operation of a new road network, improves public transport, cycling transport and walking transport, and also their multimodal integration with individual car transport.

  4. A new transport hub

    CERN Multimedia

    Corinne Pralavorio

    2016-01-01

    CERN’s new Mobility Centre, allowing you to switch easily from one mode of transport to another, has just been officially opened.   Inauguration of the CERN Mobility Centre by Martin Steinacher, Director for Finance and Human Resources, and Lluis Miralles, Head of the SMB department. CERN’s new Mobility Centre, on the car park next to the Globe of Science and Innovation was officially opened on Tuesday, 22 March. The centre brings together all of CERN’s transport options in a single location. "Our aim is to create an intermodal hub where CERN users and personnel can switch from one mode of transport to another, and from CERN transport to public transport," explains Lluis Miralles, head of the Site Management and Buildings (SMB) department. The Mobility Centre incorporates the CERN bike and car rental services, the self-service car- and bike-sharing schemes, and SIXT car rental facilities (for long-distance journeys). It is located right ne...

  5. Prehospital transported patients

    DEFF Research Database (Denmark)

    Bech, Camilla Louise Nørgaard; Brabrand, M.; Lassen, Annmarie Touborg

    2015-01-01

    Introduction The survival of patients transported by ambulance to the emergency department (ED) depends on clinical conditions, patient-related factors and organisational prehospital set up. Data and information concerning patients in the prehospital system could form a valuable resource for asse......Introduction The survival of patients transported by ambulance to the emergency department (ED) depends on clinical conditions, patient-related factors and organisational prehospital set up. Data and information concerning patients in the prehospital system could form a valuable resource...... for assessing potential risk factors associated with adverse outcomes and mortality. Our aim was to describe ambulance transports to the ED and identify prognostic factors accessible in the prehospital phase and associated with 7-day mortality. Methods We included all adult patients (>18 years) with a first......-time ambulance transport to the ED at Odense University Hospital in the period 1 April 2012 to 30 September 2013. Ambulance personnel recorded vital signs and other clinical findings on a structured form on paper during the ambulance transport. Each contact was linked to information from population...

  6. Sustainable Transport Data Collection and Application: China Urban Transport Database

    OpenAIRE

    Tian Jiang; Zhongyi Wu; Yu Song; Xianglong Liu; Haode Liu; Haozhi Zhang

    2013-01-01

    Transport policy making process of national and local governments should be supported by a comprehensive database to ensure a sustainable and healthy development of urban transport. China Urban Transport Database (CUTD) has been built to play such a role. This paper is to make an introduction of CUTD framework including user management, data warehouse, and application modules. Considering the urban transport development features of Chinese cities, sustainable urban transport development indic...

  7. Prioritized Contact Transport Stream

    Science.gov (United States)

    Hunt, Walter Lee, Jr. (Inventor)

    2015-01-01

    A detection process, contact recognition process, classification process, and identification process are applied to raw sensor data to produce an identified contact record set containing one or more identified contact records. A prioritization process is applied to the identified contact record set to assign a contact priority to each contact record in the identified contact record set. Data are removed from the contact records in the identified contact record set based on the contact priorities assigned to those contact records. A first contact stream is produced from the resulting contact records. The first contact stream is streamed in a contact transport stream. The contact transport stream may include and stream additional contact streams. The contact transport stream may be varied dynamically over time based on parameters such as available bandwidth, contact priority, presence/absence of contacts, system state, and configuration parameters.

  8. Evaluation of public transport

    DEFF Research Database (Denmark)

    Flyvbjerg, Bent; Kahr, Kjeld; Petersen, Peter Bo

    1986-01-01

    This paper discusses a method to evaluate sceduled, fixed-route public transport. One major evaluation criterion in the method is total travel time, subdivided into walking time, waiting time, time on vehicle, transfer time, and concealed waiting time. The other major criterion is cost incurred...... by a given supply of transport. In contrast with conventional methods, this method operates with real measures, i.e. real location (instead of traffic zones), real time (instead of average travel time), and real costs (instead of proxy-costs). The purpose is to produce relevant and easily understandable...... results suitable to open planning, for instance with citizen participation. Five examples of application of the method are given: (1) evaluation of changes in suburban bus services; (2) evaluation of geographical localities as regards public transport; (3) evaluation of circular bus routes; (4) evaluation...

  9. Air transport system

    CERN Document Server

    Schmitt, Dieter

    2016-01-01

    The book addresses all major aspects to be considered for the design and operation of aircrafts within the entire transportation chain. It provides the basic information about the legal environment, which defines the basic requirements for aircraft design and aircraft operation. The interactions between  airport, air traffic management and the airlines are described. The market forecast methods and the aircraft development process are explained to understand the very complex and risky business of an aircraft manufacturer. The principles of flight physics as basis for aircraft design are presented and linked to the operational and legal aspects of air transport including all environmental impacts. The book is written for graduate students as well as for engineers and experts, who are working in aerospace industry, at airports or in the domain of transport and logistics.

  10. Intestinal sugar transport

    Institute of Scientific and Technical Information of China (English)

    Laurie A Drozdowski; Alan BR Thomson

    2006-01-01

    Carbohydrates are an important component of the diet.The carbohydrates that we ingest range from simple monosaccharides (glucose, fructose and galactose) to disaccharides (lactose, sucrose) to complex polysaccharides. Most carbohydrates are digested by salivary and pancreatic amylases, and are further broken down into monosaccharides by enzymes in the brush border membrane (BBM) of enterocytes. For example, lactase-phloridzin hydrolase and sucraseisomaltase are two disaccharidases involved in the hydrolysis of nutritionally important disaccharides. Once monosaccharides are presented to the BBM, mature enterocytes expressing nutrient transporters transport the sugars into the enterocytes. This paper reviews the early studies that contributed to the development of a working model of intestinal sugar transport, and details the recent advances made in understanding the process by which sugars are absorbed in the intestine.

  11. Transportation Institutional Plan

    Energy Technology Data Exchange (ETDEWEB)

    1986-08-01

    This Institutional Plan is divided into three chapters. Chapter 1 provides background information, discusses the purposes of the Plan and the policy guidance for establishing the transportation system, and describes the projected system and the plans for its integrated development. Chapter 2 discusses the major participants who must interact to build the system. Chapter 3 suggests mechanisms for interaction that will foster wide participation in program planning and implementation and provides a framework for managing and resolving the issues related to development and operation of the transportation system. A list of acronyms and a glossary are included for the reader's convenience. Also included in this Plan are four appendices. Of particular importance is Appendix A, which includes detailed discussion of specific transportation issues. Appendices B, C, and D provide supporting material to assist the reader in understanding the roles of the involved institutions.

  12. Water transport in brain:

    DEFF Research Database (Denmark)

    MacAulay, Nanna; Hamann, Steffan; Zeuthen, Thomas

    2004-01-01

    It is generally accepted that cotransporters transport water in addition to their normal substrates, although the precise mechanism is debated; both active and passive modes of transport have been suggested. The magnitude of the water flux mediated by cotransporters may well be significant: both...... the number of cotransporters per cell and the unit water permeability are high. For example, the Na(+)-glutamate cotransporter (EAAT1) has a unit water permeability one tenth of that of aquaporin (AQP) 1. Cotransporters are widely distributed in the brain and participate in several vital functions: inorganic......(+)-lactate cotransporters. We have previously determined water transport capacities for these cotransporters in model systems (Xenopus oocytes, cell cultures, and in vitro preparations), and will discuss their role in water homeostasis of the astroglial cell under both normo- and pathophysiologal situations. Astroglia...

  13. Nitrate transport and signalling.

    Science.gov (United States)

    Miller, Anthony J; Fan, Xiaorong; Orsel, Mathilde; Smith, Susan J; Wells, Darren M

    2007-01-01

    Physiological measurements of nitrate (NO(3)(-)) uptake by roots have defined two systems of high and low affinity uptake. In Arabidopsis, genes encoding both of these two uptake systems have been identified. Most is known about the high affinity transport system (HATS) and its regulation and yet measurements of soil NO(3)(-) show that it is more often available in the low affinity range above 1 mM concentration. Several different regulatory mechanisms have been identified for AtNRT2.1, one of the membrane transporters encoding HATS; these include feedback regulation of expression, a second component protein requirement for membrane targeting and phosphorylation, possibly leading to degradation of the protein. These various changes in the protein may be important for a second function in sensing NO(3)(-) availability at the surface of the root. Another transporter protein, AtNRT1.1 also has a role in NO(3)(-) sensing that, like AtNRT2.1, is independent of their transport function. From the range of concentrations present in the soil it is proposed that the NO(3)(-)-inducible part of HATS functions chiefly as a sensor for root NO(3)(-) availability. Two other key NO(3)(-) transport steps for efficient nitrogen use by crops, efflux across membranes and vacuolar storage and remobilization, are discussed. Genes encoding vacuolar transporters have been isolated and these are important for manipulating storage pools in crops, but the efflux system is yet to be identified. Consideration is given to how well our molecular and physiological knowledge can be integrated as well to some key questions and opportunities for the future.

  14. Transportation of hazardous goods

    CERN Multimedia

    TS Department

    2008-01-01

    A general reminder: any transportation of hazardous goods by road is subject to the European ADR rules. The goods concerned are essentially the following: Explosive substances and objects; Gases (including aerosols and non-flammable gases such as helium and nitrogen); Flammable substances and liquids (inks, paints, resins, petroleum products, alcohols, acetone, thinners); Toxic substances (acids, thinners); Radioactive substances; Corrosive substances (paints, acids, caustic products, disinfectants, electrical batteries). Any requests for the transport of hazardous goods must be executed in compliance with the instructions given at this URL: http://ts-dep.web.cern.ch/ts-dep/groups/he/HH/adr.pdf Heavy Handling Section TS-HE-HH 73793 - 160364

  15. TRANSPORT OF COUNTERFEIT GOODS

    Directory of Open Access Journals (Sweden)

    Dagmar Babčanová

    2014-09-01

    Full Text Available The paper is focused on a current problem of transport of counterfeit goods in the European Union. Counterfeiting has a strong influence on the distribution organizations worldwide because most of counterfeit goods threaten the health and safety of consumers. Counterfeiting is a serious problem in the world economy today. The purpose of this paper is to point out the danger of counterfeiting in connection with the transport of Intellectual Property (IP rights - infringing goods. Background of the paper’s content is based on secondary data research of publicly available sources - international statistics and world reports.

  16. Pickering UDM transportation system

    Energy Technology Data Exchange (ETDEWEB)

    Brennan, P.J.; Vissers, J.J. [GE Canada Nuclear Products, Mechanical Engineering, Peterborough, Ontario (Canada)]. E-mail: patrick.brennan@cdnnuc.ge.com; jeff.vissers@cdnnuc.ge.com; Brown, R. [Ontario Power Generation, Inspection Services Div., Tiverton, Ontario (Canada)

    2003-07-01

    The Universal Delivery Machine (UDM) is a new CANDU reactor maintenance tool that allows safe, timely, and cost-effective inspection and maintenance of fuel channels. The UDM had to be transported through the Pickering nuclear station and installed onto the reactor bridge. This involved lifting the UDM between station levels, navigating it through several challenging airlock and vault areas, and traversing the bridge opening directly in front of the reactor. This paper describes the system used to transport and install the Pickering UDM. (author)

  17. Personalized public transportation information

    OpenAIRE

    Silva, Henrique Cabrita Marques da

    2015-01-01

    Thesis to obtain the Master of Science Degree in Computer Science and Engineering O presente trabalho de projeto foi desenvolvido em parceria com uma empresa de soluções informáticas na área dos transportes, a Tecmic. Resulta de um necessidade real da empresa e de uma oportunidade de negócio. O objetivo foi o desenvolvimento de uma aplicação para dispositivos móveis que permita a personalização da informação e acesso em tempo real à informação de transportes públicos disponível nos servido...

  18. Regional transportation simulations

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, K.; Rickert, M.; Frye, R.; Stretz, P.; Simon, P.; Jacob, R.; Barrett, C.L.

    1998-07-01

    For transportation planning applications, it is useful to not only model each individual traveler, but also the decision-making process leading to their travel demand. Simulation-based modeling of this process means iterations between the actual transportation micro-simulation and the modules simulating the process making the plans. This means that for understanding a single day of travel, it may be necessary to simulate that day hundreds of times for the iteration process, leading to a considerable strain on computational resources.

  19. The Instruments of Transport Policy

    Directory of Open Access Journals (Sweden)

    Gordana Štefančić

    2006-09-01

    Full Text Available The work proposes the transport policy instruments, suchas the infrastructure measures, management measures and informationprovision measures as the means that could reduceor eliminate transport problems. All these measures have beenfollowed through the provisions for passenger cars, provisionsfor public transport, provisions for cyclists and pedestrians andprovisions regarding transport. A range of solutions is given toreduce congestion, improve accessibility and improve the trafficconditions for those who depend on public transport along withthe improvement of environmental conditions.

  20. Transport for smart cities

    DEFF Research Database (Denmark)

    Kristensen, Niels Buus; Pedersen, Allan Schrøder

    2011-01-01

    The global megatrend of the last century’s migration from rural to ever-larger conurbations has created immense gains to society through economies of scale and benefits from agglomeration. These include – other things remaining equal – a lesser need for transport because a bigger share of peoples...

  1. School Transportation: Administrator's Handbook

    Science.gov (United States)

    Missouri Department of Elementary and Secondary Education, 2008

    2008-01-01

    Pupil transportation is an essential part of the overall school program, which requires constant supervision and direction. Perhaps no other phase of the school program is more closely observed by the public or has a greater tendency to mold public opinion about the schools than the school bus system. The success of any school district pupil…

  2. Artificial oxygen transport protein

    Science.gov (United States)

    Dutton, P. Leslie

    2014-09-30

    This invention provides heme-containing peptides capable of binding molecular oxygen at room temperature. These compounds may be useful in the absorption of molecular oxygen from molecular oxygen-containing atmospheres. Also included in the invention are methods for treating an oxygen transport deficiency in a mammal.

  3. Bystruktur og transport

    DEFF Research Database (Denmark)

    Nielsen, Thomas Alexander Sick

    2003-01-01

    Paperet præsenterer hovedkonklusionerne fra et PhD-studie af sammenhængene mellem bystruktur (særligt boliglokalisering) og transport i Aalborg. Det konkluderes at boliglokaliseringen har væsentlig betydning for transporten i det daglige. Det gælder især lokaliseringen i forhold til det samlede...

  4. Draft Transportation Institutional Plan

    Energy Technology Data Exchange (ETDEWEB)

    1985-09-01

    The Department of Energy recognizes that the success of its program to develop and implement a national system for nuclear waste management and disposal depends on broad-based public understanding and acceptance. While each program element has its particular sensitivity, the transportation of the waste may potentially affect the greatest number of people, and accordingly is highly visible and potentially issue-laden. Therefore, the Office of Civilian Radioactive Waste Management has developed this Transportation Institutional Plan to lay the foundation for interaction among all interested parties for the purpose of identifying and resolving issues of concern. The Plan is divided into four chapters. Chapter 1 provides bachground information and discusses the purpose of the Plan and the policy guidance for establishing the transportation system. Chapter 2 introduces the major participants who must interact to build both the system itself and the consensus philosophy that is essential for effective operations. Chapter 3 suggests mechanisms for interaction that will ensure wide participation in program planning and implementation. And, finally, Chapter 4 suggests a framework for managing and resolving the issues related to development and operation of the transportation system. A list of acronyms and a glossary are included for the reader's convenience. The Plan's appendices provide supporting material to assist the reader in understanding the roles of the involved institutions. 4 figs., 1 tab.

  5. Gas Transport Through Channels

    Science.gov (United States)

    2009-03-25

    HvPlP2;l increases internal CO; conductance and CO; assimilation in the leaves of transgenic rice plants. Plant Cell Physiol. 45, 521 529. Harris...human Rhesus-associated RhAG protein and a kidney homologue promote ammonium transport in yeast . Nat Genet 26 341-344 42. Payne JA, Forbush B (1994

  6. Beam transport elements

    CERN Multimedia

    1965-01-01

    Two of the beam transport elements for the slow ejection system. On the left, a quadrupole 1.2 m long with a 5 cm aperture, capable of producing a gradient of 5000 gauss. On the right, a 1 m bending magnet with a 4 cm gap; its field is 20 000 gauss.

  7. Transport and Sustainability

    DEFF Research Database (Denmark)

    Jørgensen, Kaj

    1998-01-01

    of the distribution of food and other groceries in Denmark, covering both the distribution to the shops and the shopping transport. The outputs of the technical improvementanalysis are partly estimates of improvement potentials in different technical scenarios and partly studies of the penetration...

