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Sample records for oxidase function cooperatively

  1. Reye's syndrome: salicylate and mitochondrial monoamine oxidase function

    International Nuclear Information System (INIS)

    Faraj, B.A.; Caplan, D.; Lolies, P.

    1986-01-01

    It has been suggested that aspirin is somehow linked with the onset of Reye's syndrome (RS). A general feature of Reye's syndrome is severe impairment of mitochondrial monoamine oxidase (MAO) function. The main objective of this investigation was to study the effect of salicylate on platelet mitochondrial MAO activity in three groups: group A (healthy children, n = 21) and group C (healthy adults, n = 10). Platelet MAO was measured by radio-enzymatic technique with 14 C-tyramine as a substrate. The results showed that salicyclate (10 mM) had a 20 to 60 percent inhibitory effect on platelet MAO function in only 1, 3 and 2 of the subjects in group A, B and C. Furthermore, there was an association between low enzyme activity and salicylate MAO inhibitory effect in these subjects. These preliminary findings suggest that salicylate may induce deterioration in mitochondrial function in susceptible individuals and that the assessment of salicylate MAO inhibitory effect may identify those who may be at risk to develop aspirin poisoning and Reye's syndrome

  2. Herbivore-plant interactions: mixed-function oxidases and secondary plant substances.

    Science.gov (United States)

    Brattsten, L B; Wilkinson, C F; Eisner, T

    1977-06-17

    The mixed-function oxidases of a polyphagous insect larva (the southern armyworm, Spodoptera eridania) were found to be induced by a diversity of secondary plant substances. The induction proceeds rapidly and in response to a small quantity of secondary substance. Following induction, the larva is less susceptible to dietary poisoning. It is argued that mixed-function oxidases play a major role in protecting herbivores against chemical stress from secondary plant substances.

  3. Functional Analysis of Polyphenol Oxidases by Antisense/Sense Technology

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    Jutharat Attajarusit

    2007-07-01

    Full Text Available Polyphenol oxidases (PPOs catalyze the oxidation of phenolics to quinones, the secondary reactions of which lead to oxidative browning and postharvest losses of many fruits and vegetables. PPOs are ubiquitous in angiosperms, are inducible by both biotic and abiotic stresses, and have been implicated in several physiological processes including plant defense against pathogens and insects, the Mehler reaction, photoreduction of molecular oxygen by PSI, regulation of plastidic oxygen levels, aurone biosynthesis and the phenylpropanoid pathway. Here we review experiments in which the roles of PPO in disease and insect resistance as well as in the Mehler reaction were investigated using transgenic tomato (Lycopersicon esculentum plants with modified PPO expression levels (suppressed PPO and overexpressing PPO. These transgenic plants showed normal growth, development and reproduction under laboratory, growth chamber and greenhouse conditions. Antisense PPO expression dramatically increased susceptibility while PPO overexpression increased resistance of tomato plants to Pseudomonas syringae. Similarly, PPO-overexpressing transgenic plants showed an increase in resistance to various insects, including common cutworm (Spodoptera litura (F., cotton bollworm (Helicoverpa armigera (Hübner and beet army worm (Spodoptera exigua (Hübner, whereas larvae feeding on plants with suppressed PPO activity had higher larval growth rates and consumed more foliage. Similar increases in weight gain, foliage consumption, and survival were also observed with Colorado potato beetles (Leptinotarsa decemlineata (Say feeding on antisense PPO transgenic tomatoes. The putative defensive mechanisms conferred by PPO and its interaction with other defense proteins are discussed. In addition, transgenic plants with suppressed PPO exhibited more favorable water relations and decreased photoinhibition compared to nontransformed controls and transgenic plants

  4. Biphenyl Modulates the Expression and Function of Respiratory Oxidases in the Polychlorinated-Biphenyls Degrader Pseudomonas pseudoalcaligenes KF707

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    Federica Sandri

    2017-06-01

    Full Text Available Pseudomonas pseudoalcaligenes KF707 is a soil bacterium which is known for its capacity to aerobically degrade harmful organic compounds such as polychlorinated biphenyls (PCBs using biphenyl as co-metabolite. Here we provide the first genetic and functional analysis of the KF707 respiratory terminal oxidases in cells grown with two different carbon sources: glucose and biphenyl. We identified five terminal oxidases in KF707: two c(caa3 type oxidases (Caa3 and Ccaa3, two cbb3 type oxidases (Cbb31 and Cbb32, and one bd type cyanide-insensitive quinol oxidase (CIO. While the activity and expression of both Cbb31 and Cbb32 oxidases was prevalent in glucose grown cells as compared to the other oxidases, the activity and expression of the Caa3 oxidase increased considerably only when biphenyl was used as carbon source in contrast to the Cbb32 oxidase which was repressed. Further, the respiratory activity and expression of CIO was up-regulated in a Cbb31 deletion strain as compared to W.T. whereas the CIO up-regulation was not present in Cbb32 and C(caa3 deletion mutants. These results, together, reveal that both function and expression of cbb3 and caa3 type oxidases in KF707 are modulated by biphenyl which is the co-metabolite needed for the activation of the PCBs-degradation pathway.

  5. Functional Assembly of Soluble and Membrane Recombinant Proteins of Mammalian NADPH Oxidase Complex.

    Science.gov (United States)

    Souabni, Hajer; Ezzine, Aymen; Bizouarn, Tania; Baciou, Laura

    2017-01-01

    Activation of phagocyte cells from an innate immune system is associated with a massive consumption of molecular oxygen to generate highly reactive oxygen species (ROS) as microbial weapons. This is achieved by a multiprotein complex, the so-called NADPH oxidase. The activity of phagocyte NADPH oxidase relies on an assembly of more than five proteins, among them the membrane heterodimer named flavocytochrome b 558 (Cytb 558 ), constituted by the tight association of the gp91 phox (also named Nox2) and p22 phox proteins. The Cytb 558 is the membrane catalytic core of the NADPH oxidase complex, through which the reducing equivalent provided by NADPH is transferred via the associated prosthetic groups (one flavin and two hemes) to reduce dioxygen into superoxide anion. The other major proteins (p47 phox , p67 phox , p40 phox , Rac) requisite for the complex activity are cytosolic proteins. Thus, the NADPH oxidase functioning relies on a synergic multi-partner assembly that in vivo can be hardly studied at the molecular level due to the cell complexity. Thus, a cell-free assay method has been developed to study the NADPH oxidase activity that allows measuring and eventually quantifying the ROS generation based on optical techniques following reduction of cytochrome c. This setup is a valuable tool for the identification of protein interactions, of crucial components and additives for a functional enzyme. Recently, this method was improved by the engineering and the production of a complete recombinant NADPH oxidase complex using the combination of purified proteins expressed in bacterial and yeast host cells. The reconstitution into artificial membrane leads to a fully controllable system that permits fine functional studies.

  6. Functional heterogeneity of NADPH oxidase-mediated contractions to endothelin with vascular aging.

    Science.gov (United States)

    Meyer, Matthias R; Barton, Matthias; Prossnitz, Eric R

    2014-11-24

    Aging, a physiological process and main risk factor for cardiovascular and renal diseases, is associated with endothelial cell dysfunction partly resulting from NADPH oxidase-dependent oxidative stress. Because increased formation of endothelium-derived endothelin-1 (ET-1) may contribute to vascular aging, we studied the role of NADPH oxidase function in age-dependent contractions to ET-1. Renal arteries and abdominal aortas from young and old C57BL6 mice (4 and 24 months of age) were prepared for isometric force measurements. Contractions to ET-1 (0.1-100 nmol/L) were determined in the presence and absence of the NADPH oxidase-selective inhibitor gp91ds-tat (3 μmol/L). To exclude age-dependent differential effects of NO bioactivity between vascular beds, all experiments were conducted in the presence of the NO synthase inhibitor L-NAME (300 μmol/L). In young animals, ET-1-induced contractions were 6-fold stronger in the renal artery than in the aorta (prenal artery and aorta, respectively (pAging had no effect on NADPH oxidase-dependent and -independent contractions to ET-1 in the renal artery. In contrast, contractions to ET-1 were markedly reduced in the aged aorta (5-fold, page-dependent heterogeneity of NADPH oxidase-mediated vascular contractions to ET-1, demonstrating an inherent resistance to functional changes in the renal artery but not in the aorta with aging. Thus, local activity of NADPH oxidase differentially modulates responses to ET-1 with aging in distinct vascular beds. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Glucose oxidase-functionalized fluorescent gold nanoclusters as probes for glucose

    International Nuclear Information System (INIS)

    Xia, Xiaodong; Long, Yunfei; Wang, Jianxiu

    2013-01-01

    Highlights: ► A glucose oxidase/gold nanocluster conjugates formed by etching chemistry. ► Integration of the bioactivities and fluorescence properties within a single unit. ► These conjugates serve as novel fluorescent probe for glucose. -- Abstract: Creation and application of noble metal nanoclusters have received continuous attention. By integrating enzyme activity and fluorescence for potential applications, enzyme-capped metal clusters are more desirable. This work demonstrated a glucose oxidase (an enzyme for glucose)-functionalized gold cluster as probe for glucose. Under physiological conditions, such bioconjugate was successfully prepared by an etching reaction, where tetrakis (hydroxylmethyl) phosphonium-protected gold nanoparticle and thioctic acid-modified glucose oxidase were used as precursor and etchant, respectively. These bioconjugates showed unique fluorescence spectra (λ em max = 650 nm, λ ex max = 507 nm) with an acceptable quantum yield (ca. 7%). Moreover, the conjugated glucose oxidase remained active and catalyzed reaction of glucose and dissolved O 2 to produce H 2 O 2 , which quenched quantitatively the fluorescence of gold clusters and laid a foundation of glucose detection. A linear range of 2.0 × 10 −6 –140 × 10 −6 M and a detection limit of 0.7 × 10 −6 M (S/N = 3) were obtained. Also, another horseradish peroxidase/gold cluster bioconjugate was produced by such general synthesis method. Such enzyme/metal cluster bioconjugates represented a promising class of biosensors for biologically important targets in organelles or cells

  8. Evolutionary origin and function of NOX4-art, an arthropod specific NADPH oxidase

    OpenAIRE

    Gandara, Ana Caroline Paiva; Torres, Andr?; Bahia, Ana Cristina; Oliveira, Pedro L.; Schama, Renata

    2017-01-01

    Background NADPH oxidases (NOX) are ROS producing enzymes that perform essential roles in cell physiology, including cell signaling and antimicrobial defense. This gene family is present in most eukaryotes, suggesting a common ancestor. To date, only a limited number of phylogenetic studies of metazoan NOXes have been performed, with few arthropod genes. In arthropods, only NOX5 and DUOX genes have been found and a gene called NOXm was found in mosquitoes but its origin and function has not b...

  9. Direct electrochemistry and electrocatalysis of a glucose oxidase-functionalized bioconjugate as a trace label for ultrasensitive detection of thrombin.

    Science.gov (United States)

    Bai, Lijuan; Yuan, Ruo; Chai, Yaqin; Yuan, Yali; Wang, Yan; Xie, Shunbi

    2012-11-18

    For the first time, a glucose oxidase-functionalized bioconjugate was prepared and served as a new trace label through its direct electrochemistry and electrocatalysis in a sandwich-type electrochemical aptasensor for ultrasensitive detection of thrombin.

  10. Glucose oxidase-functionalized fluorescent gold nanoclusters as probes for glucose

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Xiaodong [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Long, Yunfei, E-mail: l_yunfei927@163.com [School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Wang, Jianxiu, E-mail: jxiuwang@csu.edu.cn [College of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China)

    2013-04-15

    Highlights: ► A glucose oxidase/gold nanocluster conjugates formed by etching chemistry. ► Integration of the bioactivities and fluorescence properties within a single unit. ► These conjugates serve as novel fluorescent probe for glucose. -- Abstract: Creation and application of noble metal nanoclusters have received continuous attention. By integrating enzyme activity and fluorescence for potential applications, enzyme-capped metal clusters are more desirable. This work demonstrated a glucose oxidase (an enzyme for glucose)-functionalized gold cluster as probe for glucose. Under physiological conditions, such bioconjugate was successfully prepared by an etching reaction, where tetrakis (hydroxylmethyl) phosphonium-protected gold nanoparticle and thioctic acid-modified glucose oxidase were used as precursor and etchant, respectively. These bioconjugates showed unique fluorescence spectra (λ{sub em} {sub max} = 650 nm, λ{sub ex} {sub max} = 507 nm) with an acceptable quantum yield (ca. 7%). Moreover, the conjugated glucose oxidase remained active and catalyzed reaction of glucose and dissolved O{sub 2} to produce H{sub 2}O{sub 2}, which quenched quantitatively the fluorescence of gold clusters and laid a foundation of glucose detection. A linear range of 2.0 × 10{sup −6}–140 × 10{sup −6} M and a detection limit of 0.7 × 10{sup −6} M (S/N = 3) were obtained. Also, another horseradish peroxidase/gold cluster bioconjugate was produced by such general synthesis method. Such enzyme/metal cluster bioconjugates represented a promising class of biosensors for biologically important targets in organelles or cells.

  11. Activity and functional interaction of alternative oxidase and uncoupling protein in mitochondria from tomato fruit

    Directory of Open Access Journals (Sweden)

    F.E. Sluse

    2000-03-01

    Full Text Available Cyanide-resistant alternative oxidase (AOX is not limited to plant mitochondria and is widespread among several types of protists. The uncoupling protein (UCP is much more widespread than previously believed, not only in tissues of higher animals but also in plants and in an amoeboid protozoan. The redox energy-dissipating pathway (AOX and the proton electrochemical gradient energy-dissipating pathway (UCP lead to the same final effect, i.e., a decrease in ATP synthesis and an increase in heat production. Studies with green tomato fruit mitochondria show that both proteins are present simultaneously in the membrane. This raises the question of a specific physiological role for each energy-dissipating system and of a possible functional connection between them (shared regulation. Linoleic acid, an abundant free fatty acid in plants which activates UCP, strongly inhibits cyanide-resistant respiration mediated by AOX. Moreover, studies of the evolution of AOX and UCP protein expression and of their activities during post-harvest ripening of tomato fruit show that AOX and plant UCP work sequentially: AOX activity decreases in early post-growing stages and UCP activity is decreased in late ripening stages. Electron partitioning between the alternative oxidase and the cytochrome pathway as well as H+ gradient partitioning between ATP synthase and UCP can be evaluated by the ADP/O method. This method facilitates description of the kinetics of energy-dissipating pathways and of ATP synthase when state 3 respiration is decreased by limitation of oxidizable substrate.

  12. Molecular mechanisms of the microsomal mixed function oxidases and biological and pathological implications

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    Arthur I. Cederbaum

    2015-04-01

    Full Text Available The cytochrome P450 mixed function oxidase enzymes play a major role in the metabolism of important endogenous substrates as well as in the biotransformation of xenobiotics. The liver P450 system is the most active in metabolism of exogenous substrates. This review briefly describes the liver P450 (CYP mixed function oxidase system with respect to its enzymatic components and functions. Electron transfer by the NADPH-P450 oxidoreductase is required for reduction of the heme of P450, necessary for binding of molecular oxygen. Binding of substrates to P450 produce substrate binding spectra. The P450 catalytic cycle is complex and rate-limiting steps are not clear. Many types of chemical reactions can be catalyzed by P450 enzymes, making this family among the most diverse catalysts known. There are multiple forms of P450s arranged into families based on structural homology. The major drug metabolizing CYPs are discussed with respect to typical substrates, inducers and inhibitors and their polymorphic forms. The composition of CYPs in humans varies considerably among individuals because of sex and age differences, the influence of diet, liver disease, presence of potential inducers and/or inhibitors. Because of such factors and CYP polymorphisms, and overlapping drug specificity, there is a large variability in the content and composition of P450 enzymes among individuals. This can result in large variations in drug metabolism by humans and often can contribute to drug–drug interactions and adverse drug reactions. Because of many of the above factors, especially CYP polymorphisms, there has been much interest in personalized medicine especially with respect to which CYPs and which of their polymorphic forms are present in order to attempt to determine what drug therapy and what dosage would reflect the best therapeutic strategy in treating individual patients.

  13. Neural correlates of social cooperation and non-cooperation as a function of psychopathy.

    Science.gov (United States)

    Rilling, James K; Glenn, Andrea L; Jairam, Meeta R; Pagnoni, Giuseppe; Goldsmith, David R; Elfenbein, Hanie A; Lilienfeld, Scott O

    2007-06-01

    Psychopathy is a disorder involving a failure to experience many emotions that are necessary for appropriate social behavior. In this study, we probed the behavioral, emotional, and neural correlates of psychopathic traits within the context of a dyadic social interaction. Thirty subjects were imaged with functional magnetic resonance imaging while playing an iterated Prisoner's Dilemma game with human confederates who were outside the scanner. Subjects also completed two self-report psychopathy questionnaires. Subjects scoring higher on psychopathy, particularly males, defected more often and were less likely to continue cooperating after establishing mutual cooperation with a partner. Further, they experienced more outcomes in which their cooperation was not reciprocated (cooperate-defect outcome). After such outcomes, subjects scoring high in psychopathy showed less amygdala activation, suggesting weaker aversive conditioning to those outcomes. Compared with low-psychopathy subjects, subjects higher in psychopathy also showed weaker activation within orbitofrontal cortex when choosing to cooperate and showed weaker activation within dorsolateral prefrontal and rostral anterior cingulate cortex when choosing to defect. These findings suggest that whereas subjects scoring low on psychopathy have emotional biases toward cooperation that can only be overcome with effortful cognitive control, subjects scoring high on psychopathy have an opposing bias toward defection that likewise can only be overcome with cognitive effort.

  14. Estrogen inhibits lysyl oxidase and decreases mechanical function in engineered ligaments.

    Science.gov (United States)

    Lee, Cassandra A; Lee-Barthel, Ann; Marquino, Louise; Sandoval, Natalie; Marcotte, George R; Baar, Keith

    2015-05-15

    Women are more likely to suffer an anterior cruciate ligament (ACL) rupture than men, and the incidence of ACL rupture in women rises with increasing estrogen levels. We used an engineered ligament model to determine how an acute rise in estrogen decreases the mechanical properties of ligaments. Using fibroblasts isolated from human ACLs from male or female donors, we engineered ligaments and determined that ligaments made from female ACL cells had more collagen and were equal in strength to those made from male ACL cells. We then treated engineered ligaments for 14 days with low (5 pg/ml), medium (50 pg/ml), or high (500 pg/ml) estrogen, corresponding to the range of in vivo serum estrogen concentrations and found that collagen within the grafts increased without a commensurate increase in mechanical strength. Mimicking the menstrual cycle, with 12 days of low estrogen followed by 2 days of physiologically high estrogen, resulted in a decrease in engineered ligament mechanical function with no change in the amount of collagen in the graft. The decrease in mechanical stiffness corresponded with a 61.7 and 76.9% decrease in the activity of collagen cross-linker lysyl oxidase with 24 and 48 h of high estrogen, respectively. Similarly, grafts treated with the lysyl oxidase inhibitor β-aminoproprionitrile (BAPN) for 24 h showed a significant decrease in ligament mechanical strength [control (CON) = 1.58 ± 0.06 N; BAPN = 1.06 ± 0.13 N] and stiffness (CON = 7.7 ± 0.46 MPa; BAPN = 6.1 ± 0.71 MPa) without changing overall collagen levels (CON = 396 ± 11.5 μg; BAPN = 382 ± 11.6 μg). Together, these data suggest that the rise in estrogen during the follicular phase decreases lysyl oxidase activity in our engineered ligament model and if this occurs in vivo may decrease the stiffness of ligaments and contribute to the elevated rate of ACL rupture in women. Copyright © 2015 the American Physiological Society.

  15. Inducible bilirubin oxidase: A novel function for the mouse cytochrome P450 2A5

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Bakar, A' edah, E-mail: a.abubakar@uq.edu.au [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Arthur, Dionne Maioha [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide (Australia); Aganovic, Simona [Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Centre, Box 578, S-751 23 Uppsala (Sweden); Ng, Jack C. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Adelaide (Australia); Lang, Matti A. [The University of Queensland, National Research Centre for Environmental Toxicology (Entox), 4072 Brisbane, Queensland (Australia); Department of Pharmaceutical Biosciences, Uppsala University, Biomedical Centre, Box 578, S-751 23 Uppsala (Sweden)

    2011-11-15

    We have previously shown that bilirubin (BR), a breakdown product of haem, is a strong inhibitor and a high affinity substrate of the mouse cytochrome P450 2A5 (CYP2A5). The antioxidant BR, which is cytotoxic at high concentrations, is potentially useful in cellular protection against oxygen radicals if its intracellular levels can be strictly controlled. The mechanisms that regulate cellular BR levels are still obscure. In this paper we provide preliminary evidence for a novel function of CYP2A5 as hepatic 'BR oxidase'. A high-performance liquid chromatography/electrospray ionisation mass spectrometry screening showed that recombinant yeast microsomes expressing the CYP2A5 oxidise BR to biliverdin, as the main metabolite, and to three other smaller products with m/z values of 301, 315 and 333. The metabolic profile is significantly different from that of chemical oxidation of BR. In chemical oxidation the smaller products were the main metabolites. This suggests that the enzymatic reaction is selective, towards biliverdin production. Bilirubin treatment of primary hepatocytes increased the CYP2A5 protein and activity levels with no effect on the corresponding mRNA. Co-treatment with cycloheximide (CHX), a protein synthesis inhibitor, resulted in increased half-life of the CYP2A5 compared to cells treated only with CHX. Collectively, the observations suggest that the CYP2A5 is potentially an inducible 'BR oxidase' where BR may accelerate its own metabolism through stabilization of the CYP2A5 protein. It is possible that this metabolic pathway is potentially part of the machinery controlling intracellular BR levels in transient oxidative stress situations, in which high amounts of BR are produced. -- Highlights: Black-Right-Pointing-Pointer CYP2A5 metabolizes bilirubin to biliverdin and dipyrroles. Black-Right-Pointing-Pointer Bilirubin increased the hepatic CYP2A5 protein and activity levels. Black-Right-Pointing-Pointer Bilirubin does not

  16. Mixed function oxidase dependent biotransformation of polychlorinated biphenyls by different species of fish from the North Sea

    DEFF Research Database (Denmark)

    Mehrtens, G.; Laturnus, F.

    1999-01-01

    Mixed function oxidase (MFO) dependent biotransformation of polychlorinated biphenyls (PCBs) was measured in three different fish species from the North Sea. Liver microsomes of plaice (Pleuronectes platessa), dab (Limanda limanda) and cod (Gadus morhua) were isolated and incubated with different....... Biotransformations were also species dependent. The flatfish dab and plaice exhibited higher metabolic rates than cod (C) 1999 Elsevier Science Ltd. All rights reserved....

  17. Functional expression of amine oxidase from Aspergillus niger (AO-I) in Saccharomyces cerevisiae.

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    Kolaríková, Katerina; Galuszka, Petr; Sedlárová, Iva; Sebela, Marek; Frébort, Ivo

    2009-01-01

    The aim of this work was to prepare recombinant amine oxidase from Aspergillus niger after overexpressing in yeast. The yeast expression vector pDR197 that includes a constitutive PMA1 promoter was used for the expression in Saccharomyces cerevisiae. Recombinant amine oxidase was extracted from the growth medium of the yeast, purified to homogeneity and identified by activity assay and MALDI-TOF peptide mass fingerprinting. Similarity search in the newly published A. niger genome identified six genes coding for copper amine oxidase, two of them corresponding to the previously described enzymes AO-I a methylamine oxidase and three other genes coding for FAD amine oxidases. Thus, A. niger possesses an enormous metabolic gear to grow on amine compounds and thus support its saprophytic lifestyle.