  8. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2003-01-30

    This is the second quarterly progress report for Year-4 of the ACTS Project. It includes a review of progress made in: (1) Flow Loop construction and development and (2) research tasks during the period of time between October 1, 2002 and December 30, 2002. This report presents a review of progress on the following specific tasks. (a) Design and development of an Advanced Cuttings Transport Facility Task 3: Addition of a Cuttings Injection/Separation System, Task 4: Addition of a Pipe Rotation System. (b) New research project (Task 9b): ''Development of a Foam Generator/Viscometer for Elevated Pressure and Elevated Temperature (EPET) Conditions''. (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions''. (e) Research on three instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), Foam texture while transporting cuttings. (Task 12), and Viscosity of Foam under EPET (Task 9b). (f) New Research project (Task 13): ''Study of Cuttings Transport with Foam under Elevated Pressure and Temperature Conditions''. (g) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (h) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  9. Transporte Urbano en Venezuela

    Directory of Open Access Journals (Sweden)

    Rosa Virginia Ocaña Ortiz

    2005-01-01

    Full Text Available El diseño e implantación de políticas públicas expresas en el área del transporte urbano en Venezuela data de finales de los años ochenta. En él se contempló la “modernización” y la “municipalización” del transporte urbano. El objetivo del presente trabajo es analizar la intervención de los poderes locales en el diseño e implementación de la política de transporte urbano en las ciudades venezolanas. La metodología utilizada consistió en el análisis de información documental y entrevistas semiestructuradas a funcionarios de Alcaldías y del gobierno central. Los resultados indican que la política fue diseñada en el seno del Ministerio de Transporte y Comunicaciones y del Ministerio de Infraestructura, por un grupo de especialistas, siguiendo lineamientos de la banca multilateral, sin consultar a los actores del sistema, y muy especialmente a los Municipios o Alcaldías. Se concluye que los poderes locales han intervenido de forma limitada en la implantación de la política, con muy escaso poder de decisión y siguiendo lo establecido por el gobierno nacional.

  10. Metrics for Transportation.

    Science.gov (United States)

    Cooper, Gloria S., Ed.; Magisos, Joel H., Ed.

    Designed to meet the job-related metric measurement needs of students interested in transportation, this instructional package is one of five for the marketing and distribution cluster, part of a set of 55 packages for metric instruction in different occupations. The package is intended for students who already know the occupational terminology,…

  11. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Evren Ozbayoglu; Lei Zhou

    2002-07-30

    This is the fourth quarterly progress report for Year-3 of the ACTS Project. It includes a review of progress made in: (1) Flow Loop construction and development and (2) research tasks during the period of time between April 1, 2002 and June 30, 2002. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 3: Addition of a Cuttings Injection/Separation System), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)''; (c) Research project (Task 9b): ''Study of Foam Flow Behavior Under EPET Conditions''; (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions''; (e) Research on three instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), Foam texture while transporting cuttings. (Task 12), and Viscosity of Foam under EPET (Task 9b); (f) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S); (g) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  12. Demographic Change and Transport

    DEFF Research Database (Denmark)

    Haustein, Sonja; Siren, Anu Kristiina; Framke, Elisabeth;

    This report is the literature review on demographic changes and transport of Work Package 1 of the EU project CONSOL, “CONcerns and SOLutions – Road Safety in the Ageing Societies” (contract period: 2011-2013). The report is a state-of-the art report that combines current knowledge with new...

  13. Natural Gas Transport

    OpenAIRE

    Tomás Correa; Nelson Osorio

    2009-01-01

    This paper reviews the present and future on natural gas transportation options, from oil and gas fields to markets, including liquefied natural gas, gas pipeline, compressed natural gas, natural gas hydrates, and gas to liquids and the perspectives of using them in Colombia, since this is the main fuel alternative to supply the world in at least the next 50 years.

  14. Natural Gas Transport

    Directory of Open Access Journals (Sweden)

    Tomás Correa

    2009-06-01

    Full Text Available This paper reviews the present and future on natural gas transportation options, from oil and gas fields to markets, including liquefied natural gas, gas pipeline, compressed natural gas, natural gas hydrates, and gas to liquids and the perspectives of using them in Colombia, since this is the main fuel alternative to supply the world in at least the next 50 years.

  15. Slurry transport medium

    Energy Technology Data Exchange (ETDEWEB)

    Rosenthal, W.; Schiffman, L.

    1980-06-03

    This invention provides for an improvement in slurry transport systems, especially coal slurry lines. Instead of the usual use of fresh water resources which, in some geographic areas, are scarce for slurry transport, concentrated brine is used which is prepared from abundant salt water resources. Because of the higher density of this concentrated brine, it is a superior carrier of pulverized material. It diminishes the separation and settling tendency of slurry components during transport and particularly during shutdown. Other advantages in the use of concentrated brine include: freezing point depression which permits ease of transport during winter and at lower temperatures; dust suppression of stored coal; avoidance of spontaneous combustion of stored coal; inhibit freeze packing of dewatered pipeline coal; and diminished extent of corrosion in ferrous metal pipelines as compared to that which might occur with lower concentration brines. Important in the economy of the process is that the concentrated brine can be recycled. An inexpensive method for producing the concentrated brine is given.

  16. Thermal transport in graphene

    Science.gov (United States)

    Sadeghi, Mir Mohammad; Pettes, Michael Thompson; Shi, Li

    2012-08-01

    The recent advances in graphene isolation and synthesis methods have enabled potential applications of graphene in nanoelectronics and thermal management, and have offered a unique opportunity for investigation of phonon transport in two-dimensional materials. In this review, current understanding of phonon transport in graphene is discussed along with associated experimental and theoretical investigation techniques. Several theories and experiments have suggested that the absence of interlayer phonon scattering in suspended monolayer graphene can result in higher intrinsic basal plane thermal conductivity than that for graphite. However, accurate experimental thermal conductivity data of clean suspended graphene at different temperatures are still lacking. It is now known that contact of graphene with an amorphous solid or organic matrix can suppress phonon transport in graphene, although further efforts are needed to better quantify the relative roles of interface roughness scattering and phonon leakage across the interface and to examine the effects of other support materials. Moreover, opportunities remain to verify competing theories regarding mode specific scattering mechanisms and contributions to the total thermal conductivity of suspended and supported graphene, especially regarding the contribution from the flexural phonons. Several measurements have yielded consistent interface thermal conductance values between graphene and different dielectrics and metals. A challenge has remained in establishing a comprehensive theoretical model of coupled phonon and electron transport across the highly anisotropic and dissimilar interface.

  17. Alternate Transportation Routes

    Science.gov (United States)

    Vogel, Carl

    2009-01-01

    Since last school year, the St. Lucie County (Florida) Public Schools reduced the number of buses it operates from 399 to 362, despite opening two new schools. Add in some other smart changes in policy, and the district lowered its annual transportation costs by more than $3 million over last year. Saving $3 million a year does not come easily,…

  18. 棉花 GhMDH 基因的克隆及其蛋白诱导和酶活性分析%Cloning and Protein Expression of Malate Dehydrogenase Gene of Gossypium hirsuturm L.and Its Enzyme Activity Analysis

    Institute of Scientific and Technical Information of China (English)

    李青; 张宁; 司怀军; 吴家和

    2013-01-01

    According to the salt stress-related EST sequences of Gossypium hirsuturm L.,a malate dehydrogen-ase ( MDH) gene was isolated by the 3′,5′-RACE technology ,named GhMDH.The full-length cDNA of GhMDH is 1 130 bp,containing a 1 014 bp ORF which encodes 338 amino acids.The relative molecular weight of GhMDH protein is 35.495 kDa,and its isoelectric point (pI) is 8.94.The GhMDH ORF had been subcloned into pET23b vector for generating a His-tag fusion recombinant protein .The inducible conditions of recombinant protein expres-sion was optimized ,including IPTG contend ,temperature and time .The results showed that the target protein was packaged in inclusion body expressed under 37 ℃,1 mmol/L IPTG and 4 hrs induction conditions .The soluble re-combinant protein can only receive in less than 28 ℃and 12 hrs induction .The urea denatured protein from inclu-sion body had been purified by Ni +column .The purified protein was then renatured through ladder contend dialysis from high to low.The recombinant protein ,GhMDH,exhibited high malate dehydrogenase activates via enzymatic as-say .The results is pivotal to investigate GhMDH fuction in cell redox homeostasis and biotic and abiotic stress resist -ance in cotton .%分析棉花盐胁迫相关的EST文库,设计特异性引物,利用RACE技术从棉花中克隆出苹果酸脱氢酶( Malate dehydrogenase ,MDH)基因,命名为GhMDH。基因全长1130 bp,最大开放阅读框1014 bp,编码338个氨基酸,分子量为35.495 kDa,等电点pI=8.94。将该基因编码区插入到原核表达载体pET23b中,获得pET23b-GhMDH重组载体。利用IPTG诱导表达目标蛋白,发现通常条件下获得的重组蛋白以包涵体的形式存在。对诱导时间、IPTG浓度和温度等条件进行优化,结果表明,除了在28℃低温以下诱导的蛋白有少量为可溶,其他条件诱导的蛋白均以包涵体形式存在。为了得到足够的重组蛋白,对GhMDH包涵体蛋

  19. 一类依赖于NAD的玉米胞质型苹果酸脱氢酶基因的克隆及其序列分析%Cloning and Sequence Analysis of the NAD-dependent Cytosolic Malate Dehydrogenase Gene from Zea Mays

    Institute of Scientific and Technical Information of China (English)

    汪结明; 江海洋; 赵阳; 项艳; 朱苏文; 范军; 程备久

    2009-01-01

    Malate dehydrogenase(MDH) which catalyzes the reversible reaction from oxaloacetate to malate ubiquitously exists in nature. Higher plants contain multiple forms of MDHs that differ in co-enzyme specificity, subcellular localization and physiological function. The NAD-dependent cytosolic MDH (cyMDH ) is one class of MDH that is still seldom investigated. On the basis of the conserved amino acid residues in the published cytosolic malate dehydrogenase protein sequences from other higher plant species, a full-length cDNA was amplified by SMART RACE RT-PCR from the total RNA of maize leaves. Bioinformatics analysis of the cDNA sequence indicates that the 264 bp full length of the target clone includes a 70 bp 5'-UTR, an ORF of 999 bp, and a 195 bp 3'-UTR (GenBank accession EU625276). This cDNA sequence codes 332 amino acids residues with a predicted molecular mass of 35.6168 kD and an isoelectric point (pI) of 5.4. The deduced maize amino acids share high sequence homology with cyMDH from other species, such as O.sative, M.crystallinum, and G.max. Analysis of semiquantitive RT-PCR shows that the expression of cyMDH is higher in maize leaves than that in roots and stems. All of these results will provide a theoretical basis for further investigation of the cyMDH gene in molecular regulation mechanism.%苹果酸脱氢酶普遍存在于各种生物中,它负责催化草酰乙酸和苹果酸之间的相互转换.根据其辅酶的特异性和在细胞内的分布及其生理功能的不同,苹果酸脱氢酶在高等植物中可以区分出不同的类型,依赖于NAD的细胞质型苹果酸脱氢酶是其中研究较少的一类.根据已发表的其他高等植物的依赖于NAD的胞质型苹果酸脱氢酶基因的保守序列,运用SMART RACE RT-PCR技术,从玉米叶片中分离了cyMDH 的1 264 bp全长cDNA序列,通过生物信息学分析发现,该序列含有一个999 bp的完整的开放阅读框,其共编码332个氨基酸(GenBank登陆号 EU625276).序列联

  20. Transporte y Ciudad

    Directory of Open Access Journals (Sweden)

    GERMÁN CORREA DÍAZ

    2010-04-01

    Full Text Available Los servicios de transporte público operan de manera sistémica, así como lo hace todo aquello que se mueve en la ciudad. Toda intervención que se haga respecto a uno de los modos que la gente usa para movilizarse afecta inevitablemente al resto. Desde que en Santiago entró en operaciones un Sistema Integrado de Transporte Público, como es el Transantiago, pasó la hora de seguir haciendo inversiones en proyectos aislados relativos a la movilidad urbana. Es hora más bien de racionalizar sistémicamen-te dichas inversiones y evaluarlas en consecuencia. Los grandes proyectos de transporte urbano deben dejar de ser la idea emblemática de algún gobernante. En cambio, deben pasar a ser evaluados y decididos desde una visión sistémica y organizada sobre el territorio, el desarrollo urbano y la movilidad, estableciendo mejor el óptimo social de las inversiones públicas y privadas. De esta manera se servirá mejor al interés común de los habitantes de la ciudad.Public transport services operate in a systemic manner and so does everything that moves in the city. Interventions in one of the modes people use to move around affect inevitably the rest. Today, when a new Public Transport Integrated System as Transantiago is operating, whatever its problems, it makes no longer sense to keep making investments in isolated transport projects. It is time to rationalize such investments from a systemic point of view, evaluating them likewise. Large urban transport projects should no longer be the emblematic idea of some individual Government authority. Instead, they should be evaluated and decided upon from the standpoint of a systemic and organized vision of the territory, urban development and mobility, thus better establishing a social optimum of public and private investments. In this way the real common interest of the city dwellers would be better served.

  1. Molybdate transport through the plant sulfate transporter SHST1.

    Science.gov (United States)

    Fitzpatrick, Kate L; Tyerman, Stephen D; Kaiser, Brent N

    2008-04-30

    Molybdenum is an essential micronutrient required by plants. The mechanism of molybdenum uptake in plants is poorly understood, however, evidence has suggested that sulfate transporters may be involved. The sulfate transporter from Stylosanthes hamata, SHST1, restored growth of the sulfate transport yeast mutant, YSD1, on media containing low amounts of molybdate. Kinetic analysis using 99MoO4(2-) demonstrated that SHST1 enhanced the uptake of molybdate into yeast cells at nM concentrations. Uptake was not inhibited by sulfate, but sulfate transport via SHST1 was reduced with molybdate. These results are the first measurement of molybdate transport by a characterised plant sulfate transport protein.

  2. Liposome reconstitution and transport assay for recombinant transporters.

    Science.gov (United States)

    Johnson, Zachary Lee; Lee, Seok-Yong

    2015-01-01

    Secondary active transporters are responsible for the cellular uptake of many biologically important molecules, including neurotransmitters, nutrients, and drugs. Because of their physiological and clinical importance, a method for assessing their transport activity in vitro is necessary to gain a better understanding of how these transporters function at the molecular level. In this chapter, we describe a protocol for reconstituting the concentrative nucleoside transporter from Vibrio cholerae into proteoliposomes. We then describe a radiolabeled substrate uptake assay that can be used to functionally characterize the transporter. These methods are relatively common and can be applied to other secondary active transporters, with or without some modification.

  3. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Lei Zhou

    2000-01-30

    This is the second quarterly progress report for Year 2 of the ACTS project. It includes a review of progress made in Flow Loop development and research during the period of time between Oct 1, 2000 and December 31, 2000. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 2: Addition of a foam generation and breaker system), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (c) Research project (Task 7): ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (d) Research project (Task 8): ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (e) Research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (g) Research on instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), and Foam properties while transporting cuttings. (Task 12), (h) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (i) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members. The tasks Completed During This Quarter are Task 7 and Task 8.

  4. Visually Exploring Transportation Schedules.

    Science.gov (United States)

    Palomo, Cesar; Guo, Zhan; Silva, Cláudio T; Freire, Juliana

    2016-01-01

    Public transportation schedules are designed by agencies to optimize service quality under multiple constraints. However, real service usually deviates from the plan. Therefore, transportation analysts need to identify, compare and explain both eventual and systemic performance issues that must be addressed so that better timetables can be created. The purely statistical tools commonly used by analysts pose many difficulties due to the large number of attributes at trip- and station-level for planned and real service. Also challenging is the need for models at multiple scales to search for patterns at different times and stations, since analysts do not know exactly where or when relevant patterns might emerge and need to compute statistical summaries for multiple attributes at different granularities. To aid in this analysis, we worked in close collaboration with a transportation expert to design TR-EX, a visual exploration tool developed to identify, inspect and compare spatio-temporal patterns for planned and real transportation service. TR-EX combines two new visual encodings inspired by Marey's Train Schedule: Trips Explorer for trip-level analysis of frequency, deviation and speed; and Stops Explorer for station-level study of delay, wait time, reliability and performance deficiencies such as bunching. To tackle overplotting and to provide a robust representation for a large numbers of trips and stops at multiple scales, the system supports variable kernel bandwidths to achieve the level of detail required by users for different tasks. We justify our design decisions based on specific analysis needs of transportation analysts. We provide anecdotal evidence of the efficacy of TR-EX through a series of case studies that explore NYC subway service, which illustrate how TR-EX can be used to confirm hypotheses and derive new insights through visual exploration.

  5. 猪带绦虫苹果酸脱氢酶基因的克隆表达及免疫学分析%Expression and purification of malate dehydrogenase gene in Taenia solium and immunologic analysis of the recombinant proteins

    Institute of Scientific and Technical Information of China (English)

    江楠; 席晓兰; 王杰; 戴佳琳; 廖兴江; 黄江

    2011-01-01

    目的 对猪带绦虫苹果酸脱氢酶基因(malate dehydrogenase,MDH)进行克隆,表达及免疫学特性的初步研究.方法 将猪带绦虫MDH基因克隆到原核表达质粒pET-28a(+)中,在大肠埃希菌BL21/DE3中用异丙基-β-D-半乳糖苷(IPTG)诱导表达,表达产物通过十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)进行鉴定,用镍离子金属螯合剂亲和层析柱进行纯化,纯化的重组蛋白用蛋白印迹(Western Blot)进行免疫学分析.结果 成功构建pET-28a(+)-MDH重组质粒,并获得高纯度蛋白,该重组蛋白可被其免疫SD大鼠血清识别,同时也能被感染猪带绦虫的病人及猪、感染牛带绦虫病人及感染亚带绦虫病人血清所识别.结论 猪带绦虫苹果酸脱氢酶基因可在原核表达系统中获得具有免疫学活性的高效表达,为进一步研究该蛋白的功能奠定了基础.%The objective of this study was to clone and express the gene named as malate dehydrogenase gene (MDH) in Taenia Solium, and to analyze the immunogenicity of its recombinant protein. The coding region of MDH was amplified with PCR, cloned into the prokaryotic expression vector pET-28a(+) and expressed in E. coli BL21/DE3 with IPTG induction. In addition, the immunogenicity of the purified recombinant proteins was analyzed by Western blotting. PCR, double enzyme digestion and DNA sequencing confirmed that the recombinant expression plasmid was successfully constructed. The expression products were obtained and purified by His-Ni2+ affinity chromatography. Western blotting analysis of MDH recombinant protein testified that these proteins could be recognized by sera of the patients infected with T. asiatica and T. rhynchus saginatus. Results suggested that the MDH gene of T. solium has been cloned and expressed, and the purified protein has been confirmed with immunogenicity.