  18. Cooperative catalysis by silica-supported organic functional groups

    OpenAIRE

    Margelefsky, Eric L.; Zeidan, Ryan K.; Davis, Mark E.

    2008-01-01

    Hybrid inorganic–organic materials comprising organic functional groups tethered from silica surfaces are versatile, heterogeneous catalysts. Recent advances have led to the preparation of silica materials containing multiple, different functional groups that can show cooperative catalysis; that is, these functional groups can act together to provide catalytic activity and selectivity superior to what can be obtained from either monofunctional materials or homogeneous catalysts. This tutorial...

  19. Luminol, horseradish peroxidase, and glucose oxidase ternary functionalized graphene oxide for ultrasensitive glucose sensing.

    Science.gov (United States)

    Li, Fang; Ma, Wenjing; Liu, Jiachang; Wu, Xiang; Wang, Yan; He, Jianbo

    2018-01-01

    Luminol, horseradish peroxidase (HRP), and glucose oxidase (GOx) ternary functionalized graphene oxide (HRP/GOx-luminol-GO) with excellent chemiluminescence (CL) activity and specific enzymatic property was prepared via a simple and general strategy for the first time. In this approach, luminol functionalized GO (luminol-GO) was prepared by gently stirring GO with luminol. Then HRP and GOx were further co-immobilized onto the surface of luminol-GO by storing HRP and GOx with luminol-GO at 4 °C overnight, to form HRP/GOx-luminol-GO bionanocomposites. The synthesized HRP/GOx-luminol-GO could react with H 2 O 2 generated from GOx catalyzed glucose oxidization reaction, to produce strong CL emission in the presence of co-immobilized HRP. Thus, we developed an ultrasensitive, homogeneous, reagentless, selective, and simple CL sensing system for glucose detection. The resulting biosensors exhibited ultra-wide linear range from 5.0 nM to 5.0 mM, and an ultra-low detection limit of 1.2 nM, which was more than 3 orders of magnitude lower than previously reported methods. Furthermore, the sensing system was successfully applied for the detection of glucose in human blood samples.

  20. Cloning and Functional Analysis of the Promoter of an Ascorbate Oxidase Gene from Gossypium hirsutum.

    Directory of Open Access Journals (Sweden)

    Shan Xin

    Full Text Available Apoplastic ascorbate oxidase (AO plays significant roles in plant cell growth. However, the mechanism of underlying the transcriptional regulation of AO in Gossypium hirsutum remains unclear. Here, we obtained a 1,920-bp promoter sequence from the Gossypium hirsutum ascorbate oxidase (GhAO1 gene, and this GhAO1 promoter included a number of known cis-elements. Promoter activity analysis in overexpressing pGhAO1::GFP-GUS tobacco (Nicotiana benthamiana showed that the GhAO1 promoter exhibited high activity, driving strong reporter gene expression in tobacco trichomes, leaves and roots. Promoter 5'-deletion analysis demonstrated that truncated GhAO1 promoters with serial 5'-end deletions had different GUS activities. A 360-bp fragment was sufficient to activate GUS expression. The P-1040 region had less GUS activity than the P-720 region, suggesting that the 320-bp region from nucleotide -720 to -1040 might include a cis-element acting as a silencer. Interestingly, an auxin-responsive cis-acting element (TGA-element was uncovered in the promoter. To analyze the function of the TGA-element, tobacco leaves transformed with promoters with different 5' truncations were treated with indole-3-acetic acid (IAA. Tobacco leaves transformed with the promoter regions containing the TGA-element showed significantly increased GUS activity after IAA treatment, implying that the fragment spanning nucleotides -1760 to -1600 (which includes the TGA-element might be a key component for IAA responsiveness. Analyses of the AO promoter region and AO expression pattern in Gossypium arboreum (Ga, diploid cotton with an AA genome, Gossypium raimondii (Gr, diploid cotton with a DD genome and Gossypium hirsutum (Gh, tetraploid cotton with an AADD genome indicated that AO promoter activation and AO transcription were detected together only in D genome/sub-genome (Gr and Gh cotton. Taken together, these results suggest that the 1,920-bp GhAO1 promoter is a functional sequence

  1. Cloning and Functional Analysis of the Promoter of an Ascorbate Oxidase Gene from Gossypium hirsutum.

    Science.gov (United States)

    Xin, Shan; Tao, Chengcheng; Li, Hongbin

    2016-01-01

    Apoplastic ascorbate oxidase (AO) plays significant roles in plant cell growth. However, the mechanism of underlying the transcriptional regulation of AO in Gossypium hirsutum remains unclear. Here, we obtained a 1,920-bp promoter sequence from the Gossypium hirsutum ascorbate oxidase (GhAO1) gene, and this GhAO1 promoter included a number of known cis-elements. Promoter activity analysis in overexpressing pGhAO1::GFP-GUS tobacco (Nicotiana benthamiana) showed that the GhAO1 promoter exhibited high activity, driving strong reporter gene expression in tobacco trichomes, leaves and roots. Promoter 5'-deletion analysis demonstrated that truncated GhAO1 promoters with serial 5'-end deletions had different GUS activities. A 360-bp fragment was sufficient to activate GUS expression. The P-1040 region had less GUS activity than the P-720 region, suggesting that the 320-bp region from nucleotide -720 to -1040 might include a cis-element acting as a silencer. Interestingly, an auxin-responsive cis-acting element (TGA-element) was uncovered in the promoter. To analyze the function of the TGA-element, tobacco leaves transformed with promoters with different 5' truncations were treated with indole-3-acetic acid (IAA). Tobacco leaves transformed with the promoter regions containing the TGA-element showed significantly increased GUS activity after IAA treatment, implying that the fragment spanning nucleotides -1760 to -1600 (which includes the TGA-element) might be a key component for IAA responsiveness. Analyses of the AO promoter region and AO expression pattern in Gossypium arboreum (Ga, diploid cotton with an AA genome), Gossypium raimondii (Gr, diploid cotton with a DD genome) and Gossypium hirsutum (Gh, tetraploid cotton with an AADD genome) indicated that AO promoter activation and AO transcription were detected together only in D genome/sub-genome (Gr and Gh) cotton. Taken together, these results suggest that the 1,920-bp GhAO1 promoter is a functional sequence with a

  2. D-Amino acid oxidase bio-functionalized platforms: Toward an enhanced enzymatic bio-activity

    Science.gov (United States)

    Herrera, Elisa; Valdez Taubas, Javier; Giacomelli, Carla E.

    2015-11-01

    The purpose of this work is to study the adsorption process and surface bio-activity of His-tagged D-amino acid oxidase (DAAO) from Rhodotorula gracilis (His6-RgDAAO) as the first step for the development of an electrochemical bio-functionalized platform. With such a purpose this work comprises: (a) the His6-RgDAAO bio-activity in solution determined by amperometry, (b) the adsorption mechanism of His6-RgDAAO on bare gold and carboxylated modified substrates in the absence (substrate/COO-) and presence of Ni(II) (substrate/COO- + Ni(II)) determined by reflectometry, and (c) the bio-activity of the His6-RgDAAO bio-functionalized platforms determined by amperometry. Comparing the adsorption behavior and bio-activity of His6-RgDAAO on these different solid substrates allows understanding the contribution of the diverse interactions responsible for the platform performance. His6-RgDAAO enzymatic performance in solution is highly improved when compared to the previously used pig kidney (pk) DAAO. His6-RgDAAO exhibits an amperometrically detectable bio-activity at concentrations as low as those expected on a bio-functional platform; hence, it is a viable bio-recognition element of D-amino acids to be coupled to electrochemical platforms. Moreover, His6-RgDAAO bio-functionalized platforms exhibit a higher surface activity than pkDAAO physically adsorbed on gold. The platform built on Ni(II) modified substrates present enhanced bio-activity because the surface complexes histidine-Ni(II) provide with site-oriented, native-like enzymes. The adsorption mechanism responsible of the excellent performance of the bio-functionalized platform takes place in two steps involving electrostatic and bio-affinity interactions whose prevalence depends on the degree of surface coverage.

  3. A structural and functional model for the 1-aminocyclopropane-1-carboxylic acid oxidase.

    Science.gov (United States)

    Sallmann, Madleen; Oldenburg, Fabio; Braun, Beatrice; Réglier, Marius; Simaan, A Jalila; Limberg, Christian

    2015-10-12

    The hitherto most realistic low-molecular-weight analogue for the 1-aminocyclopropane-1-carboxylic acid oxidase (ACCO) is reported. The ACCOs 2-His-1-carboxylate iron(II) active site was mimicked by a TpFe moiety, to which the natural substrate ACC could be bound. The resulting complex [Tp(Me,Ph) FeACC] (1), according to X-ray diffraction analysis performed for the nickel analogue, represents an excellent structural model, featuring ACC coordinated in a bidentate fashion-as proposed for the enzymatic substrate complex-as well as a vacant coordination site that forms the basis for the first successful replication also of the ACCO function: 1 is the first known ACC complex that reacts with O2 to produce ethylene. As a FeOOH species had been suggested as intermediate in the catalytic cycle, H2 O2 was tested as the oxidant, too, and indeed evolution of ethylene proceeded even more rapidly to give 65 % yield. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Methodology to assay CYP2E1 mixed function oxidase catalytic activity and its induction

    Directory of Open Access Journals (Sweden)

    Arthur I. Cederbaum

    2014-01-01

    Full Text Available The cytochrome P450 mixed function oxidase enzymes are the major catalysts involved in drug metabolism. There are many forms of P450. CYP2E1 metabolizes many toxicologically important compounds including ethanol and is active in generating reactive oxygen species. Since several of the contributions in the common theme series “Role of CYP2E1 and Oxidative/Nitrosative Stress in the Hepatotoxic Actions of Alcohol” discuss CYP2E1, this methodology review describes assays on how CYP2E1 catalytic activity and its induction by ethanol and other inducers can be measured using substrate probes such as the oxidation of para-nitrophenol to para-nitrocatechol and the oxidation of ethanol to acetaldehyde. Approaches to validate that a particular reaction e.g. oxidation of a drug or toxin is catalyzed by CYP2E1 or that induction of that reaction is due to induction of CYP2E1 are important and specific examples using inhibitors of CYP2E1, anti-CYP2E1 IgG or CYP2E1 knockout and knockin mice will be discussed.

  5. Alternative oxidase in the branched mitochondrial respiratory network: an overview on structure, function, regulation, and role

    Directory of Open Access Journals (Sweden)

    Sluse F.E.

    1998-01-01

    Full Text Available Plants and some other organisms including protists possess a complex branched respiratory network in their mitochondria. Some pathways of this network are not energy-conserving and allow sites of energy conservation to be bypassed, leading to a decrease of the energy yield in the cells. It is a challenge to understand the regulation of the partitioning of electrons between the various energy-dissipating and -conserving pathways. This review is focused on the oxidase side of the respiratory chain that presents a cyanide-resistant energy-dissipating alternative oxidase (AOX besides the cytochrome pathway. The known structural properties of AOX are described including transmembrane topology, dimerization, and active sites. Regulation of the alternative oxidase activity is presented in detail because of its complexity. The alternative oxidase activity is dependent on substrate availability: total ubiquinone concentration and its redox state in the membrane and O2 concentration in the cell. The alternative oxidase activity can be long-term regulated (gene expression or short-term (post-translational modification, allosteric activation regulated. Electron distribution (partitioning between the alternative and cytochrome pathways during steady-state respiration is a crucial measurement to quantitatively analyze the effects of the various levels of regulation of the alternative oxidase. Three approaches are described with their specific domain of application and limitations: kinetic approach, oxygen isotope differential discrimination, and ADP/O method (thermokinetic approach. Lastly, the role of the alternative oxidase in non-thermogenic tissues is discussed in relation to the energy metabolism balance of the cell (supply in reducing equivalents/demand in energy and carbon and with harmful reactive oxygen species formation.

  6. Cloning and Functional Analysis of the Promoter of an Ascorbate Oxidase Gene from Gossypium hirsutum

    OpenAIRE

    Xin, Shan; Tao, Chengcheng; Li, Hongbin

    2016-01-01

    Apoplastic ascorbate oxidase (AO) plays significant roles in plant cell growth. However, the mechanism of underlying the transcriptional regulation of AO in Gossypium hirsutum remains unclear. Here, we obtained a 1,920-bp promoter sequence from the Gossypium hirsutum ascorbate oxidase (GhAO1) gene, and this GhAO1 promoter included a number of known cis-elements. Promoter activity analysis in overexpressing pGhAO1::GFP-GUS tobacco (Nicotiana benthamiana) showed that the GhAO1 promoter exhibite...

  7. NADPH oxidase AtrbohD and AtrbohF genes function in ROS-dependent ABA signaling in Arabidopsis

    Science.gov (United States)

    Kwak, June M.; Mori, Izumi C.; Pei, Zhen-Ming; Leonhardt, Nathalie; Torres, Miguel Angel; Dangl, Jeffery L.; Bloom, Rachel E.; Bodde, Sara; Jones, Jonathan D.G.; Schroeder, Julian I.

    2003-01-01

    Reactive oxygen species (ROS) have been proposed to function as second messengers in abscisic acid (ABA) signaling in guard cells. However, the question whether ROS production is indeed required for ABA signal transduction in vivo has not yet been addressed, and the molecular mechanisms mediating ROS production during ABA signaling remain unknown. Here, we report identification of two partially redundant Arabidopsis guard cell-expressed NADPH oxidase catalytic subunit genes, AtrbohD and AtrbohF, in which gene disruption impairs ABA signaling. atrbohD/F double mutations impair ABA-induced stomatal closing, ABA promotion of ROS production, ABA-induced cytosolic Ca2+ increases and ABA- activation of plasma membrane Ca2+-permeable channels in guard cells. Exogenous H2O2 rescues both Ca2+ channel activation and stomatal closing in atrbohD/F. ABA inhibition of seed germination and root elongation are impaired in atrbohD/F, suggesting more general roles for ROS and NADPH oxidases in ABA signaling. These data provide direct molecular genetic and cell biological evidence that ROS are rate-limiting second messengers in ABA signaling, and that the AtrbohD and AtrbohF NADPH oxidases function in guard cell ABA signal transduction. PMID:12773379

  8. Evolutionary origin and function of NOX4-art, an arthropod specific NADPH oxidase.

    Science.gov (United States)

    Gandara, Ana Caroline Paiva; Torres, André; Bahia, Ana Cristina; Oliveira, Pedro L; Schama, Renata

    2017-03-29

    NADPH oxidases (NOX) are ROS producing enzymes that perform essential roles in cell physiology, including cell signaling and antimicrobial defense. This gene family is present in most eukaryotes, suggesting a common ancestor. To date, only a limited number of phylogenetic studies of metazoan NOXes have been performed, with few arthropod genes. In arthropods, only NOX5 and DUOX genes have been found and a gene called NOXm was found in mosquitoes but its origin and function has not been examined. In this study, we analyzed the evolution of this gene family in arthropods. A thorough search of genomes and transcriptomes was performed enabling us to browse most branches of arthropod phylogeny. We have found that the subfamilies NOX5 and DUOX are present in all arthropod groups. We also show that a NOX gene, closely related to NOX4 and previously found only in mosquitoes (NOXm), can also be found in other taxonomic groups, leading us to rename it as NOX4-art. Although the accessory protein p22-phox, essential for NOX1-4 activation, was not found in any of the arthropods studied, NOX4-art of Aedes aegypti encodes an active protein that produces H 2 O 2 . Although NOX4-art has been lost in a number of arthropod lineages, it has all the domains and many signature residues and motifs necessary for ROS production and, when silenced, H 2 O 2 production is considerably diminished in A. aegypti cells. Combining all bioinformatic analyses and laboratory work we have reached interesting conclusions regarding arthropod NOX gene family evolution. NOX5 and DUOX are present in all arthropod lineages but it seems that a NOX2-like gene was lost in the ancestral lineage leading to Ecdysozoa. The NOX4-art gene originated from a NOX4-like ancestor and is functional. Although no p22-phox was observed in arthropods, there was no evidence of neo-functionalization and this gene probably produces H 2 O 2 as in other metazoan NOX4 genes. Although functional and present in the genomes of many

  9. Thermostability promotes the cooperative function of split adenylate kinases.

    Science.gov (United States)

    Nguyen, Peter Q; Liu, Shirley; Thompson, Jeremy C; Silberg, Jonathan J

    2008-05-01

    Proteins can often be cleaved to create inactive polypeptides that associate into functional complexes through non-covalent interactions, but little is known about what influences the cooperative function of the ensuing protein fragments. Here, we examine whether protein thermostability affects protein fragment complementation by characterizing the function of split adenylate kinases from the mesophile Bacillus subtilis (AKBs) and the hyperthermophile Thermotoga neapolitana (AKTn). Complementation studies revealed that the split AKTn supported the growth of Escherichia coli with a temperature-sensitive AK, but not the fragmented AKBs. However, weak complementation occurred when the AKBs fragments were fused to polypeptides that strongly associate, and this was enhanced by a Q16L mutation that thermostabilizes the full-length protein. To examine how the split AK homologs differ in structure and function, their catalytic activity, zinc content, and circular dichroism spectra were characterized. The reconstituted AKTn had higher levels of zinc, greater secondary structure, and >10(3)-fold more activity than the AKBs pair, albeit 17-fold less active than full-length AKTn. These findings provide evidence that the design of protein fragments that cooperatively function can be improved by choosing proteins with the greatest thermostability for bisection, and they suggest that this arises because hyperthermophilic protein fragments exhibit greater residual structure compared to their mesophilic counterparts.

  10. Inducible bilirubin oxidase: A novel function for the mouse cytochrome P450 2A5

    International Nuclear Information System (INIS)

    Abu-Bakar, A'edah; Arthur, Dionne Maioha; Aganovic, Simona; Ng, Jack C.; Lang, Matti A.

    2011-01-01

    We have previously shown that bilirubin (BR), a breakdown product of haem, is a strong inhibitor and a high affinity substrate of the mouse cytochrome P450 2A5 (CYP2A5). The antioxidant BR, which is cytotoxic at high concentrations, is potentially useful in cellular protection against oxygen radicals if its intracellular levels can be strictly controlled. The mechanisms that regulate cellular BR levels are still obscure. In this paper we provide preliminary evidence for a novel function of CYP2A5 as hepatic “BR oxidase”. A high-performance liquid chromatography/electrospray ionisation mass spectrometry screening showed that recombinant yeast microsomes expressing the CYP2A5 oxidise BR to biliverdin, as the main metabolite, and to three other smaller products with m/z values of 301, 315 and 333. The metabolic profile is significantly different from that of chemical oxidation of BR. In chemical oxidation the smaller products were the main metabolites. This suggests that the enzymatic reaction is selective, towards biliverdin production. Bilirubin treatment of primary hepatocytes increased the CYP2A5 protein and activity levels with no effect on the corresponding mRNA. Co-treatment with cycloheximide (CHX), a protein synthesis inhibitor, resulted in increased half-life of the CYP2A5 compared to cells treated only with CHX. Collectively, the observations suggest that the CYP2A5 is potentially an inducible “BR oxidase” where BR may accelerate its own metabolism through stabilization of the CYP2A5 protein. It is possible that this metabolic pathway is potentially part of the machinery controlling intracellular BR levels in transient oxidative stress situations, in which high amounts of BR are produced. -- Highlights: ► CYP2A5 metabolizes bilirubin to biliverdin and dipyrroles. ► Bilirubin increased the hepatic CYP2A5 protein and activity levels. ► Bilirubin does not change the hepatic CYP2A5 mRNA levels. ► Co-treatment with a protein synthesis inhibitor

  11. A Cooperative Harmony Search Algorithm for Function Optimization

    Directory of Open Access Journals (Sweden)

    Gang Li

    2014-01-01

    Full Text Available Harmony search algorithm (HS is a new metaheuristic algorithm which is inspired by a process involving musical improvisation. HS is a stochastic optimization technique that is similar to genetic algorithms (GAs and particle swarm optimizers (PSOs. It has been widely applied in order to solve many complex optimization problems, including continuous and discrete problems, such as structure design, and function optimization. A cooperative harmony search algorithm (CHS is developed in this paper, with cooperative behavior being employed as a significant improvement to the performance of the original algorithm. Standard HS just uses one harmony memory and all the variables of the object function are improvised within the harmony memory, while the proposed algorithm CHS uses multiple harmony memories, so that each harmony memory can optimize different components of the solution vector. The CHS was then applied to function optimization problems. The results of the experiment show that CHS is capable of finding better solutions when compared to HS and a number of other algorithms, especially in high-dimensional problems.

  12. Lysyl oxidase enzymatic function increases stiffness to drive colorectal cancer progression through FAK

    DEFF Research Database (Denmark)

    Baker, A-M; Bird, D; Lang, G

    2013-01-01

    The extracellular, matrix-modifying enzyme lysyl oxidase (LOX) has recently been linked to colorectal cancer (CRC) progression, in particular to the stages of invasion and metastasis. In this report, we use cell lines expressing a catalytically inactive mutant form of LOX to show that catalytic a...... for patients with metastatic CRC.Oncogene advance online publication, 28 May 2012; doi:10.1038/onc.2012.202....

  13. Study on autonomous decentralized-cooperative function monitoring system

    International Nuclear Information System (INIS)

    Matsuoka, Takeshi; Numano, Masayoshi; Someya, Minoru; Fukuto, Junji; Mitomo, Nobuo; Miyazaki, Keiko; Matsukura, Hiroshi

    1998-01-01

    In this study, on a base of result of a nuclear substrate cross-over study on 'Artificial intelligence for nuclear plant' promoted by 5 years plan since 1989 fiscal year, further developed studies are conducted. The studies are promoted by next 5 years plan on following 6 items: (1) Study on stratified expression technique of autonomous function. (2) Study on expression technique of motion state in decentralized-cooperative function. (3) Study on expression technique of decision making process. (4) Integration to operation control system. (5) Integration to maintenance system. And, (6) Comprehensive evaluation experiment. In 1996 fiscal year, improvement and investigation on automatic classification function of plant state were executed. And, preparation of development environment for expression of robot group motion state was conducted. Furthermore, communication experiment using network to realize integration to operation control and maintenance systems and periodical meetings with other institutes were conducted. (G.K.)

  14. Development of Galactose Biosensor Based on Functionalized ZnO Nanorods with Galactose Oxidase

    Directory of Open Access Journals (Sweden)

    K. Khun

    2012-01-01

    Full Text Available The fabrication of galactose biosensor based on functionalised ZnO nanorods is described. The galactose biosensor was developed by immobilizing galactose oxidase on ZnO nanorods in conjunction with glutaraldehyde as a cross-linker molecule. The IRAS study provided evidence for the interaction of galactose oxidase with the surface of ZnO nanorods. The electromotive force (EMF response of the galactose biosensor was measured by potentiometric method. We observed that the proposed biosensor has a linear detection range over a concentration range from 10 mM to 200 mM with good sensitivity of 89.10±1.23 mV/decade. In addition, the proposed biosensor has shown fast time response of less than 10 s and a good selectivity towards galactose in the presence of common interferents such as ascorbic acid, uric acid, glucose, and magnesium ions. The galactose biosensor based on galactose oxidase immobilized ZnO nanorods has a shelf life more than four weeks.