  6. Sustainable Transport and Performance Indicators

    DEFF Research Database (Denmark)

    Gudmundsson, Henrik

    2004-01-01

    Sustainable transport has become a major policy concern in recent years. The term suggests a need to consider transport in a comprehensive perspective including the well-being of both present and future generations, and taking environmental, social and economic issues into account. Indicators...... in forecasting and tracking the performance of transport systems increasingly guide sustainable transport policy making. This review explores the implications of the sustainable transport” concept and how it can be made operational with indicators. A number of indicator systems are reviewed, and some strengths...... and weaknesses are highlighted with regard to the support they provide for sustainable transport development....

  7. Mifepristone modulates serotonin transporter function

    Institute of Scientific and Technical Information of China (English)

    Chaokun Li; Linlin Shan; Xinjuan Li; Linyu Wei; Dongliang Li

    2014-01-01

    Regulating serotonin expression can be used to treat psychotic depression. Mifepristone, a glu-cocorticoid receptor antagonist, is an effective candidate for psychotic depression treatment. However, the underlying mechanism related to serotonin transporter expression is poorly un-derstood. In this study, we cloned the human brain serotonin transporter into Xenopus oocytes, to establish an in vitro expression system. Two-electrode voltage clamp recordings were used to detect serotonin transporter activity. Our results show that mifepristone attenuates serotonin transporter activity by directly inhibiting the serotonin transporter, and suggests that the se-rotonin transporter is a pharmacological target of mifepristone for the treatment of psychotic depression.

  8. SAFETY AND QUALITY CONTROL OF TRANSPORT SERVICES ON RAILWAY TRANSPORT

    Directory of Open Access Journals (Sweden)

    I. P. Sadlovska

    2010-10-01

    Full Text Available The article presents the provisions to improve procedure of licensing of passenger and freight transportation, technical specifications for services related to the passenger and freight transportations.

  9. Transporter taxonomy - a comparison of different transport protein classification schemes.

    Science.gov (United States)

    Viereck, Michael; Gaulton, Anna; Digles, Daniela; Ecker, Gerhard F

    2014-06-01

    Currently, there are more than 800 well characterized human membrane transport proteins (including channels and transporters) and there are estimates that about 10% (approx. 2000) of all human genes are related to transport. Membrane transport proteins are of interest as potential drug targets, for drug delivery, and as a cause of side effects and drug–drug interactions. In light of the development of Open PHACTS, which provides an open pharmacological space, we analyzed selected membrane transport protein classification schemes (Transporter Classification Database, ChEMBL, IUPHAR/BPS Guide to Pharmacology, and Gene Ontology) for their ability to serve as a basis for pharmacology driven protein classification. A comparison of these membrane transport protein classification schemes by using a set of clinically relevant transporters as use-case reveals the strengths and weaknesses of the different taxonomy approaches.

  10. EBS Radionuclide Transport Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    R. Schreiner

    2001-06-27

    The purpose of this work is to develop the Engineered Barrier System (EBS) radionuclide transport abstraction model, as directed by a written development plan (CRWMS M&O 1999a). This abstraction is the conceptual model that will be used to determine the rate of release of radionuclides from the EBS to the unsaturated zone (UZ) in the total system performance assessment-license application (TSPA-LA). In particular, this model will be used to quantify the time-dependent radionuclide releases from a failed waste package (WP) and their subsequent transport through the EBS to the emplacement drift wall/UZ interface. The development of this conceptual model will allow Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department to provide a more detailed and complete EBS flow and transport abstraction. The results from this conceptual model will allow PA0 to address portions of the key technical issues (KTIs) presented in three NRC Issue Resolution Status Reports (IRSRs): (1) the Evolution of the Near-Field Environment (ENFE), Revision 2 (NRC 1999a), (2) the Container Life and Source Term (CLST), Revision 2 (NRC 1999b), and (3) the Thermal Effects on Flow (TEF), Revision 1 (NRC 1998). The conceptual model for flow and transport in the EBS will be referred to as the ''EBS RT Abstraction'' in this analysis/modeling report (AMR). The scope of this abstraction and report is limited to flow and transport processes. More specifically, this AMR does not discuss elements of the TSPA-SR and TSPA-LA that relate to the EBS but are discussed in other AMRs. These elements include corrosion processes, radionuclide solubility limits, waste form dissolution rates and concentrations of colloidal particles that are generally represented as boundary conditions or input parameters for the EBS RT Abstraction. In effect, this AMR provides the algorithms for transporting radionuclides using the flow geometry and radionuclide concentrations

  11. Mass Transport within Soils

    Energy Technology Data Exchange (ETDEWEB)

    McKone, Thomas E.

    2009-03-01

    Contaminants in soil can impact human health and the environment through a complex web of interactions. Soils exist where the atmosphere, hydrosphere, geosphere, and biosphere converge. Soil is the thin outer zone of the earth's crust that supports rooted plants and is the product of climate and living organisms acting on rock. A true soil is a mixture of air, water, mineral, and organic components. The relative proportions of these components determine the value of the soil for agricultural and for other human uses. These proportions also determine, to a large extent, how a substance added to soil is transported and/or transformed within the soil (Spositio, 2004). In mass-balance models, soil compartments play a major role, functioning both as reservoirs and as the principal media for transport among air, vegetation, surface water, deeper soil, and ground water (Mackay, 2001). Quantifying the mass transport of chemicals within soil and between soil and atmosphere is important for understanding the role soil plays in controlling fate, transport, and exposure to multimedia pollutants. Soils are characteristically heterogeneous. A trench dug into soil typically reveals several horizontal layers having different colors and textures. As illustrated in Figure 1, these multiple layers are often divided into three major horizons: (1) the A horizon, which encompasses the root zone and contains a high concentration of organic matter; (2) the B horizon, which is unsaturated, lies below the roots of most plants, and contains a much lower organic carbon content; and (3) the C horizon, which is the unsaturated zone of weathered parent rock consisting of bedrock, alluvial material, glacial material, and/or soil of an earlier geological period. Below these three horizons lies the saturated zone - a zone that encompasses the area below ground surface in which all interconnected openings within the geologic media are completely filled with water. Similarly to the unsaturated

  12. Interaction of railway and marine transport (Murmansk Transport Hub

    Directory of Open Access Journals (Sweden)

    Sokolov A.A.

    2015-03-01

    Full Text Available The classification of problems of interaction between water (marine and railway transport on the example of the Murmansk Transport Hub has been presented; some prospects for the development of technology for interaction with the logistics of transportation of general cargo in the Murmansk Commercial Seaport, Murmansk Marine Fishing Port, and oil terminals of the Kola Bay have been shown

  13. The cost of transportation`s oil dependence

    Energy Technology Data Exchange (ETDEWEB)

    Greene, D.L.

    1995-05-01

    Transportation is critical to the world`s oil dependence problem because of the large share of world oil it consumes and because of its intense dependence on oil. This paper will focus on the economic costs of transportation`s oil dependence.

  14. Glutamate transporters combine transporter- and channel-like features

    NARCIS (Netherlands)

    Slotboom, DJ; Konings, WN; Lolkema, JS

    2001-01-01

    Glutamate transporters in the mammalian central nervous system have a unique position among secondary transport proteins as they exhibit glutamate-gated chloride-channel activity in addition to glutamate-transport activity. In this article, the available data on the structure of the glutamate transp

  15. Rail transport systems approach

    CERN Document Server

    2017-01-01

    This book shows how the systems approach is employed by scientists in various countries to solve specific problems concerning railway transport. In particular, the book describes the experiences of scientists from Romania, Germany, the Czech Republic, the UK, Russia, Ukraine, Lithuania and Poland. For many of these countries there is a problem with the historical differences between the railways. In particular, there are railways with different rail gauges, with different signaling and communication systems, with different energy supplies and, finally, with different political systems, which are reflected in the different approaches to the management of railway economies. The book’s content is divided into two main parts, the first of which provides a systematic analysis of individual means of providing and maintaining rail transport. In turn, the second part addresses infrastructure and management development, with particular attention to security issues. Though primarily written for professionals involved...

  16. Vibration enhanced quantum transport

    CERN Document Server

    Semião, F L; Milburn, G J

    2009-01-01

    In this paper, we study the role of a collective vibrational motion in the phenomenon of electronic energy transfer (EET) between chromophores with different electronic transition frequencies. Previous experimental work on EET in conjugated polymer samples has suggested that the common structural framework of the macromolecule introduce correlations in the energy gap fluctuations which cause coherent EET. We present a simple model describing the coupling between the chromophores and a common vibrational mode, and find that vibration can indeed lead to an enhancement in the transport of excitations across the quantum network. Furthermore, in our model phase information is partially retained in the transfer process from a donor to an acceptor, as experimentally demonstrated in the conjugated polymer system. Consequently, this mechanism of vibration enhanced quantum transport might find applications in quantum information transfer of qubit states or entanglement.

  17. Fractional lattice charge transport

    Science.gov (United States)

    Flach, Sergej; Khomeriki, Ramaz

    2017-01-01

    We consider the dynamics of noninteracting quantum particles on a square lattice in the presence of a magnetic flux α and a dc electric field E oriented along the lattice diagonal. In general, the adiabatic dynamics will be characterized by Bloch oscillations in the electrical field direction and dispersive ballistic transport in the perpendicular direction. For rational values of α and a corresponding discrete set of values of E(α) vanishing gaps in the spectrum induce a fractionalization of the charge in the perpendicular direction - while left movers are still performing dispersive ballistic transport, the complementary fraction of right movers is propagating in a dispersionless relativistic manner in the opposite direction. Generalizations and the possible probing of the effect with atomic Bose-Einstein condensates and photonic networks are discussed. Zak phase of respective band associated with gap closing regime has been computed and it is found converging to π/2 value. PMID:28102302

  18. Macropores and macropore transport

    DEFF Research Database (Denmark)

    Iversen, Bo Vangsø; Lamandé, Mathieu; Torp, Søren Bent

    2012-01-01

    a stronger relationship was found at saturation. Results of a test of the number of soil columns needed for a representative distribution of macropores for the measurement of saturated hydraulic conductivity indicated that approximately six soil columns were enough. Our work suggests that integrating......Preferential transport of water through soil macropores is a governing process in the facilitated transport of strongly sorbing compounds. The aim of this study was to investigate the relationships between macropore density and the hydraulic conductivity of the soil and to test the sampling...... representativeness of soil columns for the measurement of saturated hydraulic conductivity. Macropore density was determined in three horizons in four typical, Danish soil types (third year of pasture) and saturated hydraulic conductivity and near-saturated hydraulic conductivity were measured in the laboratory...

  19. Arsenite transport in plants.

    Science.gov (United States)

    Ali, Waqar; Isayenkov, Stanislav V; Zhao, Fang-Jie; Maathuis, Frans J M

    2009-07-01

    Arsenic is a metalloid which is toxic to living organisms. Natural occurrence of arsenic and human activities have led to widespread contamination in many areas of the world, exposing a large section of the human population to potential arsenic poisoning. Arsenic intake can occur through consumption of contaminated crops and it is therefore important to understand the mechanisms of transport, metabolism and tolerance that plants display in response to arsenic. Plants are mainly exposed to the inorganic forms of arsenic, arsenate and arsenite. Recently, significant progress has been made in the identification and characterisation of proteins responsible for movement of arsenite into and within plants. Aquaporins of the NIP (nodulin26-like intrinsic protein) subfamily were shown to transport arsenite in planta and in heterologous systems. In this review, we will evaluate the implications of these new findings and assess how this may help in developing safer and more tolerant crops.

  20. retardo de transporte

    Directory of Open Access Journals (Sweden)

    Paola Niño-Suárez

    2006-01-01

    Full Text Available En este trabajo se presenta la obtención del modelo exacto en tiempo discreto de un robot móvil tipo (2,0, bajo la consideración de la existencia de retardos de transporte en la señal de control, producidos por la propagación de las señales entre los sensores y actuadores del robot y el control remoto. El modelo obtenido es evaluado mediante simulación, comparando su desempeño con un modelo discreto aproximado que incluye también retardos de transporte y con el modelo en tiempo continuo del mismo sistema.

  1. Transportation and the marketplace

    Energy Technology Data Exchange (ETDEWEB)

    Soeoet, S. [Univ. of Illinois, Chicago, IL (United States)

    1996-12-31

    In the Chicago six-county metropolitan area, the number of registered vehicles grew by over 800,000 vehicles in the 1980s; by contrast the population increased by just over 150,000 during the same time. This ratio of growth in automobiles versus population (five to one) has contributed to overall increases in travel, congestion and energy use. The objective of this report is to examine how and why this has occurred and what we might expect in the near future to address the growing traffic problems and energy use. Specifically, the focus is on energy use by household vehicles and other forms of passenger travel. Data on population trends, gasoline prices, commuting and transit use, and transportation energy use are presented and interpreted. Intelligent transportation systems and decreased single vehicle emissions are briefly described as methods to decrease congestion and pollution. 9 figs., 2 tabs.

  2. Introduction to thermal transport

    Directory of Open Access Journals (Sweden)

    Simon R. Phillpot

    2005-06-01

    Full Text Available The relentless increase in the thermal loads imposed on devices and materials structures is driving renewed interest among materials scientists and engineers in the area of thermal transport. Applications include thermal barrier coatings on turbine blades, thermoelectric coolers, high-performance thermal transfer liquids, and heat dissipation in microelectronics. These, and other applications, demand not only ever more efficient thermal management, but also a better fundamental understanding of the underlying physical mechanisms.

  3. Community Sediment Transport Model

    Science.gov (United States)

    2007-01-01

    are used to determine that model results are consistent across compilers, platforms, and computer architectures , and to ensure that changes in code do...Mississippi State University: Bhate During the early months of this project, the focus was on understanding ROMS-CSTM model, architecture , and...Marchesiello, J.C. McWilliams, & K.D. Stolzenbach, 2007: Sediment transport modeling on Southern Californian shelves: A ROMS case study. Continental

  4. Transport Phenomena in Gel

    Directory of Open Access Journals (Sweden)

    Masayuki Tokita

    2016-05-01

    Full Text Available Gel becomes an important class of soft materials since it can be seen in a wide variety of the chemical and the biological systems. The unique properties of gel arise from the structure, namely, the three-dimensional polymer network that is swollen by a huge amount of solvent. Despite the small volume fraction of the polymer network, which is usually only a few percent or less, gel shows the typical properties that belong to solids such as the elasticity. Gel is, therefore, regarded as a dilute solid because its elasticity is much smaller than that of typical solids. Because of the diluted structure, small molecules can pass along the open space of the polymer network. In addition to the viscous resistance of gel fluid, however, the substance experiences resistance due to the polymer network of gel during the transport process. It is, therefore, of importance to study the diffusion of the small molecules in gel as well as the flow of gel fluid itself through the polymer network of gel. It may be natural to assume that the effects of the resistance due to the polymer network of gel depends strongly on the network structure. Therefore, detailed study on the transport processes in and through gel may open a new insight into the relationship between the structure and the transport properties of gel. The two typical transport processes in and through gel, that is, the diffusion of small molecules due to the thermal fluctuations and the flow of gel fluid that is caused by the mechanical pressure gradient will be reviewed.

  5. Transport phenomena II essentials

    CERN Document Server

    REA, The Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Transport Phenomena II covers forced convention, temperature distribution, free convection, diffusitivity and the mechanism of mass transfer, convective mass transfer, concentration

  6. Mitochondrial ABC transporters.

    Science.gov (United States)

    Lill, R; Kispal, G

    2001-01-01

    In contrast to bacteria, mitochondria contain only a few ATP binding cassette (ABC) transporters in their inner membrane. The known mitochondrial ABC proteins fall into two major classes that, in the yeast Saccharomyces cerevisiae, are represented by the half-transporter Atm1p and the two closely homologous proteins Mdl1p and Mdl2p. In humans two Atm1p orthologues (ABC7 and MTABC3) and two proteins homologous to Mdll/2p have been localized to mitochondria. The Atm1p-like proteins perform an important function in mitochondrial iron homeostasis and in the maturation of Fe/S proteins in the cytosol. Mutations in ABC7 are causative of hereditary X-linked sideroblastic anemia and cerebellar ataxia (XLSA/A). MTABC3 may be a candidate gene for the lethal neonatal syndrome. The function of the mitochondrial Mdl1/2p-like proteins is not clear at present with the notable exception of murine ABC-me that may transport intermediates of heme biosynthesis from the matrix to the cytosol in erythroid tissues.