  15. Study on autonomous decentralized-cooperative function monitoring system

    International Nuclear Information System (INIS)

    Matsuoka, Takeshi; Numano, Masayoshi; Someya, Minoru; Fukuto, Junji; Mitomo, Nobuo; Miyazaki, Keiko; Matsukura, Hiroshi; Tanba, Yasuyuki

    1999-01-01

    In this study, a study further advanced on a base of results of study on artificial intelligence for nuclear power', one of nuclear basis crossover studies, conducted at five years planning from 1989 fiscal year was executed. Here was conducted on study on a system technology for supplying cooperation, judgement process, judgement results, and so forth between decentralized artificial intelligent elements (agents) to operation managers (supervisors) by focussing a system for monitoring if autonomous decentralized system containing plant operation and robot group action functioned appropriately. In 1997 fiscal year, by mainly conducting development for displaying working state of robot group, some investigations on integrated management of each function already development and maintained were executed. Furthermore, some periodical meetings on realization of its integration with operation control system and maintenance system with other research institutes were conducted. (G.K.)

  16. Pretreatment with mixed-function oxidase inducers increases the sensitivity of the hepatocyte/DNA repair assay

    International Nuclear Information System (INIS)

    Shaddock, J.G.; Heflich, R.H.; McMillan, D.C.; Hinson, J.A.; Casciano, D.A.

    1989-01-01

    A recent National Toxicology Program evaluation indicates that the rat hepatocyte/DNA repair assay has a high false-negative rate and that it is insensitive to some genotoxic hepatocarcinogens as well as other species and organ-specific carcinogens. In this study, the authors examined whether the sensitivity of the hepatocyte/DNA repair assay might be increased through animal pretreatment with various hepatic mixed-function oxidase inducers, i.e., Aroclor 1254, phenobarbital, and 3,3',4,4'-tetrachloroazobenzene (TCAB). The effects on unscheduled DNA synthesis (UDS), a measured of DNA damage and repair, were studied in cultures exposed to known and/or potential carcinogens that had been evaluated as negative or questionable or that produced conflicting results with hepatocytes isolated from uninduced animals. 4,4'-Oxydianiline, 1-nitropy-rene, and TCAB produced concentration-dependent increases in UDS in hepatocytes from rats pretreated with Aroclor 1254. 4,4'-Oxydianiline and TCAB also induced a dose-dependent increase in DNA repair in hepatocytes from rats pretreated with phenobarbital, whereas 1-nitropyrene was negative. These data indicate that the limited sensitivity to chemical carcinogens displayed by the hepatocyte/DNA repair assay may be increased by using hepatocytes isolated from animals exposed to hepatic mixed-function oxidase inducers

  17. Pretreatment with mixed-function oxidase inducers increases the sensitivity of the hepatocyte/DNA repair assay

    Energy Technology Data Exchange (ETDEWEB)

    Shaddock, J.G.; Heflich, R.H.; McMillan, D.C.; Hinson, J.A.; Casciano, D.A. (National Center for Toxicological Research, Jefferson, AK (USA) Univ. of Arkansas for Medical Sciences, Little Rock (USA))

    1989-01-01

    A recent National Toxicology Program evaluation indicates that the rat hepatocyte/DNA repair assay has a high false-negative rate and that it is insensitive to some genotoxic hepatocarcinogens as well as other species and organ-specific carcinogens. In this study, the authors examined whether the sensitivity of the hepatocyte/DNA repair assay might be increased through animal pretreatment with various hepatic mixed-function oxidase inducers, i.e., Aroclor 1254, phenobarbital, and 3,3{prime},4,4{prime}-tetrachloroazobenzene (TCAB). The effects on unscheduled DNA synthesis (UDS), a measured of DNA damage and repair, were studied in cultures exposed to known and/or potential carcinogens that had been evaluated as negative or questionable or that produced conflicting results with hepatocytes isolated from uninduced animals. 4,4{prime}-Oxydianiline, 1-nitropy-rene, and TCAB produced concentration-dependent increases in UDS in hepatocytes from rats pretreated with Aroclor 1254. 4,4{prime}-Oxydianiline and TCAB also induced a dose-dependent increase in DNA repair in hepatocytes from rats pretreated with phenobarbital, whereas 1-nitropyrene was negative. These data indicate that the limited sensitivity to chemical carcinogens displayed by the hepatocyte/DNA repair assay may be increased by using hepatocytes isolated from animals exposed to hepatic mixed-function oxidase inducers.

  18. Inhibition of xanthine oxidase reduces oxidative stress and improves skeletal muscle function in response to electrically stimulated isometric contractions in aged mice

    Science.gov (United States)

    Ryan, Michael J.; Jackson, Janna R.; Hao, Yanlei; Leonard, Stephen S.; Alway, Stephen E.

    2012-01-01

    Oxidative stress is a putative factor responsible for reducing function and increasing apoptotic signaling in skeletal muscle with aging. This study examined the contribution and functional significance of the xanthine oxidase enzyme as a potential source of oxidant production in aged skeletal muscle during repetitive in situ electrically stimulated isometric contractions. Xanthine oxidase activity was inhibited in young adult and aged mice via a subcutaneously placed time release (2.5 mg/day) allopurinol pellet, 7 days prior to the start of in situ electrically stimulated isometric contractions. Gastrocnemius muscles were electrically activated with 20 maximal contractions for three consecutive days. Xanthine oxidase activity was 65% greater in the gastrocnemius muscle of aged mice compared to young mice. Xanthine oxidase activity also increased after in situ electrically stimulated isometric contractions in muscles from both young (33%) and aged (28%) mice, relative to contralateral non-contracted muscles. Allopurinol attenuated the exercise-induced increase in oxidative stress, but it did not affect the elevated basal levels of oxidative stress that was associated with aging. In addition, inhibition of xanthine oxidase activity decreased caspase 3 activity, but it had no effect on other markers of mitochondrial associated apoptosis. Our results show that compared to control conditions, suppression of xanthine oxidase activity by allopurinol reduced xanthine oxidase activity, H2O2 levels, lipid peroxidation and caspase-3 activity, prevented the in situ electrically stimulated isometric contraction-induced loss of glutathione, prevented the increase of catalase and copper-zinc superoxide dismutase activities, and increased maximal isometric force in the plantar flexor muscles of aged mice after repetitive electrically evoked contractions. PMID:21530649

  19. [Effect of inducers and inhibitors of mixed function oxidases on body resistance to endotoxins of gram-negative bacteria].

    Science.gov (United States)

    Liniuchev, M N; Zubik, T M; Kovelenov, A Iu; Bulyko, V I; Sergeev, V V

    1989-06-01

    Experimental typhoid intoxication in white mice leads to the inhibition of microsomal oxidation in the liver, which is manifested by the prolongation of hexenal-induced sleep and a decrease in the toxic action of parathion. Phenobarbital, capable of inducing oxidases with mixed function (OMF), enhances the process of the detoxification of endotoxin injected into the animals, which is manifested by the increase of its LD50. Soluble levomycetin succinate, widely used for the treatment of typhoid-paratyphoid infections, is a powerful inhibitor of OMF (as shown by the hexenal test). Benzonal, the analog of phenobarbital, removes the inhibitory effect of the antibiotic. Experimental studies carried out in the course of this investigation make it possible to substantiate the clinical trial of these preparations (OMF inducers) used in the complex therapy of typhoid-paratyphoid infections for the stimulation of natural detoxification mechanisms of the body. Benzonal is the preparation of choice for use in clinical practice.

  20. Rational redesign of glucose oxidase for improved catalytic function and stability.

    Directory of Open Access Journals (Sweden)

    J Todd Holland

    Full Text Available Glucose oxidase (GOx is an enzymatic workhorse used in the food and wine industries to combat microbial contamination, to produce wines with lowered alcohol content, as the recognition element in amperometric glucose sensors, and as an anodic catalyst in biofuel cells. It is naturally produced by several species of fungi, and genetic variants are known to differ considerably in both stability and activity. Two of the more widely studied glucose oxidases come from the species Aspergillus niger (A. niger and Penicillium amagasakiense (P. amag., which have both had their respective genes isolated and sequenced. GOx from A. niger is known to be more stable than GOx from P. amag., while GOx from P. amag. has a six-fold superior substrate affinity (K(M and nearly four-fold greater catalytic rate (k(cat. Here we sought to combine genetic elements from these two varieties to produce an enzyme displaying both superior catalytic capacity and stability. A comparison of the genes from the two organisms revealed 17 residues that differ between their active sites and cofactor binding regions. Fifteen of these residues in a parental A. niger GOx were altered to either mirror the corresponding residues in P. amag. GOx, or mutated into all possible amino acids via saturation mutagenesis. Ultimately, four mutants were identified with significantly improved catalytic activity. A single point mutation from threonine to serine at amino acid 132 (mutant T132S, numbering includes leader peptide led to a three-fold improvement in k(cat at the expense of a 3% loss of substrate affinity (increase in apparent K(M for glucose resulting in a specify constant (k(cat/K(M of 23.8 (mM(-1 · s(-1 compared to 8.39 for the parental (A. niger GOx and 170 for the P. amag. GOx. Three other mutant enzymes were also identified that had improvements in overall catalysis: V42Y, and the double mutants T132S/T56V and T132S/V42Y, with specificity constants of 31.5, 32.2, and 31.8 mM(-1 · s

  1. Altered Cerebellar Organization and Function in Monoamine Oxidase A Hypomorphic Mice

    Science.gov (United States)

    Alzghoul, Loai; Bortolato, Marco; Delis, Foteini; Thanos, Panayotis K.; Darling, Ryan D.; Godar, Sean C; Zhang, Junlin; Grant, Samuel; Wang, Gene-Jack; Simpson, Kimberly L.; Chen, Kevin; Volkow, Nora D.; Lin, Rick C.S.; Shih, Jean C.

    2012-01-01

    Monoamine oxidase A (MAO-A) is the key enzyme for the degradation of brain serotonin (5-hydroxytryptamine, 5-HT), norepinephrine (NE) and dopamine (DA). We recently generated and characterized a novel line of MAO-A hypormorphic mice (MAO-ANeo), featuring elevated monoamine levels, social deficits and perseverative behaviors as well as morphological changes in the basolateral amygdala and orbitofrontal cortex. Here we showed that MAO-ANeo mice displayed deficits in motor control, manifested as subtle disturbances in gait, motor coordination, and balance. Furthermore, magnetic resonance imaging of the cerebellum revealed morphological changes and a moderate reduction in the cerebellar size of MAO- ANeo mice compared to wild type (WT) mice. Histological and immunohistochemical analyses using calbindin-D-28k (CB) expression of Purkinje cells revealed abnormal cerebellar foliation with vermal hypoplasia and decreased in Purkinje cell count and their dendritic density in MAO- ANeo mice compared to WT. Our current findings suggest that congenitally low MAO-A activity leads to abnormal development of the cerebellum. PMID:22971542

  2. Functional mechanism of neuroprotection by inhibitors of type B monoamine oxidase in Parkinson's disease.

    Science.gov (United States)

    Naoi, Makoto; Maruyama, Wakako

    2009-08-01

    Neuroprotective therapy has been proposed for age-related neurodegenerative disorders, including Parkinson's disease. Inhibitors of type B monoamine oxidase (MAOB-Is), rasagiline and (-)deprenyl, are the most promising candidate neuroprotective drugs. Clinical trials of rasagiline in patients with Parkinson's disease suggest that rasagiline may have some disease-modifying effects. Results using animal and cellular models have proved that the MAOB-Is protect neurons by the intervention of 'intrinsic' mitochondrial apoptotic cascade and the induction of prosurvival antiapoptotic Bcl-2 and neurotrophic factors. Rasagiline-related MAOB-Is prevent mitochondrial permeability transition induced by various insults and activation of subsequent apoptotic cascades: cytochrome c release, casapase activation, and condensation and fragmentation of nuclear DNA. MAOB-Is increase transcription of prosurvival genes through activating the nuclear transcription factor-(NF) system. Rasagiline increases the protein and mRNA levels of GDNF in dopaminergic SH-SY5Y cells, whereas (-)deprenyl increases those of BDNF. Systemic administration of (-)deprenyl and rasagiline increases these neurotrophic factors in the cerebrospinal fluid from patients with Parkinson's disease and nonhuman primates. This review presents recent advances in our understanding of the neuroprotection offered by MAOB-Is and possible evaluation of neuroprotective efficacy in clinical samples is discussed.

  3. Cholesterol Oxidase Binds TLR2 and Modulates Functional Responses of Human Macrophages

    Directory of Open Access Journals (Sweden)

    Katarzyna Bednarska

    2014-01-01

    Full Text Available Cholesterol oxidase (ChoD is considered to be an important virulence factor for Mycobacterium tuberculosis (Mtb, but its influence on macrophage activity is unknown. Here we used Nocardia erythropolis ChoD, which is very similar to the Mtb enzyme (70% identity at the amino-acid level, to evaluate the impact of bacterial ChoD on the activity of THP-1-derived macrophages in vitro. We found that ChoD decreased the surface expression of Toll-like receptor type 2 (TLR2 and complement receptor 3 (CR3 on these macrophages. Flow cytometry and confocal microscopy showed that ChoD competed with lipoteichoic acid for ligand binding sites on TLR2 but not on CR3, suggesting that ChoD signaling is mediated via TLR2. Binding of ChoD to the membrane of macrophages had diverse effects on the activity of macrophages, activating p38 mitogen activated kinase and stimulating production of a large amount of interleukin-10. Moreover, ChoD primed macrophages to enhance the production of reactive oxygen species in response to the phorbol myristate acetate, which was reduced by “switching off” TLR-derived signaling through interleukin-1 receptor-associated kinases 1 and 4 inhibition. Our study revealed that ChoD interacts directly with macrophages via TLR2 and influences the biological activity of macrophages during the development of the initial response to infection.

  4. Cortical enlargement in autism is associated with a functional VNTR in the monoamine oxidase A gene.

    Science.gov (United States)

    Davis, Lea K; Hazlett, Heather C; Librant, Amy L; Nopoulos, Peggy; Sheffield, Val C; Piven, Joesph; Wassink, Thomas H

    2008-10-05

    Monoamine oxidase A (MAOA) is an enzyme expressed in the brain that metabolizes dopamine, norepinephrine, epinephrine, and serotonin. Abnormalities of serotonin neurotransmission have long been implicated in the psychopathology of autism. A polymorphism exists within the promoter region of the MAOA gene that influences MAOA expression levels so that "low activity" alleles are associated with increased neurotransmitter levels in the brain. Individuals with autism often exhibit elevated serotonin levels. Additional studies indicate that the "low activity" allele may be associated with lower IQ and more severe autistic symptoms. In this study we genotyped the MAOA promoter polymorphism in a group of 29 males (age 2-3 years) with autism and a group of 39 healthy pediatric controls for whom brain MRI data was available. We found a consistent association between the "low activity" allele and larger brain volumes for regions of the cortex in children with autism but not in controls. We did not find evidence for over-transmission of the "low activity" allele in a separate sample of 114 affected sib pair families. Nor did we find any unknown SNPs in yet another sample of 96 probands. Future studies will determine if there is a more severe clinical phenotype associated with both the "low activity" genotype and the larger brain volumes in our sample.

  5. Implications of terminal oxidase function in regulation of salicylic acid on soybean seedling photosynthetic performance under water stress.

    Science.gov (United States)

    Tang, Yanping; Sun, Xin; Wen, Tao; Liu, Mingjie; Yang, Mingyan; Chen, Xuefei

    2017-03-01

    The aim of this study is to investigate whether exogenous application of salicylic acid (SA) could modulate the photosynthetic capacity of soybean seedlings in water stress tolerance, and to clarify the potential functions of terminal oxidase (plastid terminal oxidase (PTOX) and alternative oxidase (AOX)) in SA' s regulation on photosynthesis. The effects of SA and water stress on gas exchange, pigment contents, chlorophyll fluorescence, enzymes (guaiacol peroxidase (POD; EC 1.11.1.7), superoxide dismutase (SOD; EC 1.15.1.1), catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APX; EC 1.11.1.11) and NADP-malate dehydrogenase (NADP-MDH; EC1.1.1.82)) activity and transcript levels of PTOX, AOX1, AOX2a, AOX2b were examined in a hydroponic cultivation system. Results indicate that water stress significantly decreased the photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (E), pigment contents (Chla + b, Chla/b, Car), maximum quantum yield of PSⅡphotochemistry (Fv/Fm), efficiency of excitation capture of open PSⅡcenter (Fv'/Fm'), quantum efficiency of PSⅡphotochemistry (ΦPSⅡ), photochemical quenching (qP), and increased malondialdehyde (MDA) content and the activity of all the enzymes. SA pretreatment led to significant decreases in Ci and MDA content, and increases in Pn, Gs, E, pigment contents, Fv/Fm, Fv'/Fm', ΦPSⅡ, qP, and the activity of all the enzymes. SA treatment and water stress alone significantly up-regulated the expression of PTOX, AOX1 and AOX2b. SA pretreatment further increased the transcript levels of PTOX and AOX2b of soybean seedling under water stress. These results indicate that SA application alleviates the water stress-induced decrease in photosynthesis may mainly through maintaining a lower reactive oxygen species (ROS) level, a greater PSⅡefficiency, and an enhanced alternative respiration and chlororespiration. PTOX and AOX may play important roles in SA-mediated resistance to water stress. Copyright © 2016

  6. Functional analysis of aldehyde oxidase using expressed chimeric enzyme between monkey and rat.

    Science.gov (United States)

    Itoh, Kunio; Asakawa, Tasuku; Hoshino, Kouichi; Adachi, Mayuko; Fukiya, Kensuke; Watanabe, Nobuaki; Tanaka, Yorihisa

    2009-01-01

    Aldehyde oxidase (AO) is a homodimer with a subunit molecular mass of approximately 150 kDa. Each subunit consists of about 20 kDa 2Fe-2S cluster domain storing reducing equivalents, about 40 kDa flavine adenine dinucleotide (FAD) domain and about 85 kDa molybdenum cofactor (MoCo) domain containing a substrate binding site. In order to clarify the properties of each domain, especially substrate binding domain, chimeric cDNAs were constructed by mutual exchange of 2Fe-2S/FAD and MoCo domains between monkey and rat. Chimeric monkey/rat AO was referred to one with monkey type 2Fe-2S/FAD domains and a rat type MoCo domain. Rat/monkey AO was vice versa. AO-catalyzed 2-oxidation activities of (S)-RS-8359 were measured using the expressed enzyme in Escherichia coli. Substrate inhibition was seen in rat AO and chimeric monkey/rat AO, but not in monkey AO and chimeric rat/monkey AO, suggesting that the phenomenon might be dependent on the natures of MoCo domain of rat. A biphasic Eadie-Hofstee profile was observed in monkey AO and chimeric rat/monkey AO, but not rat AO and chimeric monkey/rat AO, indicating that the biphasic profile might be related to the properties of MoCo domain of monkey. Two-fold greater V(max) values were observed in monkey AO than in chimeric rat/monkey AO, and in chimeric monkey/rat AO than in rat AO, suggesting that monkey has the more effective electron transfer system than rat. Thus, the use of chimeric enzymes revealed that 2Fe-2S/FAD and MoCo domains affect the velocity and the quantitative profiles of AO-catalyzed (S)-RS-8359 2-oxidation, respectively.

  7. Functional analysis of fructosyl-amino acid oxidases of Aspergillus oryzae.

    Science.gov (United States)

    Akazawa, Shin-Ichi; Karino, Tetsuya; Yoshida, Nobuyuki; Katsuragi, Tohoru; Tani, Yoshiki

    2004-10-01

    Three active fractions of fructosyl-amino acid oxidase (FAOD-Ao1, -Ao2a, and -Ao2b) were isolated from Aspergillus oryzae strain RIB40. N-terminal and internal amino acid sequences of FAOD-Ao2a corresponded to those of FAOD-Ao2b, suggesting that these two isozymes were derived from the same protein. FAOD-Ao1 and -Ao2 were different in substrate specificity and subunit assembly; FAOD-Ao2 was active toward N(epsilon)-fructosyl N(alpha)-Z-lysine and fructosyl valine (Fru-Val), whereas FAOD-Ao1 was not active toward Fru-Val. The genes encoding the FAOD isozymes (i.e., FAOAo1 and FAOAo2) were cloned by PCR with an FAOD-specific primer set. The deduced amino acid sequences revealed that FAOD-Ao1 was 50% identical to FAOD-Ao2, and each isozyme had a peroxisome-targeting signal-1, indicating their localization in peroxisomes. The genes was expressed in Escherichia coli and rFaoAo2 showed the same characteristics as FAOD-Ao2, whereas rFaoAo1 was not active. FAOAo2 disruptant was obtained by using ptrA as a selective marker. Wild-type strain grew on the medium containing Fru-Val as the sole carbon and nitrogen sources, but strain Delta faoAo2 did not grow. Addition of glucose or (NH(4))(2)SO(4) to the Fru-Val medium did not affect the assimilation of Fru-Val by wild-type, indicating glucose and ammonium repressions did not occur in the expression of the FAOAo2 gene. Furthermore, conidia of the wild-type strain did not germinate on the medium containing Fru-Val and NaNO(2) as the sole carbon and nitrogen sources, respectively, suggesting that Fru-Val may also repress gene expression of nitrite reductase. These results indicated that FAOD is needed for utilization of fructosyl-amino acids as nitrogen sources in A. oryzae.

  8. Effects of befloxatone, a reversible selective monoamine oxidase-A inhibitor, on psychomotor function and memory in healthy subjects.

    Science.gov (United States)

    Warot, D; Berlin, I; Patat, A; Durrieu, G; Zieleniuk, I; Puech, A J

    1996-10-01

    Befloxatone is a new reversible and selective monoamine oxidase (MAO-A) inhibitor that has been shown to have antidepressant activity in various animal models. To assess the effects of single oral doses of befloxatone (5, 10, and 20 mg) on psychomotor performance and memory, a randomized, double-blind, five-way, crossover study with both placebo and amitriptyline (50 mg) was carried out in 15 healthy male volunteers. Psychomotor and cognitive functions were evaluated using both objective measures, including Critical Flicker Frequency (CFF), Choice Reaction Time (CRT), Digit Symbol Substitution Test (DSST), and a picture memory test and subjective measures, including Visual Analog Scales (VAS) and Addiction Research Center Inventory (ARCI), before and 2, 4, and 8 hours after administration. Pupil diameter was recorded by videopupillography. Single doses of befloxatone from 5 to 20 mg did not result in any detrimental effects on skilled performance and memory. In contrast, amitriptyline significantly impaired arousal (CFF), speed of reaction (CRT), information processing (DSST) and long-term memory (delayed free recall of pictures) and produced subjective sedation from 2 to 8 hours after administration. At the doses studied amitriptyline induced miosis but befloxatone did not modify pupil diameter. There was no evidence in this study to suggest that befloxatone, at the doses studied, has any sedative or amnesic effects in healthy subjects.

  9. Changes in the activity of the alternative oxidase in Orobanche seeds during conditioning and their possible physiological function.

    Science.gov (United States)

    Bar Nun, Nurit; Plakhine, Dina; Joel, Daniel M; Mayer, Alfred M

    2003-09-01

    The appearance of the activity of the cyanide insensitive, alternative oxidase (AOX), pathway of oxygen uptake was followed in seeds of Orobanche aegyptiaca during conditioning. The pathway becomes operative during conditioning, up to day three as determined by inhibition of oxygen uptake of the seeds by propyl gallate. At the same time an increasing percentage of oxygen uptake is insensitive to cyanide and an increased oxygen uptake, responsive to propyl gallate, is induced by brief salicylic acid treatment of seeds. By day six of conditioning, these responses decrease and the AOX pathway could not be detected in germinating seeds, after treatment with a germination stimulant. These results were confirmed by following the reaction of extracts of fractions enriched with mitochondria from the conditioned seeds, using a specific antibody against AOX. Treatment of the seeds with inhibitors of AOX during conditioning significantly inhibited their subsequent germination. Addition of hydrogen peroxide after 4 and 7 days of conditioning resulted in reduced germination. In addition treatment of seed with propyl or octyl gallate during conditioning reduced the infection of tomato plants by Orobanche seeds and the development of tubercles of the parasite on the host roots. These results together indicate that the operation of AOX during conditioning has a significant function on the subsequent germination behaviour and pathogenicity of the root parasite. Some potential practical applications of these findings are discussed.

  10. Metabolism of benzene and phenol by a reconstituted purified phenobarbital induced rat liver mixed function oxidase system

    International Nuclear Information System (INIS)

    Griffiths, J.C.

    1986-01-01

    Cytochrome P-450 and the electron-donor, NADPH-cytochrome c reductase were isolated from phenobarbital induced rat liver microsomes. Both benzene and its primary metabolite phenol, were substrates for the reconstituted purified phenobarbital induced rat liver mixed function oxidase system. Benzene was metabolized to phenol and the polyhydroxylated metabolites; catechol, hydroquinone and 1,2,4 benzenetriol. Benzene elicited a Type I spectral change upon its interaction with the cytochrome P-450 while phenol's interaction with the cytochrome P-450 produced a reverse Type I spectra. The formation of phenol showed a pH optimum of 7.0 compared with 6.6-6.8 for the production of the polyhyrdoxylated metabolites. Cytochrome P-450 inhibitors, such as metyrapone and SKF 525A, diminished the production of phenol from benzene but not the production of the polyhydroxylated metabolites from phenol. The radical trapping agents, DMSO, KTBA and mannitol, decreased the recovery of polyhydroxylated metabolites, from 14 C-labeled benzene and/or phenol. As KTBA and DMSO interacted with OH. There was a concomitant release of ethylene and methane, which was measured. Desferrioxamine, an iron-chelator and catalase also depressed the recovery of polyhydroxylated metabolites. In summary, benzene and phenol were both substrates for this reconstituted purified enzyme system, but they differed in binding to cytochrome P-450, pH optima and mode of hydroxylation

  11. Functionally undefined gene, yggE, alleviates oxidative stress generated by monoamine oxidase in recombinant Escherichia coli.

    Science.gov (United States)

    Ojima, Yoshihiro; Kawase, Daisuke; Nishioka, Motomu; Taya, Masahito

    2009-01-01

    Real-time PCR analysis showed that yggE gene was about two and three times up-regulated in Escherichia coli cells exposed to UVA irradiation and thermal elevation, respectively, suggesting that this gene is responsive to physiological stress. The yggE gene was introduced into E. coli BL21 cells, together with a monoamine oxidase (MAO) gene as a model source for oxidative stress generation. The distribution of independently isolated transformants (two dozen isolates) was examined in terms of MAO activity and cell vitality. In the case of control strain expressing MAO alone, the largest number of transformants existed in the low range of MAO activity less than 2 units mg(-1) and the number significantly decreased at increased MAO activity. On the other hand, the distribution of MAO/YggE-coexpressing transformants shifted to higher MAO activity with frequent appearance in the activity range of 4-8 units mg(-1). The yggE gene product therefore has a possible function for alleviating the stress generated in the cells.

  12. Tissue- and Condition-Specific Isoforms of Mammalian Cytochrome c Oxidase Subunits: From Function to Human Disease

    Directory of Open Access Journals (Sweden)

    Christopher A. Sinkler

    2017-01-01

    Full Text Available Cytochrome c oxidase (COX is the terminal enzyme of the electron transport chain and catalyzes the transfer of electrons from cytochrome c to oxygen. COX consists of 14 subunits, three and eleven encoded, respectively, by the mitochondrial and nuclear DNA. Tissue- and condition-specific isoforms have only been reported for COX but not for the other oxidative phosphorylation complexes, suggesting a fundamental requirement to fine-tune and regulate the essentially irreversible reaction catalyzed by COX. This article briefly discusses the assembly of COX in mammals and then reviews the functions of the six nuclear-encoded COX subunits that are expressed as isoforms in specialized tissues including those of the liver, heart and skeletal muscle, lung, and testes: COX IV-1, COX IV-2, NDUFA4, NDUFA4L2, COX VIaL, COX VIaH, COX VIb-1, COX VIb-2, COX VIIaH, COX VIIaL, COX VIIaR, COX VIIIH/L, and COX VIII-3. We propose a model in which the isoforms mediate the interconnected regulation of COX by (1 adjusting basal enzyme activity to mitochondrial capacity of a given tissue; (2 allosteric regulation to adjust energy production to need; (3 altering proton pumping efficiency under certain conditions, contributing to thermogenesis; (4 providing a platform for tissue-specific signaling; (5 stabilizing the COX dimer; and (6 modulating supercomplex formation.

  13. Electrochemically Functionalized Seamless Three-Dimensional Graphene-Carbon Nanotube Hybrid for Direct Electron Transfer of Glucose Oxidase and Bioelectrocatalysis.

    Science.gov (United States)

    Terse-Thakoor, Trupti; Komori, Kikuo; Ramnani, Pankaj; Lee, Ilkeun; Mulchandani, Ashok

    2015-12-01

    Three-dimensional seamless chemical vapor deposition (CVD) grown graphene-carbon nanotubes (G-CNT) hybrid film has been studied for its potential in achieving direct electron transfer (DET) of glucose oxidase (GOx) and its bioelectrocatalytic activity in glucose detection. A two-step CVD method was employed for the synthesis of seamless G-CNT hybrid film where CNTs are grown on already grown graphene film on copper foil using iron as a catalyst. Physical characterization using SEM and TEM show uniform dense coverage of multiwall carbon nanotubes (MWCNT) grown directly on graphene with seamless contacts. The G-CNT hybrid film was electrochemically modified to introduce oxygenated functional groups for DET favorable immobilization of GOx. Pristine and electrochemically functionalized G-CNT film was characterized by electrochemical impedance spectroscopy (EIS), cyclic voltammetry, X-ray photoelectron-spectroscopy, and Raman spectroscopy. The DET between GOx and electrochemically oxidized G-CNT electrode was studied using cyclic voltammetry which showed a pair of well-defined and quasi-reversible redox peaks with a formal potential of -459 mV at pH 7 corresponding to the redox site of GOx. The constructed electrode detected glucose concentration over the clinically relevant range of 2-8 mM with the highest sensitivity of 19.31 μA/mM/cm(2) compared to reported composite hybrid electrodes of graphene oxide and CNTs. Electrochemically functionalized CVD grown seamless G-CNT structure used in this work has potential to be used for development of artificial mediatorless redox enzyme based biosensors and biofuel cells.

  14. Mechanism of assembly of functional cytochrome C oxidase (CCO) in yeast Candida utilis

    International Nuclear Information System (INIS)

    Keyhani, J.

    1987-01-01

    Copper deficiency prevents the assembly of functional CCO; however it was found that both the apoprotein and porphyrin a are synthesized and integrated into the mitochondrial membrane. When copper-deficient cells are grown in copper-supplemented medium in the presence of [ 14 C]δ-aminolevulinic acid, precursor of hemes (Hms) and porphyrins (Porphs), and either chloramphenicol (Cm, inhibitor of mitochondrial protein synthesis) or cycloheximide (CHI, inhibitor of cytoplasmic protein synthesis), the amount of labeled Hms and Porphs is respectively 64% and 5.5% of the control value. When isolated mitochondria from cells grown in the presence of Cm or CHI are solubilized and incubated with antibodies against CCO, radioactivity is found to be associated with the immunoprecipitate. HCl fractionation of Hms and Porphs from the mitochondria and immunoprecipitate shows that a significant amount of radioactivity is extracted with 20% HCl which is the HCl number of porphyrin a. Data indicate that the formation of functional CCO depends on the assembly of holoenzyme, so that ferrochelatase incorporates iron into porphyrin a

  15. NADPH Oxidases: Progress and Opportunities

    OpenAIRE

    San Martin, Alejandra; Griendling, Kathy K.

    2014-01-01

    From the initial discovery in 1999 that NADPH oxidases comprise a family of enzymes to our current focus on drug development to treat multiple pathologies related to this enzyme family, progress has been swift and impressive. We have expanded our understanding of the extent of the family, the basic enzymatic biochemistry, the multiple cellular functions controlled by NADPH oxidases, and their varied roles in physiology and diseases. We have developed numerous cell culture tools, animal models...

  16. Practice and Evaluation of a Cooperative Learning Support on Educational Function as Teamwork in Project-based Learning with Regional Cooperation

    Science.gov (United States)

    Aoki, Hideyuki; Kamata, Motohiro; Yamagami, Norihisa

    The purpose of my study was to develop of cooperative learning support on Educational Function as Teamwork in Project-based Learning with Regional Cooperation. Analysis of validation of the original method were made using correlation analysis of student satisfaction of relationships among teammate and educational function as teamwork, result of self-diagnose. As a result, we achieved analysis results with a collective creativity were involved in student‧s planning skill. It was shown that educational functions as teamwork plays an important part in the growth of students. Our study revealed that there was method using cooperative learning technique helps to promote improvement of educational function as teamwork.

  17. The Successor Function and Pareto Optimal Solutions of Cooperative Differential Systems with Concavity. I

    DEFF Research Database (Denmark)

    Andersen, Kurt Munk; Sandqvist, Allan

    1997-01-01

    We investigate the domain of definition and the domain of values for the successor function of a cooperative differential system x'=f(t,x), where the coordinate functions are concave in x for any fixed value of t. Moreover, we give a characterization of a weakly Pareto optimal solution.......We investigate the domain of definition and the domain of values for the successor function of a cooperative differential system x'=f(t,x), where the coordinate functions are concave in x for any fixed value of t. Moreover, we give a characterization of a weakly Pareto optimal solution....

  18. Cooperative Control for Multiple Autonomous Vehicles Using Descriptor Functions

    Directory of Open Access Journals (Sweden)

    Marta Niccolini

    2014-01-01

    Full Text Available The paper presents a novel methodology for the control management of a swarm of autonomous vehicles. The vehicles, or agents, may have different skills, and be employed for different missions. The methodology is based on the definition of descriptor functions that model the capabilities of the single agent and each task or mission. The swarm motion is controlled by minimizing a suitable norm of the error between agents’ descriptor functions and other descriptor functions which models the entire mission. The validity of the proposed technique is tested via numerical simulation, using different task assignment scenarios.

  19. Studies on the mechanism of functional cooperativity between progesterone and estrogen receptors.

    Science.gov (United States)

    Bradshaw, M S; Tsai, S Y; Leng, X H; Dobson, A D; Conneely, O M; O'Malley, B W; Tsai, M J

    1991-09-05

    Steroid response elements (SREs) cooperate with many different cis-acting elements including NF-1 sites, CACCC boxes, and other SREs to induce target gene expression (Schule, R., Muller, M., Otsuka-Murakami, H., and Renkawitz, R. (1988) Nature 332, 87-90; Strahle, U., Schmid, W., and Schutz, G. (1988) EMBO J. 7, 3389-3395). Induction of gene expression can be additive or synergistic with respect to the level of activation by either transactivators. Two mechanisms have been proposed for how synergism occurs: 1) cooperative binding of transcriptional activators to DNA or 2) simultaneous interaction of individually bound activators with a common target protein. We have shown previously that cooperative binding of receptors is important for synergism between two progesterone response elements (PREs). Here we showed that an estrogen response element (ERE) and a PRE can also functionally cooperate and this synergism between an ERE and a PRE is not contributed by cooperative DNA binding. Furthermore, we have demonstrated that the activation domains of the progesterone receptor (PR) (C1Act) are required for synergism between two PREs and sufficient for confirming cooperative binding. However these two activation domains of PR are not sufficient for synergism between an ERE and a PRE. Additional regions within the NH2-terminal and COOH-terminal domains are also required for synergistic interaction between two heterologous SREs.

  20. Students' Perceptions of Long-Functioning Cooperative Teams in Accelerated Adult Degree Programs

    Science.gov (United States)

    Favor, Judy

    2012-01-01

    This study examined 718 adult students' perceptions of long-functioning cooperative study teams in accelerated associate's, bachelor's, and master's business degree programs. Six factors were examined: attraction toward team, alignment of performance expectations, intrateam conflict, workload sharing, preference for teamwork, and impact on…

  1. Rotator side chains trigger cooperative transition for shape and function memory effect in organic semiconductors.

    Science.gov (United States)

    Chung, Hyunjoong; Dudenko, Dmytro; Zhang, Fengjiao; D'Avino, Gabriele; Ruzié, Christian; Richard, Audrey; Schweicher, Guillaume; Cornil, Jérôme; Beljonne, David; Geerts, Yves; Diao, Ying

    2018-01-18

    Martensitic transition is a solid-state phase transition involving cooperative movement of atoms, mostly studied in metallurgy. The main characteristics are low transition barrier, ultrafast kinetics, and structural reversibility. They are rarely observed in molecular crystals, and hence the origin and mechanism are largely unexplored. Here we report the discovery of martensitic transition in single crystals of two different organic semiconductors. In situ microscopy, single-crystal X-ray diffraction, Raman and nuclear magnetic resonance spectroscopy, and molecular simulations combined indicate that the rotating bulky side chains trigger cooperative transition. Cooperativity enables shape memory effect in single crystals and function memory effect in thin film transistors. We establish a molecular design rule to trigger martensitic transition in organic semiconductors, showing promise for designing next-generation smart multifunctional materials.

  2. Internal Security Cooperation under Functional Expectations: Initial Law Enforcement Europeanization - Case of Finland and Estonia

    Directory of Open Access Journals (Sweden)

    Ramon Loik

    2016-03-01

    Full Text Available Law enforcement cooperation as a central part of the EU internal security policy to combat cross-border organised crime and terrorism needs to be more effective by adopting specific provisions and tools. This paper argues that functional expectations require removal of barriers and construction of a common security area, but sometimes better cooperation in practice does not fit, as Europeanization of law enforcement still lacks understanding of objectives, values and principles for improving international trust, consensus, sincere cooperation and effective national coordination. The level of Europeanization of law enforcement could be evaluated as based on the level of implementation of the EU provisions on police cooperation related to practical enforcement, factors promoting or hindering law enforcement and changes in discursive practices due to EU provisions and professional socialisation processes. Some aspects of observed inertia characterizes the slow process of transition or tendencies for absorption in which resilience meets the necessary degree of flexibility allowing for some mutual learning and cooperation, but the result is expectedly a form of accommodation of needful policy requirements in the lack of substantial change perspective.

  3. Spectroscopy of Cu(II)-PcoC and the multicopper oxidase function of PcoA, two essential components of Escherichia coli pco copper resistance operon.

    Science.gov (United States)

    Huffman, David L; Huyett, Jennifer; Outten, F Wayne; Doan, Peter E; Finney, Lydia A; Hoffman, Brian M; O'Halloran, Thomas V

    2002-08-06

    The plasmid-encoded pco copper resistance operon in Escherichia coli consists of seven genes that are expressed from two pco promoters in response to elevated copper; however, little is known about how they mediate resistance to excess environmental copper. Two of the genes encode the soluble periplasmic proteins PcoA and PcoC. We show here that inactivation of PcoC, and PcoA to a lesser extent, causes cells to become more sensitive to copper than wild-type nonresistant strains, consistent with a tightly coupled detoxification pathway. Periplasmic extracts show copper-inducible oxidase activity, attributed to the multicopper oxidase function of PcoA. PcoC, a much smaller protein than PcoA, binds one Cu(II) and exhibits a weak electronic transition characteristic of a type II copper center. ENDOR and ESEEM spectroscopy of Cu(II)-PcoC and the (15)N- and Met-CD(3)-labeled samples are consistent with a tetragonal ligand environment of three nitrogens and one aqua ligand "in the plane". A weakly associated S-Met and aqua are likely axial ligands. At least one N is a histidine and is likely trans to the in-plane aqua ligand. The copper chemistry of PcoC and the oxidase function of PcoA are consistent with the emerging picture of the chromosomally encoded copper homeostasis apparatus in the E. coli cell envelope [Outten, F. W., Huffman, D. L., Hale, J. A., and O'Halloran, T. V. (2001) J. Biol. Chem. 276, 30670-30677]. We propose a model for the plasmid system in which Cu(I)-PcoC functions in this copper efflux pathway as a periplasmic copper binding protein that docks with the multiple repeats of Met-rich domains in PcoA to effect oxidation of Cu(I) to the less toxic Cu(II) form. The solvent accessibility of the Cu(II) in PcoC may allow for metal transfer to other plasmid and chromosomal factors and thus facilitate removal of Cu(II) from the cell envelope.

  4. Use of Behavior and Influence Functions for Relay Selection in Cooperative Communications

    DEFF Research Database (Denmark)

    Craciunescu, Razvan; Mihovska, Albena Dimitrova; Prasad, Ramjee

    2015-01-01

    This paper uses a novel set of functions to model the relay selection process in a scenario of cooperative wireless communications. We define a utility function that reflects the behavior and influence that a selected relay may have on the quality of the link to be established for the forwarding...... of data. The utility function takes into account also the strategies of other players. To this end, we define a relay selection game and a supporting Nash Equilibrium (NE) algorithm for the choice of a relay during communication. The successful selection of a relay is evaluated by simulations in terms...

  5. Revitalization BMT and Cooperatives Function in Developing Syari'ah Economy

    Directory of Open Access Journals (Sweden)

    Ach Baihaki

    2017-03-01

    Full Text Available The growth of Islamic economics have been more improvement, as in infrastructure, assets and number of employee year of the year. But by that improvement, there are some problems to be payed attention, like development of quality of human resources in Islamic economics system with holistic approach. So that, to strengthen the character of Islamic economics system need to restore it’s concept to the nature of Islamic thought consider with the Islamic economics history and also accommodate local wisdom. To support the improvement of Islamic economics proper with ideology objectives of islam, cooperation and BMT should be have priority to increase their functions and responsibilities in economics development. Operational of cooperation and BMT will make variability of Islamic contracts more variative. Then Islamic contract by partnership approach based profit and losses sharing will have more proportions and cost of control also will be more efficient and worries about information asymmetry will be declined. It caused, awareness of partnership and togetherness to increase cooperation member welfare will be easily achived. Keywords: business entity, Islamic Financial Institutions, Cooperation, BMT Judul Asli : Revitalisasi Fungsi BMT dan Koperasi dalam Pengembangan Ekonomi Syari’ah

  6. In vitro metabolism of a linear furanocoumarin (8-methoxypsoralen, xanthotoxin) by mixed-function oxidases of larvae of black swallowtail butterfly and fall armyworm

    International Nuclear Information System (INIS)

    Bull, D.L.

    1986-01-01

    Studies were made of the comparative in vitro metabolism of ( 14 C)xanthotoxin and( 14 C)aldrin by homogenate preparations of midguts and bodies (carcass minus digestive tract and head) of last-stage larvae of the black swallowtail butterfly (Papilio polyxenes Fabr.) and the fall armyworm (Spodoptera frugiperda (J. E. Smith)). The two substrates were metabolized by 10,000g supernatant microsomal preparations from both species. Evidence gained through the use of a specific inhibitor and cofactor indicated that mixed-function microsomal oxidases were major factors in the metabolism and that the specific activity of this enzyme system was considerably higher in midgut preparations from P. polyxenes than in similar preparations from S. frugiperda. Aldrin was metabolized 3-4 times faster by P. polyxenes, and xanthotoxin 6-6.5 times faster

  7. Abnormal function of monoamine oxidase-A in comorbid major depressive disorder and cardiovascular disease: pathophysiological and therapeutic implications (review).

    Science.gov (United States)

    Machado-Vieira, Rodrigo; Mallinger, Alan G

    2012-11-01

    The association between major depressive disorder (MDD) and cardiovascular disease (CVD) is among the best described medical comorbidities. The presence of MDD increases the risk of cardiac admissions and mortality and increases healthcare costs in patients with CVD, and similarly, CVD affects the course and outcome of MDD. The potential shared biological mechanisms involved in these comorbid conditions are not well known. However, the enzyme monoamine oxidase-A (MAO-A), which has a key role in the degradation of catecholamines, has been associated with the pathophysiology and therapeutics of both MDD and CVD. Increased MAO-A activity results in the dysregulation of downstream targets of this enzyme and thus affects the pathophysiology of the two diseases. These deleterious effects include altered noradrenaline turnover, with a direct elevation in oxidative stress parameters, as well as increased platelet activity and cytokine levels. These effects were shown to be reversed by MAO inhibitors. Here, a model describing a key role for the MAO-A in comorbid MDD and CVD is proposed, with focus on the shared pathophysiological mechanisms and the potential therapeutic relevance of agents targeting this enzyme.

  8. Modular in situ-Functionalization Strategy: Multicomponent Polymerization via Palladium/Norbornene Cooperative Catalysis.

    Science.gov (United States)

    Yoon, Ki-Young; Dong, Guangbin

    2018-05-23

    Herein, we report the palladium/norbornene cooperatively catalyzed polymerization, which simplifies synthesis of functional aromatic polymers, including conjugated polymers. Specifically, an A2B2C-type multicomponent polymerization is developed using ortho-amination/ipso-alkynylation reaction for preparing various amine-functionalized arylacetylene-containing polymers. Within a single catalytic cycle, the amine side-chains are site-selectively installed in situ via C-H activation during the polymerization process, which represents a major difference from conventional cross-coupling polymerizations. This in situ-functionalization strategy enables modular incorporation of functional side-chains from simple monomers, thereby conveniently affording a diverse range of functional polymers. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. The Function Analysis of Informationization in New Rural Cooperatives Medical Service Management

    Science.gov (United States)

    Zhou, Yuefeng; Liu, Min

    The establishment of new rural cooperative medical system is an important action for comprehensive affluent society. It is an important measure for Central Party Committee and State Council to solve "three rural" issue effectively and to overall urban and rural, regional, coordinated economic and social development, building a well-off society in the new situation. It has important role to alleviate farmers to see a doctor expensively, see a doctor difficultly, reduce the burden on farmers and improve their level of health protection and quality of life, solve the problem of poor because of illness and the problem of returning poor due to illness, promote the production and rural economic development and stability in the rural areas. This article will analyze the function of informationization in new rural cooperative medical service management selectively.