  7. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk, Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2002-10-30

    This is the first quarterly progress report for Year-4 of the ACTS Project. It includes a review of progress made in: (1) Flow Loop construction and development and (2) research tasks during the period of time between July 1, 2002 and Sept. 30, 2002. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility Task 3: Addition of a Cuttings Injection/Separation System, Task 4: Addition of a Pipe Rotation System, (b) New Research project (Task 9b): ''Development of a Foam Generator/Viscometer for Elevated Pressure and Elevated Temperature (EPET) Conditions'', (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (e) Research on three instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), Foam texture while transporting cuttings (Task 12), Viscosity of Foam under EPET (Task 9b). (f) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (g) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  8. Surety applications in transportation

    Energy Technology Data Exchange (ETDEWEB)

    Matalucci, R.V.; Miyoshi, D.S.

    1998-01-01

    Infrastructure surety can make a valuable contribution to the transportation engineering industry. The lessons learned at Sandia National Laboratories in developing surety principles and technologies for the nuclear weapons complex and the nuclear power industry hold direct applications to the safety, security, and reliability of the critical infrastructure. This presentation introduces the concepts of infrastructure surety, including identification of the normal, abnormal, and malevolent threats to the transportation infrastructure. National problems are identified and examples of failures and successes in response to environmental loads and other structural and systemic vulnerabilities are presented. The infrastructure surety principles developed at Sandia National Laboratories are described. Currently available technologies including (a) three-dimensional computer-assisted drawing packages interactively combined with virtual reality systems, (b) the complex calculational and computational modeling and code-coupling capabilities associated with the new generation of supercomputers, and (c) risk-management methodologies with application to solving the national problems associated with threats to the critical transportation infrastructure are discussed.

  9. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Ergun Kuru; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Len Volk; Mark Pickell; Evren Ozbayoglu; Barkim Demirdal; Paco Vieira; Affonso Lourenco

    1999-10-15

    This report includes a review of the progress made in ACTF Flow Loop development and research during 90 days pre-award period (May 15-July 14, 1999) and the following three months after the project approval date (July15-October 15, 1999) The report presents information on the following specific subjects; (a) Progress in Advanced Cuttings Transport Facility design and development, (b) Progress report on the research project ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (c) Progress report on the research project ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (d) Progress report on the research project ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (e) Progress report on the research project ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Progress report on the instrumentation tasks (Tasks 11 and 12) (g) Activities towards technology transfer and developing contacts with oil and service company members.

  10. 'Resilience thinking' in transport planning

    OpenAIRE

    Wang, JYT

    2015-01-01

    Resilience has been discussed in ecology for over forty years. While some aspects of resilience have received attention in transport planning, there is no unified definition of resilience in transportation. To define resilience in transportation, I trace back to the origin of resilience in ecology with a view of revealing the essence of resilience thinking and its relevance to transport planning. Based on the fundamental concepts of engineering resilience and ecological resilience, I define "...

  11. Saturated Zone Colloid Transport

    Energy Technology Data Exchange (ETDEWEB)

    H. S. Viswanathan

    2004-10-07

    This scientific analysis provides retardation factors for colloids transporting in the saturated zone (SZ) and the unsaturated zone (UZ). These retardation factors represent the reversible chemical and physical filtration of colloids in the SZ. The value of the colloid retardation factor, R{sub col} is dependent on several factors, such as colloid size, colloid type, and geochemical conditions (e.g., pH, Eh, and ionic strength). These factors are folded into the distributions of R{sub col} that have been developed from field and experimental data collected under varying geochemical conditions with different colloid types and sizes. Attachment rate constants, k{sub att}, and detachment rate constants, k{sub det}, of colloids to the fracture surface have been measured for the fractured volcanics, and separate R{sub col} uncertainty distributions have been developed for attachment and detachment to clastic material and mineral grains in the alluvium. Radionuclides such as plutonium and americium sorb mostly (90 to 99 percent) irreversibly to colloids (BSC 2004 [DIRS 170025], Section 6.3.3.2). The colloid retardation factors developed in this analysis are needed to simulate the transport of radionuclides that are irreversibly sorbed onto colloids; this transport is discussed in the model report ''Site-Scale Saturated Zone Transport'' (BSC 2004 [DIRS 170036]). Although it is not exclusive to any particular radionuclide release scenario, this scientific analysis especially addresses those scenarios pertaining to evidence from waste-degradation experiments, which indicate that plutonium and americium may be irreversibly attached to colloids for the time scales of interest. A section of this report will also discuss the validity of using microspheres as analogs to colloids in some of the lab and field experiments used to obtain the colloid retardation factors. In addition, a small fraction of colloids travels with the groundwater without any significant

  12. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Stefan Miska; Troy Reed; Ergun Kuru

    2004-09-30

    The Advanced Cuttings Transport Study (ACTS) was a 5-year JIP project undertaken at the University of Tulsa (TU). The project was sponsored by the U.S. Department of Energy (DOE) and JIP member companies. The objectives of the project were: (1) to develop and construct a new research facility that would allow three-phase (gas, liquid and cuttings) flow experiments under ambient and EPET (elevated pressure and temperature) conditions, and at different angle of inclinations and drill pipe rotation speeds; (2) to conduct experiments and develop a data base for the industry and academia; and (3) to develop mechanistic models for optimization of drilling hydraulics and cuttings transport. This project consisted of research studies, flow loop construction and instrumentation development. Following a one-year period for basic flow loop construction, a proposal was submitted by TU to the DOE for a five-year project that was organized in such a manner as to provide a logical progression of research experiments as well as additions to the basic flow loop. The flow loop additions and improvements included: (1) elevated temperature capability; (2) two-phase (gas and liquid, foam etc.) capability; (3) cuttings injection and removal system; (4) drill pipe rotation system; and (5) drilling section elevation system. In parallel with the flow loop construction, hydraulics and cuttings transport studies were preformed using drilling foams and aerated muds. In addition, hydraulics and rheology of synthetic drilling fluids were investigated. The studies were performed under ambient and EPET conditions. The effects of temperature and pressure on the hydraulics and cuttings transport were investigated. Mechanistic models were developed to predict frictional pressure loss and cuttings transport in horizontal and near-horizontal configurations. Model predictions were compared with the measured data. Predominantly, model predictions show satisfactory agreements with the measured data. As a

  13. Energy efficiency in refrigerated transport

    NARCIS (Netherlands)

    Gerwen, R.J.M. van; Sluis, S.M. van der; Schiphouwer, H.

    1998-01-01

    In refrigerated road transport, 10 to 40 `)/0 of the total energy consumption is related to refrigeration. However, energy consumption and energy efficiency of refrigerated transport equipment is rarely mentioned in the discussions about energy saving, potentials in road transport. Two main approach

  14. Improving Hygiene in Food Transportation

    NARCIS (Netherlands)

    Thoden van Velzen, E.U.; Lukasse, L.J.S.

    2016-01-01

    The hygiene aspect of food transport has become an issue for European transport operators. This development started roughly in 1990, when national governments urged transport operators to act on food safety. However, nowadays retailers and food producers are demanding more hygiene measures from tran

  15. Genetic defects in hepatocanalicular transport

    NARCIS (Netherlands)

    Thompson, R; Jansen, PLM

    2000-01-01

    Bile is made as the result of active transport of its constituents into the biliary space. Most of this transport occurs across the canalicular membrane, with a further contribution from cholangiocytes. Water moves passively into bile. The major substrates that are transported out of hepatocytes are

  16. Products - transport - storage; Produits - transports - stockages

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2005-04-15

    9 articles are gathered in this data-sheet; they deal with LPG products, transport and storage. Blackmer offers a full line of LPG equipment for the transfer of propane, butane and anhydrous ammonia. Clesse Industries and Gas Equipment Company equip luxury hotels in Dubai and Abu Dhabi. Since 1975 the company FAS Flussiggas-Anlagen Gmbh, Salzgitter - Germany is one of the leading manufacturers of LPG equipment and components for mobile and stationary bulk plants in Europe. The main products are dispensers, pumps, Auto-gas filling stations, vaporizers, loading arms, electronic cylinder filling scales, flanged valves and safety equipment. FAS is certified with 2 process orientated management systems according to DIN EN ISO 9001:2000 and to PED - Module H1 - Category IV. The company supplies all products and services according to the Pressure Equipment Directive 97/23/EC with CE-mark as well according to regulations ATEX, OIML, TUV, PTB... ECII Engineered Controls International/Rego USA is well known as a worldwide leader and designer/manufacturer of LPG and anhydrous ammonia equipment. The 10. of January Per Sture Jenssen retired from Ragasco A.S. Managing Director after 6 years in the company. Oyvind Hamre who has taken over from Mr. Jenssen, is 39 years of age and he has been 10 years with Ragasco, most recently as R and D Manager. Per Sture Jenssen will still be present in the company until summer 2005 to support during the transition. Corken has put in the market two new products: a new valve and a new pump. Impco Technologies announces completion of BRC acquisition. VOC reduction is a common discussion issue in almost all sectors of the oil business and beyond. Each industry sector has a different strategy towards this issue according to its perceived impact on the business. Although largely motivated by the need to satisfy national and international emission standards, the move towards reduction has encouraged equipment manufacturers to develop advanced

  17. Common folds and transport mechanisms of secondary active transporters.

    Science.gov (United States)

    Shi, Yigong

    2013-01-01

    Secondary active transporters exploit the electrochemical potential of solutes to shuttle specific substrate molecules across biological membranes, usually against their concentration gradient. Transporters of different functional families with little sequence similarity have repeatedly been found to exhibit similar folds, exemplified by the MFS, LeuT, and NhaA folds. Observations of multiple conformational states of the same transporter, represented by the LeuT superfamily members Mhp1, AdiC, vSGLT, and LeuT, led to proposals that structural changes are associated with substrate binding and transport. Despite recent biochemical and structural advances, our understanding of substrate recognition and energy coupling is rather preliminary. This review focuses on the common folds and shared transport mechanisms of secondary active transporters. Available structural information generally supports the alternating access model for substrate transport, with variations and extensions made by emerging structural, biochemical, and computational evidence.

  18. Fundamentals of Biomedical Transport Processes

    CERN Document Server

    Miller, Gerald

    2010-01-01

    Transport processes represent important life-sustaining elements in all humans. These include mass transfer processes, including gas exchange in the lungs, transport across capillaries and alveoli, transport across the kidneys, and transport across cell membranes. These mass transfer processes affect how oxygen and carbon dioxide are exchanged in your bloodstream, how metabolic waste products are removed from your blood, how nutrients are transported to tissues, and how all cells function throughout the body. A discussion of kidney dialysis and gas exchange mechanisms is included. Another elem

  19. Evolution of chloroplast vesicle transport.

    Science.gov (United States)

    Westphal, Sabine; Soll, Jürgen; Vothknecht, Ute C

    2003-02-01

    Vesicle traffic plays a central role in eukaryotic transport. The presence of a vesicle transport system inside chloroplasts of spermatophytes raises the question of its phylogenetic origin. To elucidate the evolution of this transport system we analyzed organisms belonging to different lineages that arose from the first photosynthetic eukaryote, i.e. glaucocystophytes, chlorophytes, rhodophytes, and charophytes/embryophytes. Intriguingly, vesicle transport is not apparent in any group other than embryophytes. The transfer of this eukaryotic-type vesicle transport system from the cytosol into the chloroplast thus seems a late evolutionary development that was acquired by land plants in order to adapt to new environmental challenges.

  20. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Ergun Kuru; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Neelima Godugu

    2000-07-30

    ACTS flow loop is now operational under elevated pressure and temperature. Currently, experiments with synthetic based drilling fluids under pressure and temperature are being conducted. Based on the analysis of Fann 70 data, empirical correlations defining the shear stress as a function of temperature, pressure and the shear rate have been developed for Petrobras synthetic drilling fluids. PVT equipment has been modified for testing Synthetic oil base drilling fluids. PVT tests with Petrobras Synthetic base mud have been conducted and results are being analyzed Foam flow experiments have been conducted and the analysis of the data has been carried out to characterize the rheology of the foam. Comparison of pressure loss prediction from the available foam hydraulic models and the test results has been made. Cuttings transport experiments in horizontal annulus section have been conducted using air, water and cuttings. Currently, cuttings transport tests in inclined test section are being conducted. Foam PVT analysis tests have been conducted. Foam stability experiments have also been conducted. Effects of salt and oil concentration on the foam stability have been investigated. Design of ACTS flow loop modification for foam and aerated mud flow has been completed. A flow loop operation procedure for conducting foam flow experiments under EPET conditions has been prepared Design of the lab-scale flow loop for dynamic foam characterization and cuttings monitoring instrumentation tests has been completed. The construction of the test loop is underway. As part of the technology transport efforts, Advisory Board Meeting with ACTS-JIP industry members has been organized on May 13, 2000.

  1. The Edge supersonic transport

    Science.gov (United States)

    Agosta, Roxana; Bilbija, Dushan; Deutsch, Marc; Gallant, David; Rose, Don; Shreve, Gene; Smario, David; Suffredini, Brian

    1992-01-01

    As intercontinental business and tourism volumes continue their rapid expansion, the need to reduce travel times becomes increasingly acute. The Edge Supersonic Transport Aircraft is designed to meet this demand by the year 2015. With a maximum range of 5750 nm, a payload of 294 passengers and a cruising speed of M = 2.4, The Edge will cut current international flight durations in half, while maintaining competitive first class, business class, and economy class comfort levels. Moreover, this transport will render a minimal impact upon the environment, and will meet all Federal Aviation Administration Part 36, Stage III noise requirements. The cornerstone of The Edge's superior flight performance is its aerodynamically efficient, dual-configuration design incorporating variable-geometry wingtips. This arrangement combines the benefits of a high aspect ratio wing at takeoff and low cruising speeds with the high performance of an arrow-wing in supersonic cruise. And while the structural weight concerns relating to swinging wingtips are substantial, The Edge looks to ever-advancing material technologies to further increase its viability. Heeding well the lessons of the past, The Edge design holds economic feasibility as its primary focus. Therefore, in addition to its inherently superior aerodynamic performance, The Edge uses a lightweight, largely windowless configuration, relying on a synthetic vision system for outside viewing by both pilot and passengers. Additionally, a fly-by-light flight control system is incorporated to address aircraft supersonic cruise instability. The Edge will be produced at an estimated volume of 400 aircraft and will be offered to airlines in 2015 at $167 million per transport (1992 dollars).

  2. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mengjiao Yu; Ramadan Ahmed; Mark Pickell; Len Volk; Lei Zhou; Zhu Chen; Aimee Washington; Crystal Redden

    2003-09-30

    The Quarter began with installing the new drill pipe, hooking up the new hydraulic power unit, completing the pipe rotation system (Task 4 has been completed), and making the SWACO choke operational. Detailed design and procurement work is proceeding on a system to elevate the drill-string section. The prototype Foam Generator Cell has been completed by Temco and delivered. Work is currently underway to calibrate the system. Literature review and preliminary model development for cuttings transportation with polymer foam under EPET conditions are in progress. Preparations for preliminary cuttings transport experiments with polymer foam have been completed. Two nuclear densitometers were re-calibrated. Drill pipe rotation system was tested up to 250 RPM. Water flow tests were conducted while rotating the drill pipe up to 100 RPM. The accuracy of weight measurements for cuttings in the annulus was evaluated. Additional modifications of the cuttings collection system are being considered in order to obtain the desired accurate measurement of cuttings weight in the annular test section. Cutting transport experiments with aerated fluids are being conducted at EPET, and analyses of the collected data are in progress. The printed circuit board is functioning with acceptable noise level to measure cuttings concentration at static condition using ultrasonic method. We were able to conduct several tests using a standard low pass filter to eliminate high frequency noise. We tested to verify that we can distinguish between different depths of sand in a static bed of sand. We tested with water, air and a mix of the two mediums. Major modifications to the DTF have almost been completed. A stop-flow cell is being designed for the DTF, the ACTF and Foam Generator/Viscometer which will allow us to capture bubble images without the need for ultra fast shutter speeds or microsecond flash system.

  3. Crew Transportation Plan

    Science.gov (United States)

    Zeitler, Pamela S. (Compiler); Mango, Edward J.

    2013-01-01

    The National Aeronautics and Space Administration (NASA) Commercial Crew Program (CCP) has been chartered to facilitate the development of a United States (U.S.) commercial crew space transportation capability with the goal of achieving safe, reliable, and cost effective access to and from low Earth orbit (LEO) and the International Space Station (ISS) as soon as possible. Once the capability is matured and is available to the Government and other customers, NASA expects to purchase commercial services to meet its ISS crew rotation and emergency return objectives.

  4. Management of Transportation Equipment.

    Science.gov (United States)

    1982-11-01

    Medium (10,000 up to 18,999 GVW) 96-00000 Truck, Heavy (Over 19,000 GVW) 97-00000 Trailer 98-00000 Motorcycle and Scooter 8-3 ~ ’ .j...certifications as may be required in testing personnel for issuing the SF 46, or for suspending or revoking the SF 46. Suspension or revocation of the SF 46 for...valid state license. DoD Components shall not provide the Department of Transportation with data on SF 46 suspensions or revocation action. DoD Components

  5. Transport phenomena I essentials

    CERN Document Server

    REA, The Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Transport Phenomena I includes viscosity, flow of Newtonian fluids, velocity distribution in laminar flow, velocity distributions with more than one independent variable, thermal con

  6. Transport hub flow modelling

    OpenAIRE

    Despagne, Wilfried; Frenod, Emmanuel

    2014-01-01

    Purpose: The purpose of this paper is to investigate the road freight haulage activity. Using the physical and data flow information from a freight forwarder, we intend to model the flow of inbound and outbound goods in a freight transport hub. Approach: This paper presents the operation of a road haulage group. To deliver goods within two days to any location in France, a haulage contractor needs to be part of a network. This network handles the processing of both physical goods and data. We...

  7. Groupage Cargo Transportation Model

    Directory of Open Access Journals (Sweden)

    Aleksejevs Ruslans

    2016-03-01

    Full Text Available In this work we consider a specific problem of optimal planning of maritime transportation of multiproduct cargo by ships of one (corporate strategy or several (partially corporate strategy companies: the core of the problem consists of the existence of the network of intermediate seaports (i.e. transitional seaports, where for every ship arrived the cargo handling is done, and which are situated between the starting and the finishing seaports. In this work, there are mathematical models built from scratch in the form of multicriteria optimization problem; then the goal attainment method of Gembicki is used for reducing the built models to a one-criterion problem of linear programming.

  8. Energy for Transport

    DEFF Research Database (Denmark)

    Figueroa, Maria; Lah, Oliver; Fulton, Lewis M.

    2014-01-01

    a major contribution to economic development and social well-being, but it also negatively impacts climate change, air quality, health, social cohesion, and safety. Following a review published 20 years ago in the Annual Review of Environment and Resources (then named the Annual Review of Energy...... and the Environment) by Lee Schipper, we examine current trends and potential futures, revising several major global transport/energy reports. There are significant opportunities to slow travel growth and improve efficiency. Alternatives to petroleum exist but have different characteristics in terms of availability...

  9. Stochastic models of intracellular transport

    KAUST Repository

    Bressloff, Paul C.

    2013-01-09

    The interior of a living cell is a crowded, heterogenuous, fluctuating environment. Hence, a major challenge in modeling intracellular transport is to analyze stochastic processes within complex environments. Broadly speaking, there are two basic mechanisms for intracellular transport: passive diffusion and motor-driven active transport. Diffusive transport can be formulated in terms of the motion of an overdamped Brownian particle. On the other hand, active transport requires chemical energy, usually in the form of adenosine triphosphate hydrolysis, and can be direction specific, allowing biomolecules to be transported long distances; this is particularly important in neurons due to their complex geometry. In this review a wide range of analytical methods and models of intracellular transport is presented. In the case of diffusive transport, narrow escape problems, diffusion to a small target, confined and single-file diffusion, homogenization theory, and fractional diffusion are considered. In the case of active transport, Brownian ratchets, random walk models, exclusion processes, random intermittent search processes, quasi-steady-state reduction methods, and mean-field approximations are considered. Applications include receptor trafficking, axonal transport, membrane diffusion, nuclear transport, protein-DNA interactions, virus trafficking, and the self-organization of subcellular structures. © 2013 American Physical Society.

  10. Crew Transportation Technical Management Processes

    Science.gov (United States)

    Mckinnie, John M. (Compiler); Lueders, Kathryn L. (Compiler)

    2013-01-01

    Under the guidance of processes provided by Crew Transportation Plan (CCT-PLN-1100), this document, with its sister documents, International Space Station (ISS) Crew Transportation and Services Requirements Document (CCT-REQ-1130), Crew Transportation Technical Standards and Design Evaluation Criteria (CCT-STD-1140), Crew Transportation Operations Standards (CCT STD-1150), and ISS to Commercial Orbital Transportation Services Interface Requirements Document (SSP 50808), provides the basis for a National Aeronautics and Space Administration (NASA) certification for services to the ISS for the Commercial Provider. When NASA Crew Transportation System (CTS) certification is achieved for ISS transportation, the Commercial Provider will be eligible to provide services to and from the ISS during the services phase.

  11. Bus transport in Greater Manchester

    DEFF Research Database (Denmark)

    Sørensen, Claus Hedegaard; Gudmundsson, Henrik

    Introduction and aim During the past 15 – 20 years large parts of the public sector in the OECD countries but also outside the OECD have experienced so-called New Public Management (NPM) reforms. Not least the transport sector, and in particular public transport have been objects of these reforms...... of public management. But taking a broader view on public transport policy, these are not the only things that matter. In our present work we are looking into the consequences of the NPM reforms in public transport for the realisation of Sustainable Transport objectives. Our basic assumption...... is that ‘organisation matters’ and that the reforms may have changed significantly the institutional conditions for the implementation of sustainable transport policies and easures. We have focused the research on public transport in larger cities and how their organisation has changed due to the reforms. At the NECTAR...

  12. Environmental assessment of freight transportation

    Energy Technology Data Exchange (ETDEWEB)

    Flodstroem, E. [MariTerm AB, Goeteborg (Sweden)

    1998-04-01

    This report is a short version in English of two reports in Swedish: KFB report 1994:6 `Environmental effects of change of transport mode for goods transportation` and `Combining of transport models` which was performed as a commission for the Swedish environmental protection agency. The aim of both studies is to investigate the environmental effects of political measures to transfer goods from one transport mode to another. To be able to calculate the environmental effects a method to follow the transport chains has been developed. By defining the transport chains with a main transport mode it has been possible to relate the emissions to the different modes. The main results are that the transferable volumes are limited and even if a maximum volume is transferred, the positive environmental effects are small compared to the effects of measures to reduce the emissions from the vehicles 3 refs, 22 figs, 34 tabs

  13. Innovations for sustainable public transport

    DEFF Research Database (Denmark)

    Hrelja, Robert; Hansson, Lisa; Richardson, Tim

    is to contribute effectively to the development of an efficient and sustainable transport system (for example, forms for the coordination of public transport, land use, and infrastructure planning); (ii) public transport must not be seen as an end in itself, or as merely a technical transport system; (iii......The aim of the project has been to analyse institutional and planning conditions for public transport in the Scandinavian countries from a comparative perspective, looking at the county of Skåne (Sweden) and the municipalities of Aarhus (Denmark) and Trondheim (Norway). The report considers...... qualitative case- studies of public transport in Skåne, Aarhus, and Trondheim, and uses an empirical material consisting of written material and interviews. It concludes that: (i) new forms of coordination between organizations and policy areas are called for in a number of critical areas, if public transport...

  14. OXYGEN TRANSPORT CERAMIC MEMBRANES

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2000-10-01

    This is the third quarterly report on oxygen Transport Ceramic Membranes. In the following, the report describes the progress made by our university partners in Tasks 1 through 6, experimental apparatus that was designed and built for various tasks of this project, thermodynamic calculations, where applicable and work planned for the future. (Task 1) Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. (Task 2) Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. (Task 3) Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. (Task 4) Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. (Task 5) Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. (Task 6) Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

  15. Lunar magma transport phenomena

    Science.gov (United States)

    Spera, Frank J.

    1992-01-01

    An outline of magma transport theory relevant to the evolution of a possible Lunar Magma Ocean and the origin and transport history of the later phase of mare basaltic volcanism is presented. A simple model is proposed to evaluate the extent of fractionation as magma traverses the cold lunar lithosphere. If Apollo green glasses are primitive and have not undergone significant fractionation en route to the surface, then mean ascent rates of 10 m/s and cracks of widths greater than 40 m are indicated. Lunar tephra and vesiculated basalts suggest that a volatile component plays a role in eruption dynamics. The predominant vapor species appear to be CO CO2, and COS. Near the lunar surface, the vapor fraction expands enormously and vapor internal energy is converted to mixture kinetic energy with the concomitant high-speed ejection of vapor and pyroclasts to form lunary fire fountain deposits such as the Apollo 17 orange and black glasses and Apollo 15 green glass.

  16. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2003-07-30

    This Quarter has been divided between running experiments and the installation of the drill-pipe rotation system. In addition, valves and piping were relocated, and three viewports were installed. Detailed design work is proceeding on a system to elevate the drill-string section. Design of the first prototype version of a Foam Generator has been finalized, and fabrication is underway. This will be used to determine the relationship between surface roughness and ''slip'' of foams at solid boundaries. Additional cups and rotors are being machined with different surface roughness. Some experiments on cuttings transport with aerated fluids have been conducted at EPET. Theoretical modeling of cuttings transport with aerated fluids is proceeding. The development of theoretical models to predict frictional pressure losses of flowing foam is in progress. The new board design for instrumentation to measure cuttings concentration is now functioning with an acceptable noise level. The ultrasonic sensors are stable up to 190 F. Static tests with sand in an annulus indicate that the system is able to distinguish between different sand concentrations. Viscometer tests with foam, generated by the Dynamic Test Facility (DTF), are continuing.

  17. TRANSPORT OUTSOURCING AND TRANSPORT COLLABORATION RELATIONSHIP - THE RISK HEDGING PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Đurđica M. Stojanović

    2015-04-01

    Full Text Available Although transport outsourcing decision-making and collaborative transport management (CTM have been “hot topics” for years, their links are still not thoroughly explored. The purpose of this paper is to contribute to a better understanding of the relationship between them. In particular, we focus on the conflicting and complementary features of these concepts with regard to their capability to hedge against transport outsourcing-related risks. Transport outsourcing is often a tool for transferring part of the demand risks from the primary parties in supply chains to transport service providers. However, new relationships introduce some new risks - outsourcing contract risks. It is important to identify, estimate and compare such kinds of risks. Transport collaboration may decrease both the demand risks and the outsourcing contract risks, although the relationship with the latter is more complex. It is used an exploratory research based on a combination of a literature review and empirical examples.

  18. Container Logistic Transport Planning Model

    Directory of Open Access Journals (Sweden)

    Xin Zhang

    2013-05-01

    Full Text Available The study proposed a stochastic method of container logistic transport in order to solve the unreasonable transportation’s problem and overcome the traditional models’ two shortcomings. Container transport has rapidly developed into a modern means of transportation because of their significant advantages. With the development, it also exacerbated the flaws of transport in the original. One of the most important problems was that the invalid transport had not still reduced due to the congenital imbalances of transportation. Container transport exacerbated the invalid transport for the empty containers. To solve the problem, people made many efforts, but they did not make much progress. There had two theoretical flaws by analyzing the previous management methods in container transport. The first one was the default empty containers inevitability. The second one was that they did not overall consider how to solve the problem of empty containers allocation. In order to solve the unreasonable transportation’s problem and overcome the traditional models’ two shortcomings, the study re-built the container transport planning model-gravity model. It gave the general algorithm and has analyzed the final result of model.

  19. Up-gradient transport in a probabilistic transport model

    DEFF Research Database (Denmark)

    Gavnholt, J.; Juul Rasmussen, J.; Garcia, O.E.

    2005-01-01

    The transport of particles or heat against the driving gradient is studied by employing a probabilistic transport model with a characteristic particle step length that depends on the local concentration or heat gradient. When this gradient is larger than a prescribed critical value, the standard....... These results supplement recent works by van Milligen [Phys. Plasmas 11, 3787 (2004)], which applied Levy distributed step sizes in the case of supercritical gradients to obtain the up-gradient transport. (c) 2005 American Institute of Physics....

  20. Radioactive material air transportation; Transporte aereo de material radioativo

    Energy Technology Data Exchange (ETDEWEB)

    Pader y Terry, Claudio Cosme [Varig Logistica (VARIGLOG), Sao Paulo, SP (Brazil)

    2002-07-01

    As function of the high aggregated value, safety regulations and the useful life time, the air transportation has been used more regularly because is fast, reliable, and by giving great security to the cargo. Based on the International Atomic Energy Agency (IAEA), the IATA (International Air Transportation Association) has reproduced in his dangerous goods manual (Dangerous Goods Regulations - DGR IATA), the regulation for the radioactive material air transportation. Those documents support this presentation.

  1. Energy alternatives in urban transportation; Alternativas energeticas em transportes urbanos

    Energy Technology Data Exchange (ETDEWEB)

    Mello, Jose C. [SVO, Brasilia, DF (Brazil)

    1984-12-31

    The essay remarks the high dependence of petroleum derivative fuels, by analysing the energetic characteristics of urban transportation in Brazil. However, taking the global costs of energy in the country, only a little parcel of the petroleum expense is concerned to urban collective transportation. As a result, some energetic alternatives are being studied, in order to substitute petroleum derivative fuels, and parameters are being suggested to a national policy of urban transportation. (author). 8 refs., 5 tabs

  2. Functional analysis of candidate ABC transporter proteins for sitosterol transport

    DEFF Research Database (Denmark)

    Albrecht, C; Elliott, J I; Sardini, A;

    2002-01-01

    implicated in lipid movement and expressed in tissues with a role in sterol synthesis and absorption, might also be involved in sitosterol transport. Transport by the multidrug resistance P-glycoprotein (P-gp; Abcb1), the multidrug resistance-associated protein (Mrp1; Abcc1), the breast cancer resistance...... the absorption of sitosterol and related molecules in the intestine by pumping them back into the lumen. Although mutations altering ABCG5 and ABCG8 are found in affected patients, no functional demonstration of sitosterol transport has been achieved. In this study, we investigated whether other ABC transporters...

  3. Efficiency improvements in transport

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, J. [Technical Univ. of Denmark. DTU Mechanical Engineering, Kgs. Lyngby (Denmark); Christensen, Linda; Jensen, Thomas C. [Technical Univ. of Denmark. DTU Transport, Kgs. Lyngby (Denmark)

    2012-11-15

    Transport of people, personal belongings and goods in private cars is fundamental to our modern welfare society and economic growth, and has grown steadily over many decades. Motor fuels have been based almost entirely on crude oil for the last century. During the last couple of decades engines built for traditional fuels have become more advanced and efficient; this has reduced fuel consumption by around 40% and emissions by more than 90%. Only in the same time span have we begun to look at alternatives to fossil fuels. Biofuels such as biodiesel, bioethanol, biomethanol and biogas can replace petrol and diesel, and in recent years algae have shown a new potential for diesel fuel. Natural gas is also becoming an interesting fuel due to its large resources worldwide. GTL, CTL and BTL are liquid fuels produced from solid or gaseous sources. GTL and CTL are expensive to produce and not very CO{sub 2}-friendly, but they are easily introduced and need little investment in infrastructure and vehicles. DME is an excellent fuel for diesel engines. Methanol and DME produced from biomass are among the most CO{sub 2}-reducing fuels and at the same time the most energy-efficient renewable fuels. Fuel cell vehicles (FCVs) are currently fuelled by hydrogen, but other fuels are also possible. There are, however, several barriers to the implementation of fuel cell vehicles. In particular, a hydrogen infrastructure needs to be developed. Electric vehicles (EVs) have the advantage that energy conversion is centralised at the power plant where it can be done at optimum efficiency and emissions. EVs have to be charged at home, and also away from home when travelling longer distances. With an acceptable fast charging infrastructure at least 85% of the one-car families in Denmark could be potential EV customers. Range improvements resulting from better batteries are expected to create a large increase in the number of EVs in Denmark between 2020 and 2030. The hybrid electric vehicle

  4. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2003-04-30

    Experiments on the flow loop are continuing. Improvements to the software for data acquisition are being made as additional experience with three-phase flow is gained. Modifications are being made to the Cuttings Injection System in order to improve control and the precision of cuttings injection. The design details for a drill-pipe Rotation System have been completed. A US Patent was filed on October 28, 2002 for a new design for an instrument that can generate a variety of foams under elevated pressures and temperatures and then transfer the test foam to a viscometer for measurements of viscosity. Theoretical analyses of cuttings transport phenomena based on a layered model is under development. Calibrations of two nuclear densitometers have been completed. Baseline tests have been run to determine wall roughness in the 4 different tests sections (i.e. 2-in, 3-in, 4-in pipes and 5.76-in by 3.5-in annulus) of the flow loop. Tests have also been conducted with aerated fluids at EPET conditions. Preliminary experiments on the two candidate aqueous foam formulations were conducted which included rheological tests of the base fluid and foam stability reports. These were conducted after acceptance of the proposal on the Study of Cuttings Transport with Foam Under Elevated Pressure and Elevated Temperature Conditions. Preparation of a test matrix for cuttings-transport experiments with foam in the ACTF is also under way. A controller for instrumentation to measure cuttings concentration and distribution has been designed that can control four transceivers at a time. A prototype of the control circuit board was built and tested. Tests showed that there was a problem with radiated noise. AN improved circuit board was designed and sent to an external expert to verify the new design. The new board is being fabricated and will first be tested with static water and gravel in an annulus at elevated temperatures. A series of viscometer tests to measure foam properties have

  5. Dispersive transport across interfaces

    Science.gov (United States)

    Berkowitz, Brian; Adler, Pierre

    2015-04-01

    Experiments demonstrating asymmetrical dispersive transport of a conservative tracer across interfaces between different porous materials have recently been performed. Here, this phenomenon is studied numerically on the pore scale. The flow field is derived by solving the Stokes equation. The dispersive transport is simulated by a large number of particles undergoing random walks under the simultaneous action of convection and diffusion. Two main two-dimensional configurations are studied; each consists of two segments (called coarse and fine) with the same structure, porosity, and length along the main flow, but different characteristic solid/pore sizes. One structure consists of two channels containing cavities of different sizes, and the second of square "grains" of different sizes. At time t=0, a large number of particles is injected (as a pulse) around a given cross-section. The corresponding breakthrough curves (BTCs) are registered as functions of time at six different cross sections. Calculations are made twice; in the first case (CtoF), particles are injected in the coarse side and are transported towards the fine one; in the second one (FtoC), the opposite case is studied. These calculations are performed for various Péclet numbers (Pe). Comparison of the resulting BTCs shows features that are similar to experimental observations, but with qualitative and quantitative differences. The influences of the medium, of the injection and observation planes, and of Pe are detailed and discussed. A BTC for pulse injection can be characterized by its maximum M(t_M) and the time tM at which it occurs. The observed differences for channels bounded by cavities are very small. However for the granular structures, M(t_M) is always larger for FtoC than for CtoF ; tM depends on all the parameters, namely Pe, the size ratio between the large and small grains, the injection and the observation planes. The numerical results are systematically compared with solutions of one

  6. Fuel cells in transportation

    Energy Technology Data Exchange (ETDEWEB)

    Erdmann, G. [Technische Univ., Berlin (Germany); Hoehlein, B. [Research Center Juelich (Germany)

    1996-12-01

    A promising new power source for electric drive systems is the fuel cell technology with hydrogen as energy input. The worldwide fuel cell development concentrates on basic research efforts aiming at improving this new technology and at developing applications that might reach market maturity in the very near future. Due to the progress achieved, the interest is now steadily turning to the development of overall systems such as demonstration plants for different purposes: electricity generation, drive systems for road vehicles, ships and railroads. This paper does not present results concerning the market potential of fuel cells in transportation but rather addresses some questions and reflections that are subject to further research of both engineers and economists. Some joint effort of this research will be conducted under the umbrella of the IEA Implementing Agreement 026 - Annex X, but there is a lot more to be done in this challenging but also promising fields. (EG) 18 refs.