  10. Enhancing Cooperativity in Bifunctional Acid–Pd Catalysts with Carboxylic Acid-Functionalized Organic Monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Coan, Patrick D. [Department of Chemical and Biological Engineering, University of Colorado—Boulder, Boulder, Colorado 80309, United States; Ellis, Lucas D. [Department of Chemical and Biological Engineering, University of Colorado—Boulder, Boulder, Colorado 80309, United States; Griffin, Michael B. [National Bioenergy Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States; Schwartz, Daniel K. [Department of Chemical and Biological Engineering, University of Colorado—Boulder, Boulder, Colorado 80309, United States; Medlin, J. Will [Department of Chemical and Biological Engineering, University of Colorado—Boulder, Boulder, Colorado 80309, United States

    2018-03-01

    Cooperative catalysts containing a combination of noble metal hydrogenation sites and Bronsted acid sites are critical for many reactions, including the deoxygenation (DO) of biomass-derived oxygenates in the upgrading of pyrolysis oil. One route toward the design of cooperative catalysts is to tether two different catalytically active functions so that they are in close proximity while avoiding undesirable interactions that can block active sites. Here, we deposited carboxylic acid (CA)-functionalized organophosphonate monolayers onto Al2O3-supported Pd nanoparticle catalysts to prepare bifunctional catalysts containing both Bronsted acid and metal sites. Modification with phosphonic acids (PAs) improved activity and selectivity for gas-phase DO reactions, but the degree of improvement was highly sensitive to both the presence and positioning of the CA group, suggesting a significant contribution from both the PA and CA sites. Short spacer lengths of 1-2 methylene groups between the phosphonate head and CA tail were found to yield the best DO rates and selectivities, whereas longer chains performed similarly to self-assembled monolayers having alkyl tails. Results from a combination of density functional theory and Fourier transform infrared spectroscopy suggested that the enhanced catalyst performance on the optimally positioned CAs was due to the generation of strong acid sites on the Al2O3 support adjacent to the metal. Furthermore, the high activity of these sites was found to result from a hydrogen-bonded cyclic structure involving cooperativity between the phosphonate head group and CA tail function. More broadly, these results indicate that functional groups tethered to supports via organic ligands can influence catalytic chemistry on metal nanoparticles.

  11. NADH oxidase functions as an adhesin in Streptococcus pneumoniae and elicits a protective immune response in mice.

    Directory of Open Access Journals (Sweden)

    Lena Muchnik

    Full Text Available The initial event in disease caused by S. pneumoniae is adhesion of the bacterium to respiratory epithelial cells, mediated by surface expressed molecules including cell-wall proteins. NADH oxidase (NOX, which reduces free oxygen to water in the cytoplasm, was identified in a non-lectin enriched pneumococcal cell-wall fraction. Recombinant NOX (rNOX was screened with sera obtained longitudinally from children and demonstrated age-dependent immunogenicity. NOX ablation in S. pneumoniae significantly reduced bacterial adhesion to A549 epithelial cells in vitro and their virulence in the intranasal or intraperitoneal challenge models in mice, compared to the parental strain. Supplementation of Δnox WU2 with the nox gene restored its virulence. Saturation of A549 target cells with rNOX or neutralization of cell-wall residing NOX using anti-rNOX antiserum decreased adhesion to A549 cells. rNOX-binding phages inhibited bacterial adhesion. Moreover, peptides derived from the human proteins contactin 4, chondroitin 4 sulfotraferase and laminin5, homologous to the insert peptides in the neutralizing phages, inhibited bacterial adhesion to the A549 cells. Furthermore, rNOX immunization of mice elicited a protective immune response to intranasal or intraperitoneal S. pneumoniae challenge, whereas pneumococcal virulence was neutralized by anti-rNOX antiserum prior to intraperitoneal challenge. Our results suggest that in addition to its enzymatic activity, NOX contributes to S. pneumoniae virulence as a putative adhesin and thus peptides derived from its target molecules may be considered for the treatment of pneumococcal infections. Finally, rNOX elicited a protective immune response in both aerobic and anaerobic environments, which renders NOX a candidate for future pneumococcal vaccine.

  12. Peroxidasin-mediated crosslinking of collagen IV is independent of NADPH oxidases

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    Gábor Sirokmány

    2018-06-01

    Full Text Available Collagen IV is a major component of the basement membrane in epithelial tissues. The NC1 domains of collagen IV protomers are covalently linked together through sulfilimine bonds, the formation of which is catalyzed by peroxidasin. Although hydrogen peroxide is essential for this reaction, the exact source of the oxidant remains elusive. Members of the NOX/DUOX NADPH oxidase family are specifically devoted to the production of superoxide and hydrogen peroxide. Our aim in this study was to find out if NADPH oxidases contribute in vivo to the formation of collagen IV sulfilimine crosslinks. We used multiple genetically modified in vivo model systems to provide a detailed assessment of this question. Our data indicate that in various peroxidasin-expressing tissues sulfilimine crosslinks between the NC1 domains of collagen IV can be readily detected in the absence of functioning NADPH oxidases. We also analyzed how subatmospheric oxygen levels influence the collagen IV network in collagen-producing cultured cells with rapid matrix turnover. We showed that collagen IV crosslinks remain intact even under strongly hypoxic conditions. Our hypothesis is that during collagen IV network formation PXDN cooperates with a NOX/DUOX-independent H2O2 source that is functional also at very low ambient oxygen levels. Keywords: Peroxidasin, NADPH oxidase, Hydrogen peroxide, Collagen IV, Sulfilimine

  13. Cooperative Fuzzy Games Approach to Setting Target Levels of ECs in Quality Function Deployment

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    Zhihui Yang

    2014-01-01

    Full Text Available Quality function deployment (QFD can provide a means of translating customer requirements (CRs into engineering characteristics (ECs for each stage of product development and production. The main objective of QFD-based product planning is to determine the target levels of ECs for a new product or service. QFD is a breakthrough tool which can effectively reduce the gap between CRs and a new product/service. Even though there are conflicts among some ECs, the objective of developing new product is to maximize the overall customer satisfaction. Therefore, there may be room for cooperation among ECs. A cooperative game framework combined with fuzzy set theory is developed to determine the target levels of the ECs in QFD. The key to develop the model is the formulation of the bargaining function. In the proposed methodology, the players are viewed as the membership functions of ECs to formulate the bargaining function. The solution for the proposed model is Pareto-optimal. An illustrated example is cited to demonstrate the application and performance of the proposed approach.

  14. Cooperative fuzzy games approach to setting target levels of ECs in quality function deployment.

    Science.gov (United States)

    Yang, Zhihui; Chen, Yizeng; Yin, Yunqiang

    2014-01-01

    Quality function deployment (QFD) can provide a means of translating customer requirements (CRs) into engineering characteristics (ECs) for each stage of product development and production. The main objective of QFD-based product planning is to determine the target levels of ECs for a new product or service. QFD is a breakthrough tool which can effectively reduce the gap between CRs and a new product/service. Even though there are conflicts among some ECs, the objective of developing new product is to maximize the overall customer satisfaction. Therefore, there may be room for cooperation among ECs. A cooperative game framework combined with fuzzy set theory is developed to determine the target levels of the ECs in QFD. The key to develop the model is the formulation of the bargaining function. In the proposed methodology, the players are viewed as the membership functions of ECs to formulate the bargaining function. The solution for the proposed model is Pareto-optimal. An illustrated example is cited to demonstrate the application and performance of the proposed approach.

  15. Cooperative Control for A Hybrid Rehabilitation System Combining Functional Electrical Stimulation and Robotic Exoskeleton

    Directory of Open Access Journals (Sweden)

    Dingguo Zhang

    2017-12-01

    Full Text Available Functional electrical stimulation (FES and robotic exoskeletons are two important technologies widely used for physical rehabilitation of paraplegic patients. We developed a hybrid rehabilitation system (FEXO Knee that combined FES and an exoskeleton for swinging movement control of human knee joints. This study proposed a novel cooperative control strategy, which could realize arbitrary distribution of torque generated by FES and exoskeleton, and guarantee harmonic movements. The cooperative control adopted feedfoward control for FES and feedback control for exoskeleton. A parameter regulator was designed to update key parameters in real time to coordinate FES controller and exoskeleton controller. Two muscle groups (quadriceps and hamstrings were stimulated to generate active torque for knee joint in synchronization with torque compensation from exoskeleton. The knee joint angle and the interactive torque between exoskeleton and shank were used as feedback signals for the control system. Central pattern generator (CPG was adopted that acted as a phase predictor to deal with phase confliction of motor patterns, and realized synchronization between the two different bodies (shank and exoskeleton. Experimental evaluation of the hybrid FES-exoskeleton system was conducted on five healthy subjects and four paraplegic patients. Experimental results and statistical analysis showed good control performance of the cooperative control on torque distribution, trajectory tracking, and phase synchronization.

  16. Cooperative Control for A Hybrid Rehabilitation System Combining Functional Electrical Stimulation and Robotic Exoskeleton.

    Science.gov (United States)

    Zhang, Dingguo; Ren, Yong; Gui, Kai; Jia, Jie; Xu, Wendong

    2017-01-01

    Functional electrical stimulation (FES) and robotic exoskeletons are two important technologies widely used for physical rehabilitation of paraplegic patients. We developed a hybrid rehabilitation system (FEXO Knee) that combined FES and an exoskeleton for swinging movement control of human knee joints. This study proposed a novel cooperative control strategy, which could realize arbitrary distribution of torque generated by FES and exoskeleton, and guarantee harmonic movements. The cooperative control adopted feedfoward control for FES and feedback control for exoskeleton. A parameter regulator was designed to update key parameters in real time to coordinate FES controller and exoskeleton controller. Two muscle groups (quadriceps and hamstrings) were stimulated to generate active torque for knee joint in synchronization with torque compensation from exoskeleton. The knee joint angle and the interactive torque between exoskeleton and shank were used as feedback signals for the control system. Central pattern generator (CPG) was adopted that acted as a phase predictor to deal with phase confliction of motor patterns, and realized synchronization between the two different bodies (shank and exoskeleton). Experimental evaluation of the hybrid FES-exoskeleton system was conducted on five healthy subjects and four paraplegic patients. Experimental results and statistical analysis showed good control performance of the cooperative control on torque distribution, trajectory tracking, and phase synchronization.

  17. A role for NADPH oxidase in antigen presentation

    Directory of Open Access Journals (Sweden)

    Gail J Gardiner

    2013-09-01

    Full Text Available The nicotinamide adenine dinucleotide phosphate (NADPH oxidase expressed in phagocytes is a multi-subunit enzyme complex that generates superoxide (O2.-. This radical is an important precursor of hydrogen peroxide (H2O2 and other reactive oxygen species (ROS needed for microbicidal activity during innate immune responses. Inherited defects in NADPH oxidase give rise to chronic granulomatous disease (CGD, a primary immunodeficiency characterized by recurrent infections and granulomatous inflammation. Interestingly, CGD, CGD carrier status, and oxidase gene polymorphisms have all been associated with autoinflammatory and autoimmune disorders, suggesting a potential role for NADPH oxidase in regulating adaptive immune responses. Here, NADPH oxidase function in antigen processing and presentation is reviewed. NADPH oxidase influences dendritic cell (DC crosspresentation by major histocompatibility complex class I molecules (MHC-I through regulation of the phagosomal microenvironment, while in B lymphocytes, NADPH oxidase alters epitope selection by major histocompatibility complex class II molecules (MHC-II.

  18. Functional asymmetry and interhemispheric cooperation in the perception of emotions from facial expressions.

    Science.gov (United States)

    Tamietto, Marco; Latini Corazzini, Luca; de Gelder, Beatrice; Geminiani, Giuliano

    2006-05-01

    The present study used the redundant target paradigm on healthy subjects to investigate functional hemispheric asymmetries and interhemispheric cooperation in the perception of emotions from faces. In Experiment 1 participants responded to checkerboards presented either unilaterally to the left (LVF) or right visual half field (RVF), or simultaneously to both hemifields (BVF), while performing a pointing task for the control of eye movements. As previously reported (Miniussi et al. in J Cogn Neurosci 10:216-230, 1998), redundant stimulation led to shorter latencies for stimulus detection (bilateral gain or redundant target effect, RTE) that exceeded the limit for a probabilistic interpretation, thereby validating the pointing procedure and supporting interhemispheric cooperation. In Experiment 2 the same pointing procedure was used in a go/no-go task requiring subjects to respond when seeing a target emotional expression (happy or fearful, counterbalanced between blocks). Faster reaction times to unilateral LVF than RVF emotions, regardless of valence, indicate that the perception of positive and negative emotional faces is lateralized toward the right hemisphere. Simultaneous presentation of two congruent emotional faces, either happy or fearful, produced an RTE that cannot be explained by probability summation and suggests interhemispheric cooperation and neural summation. No such effect was present with BVF incongruent facial expressions. In Experiment 3 we studied whether the RTE for emotional faces depends on the physical identity between BVF stimuli, and we set a second BVF congruent condition in which there was only emotional but not physical or gender identity between stimuli (i.e. two different faces expressing the same emotion). The RTE and interhemispheric cooperation were present also in this second BVF congruent condition. This shows that emotional congruency is the sufficient condition for the RTE to take place in the intact brain and that the

  19. Direct electrochemical sensing of glucose using glucose oxidase immobilized on functionalized carbon nanotubes via a novel metal chelate-based affinity method

    International Nuclear Information System (INIS)

    Tu, X.; Zhao, Y.; Luo, S.; Luo, X.; Feng, L.

    2012-01-01

    We report on a novel amperometric glassy carbon biosensing electrode for glucose. It is based on the immobilization of a highly sensitive glucose oxidase (GOx) by affinity interaction on carbon nanotubes (CNTs) functionalized with iminodiacetic acid and metal chelates. The new technique for immobilization is exploiting the affinity of Co(II) ions to the histidine and cysteine moieties on the surface of GOx. The direct electrochemistry of immobilized GOx revealed that the functionalized CNTs greatly improve the direct electron transfer between GOx and the surface of the electrode to give a pair of well-defined and almost reversible redox peaks and undergoes fast heterogeneous electron transfer with a rate constant (k s) of 0. 59 s -1 . The GOx immobilized in this way fully retained its activity for the oxidation of glucose. The resulting biosensor is capable of detecting glucose at levels as low as 0.01 mM, and has excellent operational stability (with no decrease in the activity of enzyme over a 10 days period). The method of immobilizing GOx is easy and also provides a model technique for potential use with other redox enzymes and proteins. (author)

  20. Layer-by-Layer Self-Assembling Gold Nanorods and Glucose Oxidase onto Carbon Nanotubes Functionalized Sol-Gel Matrix for an Amperometric Glucose Biosensor.

    Science.gov (United States)

    Wu, Baoyan; Hou, Shihua; Miao, Zhiying; Zhang, Cong; Ji, Yanhong

    2015-09-18

    A novel amperometric glucose biosensor was fabricated by layer-by-layer self-assembly of gold nanorods (AuNRs) and glucose oxidase (GOD) onto single-walled carbon nanotubes (SWCNTs)-functionalized three-dimensional sol-gel matrix. A thiolated aqueous silica sol containing SWCNTs was first assembled on the surface of a cleaned Au electrode, and then the alternate self-assembly of AuNRs and GOD were repeated to assemble multilayer films of AuNRs-GOD onto SWCNTs-functionalized silica gel for optimizing the biosensor. Among the resulting glucose biosensors, the four layers of AuNRs-GOD-modified electrode showed the best performance. The sol-SWCNTs-(AuNRs- GOD)₄/Au biosensor exhibited a good linear range of 0.01-8 mM glucose, high sensitivity of 1.08 μA/mM, and fast amperometric response within 4 s. The good performance of the proposed glucose biosensor could be mainly attributed to the advantages of the three-dimensional sol-gel matrix and stereo self-assembly films, and the natural features of one-dimensional nanostructure SWCNTs and AuNRs. This study may provide a new facile way to fabricate the enzyme-based biosensor with high performance.

  1. Layer-by-Layer Self-Assembling Gold Nanorods and Glucose Oxidase onto Carbon Nanotubes Functionalized Sol-Gel Matrix for an Amperometric Glucose Biosensor

    Directory of Open Access Journals (Sweden)

    Baoyan Wu

    2015-09-01

    Full Text Available A novel amperometric glucose biosensor was fabricated by layer-by-layer self-assembly of gold nanorods (AuNRs and glucose oxidase (GOD onto single-walled carbon nanotubes (SWCNTs-functionalized three-dimensional sol-gel matrix. A thiolated aqueous silica sol containing SWCNTs was first assembled on the surface of a cleaned Au electrode, and then the alternate self-assembly of AuNRs and GOD were repeated to assemble multilayer films of AuNRs-GOD onto SWCNTs-functionalized silica gel for optimizing the biosensor. Among the resulting glucose biosensors, the four layers of AuNRs-GOD-modified electrode showed the best performance. The sol-SWCNTs-(AuNRs- GOD4/Au biosensor exhibited a good linear range of 0.01–8 mM glucose, high sensitivity of 1.08 μA/mM, and fast amperometric response within 4 s. The good performance of the proposed glucose biosensor could be mainly attributed to the advantages of the three-dimensional sol-gel matrix and stereo self-assembly films, and the natural features of one-dimensional nanostructure SWCNTs and AuNRs. This study may provide a new facile way to fabricate the enzyme-based biosensor with high performance.

  2. Roothairless5, which functions in maize (Zea mays L.) root hair initiation and elongation encodes a monocot-specific NADPH oxidase.

    Science.gov (United States)

    Nestler, Josefine; Liu, Sanzhen; Wen, Tsui-Jung; Paschold, Anja; Marcon, Caroline; Tang, Ho Man; Li, Delin; Li, Li; Meeley, Robert B; Sakai, Hajime; Bruce, Wesley; Schnable, Patrick S; Hochholdinger, Frank

    2014-09-01

    Root hairs are instrumental for nutrient uptake in monocot cereals. The maize (Zea mays L.) roothairless5 (rth5) mutant displays defects in root hair initiation and elongation manifested by a reduced density and length of root hairs. Map-based cloning revealed that the rth5 gene encodes a monocot-specific NADPH oxidase. RNA-Seq, in situ hybridization and qRT-PCR experiments demonstrated that the rth5 gene displays preferential expression in root hairs but also accumulates to low levels in other tissues. Immunolocalization detected RTH5 proteins in the epidermis of the elongation and differentiation zone of primary roots. Because superoxide and hydrogen peroxide levels are reduced in the tips of growing rth5 mutant root hairs as compared with wild-type, and Reactive oxygen species (ROS) is known to be involved in tip growth, we hypothesize that the RTH5 protein is responsible for establishing the high levels of ROS in the tips of growing root hairs required for elongation. Consistent with this hypothesis, a comparative RNA-Seq analysis of 6-day-old rth5 versus wild-type primary roots revealed significant over-representation of only two gene ontology (GO) classes related to the biological functions (i.e. oxidation/reduction and carbohydrate metabolism) among 893 differentially expressed genes (FDR <5%). Within these two classes the subgroups 'response to oxidative stress' and 'cellulose biosynthesis' were most prominently represented. © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

  3. Glucose oxidase-initiated cascade catalysis for sensitive impedimetric aptasensor based on metal-organic frameworks functionalized with Pt nanoparticles and hemin/G-quadruplex as mimicking peroxidases.

    Science.gov (United States)

    Zhou, Xingxing; Guo, Shijing; Gao, Jiaxi; Zhao, Jianmin; Xue, Shuyan; Xu, Wenju

    2017-12-15

    Based on cascade catalysis amplification driven by glucose oxidase (GOx), a sensitive electrochemical impedimetric aptasensor for protein (carcinoembryonic antigen, CEA as tested model) was proposed by using Cu-based metal-organic frameworks functionalized with Pt nanoparticles, aptamer, hemin and GOx (Pt@CuMOFs-hGq-GOx). CEA aptamer loaded onto Pt@CuMOFs was bound with hemin to form hemin@G-quadruplex (hGq) with mimicking peroxidase activity. Through sandwich-type reaction of target CEA and CEA aptamers (Apt1 and Apt2), the obtained Pt@CuMOFs-hGq-GOx as signal transduction probes (STPs) was captured to the modified electrode interface. When 3,3-diaminobenzidine (DAB) and glucose were introduced, the cascade reaction was initiated by GOx to catalyze the oxidation of glucose, in situ generating H 2 O 2 . Simultaneously, the decomposition of the generated H 2 O 2 was greatly promoted by Pt@CuMOFs and hGq as synergistic peroxide catalysts, accompanying with the significant oxidation process of DAB and the formation of nonconductive insoluble precipitates (IPs). As a result, the electron transfer in the resultant sensing interface was effectively hindered and the electrochemical impedimetric signal (EIS) was efficiently amplified. Thus, the high sensitivity of the proposed CEA aptasensor was successfully improved with 0.023pgmL -1 , which may be promising and potential in assaying certain clinical disease related to CEA. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. A novel electrochemical immunosensor using β-cyclodextrins functionalized silver supported adamantine-modified glucose oxidase as labels for ultrasensitive detection of alpha-fetoprotein.

    Science.gov (United States)

    Gao, Jian; Ma, Hongmin; Lv, Xiaohui; Yan, Tao; Li, Na; Cao, Wei; Wei, Qin

    2015-09-17

    In this work, a novel sandwich-type electrochemical immunosensor based on host-guest interaction was fabricated for the detection of alpha-fetoprotein (AFP). Due to the large specific surface area of multiwalled carbon nanotubes and the unique supramolecular recognition ability of β-cyclodextrins, ferrocenecarboxylic acid (Fc) was incorporated into this sensor platform by host-guest interaction to generate an electrochemical signal. And β-cyclodextrins functionalized silver supported adamantine-modified glucose oxidase (GOD-CD-Ag), was used as a label to improve the analytical performance of the immunosensor by the dual amplification strategy. The obtained GOD-CD-Ag conjugates could convert glucose into gluconic acid with the formation of hydrogen peroxide (H2O2). And then silver nanoparticles could in situ catalyze the reduction of the generated H2O2, dramatically improving the oxidation reaction of Fc. The developed immunosensor shows a wide linear calibration range from 0.001 to 5.0 ng/mL with a low detection limit (0.2 pg/mL) for the detection of AFP. The method, with ideal reproducibility and selectivity, has a wide application prospect in clinical research. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. On the structure and function of the phytoene desaturase CRTI from Pantoea ananatis, a membrane-peripheral and FAD-dependent oxidase/isomerase.

    Directory of Open Access Journals (Sweden)

    Patrick Schaub

    Full Text Available CRTI-type phytoene desaturases prevailing in bacteria and fungi can form lycopene directly from phytoene while plants employ two distinct desaturases and two cis-tans isomerases for the same purpose. This property renders CRTI a valuable gene to engineer provitamin A-formation to help combat vitamin A malnutrition, such as with Golden Rice. To understand the biochemical processes involved, recombinant CRTI was produced and obtained in homogeneous form that shows high enzymatic activity with the lipophilic substrate phytoene contained in phosphatidyl-choline (PC liposome membranes. The first crystal structure of apo-CRTI reveals that CRTI belongs to the flavoprotein superfamily comprising protoporphyrinogen IX oxidoreductase and monoamine oxidase. CRTI is a membrane-peripheral oxidoreductase which utilizes FAD as the sole redox-active cofactor. Oxygen, replaceable by quinones in its absence, is needed as the terminal electron acceptor. FAD, besides its catalytic role also displays a structural function by enabling the formation of enzymatically active CRTI membrane associates. Under anaerobic conditions the enzyme can act as a carotene cis-trans isomerase. In silico-docking experiments yielded information on substrate binding sites, potential catalytic residues and is in favor of single half-site recognition of the symmetrical C(40 hydrocarbon substrate.

  6. [The effect of monensin, tiamulin and the simultaneous administration of both substances on the microsomal mixed function oxidases and on the peroxide formation in broilers].