  7. Serotonin transporter and memory.

    Science.gov (United States)

    Meneses, Alfredo; Perez-Garcia, Georgina; Ponce-Lopez, Teresa; Tellez, Ruth; Castillo, Carlos

    2011-09-01

    The serotonin transporter (SERT) has been associated to diverse functions and diseases, though seldom to memory. Therefore, we made an attempt to summarize and discuss the available publications implicating the involvement of the SERT in memory, amnesia and anti-amnesic effects. Evidence indicates that Alzheimer's disease and drugs of abuse like d-methamphetamine (METH) and (+/-)3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") have been associated to decrements in the SERT expression and memory deficits. Several reports have indicated that memory formation and amnesia affected the SERT expression. The SERT expression seems to be a reliable neural marker related to memory mechanisms, its alterations and potential treatment. The pharmacological, neural and molecular mechanisms associated to these changes are of great importance for investigation.

  8. Dynamic Transportation Navigation

    Science.gov (United States)

    Meng, Xiaofeng; Chen, Jidong

    Miniaturization of computing devices, and advances in wireless communication and sensor technology are some of the forces that are propagating computing from the stationary desktop to the mobile outdoors. Some important classes of new applications that will be enabled by this revolutionary development include intelligent traffic management, location-based services, tourist services, mobile electronic commerce, and digital battlefield. Some existing application classes that will benefit from the development include transportation and air traffic control, weather forecasting, emergency response, mobile resource management, and mobile workforce. Location management, i.e., the management of transient location information, is an enabling technology for all these applications. In this chapter, we present the applications of moving objects management and their functionalities, in particular, the application of dynamic traffic navigation, which is a challenge due to the highly variable traffic state and the requirement of fast, on-line computations.

  9. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Stefan Miska; Nicholas Takach; Kaveh Ashenayi

    2004-01-31

    Final design of the mast was completed (Task 5). The mast is consisting of two welded plate girders, set next to each other, and spaced 14-inches apart. Fabrication of the boom will be completed in two parts solely for ease of transportation. The end pivot connection will be made through a single 2-inch diameter x 4 feet-8 inch long 316 SS bar. During installation, hard piping make-ups using Chiksan joints will connect the annular section and 4-inch return line to allow full movement of the mast from horizontal to vertical. Additionally, flexible hoses and piping will be installed to isolate both towers from piping loads and allow recycling operations respectively. Calibration of the prototype Foam Generator Cell has been completed and experiments are now being conducted. We were able to generate up to 95% quality foam. Work is currently underway to attach the Thermo-Haake RS300 viscometer and install a view port with a microscope to measure foam bubble size and bubble size distribution. Foam rheology tests (Task 13) were carried out to evaluate the rheological properties of the proposed foam formulation. After successful completion of the first foam test, two sets of rheological tests were conducted at different foam flow rates while keeping other parameters constant (100 psig, 70F, 80% quality). The results from these tests are generally in agreement with the previous foam tests done previously during Task 9. However, an unanticipated observation during these tests was that in both cases, the frictional pressure drop in 2 inch pipe was lower than that in the 3 inch and 4 inch pipes. We also conducted the first foam cuttings transport test during this quarter. Experiments on aerated fluids without cuttings have been completed in ACTF (Task 10). Gas and liquid were injected at different flow rates. Two different sets of experiments were carried out, where the only difference was the temperature. Another set of tests was performed, which covered a wide range of

  10. Random Access Transport Capacity

    CERN Document Server

    Andrews, Jeffrey G; Kountouris, Marios; Haenggi, Martin

    2009-01-01

    We develop a new metric for quantifying end-to-end throughput in multihop wireless networks, which we term random access transport capacity, since the interference model presumes uncoordinated transmissions. The metric quantifies the average maximum rate of successful end-to-end transmissions, multiplied by the communication distance, and normalized by the network area. We show that a simple upper bound on this quantity is computable in closed-form in terms of key network parameters when the number of retransmissions is not restricted and the hops are assumed to be equally spaced on a line between the source and destination. We also derive the optimum number of hops and optimal per hop success probability and show that our result follows the well-known square root scaling law while providing exact expressions for the preconstants as well. Numerical results demonstrate that the upper bound is accurate for the purpose of determining the optimal hop count and success (or outage) probability.

  11. Thermalization through parton transport

    CERN Document Server

    Zhang, Bin

    2009-01-01

    A radiative transport model is used to study kinetic equilibration during the early stage of a relativistic heavy ion collision. The parton system is found to be able to overcome expansion and move toward thermalization via parton collisions. Scaling behaviors show up in both the pressure anisotropy and the energy density evolutions. In particular, the pressure anisotropy evolution shows an approximate alpha_s scaling when radiative processes are included. It approaches an asymptotic time evolution on a time scale of 1 to 2 fm/c. The energy density evolution shows an asymptotic time evolution that decreases slower than the ideal hydro evolution. These observations indicate that partial thermalization can be achieved and viscosity is important for the evolution during the early longitudinal expansion stage of a relativistic heavy ion collision.

  12. Skyrmions and Hall Transport

    Science.gov (United States)

    Kim, Bom Soo; Shapere, Alfred D.

    2016-09-01

    We derive a generalized set of Ward identities that captures the effects of topological charge on Hall transport. The Ward identities follow from the (2 +1 )-dimensional momentum algebra, which includes a central extension proportional to the topological charge density. In the presence of topological objects like Skyrmions, we observe that the central term leads to a direct relation between the thermal Hall conductivity and the topological charge density. We extend this relation to incorporate the effects of a magnetic field and an electric current. The topological charge density produces a distinct signature in the electric Hall conductivity, which is identified in existing experimental data and yields further novel predictions. For insulating materials with translation invariance, the Hall viscosity can be directly determined from the Skyrmion density and the thermal Hall conductivity to be measured as a function of momentum.

  13. Hydrogen transport membranes

    Science.gov (United States)

    Mundschau, Michael V.

    2005-05-31

    Composite hydrogen transport membranes, which are used for extraction of hydrogen from gas mixtures are provided. Methods are described for supporting metals and metal alloys which have high hydrogen permeability, but which are either too thin to be self supporting, too weak to resist differential pressures across the membrane, or which become embrittled by hydrogen. Support materials are chosen to be lattice matched to the metals and metal alloys. Preferred metals with high permeability for hydrogen include vanadium, niobium, tantalum, zirconium, palladium, and alloys thereof. Hydrogen-permeable membranes include those in which the pores of a porous support matrix are blocked by hydrogen-permeable metals and metal alloys, those in which the pores of a porous metal matrix are blocked with materials which make the membrane impervious to gases other than hydrogen, and cermets fabricated by sintering powders of metals with powders of lattice-matched ceramic.

  14. Nanoengineered membranes for controlled transport

    Science.gov (United States)

    Doktycz, Mitchel J [Oak Ridge, TN; Simpson, Michael L [Knoxville, TN; McKnight, Timothy E [Greenback, TN; Melechko, Anatoli V [Oak Ridge, TN; Lowndes, Douglas H [Knoxville, TN; Guillorn, Michael A [Knoxville, TN; Merkulov, Vladimir I [Oak Ridge, TN

    2010-01-05

    A nanoengineered membrane for controlling material transport (e.g., molecular transport) is disclosed. The membrane includes a substrate, a cover definining a material transport channel between the substrate and the cover, and a plurality of fibers positioned in the channel and connected to an extending away from a surface of the substrate. The fibers are aligned perpendicular to the surface of the substrate, and have a width of 100 nanometers or less. The diffusion limits for material transport are controlled by the separation of the fibers. In one embodiment, chemical derivitization of carbon fibers may be undertaken to further affect the diffusion limits or affect selective permeability or facilitated transport. For example, a coating can be applied to at least a portion of the fibers. In another embodiment, individually addressable carbon nanofibers can be integrated with the membrane to provide an electrical driving force for material transport.

  15. Benchmarking & European Sustainable Transport Policies

    DEFF Research Database (Denmark)

    Gudmundsson, H.

    2003-01-01

    , Benchmarking is one of the management tools that have recently been introduced in the transport sector. It is rapidly being applied to a wide range of transport operations, services and policies. This paper is a contribution to the discussion of the role of benchmarking in the future efforts...... to support Sustainable European Transport Policies. The key message is that transport benchmarking has not yet been developed to cope with the challenges of this task. Rather than backing down completely, the paper suggests some critical conditions for applying and adopting benchmarking for this purpose. One...... way forward is to ensure a higher level of environmental integration in transport policy benchmarking. To this effect the paper will discuss the possible role of the socalled Transport and Environment Reporting Mechanism developed by the European Environment Agency. The paper provides an independent...

  16. New transport and handling contract

    CERN Multimedia

    SC Department

    2008-01-01

    A new transport and handling contract entered into force on 1.10.2008. As with the previous contract, the user interface is the internal transport/handling request form on EDH: https://edh.cern.ch/Document/TransportRequest/ To ensure that you receive the best possible service, we invite you to complete the various fields as accurately as possible and to include a mobile telephone number on which we can reach you. You can follow the progress of your request (schedule, completion) in the EDH request routing information. We remind you that the following deadlines apply: 48 hours for the transport of heavy goods (up to 8 tonnes) or simple handling operations 5 working days for crane operations, transport of extra-heavy goods, complex handling operations and combined transport and handling operations in the tunnel. For all enquiries, the number to contact remains unchanged: 72202. Heavy Handling Section TS-HE-HH 72672 - 160319

  17. Electricity as Transportation ``Fuel''

    Science.gov (United States)

    Tamor, Michael

    2013-04-01

    The personal automobile is a surprisingly efficient device, but its place in a sustainable transportation future hinges on its ability use a sustainable fuel. While electricity is widely expected to be such a ``fuel,'' the viability of electric vehicles rests on the validity of three assumptions. First, that the emissions from generation will be significantly lower than those from competing chemical fuels whether `renewable' or fossil. Second, that advances in battery technology will deliver adequate range and durability at an affordable cost. Third, that most customers will accept any functional limitations intrinsic to electrochemical energy storage. While the first two are subjects of active research and vigorous policy debate, the third is treated virtually as a given. Popular statements to the effect that ``because 70% of all daily travel is accomplished in less than 100 miles, mass deployment of 100 mile EVs will electrify 70% of all travel'' are based on collections of one-day travel reports such as the National Household Travel Survey, and so effectively ignore the complexities of individual needs. We have analyzed the day-to-day variations of individual vehicle usage in multiple regions and draw very different conclusions. Most significant is that limited EV range results in a level of inconvenience that is likely to be unacceptable to the vast majority of vehicle owners, and for those who would accept that inconvenience, battery costs must be absurdly low to achieve any economic payback. In contrast, the plug-in hybrid (PHEV) does not suffer range limitations and delivers economic payback for most users at realistic battery costs. More importantly, these findings appear to be universal in developed nations, with labor market population density being a powerful predictor of personal vehicle usage. This ``scalable city'' hypothesis may prove to a powerful predictor of the evolution of transportation in the large cities of the developing world.

  18. Atomic transportation via carbon nanotubes.

    Science.gov (United States)

    Wang, Quan

    2009-01-01

    The transportation of helium atoms in a single-walled carbon nanotube is reported via molecular dynamics simulations. The efficiency of the atomic transportation is found to be dependent on the type of the applied loading and the loading rate as well as the temperature in the process. Simulations show the transportation is a result of the van der Waals force between the nanotube and the helium atoms through a kink propagation initiated in the nanotube.

  19. Transporting the first ATLAS toroid

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    The first coil for the ATLAS toroid magnet is transported from its assembly hall at the CERN Meyrin site to the storage hall above the ATLAS cavern. This involves driving the massive transportation vehicle first through the Meyrin site and then across a main road only metres from the France-Swiss border. Eight magnets in total will be transported in this way before being lowered into the experimental cavern where they will be mounted in a huge ring surrounding the detector.

  20. Transport methods for energetic particles

    Institute of Scientific and Technical Information of China (English)

    WuHong-Lu; YangChui-Hsu

    1997-01-01

    In order to estimate radiation risk assessment for astronaut's radiation safety in space activities.transport codes for high energy particles have been created.Two of the transport methods,perturbation and Green function methods,for high energy particles are reviewed in this paper,and some of the calculated results with the perturbation method are presented.Finally,the low energy transport in the regard of the biological effects by low energy ions in also briefly discussed.

  1. Transportation energy use in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Sheinbaum, C.; Meyers, S.; Sathaye, J.

    1994-07-01

    This report presents data on passenger travel and freight transport and analysis of the consequent energy use in Mexico during the 1970--1971 period. We describe changes in modal shares for passenger travel and freight transport, and analyze trends in the energy intensity of different modes. We look in more detail at transportation patterns, energy use, and the related environmental problems in the Mexico City Metropolitan Area, and also discuss policies that have been implemented there to reduce emissions from vehicles.

  2. Heat transport within the Earth

    CERN Document Server

    Herndon, J Marvin

    2011-01-01

    Numerous attempts have been made to interpret Earth's dynamic processes based upon heat transport concepts derived from ordinary experience. But, ordinary experience can be misleading, especially when underlain by false assumptions. Geodynamic considerations traditionally have embraced three modes of heat transport: conduction, convection, and radiation. Recently, I introduced a fourth, "mantle decompression thermal tsunami" that, I submit, is responsible for emplacing heat at the base of the Earth's crust. Here, I review thermal transport within the Earth and speculate that there might be a fifth mode: "heat channeling", involving heat transport from the core to "hot-spots" such as those that power the Hawaiian Islands and Iceland.

  3. Transportation Statistics Annual Report 1997

    Energy Technology Data Exchange (ETDEWEB)

    Fenn, M.

    1997-01-01

    This document is the fourth Transportation Statistics Annual Report (TSAR) prepared by the Bureau of Transportation Statistics (BTS) for the President and Congress. As in previous years, it reports on the state of U.S. transportation system at two levels. First, in Part I, it provides a statistical and interpretive survey of the system—its physical characteristics, its economic attributes, aspects of its use and performance, and the scale and severity of unintended consequences of transportation, such as fatalities and injuries, oil import dependency, and environment impacts. Part I also explores the state of transportation statistics, and new needs of the rapidly changing world of transportation. Second, Part II of the report, as in prior years, explores in detail the performance of the U.S. transportation system from the perspective of desired social outcomes or strategic goals. This year, the performance aspect of transportation chosen for thematic treatment is “Mobility and Access,” which complements past TSAR theme sections on “The Economic Performance of Transportation” (1995) and “Transportation and the Environment” (1996). Mobility and access are at the heart of the transportation system’s performance from the user’s perspective. In what ways and to what extent does the geographic freedom provided by transportation enhance personal fulfillment of the nation’s residents and contribute to economic advancement of people and businesses? This broad question underlies many of the topics examined in Part II: What is the current level of personal mobility in the United States, and how does it vary by sex, age, income level, urban or rural location, and over time? What factors explain variations? Has transportation helped improve people’s access to work, shopping, recreational facilities, and medical services, and in what ways and in what locations? How have barriers, such as age, disabilities, or lack of an automobile, affected these

  4. Charge transport in polymeric transistors

    Directory of Open Access Journals (Sweden)

    Alberto Salleo

    2007-03-01

    Full Text Available Polymeric semiconductors have attracted much attention because of their possible use as active materials in printed electronics. Thin-film transistors (TFTs are a convenient tool for studying charge-transport physics in conjugated polymers. Two families of materials are reviewed here: fluorene copolymers and polythiophenes. Because charge transport is highly anisotropic in molecular conductors, the electrical properties of conjugated polymers are strongly dependent on microstructure. Molecular weight, polydispersity, and regioregularity all affect morphology and charge-transport in these materials. Charge transport models based on microstructure are instrumental in identifying the electrical bottlenecks in these materials.