    Science.gov (United States)

    Laczay, P; Simon, F; Lehel, J

    1990-09-01

    The influence of Monensin, Tiamulin and the simultaneous administration of the two substances on the microsomal, mixed function oxidases was studied on cockerels. Monensin was seen to cause a slight depression in the amount of cytochrome P-450 and cytochrome b5 as well as in the activities of aniline-p-hydroxylase, p-nitrophenol-hydroxylase and p-nitroanisole-O-demethylase. Tiamulin induced a moderate increase in the amount of cytochrome P-450 and in the activities of aniline-p-hydroxylase, p-nitrophenol-hydroxylase and aminopyrine-N-demethylase. The combined administration of monensin and tiamulin resulted in marked induction of the microsomal enzymes; the amount of cytochrome P-450 reduced by metyrapone or carbon monoxide increased 2.5 or 2-times, respectively, and the activities of the tested microsomal hydroxylases and demethylases showed also an expressed increase. At the same time the formation of lipid peroxides also markedly increased and the GSH concentration was reduced. In conclusion, the results of the investigations indicate that the simultaneous application of monensin and tiamulin cause a marked induction of the drug-metabolizing microsomal enzymes and a significant increase in the lipid peroxide formation.

  7. Interaction of L-lysine and soluble elastin with the semicarbazide-sensitive amine oxidase in the context of its vascular-adhesion and tissue maturation functions.

    LENUS (Irish Health Repository)

    Olivieri, Aldo

    2010-04-01

    The copper-containing quinoenzyme semicarbazide-sensitive amine oxidase (EC 1.4.3.21; SSAO) is a multifunctional protein. In some tissues, such as the endothelium, it also acts as vascular-adhesion protein 1 (VAP-1), which is involved in inflammatory responses and in the chemotaxis of leukocytes. Earlier work had suggested that lysine might function as a recognition molecule for SSAO\\/VAP-1. The present work reports the kinetics of the interaction of L-lysine and some of its derivatives with SSAO. Binding was shown to be saturable, time-dependent but reversible and to cause uncompetitive inhibition with respect to the amine substrate. It was also specific, since D-lysine, L-lysine ethyl ester and epsilon-acetyl-L-lysine, for example, did not bind to the enzyme. The lysine-rich protein soluble elastin bound to the enzyme relatively tightly, which may have relevance to the reported roles of SSAO in maintaining the extracellular matrix (ECM) and in the maturation of elastin. Our data show that lysyl residues are not oxidized by SSAO, but they bind tightly to the enzyme in the presence of hydrogen peroxide. This suggests that binding in vivo of SSAO to lysyl residues in physiological targets might be regulated in the presence of H(2)O(2), formed during the oxidation of a physiological SSAO substrate, yet to be identified.

  8. Correlation between mixed-function oxidase enzyme induction and aflatoxin B1-induced unscheduled DNA synthesis in the chick embryo, in vivo

    International Nuclear Information System (INIS)

    Hamilton, J.W.; Bloom, S.E.

    1984-01-01

    The unscheduled DNA synthesis (UDS) technique has been adapted for use in the chick embryo, in vivo, to determine the relationship between induction of the mixed-function oxidase (MFO) enzyme system and genetic damage from an indirect-acting mutagen-carcinogen. Embryos were injected at 6 days of incubation (DI) with either phenobarbital (PB), a specific inducer of P-450-associated enzyme activities, or 3,4,3',4'-tetrachlorobiphenyl (TCB), a specific inducer of P 1 -450-associated enzyme activities. Aflatoxin B 1 (AFB1) was injected 24 hr later (7 DI), followed by a 5-hr continuous 3 H-thymidine exposure. The livers were removed, prepared for autoradiography, and hepatocytes were scored for an increase in grains/nucleus, indicative of UDS. Aflatoxin B 1 caused a dose-related increase in UDS in all control and induction groups. Phenobarbital-induced embryos had an increased UDS response while TCB-induced embryos had a decreased UDS response, relative to noninduced embryos, for each dosage of AFB1. This suggests that the genotoxicity of an indirect-acting mutagen-carcinogen can be either increased or decreased, in vivo, depending on the inducer used. The chick embryo provides an excellent system for studying the effect of MFO induction on the genotoxicity of promutagen-carcinogens in a developing system

  9. Expression and functional analysis of the lysine decarboxylase and copper amine oxidase genes from the endophytic fungus Colletotrichum gloeosporioides ES026.

    Science.gov (United States)

    Zhang, Xiangmei; Wang, Zhangqian; Jan, Saad; Yang, Qian; Wang, Mo

    2017-06-05

    Huperzine A (HupA) isolated from Huperzia serrata is an important compound used to treat Alzheimer's disease (AD). Recently, HupA was reported in various endophytic fungi, with Colletotrichum gloeosporioides ES026 previously isolated from H. serrata shown to produce HupA. In this study, we performed next-generation sequencing and de novo RNA sequencing of C. gloeosporioides ES026 to elucidate the molecular functions, biological processes, and biochemical pathways of these unique sequences. Gene ontology and Kyoto Encyclopedia of Genes and Genomes assignments allowed annotation of lysine decarboxylase (LDC) and copper amine oxidase (CAO) for their conversion of L-lysine to 5-aminopentanal during HupA biosynthesis. Additionally, we constructed a stable, high-yielding HupA-expression system resulting from the overexpression of CgLDC and CgCAO from the HupA-producing endophytic fungus C. gloeosporioides ES026 in Escherichia coli. Quantitative reverse transcription polymerase chain reaction analysis confirmed CgLDC and CgCAO expression, and quantitative determination of HupA levels was assessed by liquid chromatography high-resolution mass spectrometry, which revealed that elevated expression of CgLDC and CgCAO produced higher yields of HupA than those derived from C. gloeosporioides ES026. These results revealed CgLDC and CgCAO involvement in HupA biosynthesis and their key role in regulating HupA content in C. gloeosporioides ES026.

  10. Mixed function oxidase induction in Carcinus aestuarii. Field and experimental studies for the evaluation of toxicological risk due to Mediterranean contaminants

    International Nuclear Information System (INIS)

    Fossi, M.C.; Savelli, C.; Casini, S.

    1998-01-01

    The aim of this study was to test and validate the use of mixed function oxidase (MFO) induction, in the crab Carcinus aestuarii, under experimental and field studies, for the evaluation of toxicological risk due to the main contaminants in the Mediterranean. Two different experiments were performed in the laboratory in order to identify the most suitable tissues for MFO studies in this species and the most suitable and sensitive MFO responses for evaluating chemical stress due to lipophilic contaminants. In order to validate this methodology in the field, two studies were carried out in two polluted Mediterranean lagoons: a transplant experiment in Orbetello Lagoon and an in situ experiment in Venice Lagoon. The following MFO responses were investigated in hepatopancres and gills of the crabs: ethoxyresorufin-O-deethylase (EROD) and benzo(a)pyrene hydroxylase (BPH) activities and reductase enzyme activities. The main results can be summarised as follows: midgut-gland and gills were confirmed to be useful for MFO tests; BPH activity in hepatopancreas was the most suitable and sensitive MFO response for evaluating chemical stress due to Mediterranean contaminants in laboratory and field studies; in the Orbetello Lagoon experiment, a statistically significant difference was found between sites subject to different human impact. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. Monoamine Oxidase Inhibitors (MAOIs)

    Science.gov (United States)

    ... health-medications/index.shtml. Accessed May 16, 2016. Hirsch M, et al. Monoamine oxidase inhibitors (MAOIs) for ... www.uptodate.com/home. Accessed May 16, 2016. Hirsch M, et al. Discontinuing antidepressant medications in adults. ...

  12. The role of oligomerization and cooperative regulation in protein function: the case of tryptophan synthase.

    Directory of Open Access Journals (Sweden)

    M Qaiser Fatmi

    Full Text Available The oligomerization/co-localization of protein complexes and their cooperative regulation in protein function is a key feature in many biological systems. The synergistic regulation in different subunits often enhances the functional properties of the multi-enzyme complex. The present study used molecular dynamics and Brownian dynamics simulations to study the effects of allostery, oligomerization and intermediate channeling on enhancing the protein function of tryptophan synthase (TRPS. TRPS uses a set of α/β-dimeric units to catalyze the last two steps of L-tryptophan biosynthesis, and the rate is remarkably slower in the isolated monomers. Our work shows that without their binding partner, the isolated monomers are stable and more rigid. The substrates can form fairly stable interactions with the protein in both forms when the protein reaches the final ligand-bound conformations. Our simulations also revealed that the α/β-dimeric unit stabilizes the substrate-protein conformation in the ligand binding process, which lowers the conformation transition barrier and helps the protein conformations shift from an open/inactive form to a closed/active form. Brownian dynamics simulations with a coarse-grained model illustrate how protein conformations affect substrate channeling. The results highlight the complex roles of protein oligomerization and the fine balance between rigidity and dynamics in protein function.

  13. Testing the ecotoxicology of vegetable versus mineral based lubricating oils: 2. Induction of mixed function oxidase enzymes in barramundi, Lates calcarifer, a tropical fish species

    Energy Technology Data Exchange (ETDEWEB)

    Mercurio, Philip; Burns, Kathryn A.; Cavanagh, Joanne

    2004-05-01

    An increasing number of vegetable-based oils are being developed as environmentally friendly alternatives to petroleum products. However, toxicity towards key tropical marine species has not been investigated. In this study we used laboratory-based biomarker induction experiments to compare the relative stress of a vegetable-based lubricating oil for marine 2-stroke engines with its mineral oil-based counterpart on tropical fish. The sub-lethal stress of 2-stoke outboard lubricating oils towards the fish Lates calcarifer (barramundi) was examined using liver microsomal mixed function oxidase (MFO) induction assays. This study is the first investigation into the use of this key commercial species in tropical North Queensland, Australia in stress assessment of potential hydrocarbon pollution using ethoxyresorufin O-deethylase (EROD) induction. Our results indicated that barramundi provide a wide range of inducible rates of EROD activity in response to relevant organic stressors. The vegetable- and mineral-based lubricants induced significant EROD activity at 1.0 mg kg{sup -1} and there was no significant difference between the two oil treatments at that concentration. At increasing concentrations of 2 and 3 mg kg{sup -1}, the mineral-based lubricant resulted in slightly higher EROD activity than the vegetable-based lubricant. The EROD activity of control and treated barramundi are found to be within ranges for other species from temperate and tropical environments. These results indicate that vegetable-based lubricants may be less stressful to barramundi than their mineral counterparts at concentrations of lubricant {>=}2 mg kg{sup -1}. There is great potential for this species to be used in the biomonitoring of waterways around tropical North Queensland and SE Asia. - Vegetable-based lubricating oils appear to cause a tropical fish species less stress than mineral oils.

  14. Xanthine oxidase functionalized Ta2O5 nanostructures as a novel scaffold for highly sensitive SPR based fiber optic xanthine sensor.

    Science.gov (United States)

    Kant, Ravi; Tabassum, Rana; Gupta, Banshi D

    2018-01-15

    Fabrication and characterization of a surface plasmon resonance based fiber optic xanthine sensor using entrapment of xanthine oxidase (XO) enzyme in several nanostructures of tantalum (v) oxide (Ta 2 O 5 ) have been reported. Chemical route was adopted for synthesizing Ta 2 O 5 nanoparticles, nanorods, nanotubes and nanowires while Ta 2 O 5 nanofibers were prepared by electrospinning technique. The synthesized Ta 2 O 5 nanostructures were characterized by photoluminescence, scanning electron microscopy, UV-Visible spectra and X-ray diffraction pattern. The probes were fabricated by coating an unclad core of the fiber with silver layer followed by the deposition of XO entrapped Ta 2 O 5 nanostructures. The crux of sensing mechanism relies on the modification of dielectric function of sensing layer upon exposure to xanthine solution of diverse concentrations, reflected in terms of shift in resonance wavelength. The sensing probe coated with XO entrapped Ta 2 O 5 nanofibers has been turned out to possess maximum sensitivity amongst the synthesized nanostructures. The probe was optimized in terms of pH of the sample and the concentration of XO entrapped in Ta 2 O 5 nanofibers. The optimized sensing probe possesses a remarkably good sensitivity of 26.2nm/µM in addition to linear range from 0 to 3µM with an invincible LOD value of 0.0127µM together with a response time of 1min. Furthermore, probe selectivity with real sample analysis ensure the usage of the sensor for practical scenario. The results reported open a novel perspective towards a sensitive, rapid, reliable and selective detection of xanthine. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Testing the ecotoxicology of vegetable versus mineral based lubricating oils: 2. Induction of mixed function oxidase enzymes in barramundi, Lates calcarifer, a tropical fish species

    International Nuclear Information System (INIS)

    Mercurio, Philip; Burns, Kathryn A.; Cavanagh, Joanne

    2004-01-01

    An increasing number of vegetable-based oils are being developed as environmentally friendly alternatives to petroleum products. However, toxicity towards key tropical marine species has not been investigated. In this study we used laboratory-based biomarker induction experiments to compare the relative stress of a vegetable-based lubricating oil for marine 2-stroke engines with its mineral oil-based counterpart on tropical fish. The sub-lethal stress of 2-stoke outboard lubricating oils towards the fish Lates calcarifer (barramundi) was examined using liver microsomal mixed function oxidase (MFO) induction assays. This study is the first investigation into the use of this key commercial species in tropical North Queensland, Australia in stress assessment of potential hydrocarbon pollution using ethoxyresorufin O-deethylase (EROD) induction. Our results indicated that barramundi provide a wide range of inducible rates of EROD activity in response to relevant organic stressors. The vegetable- and mineral-based lubricants induced significant EROD activity at 1.0 mg kg -1 and there was no significant difference between the two oil treatments at that concentration. At increasing concentrations of 2 and 3 mg kg -1 , the mineral-based lubricant resulted in slightly higher EROD activity than the vegetable-based lubricant. The EROD activity of control and treated barramundi are found to be within ranges for other species from temperate and tropical environments. These results indicate that vegetable-based lubricants may be less stressful to barramundi than their mineral counterparts at concentrations of lubricant ≥2 mg kg -1 . There is great potential for this species to be used in the biomonitoring of waterways around tropical North Queensland and SE Asia. - Vegetable-based lubricating oils appear to cause a tropical fish species less stress than mineral oils

  16. High-performance glucose biosensor based on chitosan-glucose oxidase immobilized polypyrrole/Nafion/functionalized multi-walled carbon nanotubes bio-nanohybrid film.

    Science.gov (United States)

    Shrestha, Bishnu Kumar; Ahmad, Rafiq; Mousa, Hamouda M; Kim, In-Gi; Kim, Jeong In; Neupane, Madhav Prasad; Park, Chan Hee; Kim, Cheol Sang

    2016-11-15

    A highly electroactive bio-nanohybrid film of polypyrrole (PPy)-Nafion (Nf)-functionalized multi-walled carbon nanotubes (fMWCNTs) nanocomposite was prepared on the glassy carbon electrode (GCE) by a facile one-step electrochemical polymerization technique followed by chitosan-glucose oxidase (CH-GOx) immobilization on its surface to achieve a high-performance glucose biosensor. The as-fabricated nanohybrid composite provides high surface area for GOx immobilization and thus enhances the enzyme-loading efficiency. The structural characterization revealed that the PPy-Nf-fMWCNTs nanocomposite films were uniformly formed on GCE and after GOx immobilization, the surface porosities of the film were decreased due to enzyme encapsulation inside the bio-nanohybrid composite materials. The electrochemical behavior of the fabricated biosensor was investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and amperometry measurements. The results indicated an excellent catalytic property of bio-nanohybrid film for glucose detection with improved sensitivity of 2860.3μAmM(-1)cm(-2), the linear range up to 4.7mM (R(2)=0.9992), and a low detection limit of 5μM under a signal/noise (S/N) ratio of 3. Furthermore, the resulting biosensor presented reliable selectivity, better long-term stability, good repeatability, reproducibility, and acceptable measurement of glucose concentration in real serum samples. Thus, this fabricated biosensor provides an efficient and highly sensitive platform for glucose sensing and can open up new avenues for clinical applications. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Molecular cloning, expression, and functional analysis of the copper amine oxidase gene in the endophytic fungus Shiraia sp. Slf14 from Huperzia serrata.

    Science.gov (United States)

    Yang, Huilin; Peng, Silu; Zhang, Zhibin; Yan, Riming; Wang, Ya; Zhan, Jixun; Zhu, Du

    2016-12-01

    Huperzine A (HupA) is a drug used for the treatment of Alzheimer's disease. However, the biosynthesis of this medicinally important compound is not well understood. The HupA biosynthetic pathway is thought to be initiated by the decarboxylation of lysine to form cadaverine, which is then converted to 5-aminopentanal by copper amine oxidase (CAO). In this study, we cloned and expressed an SsCAO gene from a HupA-producing endophytic fungus, Shiraia sp. Slf14. Analysis of the deduced protein amino acid sequence showed that it contained the Asp catalytic base, conserved motif Asn-Tyr-Asp/Glu, and three copper-binding histidines. The cDNA of SsCAO was amplified and expressed in Escherichia coli BL21(DE3), from which a 76 kDa protein was obtained. The activity of this enzyme was tested, which provided more information about the SsCAO gene in the endophytic fungus. Gas Chromatograph-Mass Spectrometry (GC-MS) revealed that this SsCAO could accept cadaverine as a substrate to produce 5-aminopentanal, the precursor of HupA. Phylogenetic tree analysis indicated that the SsCAO from Shiraia sp. Slf14 was closely related to Stemphylium lycopersici CAO. This is the first report on the cloning and expression of a CAO gene from HupA-producing endophytic fungi. Functional characterization of this enzyme provides new insights into the biosynthesis of the HupA an anti-Alzheimer's drug. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Quadruped robots for nuclear facilities. Development of cooperative carrying and unloading functions

    International Nuclear Information System (INIS)

    2016-01-01

    As the Fukushima Daiichi Nuclear Power Station (hereafter refers to as 1F) became the high dose environment by the Great East Japan Earthquake, remotely operated robots were required in order to reduce workers' radiation exposure. We developed a quadruped robot to walk the stairs and narrow passages with carrying burdens such as investigation tools. This robot investigated water leakage from vent pipes at underground of 1F unit 2. There are various works towards the decommissioning such as measuring doses of radiation, cutting pipes, connecting wires and more. It is desirable to carry various work tools and to unload them at destinations with remotely operated robots. To this end, we have developed carrying and unloading functions of the robot. In addition, we have developed cooperative carrying functions that two quadruped robots carry and unload a burden which is too long or heavy for individual robot. As a result, it was realized that two robots carried the pipe of 48 kg while getting over a step of 100 mm and unloading it at a destination. (author)

  19. YY1 regulates melanocyte development and function by cooperating with MITF.

    Directory of Open Access Journals (Sweden)

    Juying Li

    Full Text Available Studies of coat color mutants have greatly contributed to the discovery of genes that regulate melanocyte development and function. Here, we generated Yy1 conditional knockout mice in the melanocyte-lineage and observed profound melanocyte deficiency and premature gray hair, similar to the loss of melanocytes in human piebaldism and Waardenburg syndrome. Although YY1 is a ubiquitous transcription factor, YY1 interacts with M-MITF, the Waardenburg Syndrome IIA gene and a master transcriptional regulator of melanocytes. YY1 cooperates with M-MITF in regulating the expression of piebaldism gene KIT and multiple additional pigmentation genes. Moreover, ChIP-seq identified genome-wide YY1 targets in the melanocyte lineage. These studies mechanistically link genes implicated in human conditions of melanocyte deficiency and reveal how a ubiquitous factor (YY1 gains lineage-specific functions by co-regulating gene expression with a lineage-restricted factor (M-MITF-a general mechanism which may confer tissue-specific gene expression in multiple lineages.

  20. Functional cooperation between FACT and MCM is coordinated with cell cycle and differential complex formation

    Directory of Open Access Journals (Sweden)

    Lin Chih-Li

    2010-02-01

    Full Text Available Abstract Background Functional cooperation between FACT and the MCM helicase complex constitutes an integral step during DNA replication initiation. However, mode of regulation that underlies the proper functional interaction of FACT and MCM is poorly understood. Methods & Results Here we present evidence indicating that such interaction is coordinated with cell cycle progression and differential complex formation. We first demonstrate the existence of two distinct FACT-MCM subassemblies, FACT-MCM2/4/6/7 and FACT-MCM2/3/4/5. Both complexes possess DNA unwinding activity and are subject to cell cycle-dependent enzymatic regulation. Interestingly, analysis of functional attributes further suggests that they act at distinct, and possibly sequential, steps during origin establishment and replication initiation. Moreover, we show that the phosphorylation profile of the FACT-associated MCM4 undergoes a cell cycle-dependent change, which is directly correlated with the catalytic activity of the FACT-MCM helicase complexes. Finally, at the quaternary structure level, physical interaction between FACT and MCM complexes is generally dependent on persistent cell cycle and further stabilized upon S phase entry. Cessation of mitotic cycle destabilizes the complex formation and likely leads to compromised coordination and activities. Conclusions Together, our results correlate FACT-MCM functionally and temporally with S phase and DNA replication. They further demonstrate that enzymatic activities intrinsically important for DNA replication are tightly controlled at various levels, thereby ensuring proper progression of, as well as exit from, the cell cycle and ultimately euploid gene balance.

  1. Export of functional Streptomyces coelicolor alditol oxidase to the periplasm or cell surface of Escherichia coli and its application in whole-cell biocatalysis

    NARCIS (Netherlands)

    van Bloois, Edwin; Winter, Remko T.; Janssen, Dick B.; Fraaije, Marco W.

    Streptomyces coelicolor A3(2) alditol oxidase (AldO) is a soluble monomeric flavoprotein in which the flavin cofactor is covalently linked to the polypeptide chain. AldO displays high reactivity towards different polyols such as xylitol and sorbitol. These characteristics make AldO industrially

  2. Functional Patterns in International Organizations for University Cooperation in Latin America and the Caribbean

    Science.gov (United States)

    Lopez, Daniel A.; Lopez, Daniel C.; Andrade, Lorenzo I.; Lopez, Boris A.

    2011-01-01

    This study analyzes the coverage, organizational patterns, problems and trends of international organizations for university cooperation in Latin America and the Caribbean. More than 30 international organizations for cooperation currently operating in Latin America and the Caribbean were identified. Two groups of institutions with more than 60%…

  3. [Configuring relationship--a condition for a functional institutional cooperation to assure assistance for children with mentally ill parents].

    Science.gov (United States)

    Brockmann, Eva; Lenz, Albert

    2010-01-01

    A functional cooperation between support systems of psychiatric and psychotherapeutic facilities and of youth-welfare institutions is necessary to assure operant assistance for children of parents with psychiatric illness and their families. In many cases the cooperation efforts stay on structural layer without taking the configuration of the relationship between the agents into consideration. Despite high relevance for practical working there are only a few empirical studies, which are concerned with relationship configuration. In a quality investigation requirements of collaboration on inter-institutional and internal-institutional layer were explored as well as case-related and case-crossed cooperation. On the basis of empirical results concretical recommended proceedures were given for configure the relationship in coorporation at the interface of support systems and amplified of specifical requirements of psychiatric/psychotherapeutic and youth-welfare institutions.

  4. Isolated sulfite oxidase deficiency.

    Science.gov (United States)

    Rupar, C A; Gillett, J; Gordon, B A; Ramsay, D A; Johnson, J L; Garrett, R M; Rajagopalan, K V; Jung, J H; Bacheyie, G S; Sellers, A R

    1996-12-01

    Isolated sulfite oxidase (SO) deficiency is an autosomal recessively inherited inborn error of sulfur metabolism. In this report of a ninth patient the clinical history, laboratory results, neuropathological findings and a mutation in the sulfite oxidase gene are described. The data from this patient and previously published patients with isolated sulfite oxidase deficiency and molybdenum cofactor deficiency are summarized to characterize this rare disorder. The patient presented neonatally with intractable seizures and did not progress developmentally beyond the neonatal stage. Dislocated lenses were apparent at 2 months. There was increased urine excretion of sulfite and S-sulfocysteine and a decreased concentration of plasma cystine. A lactic acidemia was present for 6 months. Liver sulfite oxidase activity was not detectable but xanthine dehydrogenase activity was normal. The boy died of respiratory failure at 32 months. Neuropathological findings of cortical necrosis and extensive cavitating leukoencephalopathy were reminiscent of those seen in severe perinatal asphyxia suggesting an etiology of energy deficiency. A point mutation that resulted in a truncated protein missing the molybdenum-binding site has been identified.

  5. Association of ventral striatum monoamine oxidase-A binding and functional connectivity in antisocial personality disorder with high impulsivity: A positron emission tomography and functional magnetic resonance imaging study.

    Science.gov (United States)

    Kolla, Nathan J; Dunlop, Katharine; Downar, Jonathan; Links, Paul; Bagby, R Michael; Wilson, Alan A; Houle, Sylvain; Rasquinha, Fawn; Simpson, Alexander I; Meyer, Jeffrey H

    2016-04-01

    Impulsivity is a core feature of antisocial personality disorder (ASPD) associated with abnormal brain function and neurochemical alterations. The ventral striatum (VS) is a key region of the neural circuitry mediating impulsive behavior, and low monoamine oxidase-A (MAO-A) level in the VS has shown a specific relationship to the impulsivity of ASPD. Because it is currently unknown whether phenotypic MAO-A markers can influence brain function in ASPD, we investigated VS MAO-A level and the functional connectivity (FC) of two seed regions, superior and inferior VS (VSs, VSi). Nineteen impulsive ASPD males underwent [(11)C] harmine positron emission tomography scanning to measure VS MAO-A VT, an index of MAO-A density, and resting-state functional magnetic resonance imaging that assessed the FC of bilateral seed regions in the VSi and VSs. Subjects also completed self-report impulsivity measures. Results revealed functional coupling of the VSs with bilateral dorsomedial prefrontal cortex (DMPFC) that was correlated with VS MAO-A VT (r=0.47, p=0.04), and functional coupling of the VSi with right hippocampus that was anti-correlated with VS MAO-A VT (r=-0.55, p=0.01). Additionally, VSs-DMPFC FC was negatively correlated with NEO Personality Inventory-Revised impulsivity (r=-0.49, p=0.03), as was VSi-hippocampus FC with Barratt Impulsiveness Scale-11 motor impulsiveness (r=-0.50, p=0.03). These preliminary results highlight an association of VS MAO-A level with the FC of striatal regions linked to impulsive behavior in ASPD and suggest that phenotype-based brain markers of ASPD have relevance to understanding brain function. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

  6. THE RISKS OF OUTSOURCING TRANSPORT FUNCTIONS IN RELATIONS BETWEEN THE COOPERATION FIRMS

    Directory of Open Access Journals (Sweden)

    Paweł Romanow

    2011-01-01

    Full Text Available The paper presents the thesis that in the process of analysis and decision-making on the scope, duration and depth of cooperation in the framework of outsourcing in the area of transport is necessary to follow a set of business rules-oriented, both the strategic and operational aspects of business operations. The paper also discusses the errors committed in the decision making process concerning the selection and cooperation with suppliers of transport services.

  7. A study on the observation system for autonomous, distributed and cooperative function in a future type nuclear power plant

    International Nuclear Information System (INIS)

    Matsuoka, Takeshi; Numano, Masayoshi; Someya, Minoru; Fukuto, Junji; Mitomo, Nobuo; Miyazaki, Keiko; Matsukura, Hiroshi; Niwa, Yasuyuki; Takahashi, Masato

    2000-01-01

    The concept of advanced future plants are discussed by five research institutes; Ship Research Institute, Electrotechnical Laboratory, The Institute of Physical and Chemical Research, Japan Atomic Energy Research Institute, and Power Reactor and Nuclear Fuel Development Corporation (Cross-over group). And, an autonomous plant is identified as a future type plant. In this future type plant, there are many agents that consist plant sub-systems or plant components and have artificial intelligence. They are distributed in plant and have autonomous functions, and cooperate each other to establish total plant function. Even if the plant has autonomous function, human operators have to always watch the plant state. Therefore, the needs of the observation system for autonomous, distributed, and cooperative functions are strongly required. The present paper has presented a new idea about the observation system, and developed fundamental functions for this observation system, that is, plant function model, auto-classification of plant states, three dimensional graphical display, expression of robot group's activity. Also, autonomous plant simulator has been developed for this research activity. Finally, the effectiveness of this observation system has been evaluated by experiments of operator's reaction to this system. (author)

  8. Identification of aldehyde oxidase 1 and aldehyde oxidase homologue 1 as dioxin-inducible genes

    International Nuclear Information System (INIS)

    Rivera, Steven P.; Choi, Hyun Ho; Chapman, Brett; Whitekus, Michael J.; Terao, Mineko; Garattini, Enrico; Hankinson, Oliver

    2005-01-01

    Aldehyde oxidases are a family of highly related molybdo-flavoenzymes acting upon a variety of compounds of industrial and medical importance. We have identified aldehyde oxidase 1 (AOX1) as a 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin) inducible gene in the mouse hepatoma cell line Hepa-1. AOX1 mRNA levels were not increased by dioxin in mutant derivatives of the Hepa-1 cell line lacking either functional aryl hydrocarbon receptor (AHR) or aryl hydrocarbon receptor nuclear translocator (ARNT) proteins, thus demonstrating that transcriptional induction of AOX1 in response to dioxin occurs through the AHR pathway. Dioxin induction of AOX1 mRNA was also observed in mouse liver. In addition, levels of AOX1 protein as well as those of aldehyde oxidase homologue 1 (AOH1), a recently identified homolog of AOX1, were elevated in mouse liver in response to dioxin. Employing an aldehyde oxidase specific substrate, AOX1/AOH1 activity was shown to be induced by dioxin in mouse liver. This activity was inhibited by a known inhibitor of aldehyde oxidases, and eliminated by including tungstate in the mouse diet, which is known to lead to inactivation of molybdoflavoenzymes, thus confirming that the enzymatic activity was attributable to AOX1/AOH1. Our observations thus identify two additional xenobiotic metabolizing enzymes induced by dioxin

  9. Oxidase-based biocatalytic processes

    DEFF Research Database (Denmark)

    Ramesh, Hemalata; Woodley, John; Krühne, Ulrich

    interestingbiocatalystsbecause they use a mild oxidant (oxygen) as a substrateas opposed to their chemical counterparts which use strong oxidants such as permanganates. A class of oxidases calledmonoamine oxidases has been used as the central case study for the thesis. The rationale for choosing thissystemis that it has been...

  10. Temporal development of near-native functional properties and correlations with qMRI in self-assembling fibrocartilage treated with exogenous lysyl oxidase homolog 2.

    Science.gov (United States)

    Hadidi, Pasha; Cissell, Derek D; Hu, Jerry C; Athanasiou, Kyriacos A

    2017-12-01

    Advances in cartilage tissue engineering have led to constructs with mechanical integrity and biochemical composition increasingly resembling that of native tissues. In particular, collagen cross-linking with lysyl oxidase has been used to significantly enhance the mechanical properties of engineered neotissues. In this study, development of collagen cross-links over time, and correlations with tensile properties, were examined in self-assembling neotissues. Additionally, quantitative MRI metrics were examined in relation to construct mechanical properties as well as pyridinoline cross-link content and other engineered tissue components. Scaffold-free meniscus fibrocartilage was cultured in the presence of exogenous lysyl oxidase, and assessed at multiple time points over 8weeks starting from the first week of culture. Engineered constructs demonstrated a 9.9-fold increase in pyridinoline content, reaching 77% of native tissue values, after 8weeks of culture. Additionally, engineered tissues reached 66% of the Young's modulus in the radial direction of native tissues. Further, collagen cross-links were found to correlate with tensile properties, contributing 67% of the tensile strength of engineered neocartilages. Finally, examination of quantitative MRI metrics revealed several correlations with mechanical and biochemical properties of engineered constructs. This study displays the importance of culture duration for collagen cross-link formation, and demonstrates the potential of quantitative MRI in investigating properties of engineered cartilages. This is the first study to demonstrate near-native cross-link content in an engineered tissue, and the first study to quantify pyridinoline cross-link development over time in a self-assembling tissue. Additionally, this work shows the relative contributions of collagen and pyridinoline to the tensile properties of collagenous tissue for the first time. Furthermore, this is the first investigation to identify a

  11. Cooperative function of Pdx1 and Oc1 in multipotent pancreatic progenitors impacts postnatal islet maturation and adaptability.

    Science.gov (United States)

    Kropp, Peter A; Dunn, Jennifer C; Carboneau, Bethany A; Stoffers, Doris A; Gannon, Maureen

    2018-04-01

    The transcription factors pancreatic and duodenal homeobox 1 (Pdx1) and onecut1 (Oc1) are coexpressed in multipotent pancreatic progenitors (MPCs), but their expression patterns diverge in hormone-expressing cells, with Oc1 expression being extinguished in the endocrine lineage and Pdx1 being maintained at high levels in β-cells. We previously demonstrated that cooperative function of these two factors in MPCs is necessary for proper specification and differentiation of pancreatic endocrine cells. In those studies, we observed a persistent decrease in expression of the β-cell maturity factor MafA. We therefore hypothesized that Pdx1 and Oc1 cooperativity in MPCs impacts postnatal β-cell maturation and function. Here our model of Pdx1-Oc1 double heterozygosity was used to investigate the impact of haploinsufficiency for both of these factors on postnatal β-cell maturation, function, and adaptability. Examining mice at postnatal day (P) 14, we observed alterations in pancreatic insulin content in both Pdx1 heterozygotes and double heterozygotes. Gene expression analysis at this age revealed significantly decreased expression of many genes important for glucose-stimulated insulin secretion (e.g., Glut2, Pcsk1/2, Abcc8) exclusively in double heterozygotes. Analysis of P14 islets revealed an increase in the number of mixed islets in double heterozygotes. We predicted that double-heterozygous β-cells would have an impaired ability to respond to stress. Indeed, we observed that β-cell proliferation fails to increase in double heterozygotes in response to either high-fat diet or placental lactogen. We thus report here the importance of cooperation between regulatory factors early in development for postnatal islet maturation and adaptability.

  12. APPLICATION OF COOPERATIVE LEARNING MODEL INDEX CARD MATCH TYPE IN IMPROVING STUDENT LEARNING RESULTS ON COMPOSITION AND COMPOSITION FUNCTIONS OF FUNCTIONS INVERS IN MAN 1 MATARAM

    Directory of Open Access Journals (Sweden)

    Syahrir Syahrir

    2017-12-01

    Full Text Available Lack of student response in learning mathematics caused by passive of student in process of learning progress so that student consider mathematics subject is difficult subject to be understood. The research is Classroom Action Research (PTK using 2 cycles, then the purpose of this research is how the implementation of cooperative learning type of index card match in improving student learning outcomes on the subject matter of composition function and inverse function in MAN 1 Mataram. While the results of the analysis in the study showed that there is in cycle I obtained classical completeness 78.79% with the average score of student learning outcomes 69.78 and the average value of student learning responses with the category Enough, then in cycle II shows that classical thoroughness 87 , 89% with mean score of student learning result 78,94 and average value of student learning response with good category. So it can be concluded that the implementation of Model Cooperative Learning Type Index Card Match can improve student learning outcomes on the subject matter of composition function and inverse function.

  13. Congruence between PM H+-ATPase and NADPH oxidase during root growth: a necessary probability.

    Science.gov (United States)

    Majumdar, Arkajo; Kar, Rup Kumar

    2018-07-01

    Plasma membrane (PM) H + -ATPase and NADPH oxidase (NOX) are two key enzymes responsible for cell wall relaxation during elongation growth through apoplastic acidification and production of ˙OH radical via O 2 ˙ - , respectively. Our experiments revealed a putative feed-forward loop between these enzymes in growing roots of Vigna radiata (L.) Wilczek seedlings. Thus, NOX activity was found to be dependent on proton gradient generated across PM by H + -ATPase as evident from pharmacological experiments using carbonyl cyanide m-chlorophenylhydrazone (CCCP; protonophore) and sodium ortho-vanadate (PM H + -ATPase inhibitor). Conversely, H + -ATPase activity retarded in response to different ROS scavengers [CuCl 2 , N, N' -dimethylthiourea (DMTU) and catalase] and NOX inhibitors [ZnCl 2 and diphenyleneiodonium (DPI)], while H 2 O 2 promoted PM H + -ATPase activity at lower concentrations. Repressing effects of Ca +2 antagonists (La +3 and EGTA) on the activity of both the enzymes indicate its possible mediation. Since, unlike animal NOX, the plant versions do not possess proton channel activity, harmonized functioning of PM H + -ATPase and NOX appears to be justified. Plasma membrane NADPH oxidase and H + -ATPase are functionally synchronized and they work cooperatively to maintain the membrane electrical balance while mediating plant cell growth through wall relaxation.

  14. Selective fishing and analysis of xanthine oxidase binders from two Fabaceae species by coupling enzyme functionalized core-shell magnetic nanoparticles with HPLC-MS.

    Science.gov (United States)

    Liu, Liangliang; Shi, Shuyun; Zhao, Huading; Yu, Jingang; Jiang, Xinyu; Chen, Xiaoqing

    2014-01-15

    Xanthine oxidase (XOD) immobilized core-shell magnetic silica (Fe3O4@SiO2-XOD) nanoparticles coupled with high performance liquid chromatography-mass spectrometry (HPLC-MS) was developed to fish out and analyze XOD binders from two Fabaceae species, Puerariae lobata flower and Glycyrrhiza uralensis root. The prepared Fe3O4@SiO2-XOD nanoparticles exhibited good specificity for XOD binders, better dispersion in aqueous solution and reusability than those of Fe3O4-XOD nanoparticles. The amount of XOD immobilized onto Fe3O4@SiO2 nanoparticles was 339.9μg/mg and the activity of Fe3O4@SiO2-XOD nanoparticles remained 95% after ten times usage. The optimum conditions of selective fishing were optimized, and finally incubating pH was set at 7, incubating temperature at 25°C and adsorption time at 30min. Twelve XOD binders were successfully identified from ethyl acetate extract of P. lobata flower and G. uralensis root. The developed method provides a rapid, purposeful and effective way to identify active compounds from natural complex mixtures. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Functional Analysis of the Trichoderma harzianum nox1 Gene, Encoding an NADPH Oxidase, Relates Production of Reactive Oxygen Species to Specific Biocontrol Activity against Pythium ultimum▿†

    Science.gov (United States)

    Montero-Barrientos, M.; Hermosa, R.; Cardoza, R. E.; Gutiérrez, S.; Monte, E.

    2011-01-01

    The synthesis of reactive oxygen species (ROS) is one of the first events following pathogenic interactions in eukaryotic cells, and NADPH oxidases are involved in the formation of such ROS. The nox1 gene of Trichoderma harzianum was cloned, and its role in antagonism against phytopathogens was analyzed in nox1-overexpressed transformants. The increased levels of nox1 expression in these transformants were accompanied by an increase in ROS production during their direct confrontation with Pythium ultimum. The transformants displayed an increased hydrolytic pattern, as determined by comparing protease, cellulase, and chitinase activities with those for the wild type. In confrontation assays against P. ultimum the nox1-overexpressed transformants were more effective than the wild type, but not in assays against Botrytis cinerea or Rhizoctonia solani. A transcriptomic analysis using a Trichoderma high-density oligonucleotide (HDO) microarray also showed that, compared to gene expression for the interaction of wild-type T. harzianum and P. ultimum, genes related to protease, cellulase, and chitinase activities were differentially upregulated in the interaction of a nox1-overexpressed transformant with this pathogen. Our results show that nox1 is involved in T. harzianum ROS production and antagonism against P. ultimum. PMID:21421791

  16. Combined use of chondroitinase-ABC, TGF-β1, and collagen crosslinking agent lysyl oxidase to engineer functional neotissues for fibrocartilage repair.

    Science.gov (United States)

    Makris, Eleftherios A; MacBarb, Regina F; Paschos, Nikolaos K; Hu, Jerry C; Athanasiou, Kyriacos A

    2014-08-01

    Patients suffering from damaged or diseased fibrocartilages currently have no effective long-term treatment options. Despite their potential, engineered tissues suffer from inferior biomechanical integrity and an inability to integrate in vivo. The present study identifies a treatment regimen (including the biophysical agent chondroitinase-ABC, the biochemical agent TGF-β1, and the collagen crosslinking agent lysyl oxidase) to prime highly cellularized, scaffold-free neofibrocartilage implants, effecting continued improvement in vivo. We show these agents drive in vitro neofibrocartilage matrix maturation toward synergistically enhanced Young's modulus and ultimate tensile strength values, which were increased 245% and 186%, respectively, over controls. Furthermore, an in vitro fibrocartilage defect model found this treatment regimen to significantly increase the integration tensile properties between treated neofibrocartilage and native tissue. Through translating this technology to an in vivo fibrocartilage defect model, our results indicate, for the first time, that a pre-treatment can prime neofibrocartilage for significantly enhanced integration potential in vivo, with interfacial tensile stiffness and strength increasing by 730% and 745%, respectively, compared to integration values achieved in vitro. Our results suggest that specifically targeting collagen assembly and organization is a powerful means to augment overall neotissue mechanics and integration potential toward improved clinical feasibility. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Cloning and functional expression of the mitochondrial alternative oxidase gene (aox1) of Aspergillus niger in Lactococcus lactis and its induction by oxidizing conditions.

    Science.gov (United States)

    Papagianni, Maria; Avramidis, Nicholaos

    2012-01-05

    Lactococcus lactis is a widely used food bacterium mainly known for its fermentation metabolism. An important, and for long time overlooked, trait of this species is its ability to perform respiratory metabolism in the presence of heme and under aerobic conditions. There is no evidence however for the presence of an alternative respiration pathway and AOX activity. In this study, a cDNA fragment encoding the mitochondrial alternative oxidase, the enzyme responsible for alternative respiration, from a citric acid producing Aspergillus niger strain was cloned and expressed in L. lactis as a host strain. Expression of aox1 conferred on this organism cyanide-resistant and salicylhydroxamate-sensitive growth. Bioreactor cultures under fully aerobic conditions of the transformed L. lactis showed that the alternative respiratory pathway operates and improves significantly the microorganism's response to oxidizing stress conditions as it enhances biomass production, suppresses lactate formation, and leads to accumulation of large amounts of nisin. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Oxidases as Breast Cancer Oncogens

    National Research Council Canada - National Science Library

    Yeldandi, Anjana

    2000-01-01

    ...) in a non-tumorigenic human mammary epithelial cell line to ascertain whether oxidase overexpressing cells undergo transformation when exposed to substrate xanthine for XOX and uric acid for UOX...

  19. Glucose oxidase variants with improved properities

    OpenAIRE

    Fischer, Rainer; Ostafe, Raluca; Prodanovic, Radivoje

    2014-01-01

    Source: WO14173822A3 [EN] The technology provided herein relates to novel variants of microbial glucose oxidase with improved properties, more specifically to polypeptides having glucose oxidase activity as their major enzymatic activity; to nucleic acid molecules encoding said glucose oxidases; vectors and host cells containing the nucleic acids and methods for producing the glucose oxidase; compositions comprising said glucose oxidase; methods for the preparation and production of such enzy...

  20. Prolonged Exposure of Cortical Neurons to Oligomeric Amyloid-β Impairs NMDA Receptor Function Via NADPH Oxidase-Mediated ROS Production: Protective Effect of Green Tea (--Epigallocatechin-3-Gallate

    Directory of Open Access Journals (Sweden)

    Yan He

    2011-01-01

    Full Text Available Excessive production of Aβ (amyloid β-peptide has been shown to play an important role in the pathogenesis of AD (Alzheimer's disease. Although not yet well understood, aggregation of Aβ is known to cause toxicity to neurons. Our recent study demonstrated the ability for oligomeric Aβ to stimulate the production of ROS (reactive oxygen species in neurons through an NMDA (N-methyl-D-aspartate-dependent pathway. However, whether prolonged exposure of neurons to aggregated Aβ is associated with impairment of NMDA receptor function has not been extensively investigated. In the present study, we show that prolonged exposure of primary cortical neurons to Aβ oligomers caused mitochondrial dysfunction, an attenuation of NMDA receptor-mediated Ca2+ influx and inhibition of NMDA-induced AA (arachidonic acid release. Mitochondrial dysfunction and the decrease in NMDA receptor activity due to oligomeric Aβ are associated with an increase in ROS production. Gp91ds-tat, a specific peptide inhibitor of NADPH oxidase, and Mn(III-tetrakis(4-benzoic acid-porphyrin chloride, an ROS scavenger, effectively abrogated Aβ-induced ROS production. Furthermore, Aβ-induced mitochondrial dysfunction, impairment of NMDA Ca2+ influx and ROS production were prevented by pretreatment of neurons with EGCG [(–-epigallocatechin-3-gallate], a major polyphenolic component of green tea. Taken together, these results support a role for NADPH oxidase-mediated ROS production in the cytotoxic effects of Aβ, and demonstrate the therapeutic potential of EGCG and other dietary polyphenols in delaying onset or retarding the progression of AD.

  1. Banks’ internal controls and risk management: Value-added functions in Italian credit cooperative banks

    Directory of Open Access Journals (Sweden)

    Rosaria Cerrone

    2013-12-01

    Full Text Available A critical component of safe and sound bank management is constituted by an effective and efficient system of internal controls, which help to ensure that the goals and objectives of a bank will be met, that long-term profitability targets will be achieved, and maintain reliable financial and managerial reporting. Such a system can also ensure that the bank will comply with laws and regulations as well as policies, plans, internal rules and procedures, and decrease the risk of unexpected losses or damage to the bank’s reputation. The paper describes the essential elements of a sound internal control system and through a qualitative approach, it shows how is tied to the rules attaining capital requirements and, above all, to the purpose of the Internal Capital Adequacy Assessment Process (ICAAP which aims at determining the adequate capitalisation of a bank given the risks endured as well as future risks arising from growth, and new business lines. After the recent financial crisis ICAAP is becoming more and more relevant and a central component of an effective strategy for managing risk and creating value. All principles and considerations are referred to Italian Credit Cooperative Banks particular both for dimension and for governance and risk management. They have been contacted though local federations and the results confirm the existing of weakness in internal controls.

  2. The functional power of the CPLP in the framework ok development cooperation in food security and nutrition (FSN

    Directory of Open Access Journals (Sweden)

    Manuel Lapão

    2016-05-01

    Full Text Available The Community of Portuguese Speaking Countries (CPLP, about to celebrate its twenty year of existence, was born to preserve the language and a common cultural heritage and has been gradually strengthening other policy dimensions which have led to increased visibility. The cooperation in the areas of Health and Food and Nutrition Security (SAN is such an example. In fact, the "Food Security and Nutrition Strategy (ESAN-CPLP", adopted in 2011, is a real and operational tool to improve levels of human development in the member states of the CPLP, and is recognized in international fora as an example of good practice by partners such as the European Union, while also being perfectly aligned with the U.N.'s Goals of Sustainable Development. Despite the unique role of the CPLP and its potential functional power in the framework of international cooperation, some threats have emerged, preventing its further affirmation, namely the assertion of a clear political will by the member states. Despite the gap between the present CPLP and the Agostinho da Silva's dream of creating a true Lusophone community, its contemporary role and potential is quite clear, and outstanding are the efforts to establish in its framework the Human Right to Adequate Food.