  5. The role of public transport

    Energy Technology Data Exchange (ETDEWEB)

    Bayliss, D. [London Transport, London (United Kingdom)

    1996-11-01

    This paper considers the types and scale of the contributions that public transport can make to sustainable personal mobility. It recognises that public transport actions must be part of a wider concerted effort if real progress is to be made in promoting sustainable mobility. Parallel actions will be needed in the areas of land use patterns, technology and activity patterns as well as other elements of transport planning and management. The energy efficiency, environmental impacts, space effects and mobility characteristics of the main forms of public transport are examined and related, where appropriate, to those of cars. (author) 1 fig., 11 tabs., refs.

  6. TRANSPORT AND EMPLACEMENT EQUIPMENT DESCRIPTIONS

    Energy Technology Data Exchange (ETDEWEB)

    NA

    1997-09-29

    The objective and the scope of this document are to list and briefly describe the major mobile equipment necessary for waste package (WP) Transport and Emplacement in the proposed subsurface nuclear waste repository at Yucca Mountain. Primary performance characteristics and some specialized design features of the equipment are explained and summarized in the individual subsections of this document. The Transport and Emplacement equipment described in this document consists of the following: (1) WP Transporter; (2) Reusable Rail Car; (3) Emplacement Gantry; (4) Gantry Carrier; and (5) Transport Locomotive.

  7. Technology Roadmaps: Biofuels for Transport

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Biofuels could provide up to 27% of total transport fuel worldwide by 2050. The use of transport fuels from biomass, when produced sustainably, can help cut petroleum use and reduce CO2 emissions in the transport sector, especially in heavy transport. Sustainable biofuel technologies, in particular advanced biofuels, will play an important role in achieving this roadmap vision. The roadmap describes the steps necessary to realise this ambitious biofuels target; identifies key actions by different stakeholders, and the role for government policy to adopt measures needed to ensure the sustainable expansion of both conventional and advanced biofuel production.

  8. Aluminum-activated Oxalate Secretion does not Associate with Internal Content among Some Oxalate Accumulators

    Institute of Scientific and Technical Information of China (English)

    Jian Li Yang; Lei Zhang; Shao Jian Zheng

    2008-01-01

    Although aluminum (AI)-activated secretion of oxalate has been considered to be an Important AI-exclusion mechanism,whether it is a general response in oxalate accumulators and related to oxalate content in roots are still not clear.Here,we examined the oxalate secretion and oxalate content in some oxalate accumulators,and investigated the role of oxalate secretion in AI resistance.When oxalate content in amaranth roots was decreased by about 50% with the increased ratio of NH4+-N to NO3——N in nutrient solution,the amount of AI-activated oxalate secretion still remained constant.There was no relationship between the content of the water soluble oxalate in four species of oxalate accumulators and the amount of the AI-activated oxalate secretion in roots.Furthermore,oxalate secretion is poorly associated with AI resistance among these species.Based on the above results,we concluded that although all of the oxalate accumulators tested could secrete oxalate rapidly,the density of anion channels in plasma membrane may play a more important role in AI-activated oxalate secretion.Key words: aluminum toxicity; Amaranthus; anion channel; oxalate accumulator; oxalate secretion.

  9. 殊异韦荣菌苹果酸脱氢酶的基因克隆及其重组蛋白的表达和活性测定%Cloning, the Recombinant Protein Expressing and the Activity of Malate Dehydrogenase Gene of Veillonella Dispar

    Institute of Scientific and Technical Information of China (English)

    刘晓红; 何钟勤; 孙晓宇; 高心; 薛莹; 李倪娜

    2013-01-01

    目的:对殊异韦荣菌(V·dispar)苹果酸脱氢酶(malate dehydrogenase,MDH)基因进行克隆和重组表达,并对其重组蛋白进行纯化和活性测定.方法:提取殊异韦荣菌基因组DNA,PCR扩增MDH同源区序列片段,克隆入pET-28a载体并转化至大肠杆菌DH5α,酶切及PCR鉴定,测序.将重组质粒转入BL21 (DE3)中,选择最佳表达条件,提纯及测定活性.结果:PCR扩增产物特异,全长1139 bp.测序结果包含MDH基因,并与GenBank中所报道的大肠杆菌MDH基因序列进行对比分析,其同源性为99%.MDH纯化后的蛋白活性值为0.4403 U/mL.结论:成功克隆殊异韦荣菌MDH基因,并通过基因序列和氨基酸分析证明其具有完整的阅读框架.还获得了重组表达MDH蛋白的最适表达条件,并测出韦荣菌苹果酸脱氢酶的活性.

  10. Chilling enhances the NAD levels and cytosolic malate dehydrogenase activity in diapause eggs of the silkworm, Bombyx mori%低温冷藏提高家蚕滞育卵 NAD 含量和胞质苹果酸脱氢酶活性

    Institute of Scientific and Technical Information of China (English)

    王启龙; 万华星; 姚金美; 司马杨虎; 赵林川

    2012-01-01

    为了调查5℃低温处理是否改变家蚕Bombyx mori卵滞育NAD代谢,本研究利用HPLC和分光光度法测定了经25℃和5℃分别处理的滞育卵中NADH含量、NAD+含量、乳酸脱氢酶(LDH)活性和胞质苹果酸脱氢酶(cMDH)活性.结果表明:5℃处理的NAD(NADH+NAD+)含量和cMDH活性分别增加了 106%和53%,并且 显著高于25℃处理(P<0.01);但是两种处理的NADH/NAD+比值和LDH活性没有显著差异(P>0.05).据此推测,5℃低温处理加强了家蚕滞育卵NAD+合成和再生能力.%To investigate whether chilling at 5℃ changes the metabolism of NAD in diapause eggs of the silkworm, Bombyx mori, the levels of NADH and NAD+ along with the activities of lactate dehydrogenase (LDH) and cytosolic malate dehydrogenase ( cMDH ) in diapause eggs incubated at 25℃ and 5℃ , respectively, were determined using HPLC and spectrophotometric methods. NAD (NADH + NAD+) levels and the cMDH activity in diapause eggs incubated at 5℃ increased by 106% and 53% , respectively, which were significantly higher than those in diapause eggs incubated at 25℃ (P 0.05 ). It is so inferred that the ability for NAD + synthesis and regeneration in Bombyx diapause eggs is enhanced by chilling.

  11. 亚洲牛带绦虫36kDa胞浆型苹果酸脱氢酶基因的表达、纯化及免疫学分析%The expression and purification of the 36 kDa cytoplasmic malate dehydrogenase gene in Taenia saginata asiatica and the immunologic analysis of the recombinant proteins

    Institute of Scientific and Technical Information of China (English)

    黄江; 胡旭初; 徐劲; 余新炳; 包怀恩; 郎书源; 廖兴江

    2008-01-01

    目的 对亚洲牛带绦虫胞浆型苹果酸脱氢酶基因(malate dehydrogenase,MDH)进行克隆、表达和免疫学研究.方法 将亚洲牛带绦虫成虫MDH克隆到原核表达质粒pET-30a(+)中.在大肠埃希菌BL-21/DE3中用IPTG诱导表达,表达产物通过十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)进行鉴定.用镍离子金属螯合剂亲和层析柱进行纯化,纯化的重组蛋白用蛋白印迹(Western Blotting)进行免疫学分析.结果 PCR、双酶切及DNA测序结果均表明pET-30a(+)-TaMDH重组质粒构建成功.SDS-PAGE结果表明目的基因在大肠埃希菌BL-21/DE3中获得高效表达,经亲和层析获得了商纯度蛋白.重组蛋白可被其免疫的SD大鼠血清识别,表明其具有免疫原性;并且能识别感染了亚洲牛带绦虫的猪血清.表明其具有免疫反应性.结论 亚洲牛带绦虫苹果酸脱氢酶基因可在原核表达系统中获得具有免疫学活性的高效表达,为进一步研究该蛋白的功能奠定了基础.

  12. Development of Regional Transport Logistics Terminal- Transport Logistics Approach

    Directory of Open Access Journals (Sweden)

    Peter Jenček

    2008-07-01

    Full Text Available Reaching decisions in the process of establishment and operationof a regional transport logistics terminal performingintermodal transport and related activities should be based onthe results of preliminary analysis. The selection of the appropriatelocation for the regional transport logistics terminal is ofcrucial importance as it affects directly and/or indirectly the initialfinancial investment, environmental and spatial issues aswell as terminal operating costs and commercial sustainability.In the decision-making process regarding the location ofintermodal terminals or with regard to building of a new regionalintermodal terminal at a specific location a thoroughtransport logistics analysis should be performed. The paperpresents the methodology developed for transport logisticsanalysis of regional intermodal transport logistics terminals,based on the sets of parameters, criteria and indicators whichenable the determination of the overall performance index for aparticular terminal location.

  13. Transportation System Concept of Operations

    Energy Technology Data Exchange (ETDEWEB)

    N. Slater-Thompson

    2006-08-16

    The Nuclear Waste Policy Act of 1982 (NWPA), as amended, authorized the DOE to develop and manage a Federal system for the disposal of SNF and HLW. OCRWM was created to manage acceptance and disposal of SNF and HLW in a manner that protects public health, safety, and the environment; enhances national and energy security; and merits public confidence. This responsibility includes managing the transportation of SNF and HLW from origin sites to the Repository for disposal. The Transportation System Concept of Operations is the core high-level OCRWM document written to describe the Transportation System integrated design and present the vision, mission, and goals for Transportation System operations. By defining the functions, processes, and critical interfaces of this system early in the system development phase, programmatic risks are minimized, system costs are contained, and system operations are better managed, safer, and more secure. This document also facilitates discussions and understanding among parties responsible for the design, development, and operation of the Transportation System. Such understanding is important for the timely development of system requirements and identification of system interfaces. Information provided in the Transportation System Concept of Operations includes: the functions and key components of the Transportation System; system component interactions; flows of information within the system; the general operating sequences; and the internal and external factors affecting transportation operations. The Transportation System Concept of Operations reflects OCRWM's overall waste management system policies and mission objectives, and as such provides a description of the preferred state of system operation. The description of general Transportation System operating functions in the Transportation System Concept of Operations is the first step in the OCRWM systems engineering process, establishing the starting point for the lower

  14. Effect of glutamine on the mRNA level of key enzymes of malate-aspartate shuttle in the rat intestine subjected to ischemia reperfusion Efeito da glutamina sobre o nível de RNA Mensageiro das enzimas-chave do ciclo malato-aspartato no intestino de ratos submetidos à isquemia e reperfusão

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Cavalcante de Vasconcelos

    2011-01-01

    Full Text Available PURPOSE: To determine the effects of oral L-glutamine (L-Gln and the dipeptide l-alanyl-glutamine (L-Ala-Gln upon the activity of the malate-aspartate shuttle in the rat distal small intestine following ischemia and reperfusion. METHODS: Seventy-two Wistar rats (350-400g, were randomized in 2 groups (n = 36: group S (Sham and Group T (Treatment and divided into 12 subgroups (n = 6: A-A6, and B1-B6. The subgroups A1-A3 were subjected to sham procedures at 30 and 60 minutes. Thirty minutes before the study, rats were treated with calcium caseinate, 0.5g/Kg (subgroups A1, A4, B1, B4, L-Gln, 0.5g / kg (subgroups A2, A5, B2 and B5 or L-Ala-Gln, 0.75g/Kg (subgroups A3, A6, B3, B6, administered by gavage. Ischemia was achieved by clamping the mesenteric vessels, delimiting a segment of bowel 5 cm long and 5 cm apart from the ileocecal valve. Samples were collected 30 and 60 minutes after start of the study for real-time PCR assay of malate dehydrogenases (MDH1-2 and aspartate-aminotransferases (GOT1-2 enzymes. RESULTS: Tissue MDH and GOT mRNA expression in intestinal samples from rats preconditioned with either L-Gln or L-Ala-Gln showed no significant differences both during ischemia and early reperfusion. CONCLUSION: Activation of the malate-aspartate shuttle system appears not to be the mechanism of glutamine-mediated elevation of glucose oxidation in rat intestine during ischemia/reperfusion injury.OBJETIVO: Determinar os efeitos da administração oral de L-glutamina (L-Gln e do dipeptídeo L-alanil-glutamina (L-Ala-Gln sobre a atividade do ciclo malato-aspartato no intestino delgado distal de ratos após isquemia/reperfusão. MÉTODOS: Setenta e dois ratos Wistar (350-400g foram randomizados em 2 grupos (n = 36: T grupo S (Sham e grupo (Tratamento e distribuídos em 12 subgrupos (n = 6: A-A6, e B1-B6. Os subgrupos A1-A3 foram submetidos a procedimentos "sham" aos 30 e 60 minutos. Trinta minutos antes do estudo, os ratos foram tratados com

  15. Correlation Analysis Between Single-Nucleotide Polymorphism of Malate Dehydrogenase Gene 5'-Flanking Region and Growth and Body Composition Traits in Chicken%鸡MD基因5'侧翼区多态性与鸡生长和体组成性状的相关研究

    Institute of Scientific and Technical Information of China (English)

    关洪英; 唐志权; 李辉

    2006-01-01

    苹果酸脱氢酶(Malate Dehydrogenase,MD)是一种氧化还原性酶,参与体内多种能量代谢反应.它可以催化苹果酸氧化脱羧生成丙酮酸和CO2,并使NADP+还原成NADPH,NADPH是脂肪酸合成所必需的载体,棕榈酸可以利用生成的NADPH来合成长链脂肪酸,MD的活性与脂肪酸合成效率之间存在密切的相关,MD也参与体内骨骼肌、心肌的能量代谢,并对肌纤维的生长有一定的调节作用.根据鸡MD基因的5侧翼区序列设计一对引物,用直接测序的方法在侧翼区检测多态性位点,在235bp(GenBank登录号:U49693)处发现一个SNP位点,此位点是一个限制性内切酶(SphⅠ酶)发生变化的位点.以东北农业大学高低脂双向选择系的第8世代肉鸡和东农F2资源群体为实验材料,用PCR-RFLP的方法进行基因型分析,建立适合的统计模型,进行基因型与生长和体组成性状的相关分析.结果表明:在高低脂系第8世代肉鸡中AA基因型个体的腹脂重和腹脂率显著高于BB基因型个体(P<0.05);BB基因型个体的大胸肌重和大胸肌率显著高于AA基因型个体(P<0.05).在东农F2资源家系中BB基因型个体的大胸肌重和大胸肌率显著高于AA和AB基因型个体(P<0.05);AA基因型个体的肝脏重和肝脏率显著高于BB基因型个体(P<0.05).综上所述,MD基因可能是影响鸡生长和体组成性状的主效基因或与控制生长和体组成性状的主效基因相连锁.%Malate dehydrogenase (MD) is a key enzyme that plays an important role in energy metabolism. It catalyzes the oxidative decarboxylation of L-malate to yield CO2 and pyruvate, while simultaneously generating NADPH from NADP+. The NADPH generated can be utilized in de novo synthesis of palmitate, which is the precursor molecule for the formation of other long-chain fatty acids.And high levels of MD will also activate muscle development.The current study was designed to investigate the effects of MD gene on growth

  16. Transport Costs and Rural Development

    OpenAIRE

    Maureen Kilkenny

    1995-01-01

    Can rural development be assisted by improving accessibility? This paper describes how transport costs condition the choices by firms and people to concentrate in cities or to spread out across agricultural hinterlands and considers the impacts of zero and relatively high agricultural transport costs.

  17. Local Transport Policy and Planning

    DEFF Research Database (Denmark)

    Hansen, Carsten Jahn

    The Ph. D. thesis describes and analyses how environmental obejctives and strategies have materialised in the real-life context of local transport policies and plans, how environmental perspectives have been picked up by policy makers concerned with transport issues, how policy and planning...

  18. Gradation effects in sediment transport

    NARCIS (Netherlands)

    de Meijer, RJ; Bosboom, J; Cloin, B; Katopodi, [No Value; Kitou, N; Koomans, RL; Manso, F

    2002-01-01

    To determine the effects of grain size and density gradation in oscillatory sheet-flow, experiments are conducted in an oscillating water tunnel. A formal derivation of a schematised transport model shows that the transport rates per sediment fraction can be determined with and without the assumptio

  19. Operational Control of Internal Transport

    NARCIS (Netherlands)

    J.R. van der Meer (Robert)

    2000-01-01

    textabstractOperational Control of Internal Transport considers the control of guided vehicles in vehicle-based internal transport systems found in facilities such as warehouses, production plants, distribution centers and transshipment terminals. The author's interest of research having direct use

  20. Sustainable Transport and Performance Indicators

    DEFF Research Database (Denmark)

    Gudmundsson, H.

    2004-01-01

    ustainable transport has become a major policy concern in recent years. The term suggests a need to consider transport in a comprehensive perspective including the well-being of both present and future generations, and taking environmental, social and economic issues into account. Indicators in f...

  1. Carrier transport uphill. I. General

    DEFF Research Database (Denmark)

    Rosenberg, T; Wilbrandt, W

    1963-01-01

    are worked out with respect to net transport rate, initial rate, unidirectional fluxes including back-flow through the pump, maximum accumulation ratio, competitive inhibition and acceleration, counter transport, and metabolic poisoning. The energetics of the system are treated. The fact that the system...

  2. IMPROVEMENT OF INTERNATIONAL WOOD TRANSPORTATION

    Directory of Open Access Journals (Sweden)

    Sokolov A. P.

    2014-10-01

    Full Text Available The article gives an example of usage of the tool for round-wood transport planning from the Decision Support System “Forest Logistic Toolset” for com-pare of two approaches to the organization of international wood transportation

  3. Goods Transport Modelling, Vol 1

    DEFF Research Database (Denmark)

    Petersen, Morten Steen (red.); Kristiansen, Jørgen

    The report is a study of data requirements and methodologies for goods transport. The study is intended to provide the basis for general discussion about the application of goods transport models in Denmark. The report provides an overview of different types of models and data availability....

  4. Glutamine transport in submitochondrial particles

    Energy Technology Data Exchange (ETDEWEB)

    Sastrasinh, S.; Sastrasinh, M.

    1989-12-01

    Glutamine transport was studied in submitochondrial particles (SMP) to avoid interference from glutamine metabolism. Phosphate-dependent glutaminase activity in SMP was only 0.04% of that in intact mitochondria. The uptake of glutamine in SMP represented both the transport into vesicles and membrane binding (about one-third of total uptake). Sulfhydryl reagents inhibited glutamine uptake in SMP. The uptake of L-({sup 3}H)glutamine increased more than twofold in SMP preloaded with 1 mM L-glutamine, an effect that was not seen with 1 mM D-glutamine. The uptake of L-({sup 3}H)glutamine was inhibited in the presence of either L-glutamine or L-alanine in the incubation medium. Other amino acids did not inhibit glutamine uptake. Alanine was also shown to trans-stimulate glutamine transport in SMP and cis-inhibit glutamine transport in both SMP and intact mitochondria. Glutamine transport showed a positive cooperativity effect with a Hill coefficient of 1.45. Metabolic acidosis increased the affinity of the transporter for glutamine without any change in other kinetic parameters. These data indicated that mitochondrial glutamine transport occurs via a specific carrier with multiple binding sites and that the transport of glutamine into mitochondria has an important role in increased ammoniagenesis during metabolic acidosis.

  5. Lithium transport across biological membranes

    DEFF Research Database (Denmark)

    Holstein-Rathlou, N H

    1990-01-01

    Li+ is actively transported out of cells, and across different epithelia of both mammalian and amphibian origin. Due to the low affinity of the Na+/K(+)-ATPase for Li+, the transport is most likely energized by exchange and/or cotransport processes. The detailed mechanism by which Li+ is reabsorb...

  6. Dipeptide transporters in Fusarium graminearum

    DEFF Research Database (Denmark)

    Droce, Aida; Giese, Henriette; Søndergaard, Teis;

    Fungi have evolved different transport mechanisms in order to utilize both inorganic and organic nitrogen sources because nitrogen availability often is one of the limiting factors in pathogenic processes. In this study we have characterized four di/tripeptide transporters in the necrotrophic plant...

  7. TRANSPORT OUT OF THE GREENHOUSE

    DEFF Research Database (Denmark)

    Transport emissions are growing, while climate targets are getting stricter: the gap is closing. We are rapidly approaching a future where transport could occupy or even exceed all of the ‘allowed’ CO2 emissions, if measures are not taken. Many potential climate policies and strategies...

  8. Transport and Sustainable Regional Development

    NARCIS (Netherlands)

    Nijkamp, Peter

    1995-01-01

    Transport plays a pivotal role in the dynamics of our society, not only in economic terms but also in a spatial setting. New driving forces such as technological progress, privatisation and deregulation exert a structuring impact on transport systems and on their related consequences induding enviro

  9. Photoinduced diffusion molecular transport

    Science.gov (United States)

    Rozenbaum, Viktor M.; Dekhtyar, Marina L.; Lin, Sheng Hsien; Trakhtenberg, Leonid I.

    2016-08-01

    We consider a Brownian photomotor, namely, the directed motion of a nanoparticle in an asymmetric periodic potential under the action of periodic rectangular resonant laser pulses which cause charge redistribution in the particle. Based on the kinetics for the photoinduced electron redistribution between two or three energy levels of the particle, the time dependence of its potential energy is derived and the average directed velocity is calculated in the high-temperature approximation (when the spatial amplitude of potential energy fluctuations is small relative to the thermal energy). The thus developed theory of photoinduced molecular transport appears applicable not only to conventional dichotomous Brownian motors (with only two possible potential profiles) but also to a much wider variety of molecular nanomachines. The distinction between the realistic time dependence of the potential energy and that for a dichotomous process (a step function) is represented in terms of relaxation times (they can differ on the time intervals of the dichotomous process). As shown, a Brownian photomotor has the maximum average directed velocity at (i) large laser pulse intensities (resulting in short relaxation times on laser-on intervals) and (ii) excited state lifetimes long enough to permit efficient photoexcitation but still much shorter than laser-off intervals. A Brownian photomotor with optimized parameters is exemplified by a cylindrically shaped semiconductor nanocluster which moves directly along a polar substrate due to periodically photoinduced dipole moment (caused by the repetitive excited electron transitions to a non-resonant level of the nanocylinder surface impurity).

  10. Tesseract supersonic business transport

    Science.gov (United States)

    Reshotko, Eli; Garbinski, Gary; Fellenstein, James; Botting, Mary; Hooper, Joan; Ryan, Michael; Struk, Peter; Taggart, Ben; Taillon, Maggie; Warzynski, Gary

    1992-01-01

    This year, the senior level Aerospace Design class at Case Western Reserve University developed a conceptual design of a supersonic business transport. Due to the growing trade between Asia and the United States, a transpacific range was chosen for the aircraft. A Mach number of 2.2 was chosen, too, because it provides reasonable block times and allows the use of a large range of materials without a need for active cooling. A payload of 2,500 lbs. was assumed corresponding to a complement of nine passengers and crew, plus some light cargo. With these general requirements set, the class was broken down into three groups. The aerodynamics of the aircraft were the responsibility of the first group. The second developed the propulsion system. The efforts of both the aerodynamics and propulsion groups were monitored and reviewed for weight considerations and structural feasibility by the third group. Integration of the design required considerable interaction between the groups in the final stages. The fuselage length of the final conceptual design was 107.0 ft, while the diameter of the fuselage was 7.6 ft. The delta wing design consisted of an aspect ratio of 1.9 with a wing span of 47.75 ft and mid-chord length of 61.0 ft. A SNECMA MCV 99 variable-cycle engine design was chosen for this aircraft.

  11. Tesseract: Supersonic business transport

    Science.gov (United States)

    Reshotko, Eli; Garbinski, Gary

    1992-01-01

    This year, the senior level Aerospace Design class at Case Western Reserve University developed a conceptual design of a supersonic business transport. Due to the growing trade between Asia and the United States, a transpacific range has been chosen for the aircraft. A Mach number of 2.2 was chosen too because it provides reasonable block times and allows the use of a large range of materials without a need for active cooling. A payload of 2500 lbs. has been assumed corresponding to a complement of nine (passengers and crew) plus some light cargo. With these general requirements set, the class was broken down into three groups. The aerodynamics of the aircraft were the responsibility of the first group. The second developed the propulsion system. The efforts of both the aerodynamics and propulsion groups were monitored and reviewed for weight considerations and structural feasibility by the third group. Integration of the design required considerable interaction between the groups in the final stages. The fuselage length of the final conceptual design was 107.0 ft. while the diameter of the fuselage was 7.6 ft. The delta wing design consisted of an aspect ratio of 1.9 with a wing span of 47.75 ft and midcord length of 61.0 ft. A SNEMCA MCV 99 variable-cycle engine design was chosen for this aircraft.

  12. Transport Protocol Throughput Fairness

    Directory of Open Access Journals (Sweden)

    Saleem Bhatti

    2009-11-01

    Full Text Available Interest continues to grow in alternative transport protocols to the Transmission Control Protocol (TCP. These alternatives include protocols designed to give greater efficiency in high-speed, high-delay environments (so-called high-speed TCP variants, and protocols that provide congestion control without reliability. For the former category, along with the deployed base of ‘vanilla’ TCP – TCP NewReno – the TCP variants BIC and CUBIC are widely used within Linux: for the latter category, the Datagram Congestion Control Protocol (DCCP is currently on the IETF Standards Track. It is clear that future traffic patterns will consist of a mix of flows from these protocols (and others. So, it is important for users and network operators to be aware of the impact that these protocols may have on users. We show the measurement of fairness in throughput performance of DCCP Congestion Control ID 2 (CCID2 relative to TCP NewReno, and variants Binary Increase Congestion control (BIC, CUBIC and Compound, all in “out-of-the box” configurations. We use a testbed and endto- end measurements to assess overall throughput, and also to assess fairness – how well these protocols might respond to each other when operating over the same end-to-end network path. We find that, in our testbed, DCCP CCID2 shows good fairness with NewReno, while BIC, CUBIC and Compound show unfairness above round-trip times of 25ms.

  13. Free Monotone Transport

    CERN Document Server

    Guionnet, A

    2012-01-01

    By solving a free analog of the Monge-Amp\\`ere equation, we prove a non-commutative analog of Brenier's monotone transport theorem: if an $n$-tuple of self-adjoint non-commutative random variables $Z_{1},...,Z_{n}$ satisfies a regularity condition (its conjugate variables $\\xi_{1},...,\\xi_{n}$ should be analytic in $Z_{1},...,Z_{n}$ and $\\xi_{j}$ should be close to $Z_{j}$ in a certain analytic norm), then there exist invertible non-commutative functions $F_{j}$ of an $n$-tuple of semicircular variables $S_{1},...,S_{n}$, so that $Z_{j}=F_{j}(S_{1},...,S_{n})$. Moreover, $F_{j}$ can be chosen to be monotone, in the sense that $F_{j}=\\mathscr{D}_{j}g$ and $g$ is a non-commutative function with a positive definite Hessian. In particular, we can deduce that $C^{*}(Z_{1},...,Z_{n})\\cong C^{*}(S_{1},...,S_{n})$ and $W^{*}(Z_{1},...,Z_{n})\\cong L(\\mathbb{F}(n))$. Thus our condition is a useful way to recognize when an $n$-tuple of operators generate a free group factor. We obtain as a consequence that the q-deforme...

  14. Towards Optimal Transport Networks

    Directory of Open Access Journals (Sweden)

    Erik P. Vargo

    2010-08-01

    Full Text Available Our ultimate goal is to design transportation net- works whose dynamic performance metrics (e.g. pas- senger throughput, passenger delay, and insensitivity to weather disturbances are optimized. Here the fo- cus is on optimizing static features of the network that are known to directly affect the network dynamics. First, we present simulation results which support a connection between maximizing the first non-trivial eigenvalue of a network's Laplacian and superior air- port network performance. Then, we explore the ef- fectiveness of a tabu search heuristic for optimizing this metric by comparing experimental results to the- oretical upper bounds. We also consider generating upper bounds on a network's algebraic connectivity via the solution of semidefinite programming (SDP relaxations. A modification of an existing subgraph extraction algorithm is implemented to explore the underlying regional structures in the U.S. airport net- work, with the hope that the resulting localized struc- tures can be optimized independently and reconnected via a "backbone" network to achieve superior network performance.

  15. SUBSURFACE EMPLACEMENT TRANSPORTATION SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    T. Wilson; R. Novotny

    1999-11-22

    The objective of this analysis is to identify issues and criteria that apply to the design of the Subsurface Emplacement Transportation System (SET). The SET consists of the track used by the waste package handling equipment, the conductors and related equipment used to supply electrical power to that equipment, and the instrumentation and controls used to monitor and operate those track and power supply systems. Major considerations of this analysis include: (1) Operational life of the SET; (2) Geometric constraints on the track layout; (3) Operating loads on the track; (4) Environmentally induced loads on the track; (5) Power supply (electrification) requirements; and (6) Instrumentation and control requirements. This analysis will provide the basis for development of the system description document (SDD) for the SET. This analysis also defines the interfaces that need to be considered in the design of the SET. These interfaces include, but are not limited to, the following: (1) Waste handling building; (2) Monitored Geologic Repository (MGR) surface site layout; (3) Waste Emplacement System (WES); (4) Waste Retrieval System (WRS); (5) Ground Control System (GCS); (6) Ex-Container System (XCS); (7) Subsurface Electrical Distribution System (SED); (8) MGR Operations Monitoring and Control System (OMC); (9) Subsurface Facility System (SFS); (10) Subsurface Fire Protection System (SFR); (11) Performance Confirmation Emplacement Drift Monitoring System (PCM); and (12) Backfill Emplacement System (BES).

  16. Sustainable transport studies in Asia

    CERN Document Server

    Zhang, Junyi

    2013-01-01

    This book aims to provide a good understanding of and perspective on sustainable transport in Asia by focusing on economic, environmental, and social sustainability. It is widely acknowledged that the current situation and trends in transport are not always sustainable in Asia, due in part to the fast-growing economy and the astounding speed of urbanization as well as least-mature governance. As essential research material, the book provides strong support for policy makers and planners by comprehensively covering three groups of strategies, characterized by the words “avoid” (e.g., urban form design and control of car ownership), “shift” (e.g., establishing comprehensive transportation systems and increasing public transportation systems for both intracity and intercity travel), and “improve” (e.g., redesign of paratransit system, low-emission vehicles, intelligent transportation systems, and eco-life). These are elaborated in the book alongside consideration of the uncertainty of policy effects ...

  17. Heat transport through atomic contacts.

    Science.gov (United States)

    Mosso, Nico; Drechsler, Ute; Menges, Fabian; Nirmalraj, Peter; Karg, Siegfried; Riel, Heike; Gotsmann, Bernd

    2017-02-06

    Heat transport and dissipation at the nanoscale severely limit the scaling of high-performance electronic devices and circuits. Metallic atomic junctions serve as model systems to probe electrical and thermal transport down to the atomic level as well as quantum effects that occur in one-dimensional (1D) systems. Whereas charge transport in atomic junctions has been studied intensively in the past two decades, heat transport remains poorly characterized because it requires the combination of a high sensitivity to small heat fluxes and the formation of stable atomic contacts. Here we report heat-transfer measurements through atomic junctions and analyse the thermal conductance of single-atom gold contacts at room temperature. Simultaneous measurements of charge and heat transport reveal the proportionality of electrical and thermal conductance, quantized with the respective conductance quanta. This constitutes a verification of the Wiedemann-Franz law at the atomic scale.

  18. SEDIMENT TRANSPORT EXPERIMENTSIN UNSTEADY FLOWS

    Institute of Scientific and Technical Information of China (English)

    DE SUTTER R.; HUYGENS M.; VERHOEVEN R.

    2001-01-01

    By means of a test flume with semi-circular cross-section, bedload and suspended-sediment transport of non-cohesive material have been studied in transient flow. The experimental facility enables us to investigate the time evolution of friction and transport parameters. Preliminary measurements with a fixed bottom instead of a sediment bed yield a reliable assessment of flow and friction characteristics. Time sequence in unsteady flow of the relevant parameters is revealed. The influence of turbulence variation and shear stress variation on the transport is investigated. As existing transport equations are found to be in poor agreement with experimental data, a new "engineering" concept is constructed which relates friction velocity to transport.

  19. Sediment transport under breaking waves

    DEFF Research Database (Denmark)

    Christensen, Erik Damgaard; Hjelmager Jensen, Jacob; Mayer, Stefan

    2000-01-01

    The sediment transport in the surf zone is modelled by combining a Navier-Stokes solver, a free surface model, a turbulence model, and a sediment transport model. The flow solver is based on the finite volume technique for non-orthogonal grids. The model is capable of simulating the turbulence...... generated at the surface where the wave breaks as well as the turbulence generated near the bed due to the wave-motion and the undertow. In general, the levels of turbulent kinetic energy are found to be higher than experiments show. This results in an over prediction of the sediment transport. Nevertheless......, some qualitative features have been modelled with success such as the onshore transport under plunging breakers and offshore transport under spilling breakers....

  20. Benchmarking and Sustainable Transport Policy

    DEFF Research Database (Denmark)

    Gudmundsson, Henrik; Wyatt, Andrew; Gordon, Lucy

    2004-01-01

    Order to learn from the best. In 2000 the European Commission initiated research to explore benchmarking as a tool to promote policies for ‘sustainable transport’. This paper reports findings and recommendations on how to address this challenge. The findings suggest that benchmarking is a valuable...... tool that may indeed help to move forward the transport policy agenda. However, there are major conditions and limitations. First of all it is not always so straightforward to delimit, measure and compare transport services in order to establish a clear benchmark. Secondly ‘sustainable transport......’ evokes a broad range of concerns that are hard to address fully at the level of specific practices. Thirdly policies are not directly comparable across space and context. For these reasons attempting to benchmark ‘sustainable transport policies’ against one another would be a highly complex task, which...