  3. Covalently bound phosphate residues in bovine milk xanthine oxidase and in glucose oxidase from Aspergillus niger: A reevaluation

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.L.; Rajagopalan, K.V. (Duke Univ. Medical Center, Durham, NC (USA)); London, R.E. (National Institute of Environmental Health Science, Research Triangle Park, NC (USA))

    1989-09-01

    The reported presence of covalently bound phosphate residues in flavoproteins has significant implications with regard to the catalytic mechanisms and structural stability of the specific enzymes themselves and in terms of general cellular metabolic regulation. These considerations have led to a reevaluation of the presence of covalently bound phosphorus in the flavoproteins xanthine oxidase and glucose oxidase. Milk xanthine oxidase purified by a procedure that includes anion-exchange chromatography is shown to contain three phosphate residues. All three are noncovalently associated with the protein, two with the FAD cofactor, and one with the molybdenum cofactor. Results of chemical analysis and {sup 31}P NMR spectroscopy indicate that enzyme purified by this method contains no phosphoserine residues. Xanthine oxidase preparations purified by chromatography on calcium phosphate gel in place of DEAE-Sephadex yielded higher phosphate-to-protein ratios, which could be reduced to the expected values by additional purification on a folate affinity column. Highly active, highly purified preparations of glucose oxidase are shown to contain only the two phosphate residues of the FAD cofactor. The covalently bound bridging phosphate reported by others may arise in aged or degraded preparations of the enzyme but appears not to be a constituent of functional glucose oxidase. These results suggest that the presence of covalent phosphate residues in other flavoproteins should be rigorously reevaluated as well.

  4. Covalently bound phosphate residues in bovine milk xanthine oxidase and in glucose oxidase from Aspergillus niger: A reevaluation

    International Nuclear Information System (INIS)

    Johnson, J.L.; Rajagopalan, K.V.; London, R.E.

    1989-01-01

    The reported presence of covalently bound phosphate residues in flavoproteins has significant implications with regard to the catalytic mechanisms and structural stability of the specific enzymes themselves and in terms of general cellular metabolic regulation. These considerations have led to a reevaluation of the presence of covalently bound phosphorus in the flavoproteins xanthine oxidase and glucose oxidase. Milk xanthine oxidase purified by a procedure that includes anion-exchange chromatography is shown to contain three phosphate residues. All three are noncovalently associated with the protein, two with the FAD cofactor, and one with the molybdenum cofactor. Results of chemical analysis and 31 P NMR spectroscopy indicate that enzyme purified by this method contains no phosphoserine residues. Xanthine oxidase preparations purified by chromatography on calcium phosphate gel in place of DEAE-Sephadex yielded higher phosphate-to-protein ratios, which could be reduced to the expected values by additional purification on a folate affinity column. Highly active, highly purified preparations of glucose oxidase are shown to contain only the two phosphate residues of the FAD cofactor. The covalently bound bridging phosphate reported by others may arise in aged or degraded preparations of the enzyme but appears not to be a constituent of functional glucose oxidase. These results suggest that the presence of covalent phosphate residues in other flavoproteins should be rigorously reevaluated as well

  5. The cooperation of the functional activation areas in human brain: an application of event-related fMRI study of the voluntary motor function

    International Nuclear Information System (INIS)

    Li Enzhong; Tian Jie; Dai Ruwei

    2002-01-01

    Objective: To detect the cooperation of the functional activation areas in human brain using event-related fMRI technique developed in recent years. Methods: Forty-four subjects were selected in this experiment and scanned by GE Signa Horizon 1.5 Tesla superconductive MR system. A CUE-GO paradigm was used in this experiment. The data were analyzed in SUN and SGI workstation. Results: The activation areas were found in contralateral primary motor area (Ml), bilateral supplementary motor areas (SMA), pre-motor areas (PMA), basal ganglia, and cerebellar cortices. The time-signal curve of Ml was a typical single-peak curve, but the curves in PMA, basal ganglia, and cerebellar cortices were double-peak curves. SMA had 2 parts, one was Pre-SMA, and another was SMA Proper. The curve was double-peak type in Pre-SMA and single-peak type in SMA Proper. There was difference between the time-signal intensity curves in above-mentioned areas. Conclusion: (1) Ml is mainly associated with motor execution, while others with both motor preparation and execution. There are differences in the function at the variant areas in the brain. (2) The fact that bilateral SMA, PMA, basal ganglia, and cerebellar cortices were activated, is different from what the classical theories told. (3) Event-related fMRI technique has higher temporary and spatial resolutions. (4) There is cooperation among different cortical areas, basal ganglia, and cerebellum

  6. Towards real-time diffuse optical tomography for imaging brain functions cooperated with Kalman estimator

    Science.gov (United States)

    Wang, Bingyuan; Zhang, Yao; Liu, Dongyuan; Ding, Xuemei; Dan, Mai; Pan, Tiantian; Wang, Yihan; Li, Jiao; Zhou, Zhongxing; Zhang, Limin; Zhao, Huijuan; Gao, Feng

    2018-02-01

    Functional near-infrared spectroscopy (fNIRS) is a non-invasive neuroimaging method to monitor the cerebral hemodynamic through the optical changes measured at the scalp surface. It has played a more and more important role in psychology and medical imaging communities. Real-time imaging of brain function using NIRS makes it possible to explore some sophisticated human brain functions unexplored before. Kalman estimator has been frequently used in combination with modified Beer-Lamber Law (MBLL) based optical topology (OT), for real-time brain function imaging. However, the spatial resolution of the OT is low, hampering the application of OT in exploring some complicated brain functions. In this paper, we develop a real-time imaging method combining diffuse optical tomography (DOT) and Kalman estimator, much improving the spatial resolution. Instead of only presenting one spatially distributed image indicating the changes of the absorption coefficients at each time point during the recording process, one real-time updated image using the Kalman estimator is provided. Its each voxel represents the amplitude of the hemodynamic response function (HRF) associated with this voxel. We evaluate this method using some simulation experiments, demonstrating that this method can obtain more reliable spatial resolution images. Furthermore, a statistical analysis is also conducted to help to decide whether a voxel in the field of view is activated or not.

  7. Cooperation and Noise in Public Goods Experiments: Applying the Contribution Function Approach

    NARCIS (Netherlands)

    Brandts, J.; Schram, A.

    2001-01-01

    We introduce a new design for experiments with the voluntary contributions mechanism for public goods. Subjects report a complete con-tri-bution function in each period, i.e., a contribution level for various marginal rates of transformation between a public and a private good. The results show that

  8. NADPH oxidase: an enzyme for multicellularity?

    Science.gov (United States)

    Lalucque, Hervé; Silar, Philippe

    2003-01-01

    Multicellularity has evolved several times during the evolution of eukaryotes. One evolutionary pressure that permits multicellularity relates to the division of work, where one group of cells functions as nutrient providers and the other in specialized roles such as defence or reproduction. This requires signalling systems to ensure harmonious development of multicellular structures. Here, we show that NADPH oxidases are specifically present in organisms that differentiate multicellular structures during their life cycle and are absent from unicellular life forms. The biochemical properties of these enzymes make them ideal candidates for a role in intercellular signalling.

  9. International cooperation

    International Nuclear Information System (INIS)

    2008-01-01

    In this chapter international cooperation of the Division for Radiation Safety, NPP Decommissioning and Radwaste Management of the VUJE, a. s. is presented. Very important is cooperation with the International Atomic Energy Agency. This cooperation has various forms - national and regional projects of technical cooperation, coordinated research activities, participation of our experts in preparation of the IAEA documentation etc.

  10. Classical and alternative NF-κB signaling cooperate in regulating adipocyte differentiation and function

    DEFF Research Database (Denmark)

    Weidemann, A.; Lovas, A.; Rauch, A.

    2016-01-01

    Background and objective:Inflammation of adipose tissue (AT) is a central mediator of insulin resistance. However, the molecular mechanisms triggered by inflammatory cells are not fully understood. The aim of this study was to analyze the metabolic functions of lymphotoxin-β-receptor (LTβ...... to adipocytes. The molecular mechanism was elucidated by chromatin immunoprecipitation and combinatorial treatment with α-LTβR and tumor necrosis factor (TNF).Results:RelB FatKO mice showed improved insulin sensitivity despite increased adiposity and adipocyte hypertrophy. LTβR-induced activation of p52-Rel.......Conclusions:Our data describe an anti-adipogenic action of LTβR signaling and a novel synergism of alternative and classical NF-κB signaling in the regulation of adipocytes. In conclusion, this strong synergism between the two NF-κB pathways shows a method to inhibit adipocyte differentiation and to improve insulin...

  11. Cooperative Trust Games

    Science.gov (United States)

    2013-01-01

    the more widely recognized competitive (non-cooperative) game theory. Cooperative game theory focuses on what groups of self-interested agents can...provides immediate justification for using non-cooperative game theory as the basis for modeling the purely competitive agents. 2.4. Superadditive...the competitive and altruistic contributions of the subset team. Definition: Given a payoff function ( ) in a subset team game , the total marginal

  12. Lysyl oxidase in colorectal cancer

    DEFF Research Database (Denmark)

    Cox, Thomas R; Erler, Janine T

    2013-01-01

    Colorectal cancer is the third most prevalent form of cancer worldwide and fourth-leading cause of cancer-related mortality, leading to ~600,000 deaths annually, predominantly affecting the developed world. Lysyl oxidase is a secreted, extracellular matrix-modifying enzyme previously suggested...... to act as a tumor suppressor in colorectal cancer. However, emerging evidence has rapidly implicated lysyl oxidase in promoting metastasis of solid tumors and in particular colorectal cancer at multiple stages, affecting tumor cell proliferation, invasion, and angiogenesis. This emerging research has...... advancements in the field of colorectal cancer....

  13. Competitive versus Cooperative Exergame Play for African American Adolescents' Executive Function Skills: Short-Term Effects in a Long-Term Training Intervention

    Science.gov (United States)

    Staiano, Amanda E.; Abraham, Anisha A.; Calvert, Sandra L.

    2012-01-01

    Exergames are videogames that require gross motor activity, thereby combining gaming with physical activity. This study examined the role of competitive versus cooperative exergame play on short-term changes in executive function skills, following a 10-week exergame training intervention. Fifty-four low-income overweight and obese African American…

  14. Lysyl oxidase in cancer research

    DEFF Research Database (Denmark)

    Perryman, Lara; Erler, Janine Terra

    2014-01-01

    Metastasis is the main reason for cancer-associated deaths and therapies are desperately needed to target the progression of cancer. Lysyl oxidase (LOX) plays a pivotal role in cancer progression, including metastasis, and is therefore is an attractive therapeutic target. In this review we...

  15. Expression and functional analysis of the lysine decarboxylase and copper amine oxidase genes from the endophytic fungus Colletotrichum gloeosporioides ES026

    OpenAIRE

    Zhang, Xiangmei; Wang, Zhangqian; Jan, Saad; Yang, Qian; Wang, Mo

    2017-01-01

    Huperzine A (HupA) isolated from Huperzia serrata is an important compound used to treat Alzheimer?s disease (AD). Recently, HupA was reported in various endophytic fungi, with Colletotrichum gloeosporioides ES026 previously isolated from H. serrata shown to produce HupA. In this study, we performed next-generation sequencing and de novo RNA sequencing of C. gloeosporioides ES026 to elucidate the molecular functions, biological processes, and biochemical pathways of these unique sequences. Ge...

  16. Conflictual cooperation

    DEFF Research Database (Denmark)

    Axel, Erik

    2011-01-01

    , cooperation appeared as the continuous reworking of contradictions in the local arrangement of societal con- ditions. Subjects were distributed and distributed themselves according to social privileges, resources, and dilemmas in cooperation. Here, the subjects’ activities and understandings took form from...

  17. Engineering the central pathways in Lactococcus lactis: functional expression of the phosphofructokinase (pfk) and alternative oxidase (aox1) genes from Aspergillus niger in Lactococcus lactis facilitates improved carbon conversion rates under oxidizing conditions.

    Science.gov (United States)

    Papagianni, Maria; Avramidis, Nicholaos

    2012-08-10

    The present work describes a novel central pathway engineering method that has been designed with the aim to increase the carbon conversion rates under oxidizing conditions in L. lactis fermentations. The nisin producer L. lactis ATCC11454 strain has been genetically engineered by cloning a truncated version of the phosphofructokinase gene (pfk13), along with the pkaC, encoding for the catalytic subunit of cAMP-dependent protein kinase, and the alternative oxidase (aox1) genes of A. niger. Functional expression of the above genes resulted in enhanced PFK activity and the introduction of AOX activity and alternative respiration in the presence of a source of heme in the substrate, under fully aerobic growth conditions. The constructed strain is capable of fermenting high concentrations of glucose as was demonstrated in a series of glucostat fed-batch fermentations with glucose levels maintained at 55, 138 and 277 mM. The high maximum specific uptake rate of glucose of 1.8 mMs(-1)gCDW(-1) at 277 mM glucose is characteristic of the improved ability of the microorganism to handle elevated glucose concentrations under conditions otherwise causing severe reduction of PFK activity. The increased carbon flow through glycolysis led to increased protein synthesis that was reflected in increased biomass and nisin levels. The pfk 13-pkaC-aox1-transformant strain's fermentation at 277 mM glucose gave a final biomass concentration of 7.5 g/l and nisin activity of 14,000 IU/ml which is, compared to the parental strain's production levels at its optimal 55 mM glucose, increased by a factor of 2.34 for biomass and 4.37 for nisin. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Peroxisomal Polyamine Oxidase and NADPH-Oxidase cross-talk for ROS homeostasis which affects respiration rate in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Efthimios A. Andronis

    2014-04-01

    Full Text Available Homeostasis of reactive oxygen species (ROS in the intracellular compartments is of critical importance as ROS have been linked with nearly all cellular processes and more importantly with diseases and aging. PAs are nitrogenous molecules with an evolutionary conserved role in the regulation of metabolic and energetic status of cells. Recent evidence also suggests that polyamines (PA are major regulators of ROS homeostasis. In Arabidopsis the backconversion of the PAs spermidine (Spd and spermine (Spm to putrescine (Put and Spd, respectively is catalyzed by two peroxisomal PA oxidases (AtPAO. However, the physiological role of this pathway remains largely elusive. Here we explore the role of peroxisomal PA backconversion and in particular that catalyzed by the highly expressed AtPAO3 in the regulation of ROS homeostasis and mitochondrial respiratory burst. Exogenous PAs exert an NADPH-oxidase dependent stimulation of oxygen consumption, with Spd exerting the strongest effect. This increase is attenuated by treatment with the NADPH-oxidase blocker diphenyleneiodonium iodide (DPI. Loss-of-function of AtPAO3 gene results to increased NADPH-oxidase-dependent production of superoxide anions (O2.-, but not H2O2, which activate the mitochondrial alternative oxidase pathway (AOX. On the contrary, overexpression of AtPAO3 results to an increased but balanced production of both H2O2 and O2.-. These results suggest that the ratio of O2.-/H2O2 regulates respiratory chain in mitochondria, with PA-dependent production of O2.- by NADPH-oxidase tilting the balance of electron transfer chain in favor of the AOX pathway. In addition, AtPAO3 seems to be an important component in the regulating module of ROS homeostasis, while a conserved role for PA backconversion and ROS across kingdoms is discussed.

  19. International cooperation

    International Nuclear Information System (INIS)

    Prieto, F.E.

    1984-01-01

    It looks doubtless that the need for an international cooperation to solve the worldwide energy problems is already a concern of individuals, institutions, and governments. This is an improvement. But there is something lacking. The author refers to the Atoms for Peace speech, the origin of the IAEA and of the subsequent spreading of the nuclear option. He also refers back to the call made by the Mexican government for a worldwide energy cooperation. He stresses the need for governments to cooperate, so that this international cooperation on energy can be put into operation for the benefit of mankind

  20. Investigation of association between donors' and recipients' NADPH oxidase p22(phox) C242T polymorphism and acute rejection, delayed graft function and blood pressure in renal allograft recipients.

    Science.gov (United States)

    Mandegary, Ali; Rahmanian-Koshkaki, Sara; Mohammadifar, Mohammad-Amir; Pourgholi, Leila; Mehdipour, Mohammad; Etminan, Abbas; Ebadzadeh, Mohammad-Reza; Fazeli, Faramarz; Azmandian, Jalal

    2015-01-01

    Production of reactive oxygen species (ROS) and thereby induction of oxidative stress seem to be one of the major mediators of inflammatory adverse outcomes after renal transplantation. p22(phox) is a polymorphic subunit of NAD(P)H-oxidase that is critical for activation and stabilization of the enzyme. This enzyme is involved in the production of superoxide that triggers inflammatory injuries to the kidney. So in this study, the association between donors and recipients' C242T polymorphism of p22(phox) and acute rejection (AR), delayed graft function (DGF), creatinine clearance (CrCl), and blood pressure in renal-allograft recipients was studied. One hundred ninety six donor-recipient pairs were studied. The C242T polymorphism of p22(phox) was determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). According to p22 genotype, the subjects were divided in wild-type (CC) and T allele carriers (CT+TT). Transplantation outcomes were determined using acute rejection and delayed graft function criteria. The mean arterial pressure was also measured monthly after transplantation. There was a significant association between the recipients' p22(phox) polymorphism and DGF occurrence (OR=2.5, CI: 1.2-4.9, p=0.0009). No significant association was detected between donors' p22(phox) polymorphism and AR and DGF events. CrCl during the six months follow-up after transplantation was lower in the patients who received allograft from donors carrying 242T allele (B=-12.8, CI: -22.9-12.8 (-22.9 to -2.6)). Changes in the blood pressure were not different among the patients having different genotypes of p22(phox). These results suggest that the recipients' p22(phox) C242T polymorphism may be a major risk factor for DGF in renal transplantation. Moreover, the donors' 242T allele seems to affect the rate of CrCl in the renal allograft recipients. Copyright © 2014. Published by Elsevier B.V.

  1. International cooperation

    International Nuclear Information System (INIS)

    1996-01-01

    In 1995, Nuclear Regulatory Authority of the Slovak Republic (NRA SR) ensured foreign cooperation particularly in the frame of the Slovak Republic is membership in the IAEA, as well as cooperation with the Nuclear Energy Agency of the Organization for Economic Cooperation and Development (OECD NEA), cooperation with European Union in the frame of PHARE programmes, and intergovernmental cooperation and cooperation among nuclear regulatory authorities. With respect to an international importance, prestige and a wide-scope possibilities of a technical assistance , either a direct one (expert assessments, technology supplies, work placement, scientific trips, training courses) or indirect one (participation at various conferences, seminars, technical committees, etc), the most important cooperation with the IAEA in Vienna. In 1994, the Slovak Republic, was elected to the Board Governors, the represent the group of Eastern European countries. The Slovak Government entrusted the NRA SR's Chairman with representing the Slovak Republic in the Board of Governors. Owing to a good name of Slovakia was elected to the one of two Vice-Chairmen of the Board of Governors at the 882-nd session on the Board. IAEA approved and developed 8 national projects for Slovakia in 1995. Generally, IAEA is contracting scientific contracts with research institutes, nuclear power plants and other organizations. Slovak organizations used these contracts as complementary funding of their tasks. In 1995, there were 12 scientific contracts in progress, or approved respectively. Other international activities of the NRA SR, international co-operations as well as foreign affairs are reported

  2. Links between internal and external cooperation in product development : An exploratory study

    NARCIS (Netherlands)

    Hillebrand, B; Biemans, WG

    While there is an overwhelming amount of publications on cooperation in product development projects, they mainly,focus on cooperation between business functions within an organization (internal cooperation) or on cooperation between organizations (external cooperation). Yet the relationship between

  3. Molecular Basis for Converting (2S-Methylsuccinyl-CoA Dehydrogenase into an Oxidase

    Directory of Open Access Journals (Sweden)

    Simon Burgener

    2017-12-01

    Full Text Available Although flavoenzymes have been studied in detail, the molecular basis of their dioxygen reactivity is only partially understood. The members of the flavin adenosine dinucleotide (FAD-dependent acyl-CoA dehydrogenase and acyl-CoA oxidase families catalyze similar reactions and share common structural features. However, both enzyme families feature opposing reaction specificities in respect to dioxygen. Dehydrogenases react with electron transfer flavoproteins as terminal electron acceptors and do not show a considerable reactivity with dioxygen, whereas dioxygen serves as a bona fide substrate for oxidases. We recently engineered (2S-methylsuccinyl-CoA dehydrogenase towards oxidase activity by rational mutagenesis. Here we characterized the (2S-methylsuccinyl-CoA dehydrogenase wild-type, as well as the engineered (2S-methylsuccinyl-CoA oxidase, in detail. Using stopped-flow UV-spectroscopy and liquid chromatography-mass spectrometry (LC-MS based assays, we explain the molecular base for dioxygen reactivity in the engineered oxidase and show that the increased oxidase function of the engineered enzyme comes at a decreased dehydrogenase activity. Our findings add to the common notion that an increased activity for a specific substrate is achieved at the expense of reaction promiscuity and provide guidelines for rational engineering efforts of acyl-CoA dehydrogenases and oxidases.

  4. Exploring flavin-containing carbohydrate oxidases

    NARCIS (Netherlands)

    Ferrari, Alessandro Renato

    2017-01-01

    Oxidases are enzymes capable of removing one or more electrons from their substrate and transfer them to molecular oxygen, forming hydrogen peroxide. Due to their high regio- and enantioselectivity, their use is preferred over traditional organic chemistry methods. Among the oxidases, flavoprotein

  5. The terminal oxidases of Paracoccus denitrificans

    NARCIS (Netherlands)

    de Gier, J.-W.; Lübben, M; Reijnders, W N; Tipker, C A; Slotboom, D.J.; van Spanning, R J; Stouthamer, A.H.; van der Oost, J.

    Three distinct types of terminal oxidases participate in the aerobic respiratory pathways of Paracoccus denitrificans. Two alternative genes encoding subunit I of the aa3-type cytochrome c oxidase have been isolated before, namely ctaDI and ctaDII. Each of these genes can be expressed separately to

  6. Soft cooperation systems and games

    Science.gov (United States)

    Fernández, J. R.; Gallego, I.; Jiménez-Losada, A.; Ordóñez, M.

    2018-04-01

    A cooperative game for a set of agents establishes a fair allocation of the profit obtained for their cooperation. In order to obtain this allocation, a characteristic function is known. It establishes the profit of each coalition of agents if this coalition decides to act alone. Originally players are considered symmetric and then the allocation only depends on the characteristic function; this paper is about cooperative games with an asymmetric set of agents. We introduced cooperative games with a soft set of agents which explains those parameters determining the asymmetry among them in the cooperation. Now the characteristic function is defined not over the coalitions but over the soft coalitions, namely the profit depends not only on the formed coalition but also on the attributes considered for the players in the coalition. The best known of the allocation rules for cooperative games is the Shapley value. We propose a Shapley kind solution for soft games.

  7. Angiotensin II inhibits the Na+-K+ pump via PKC-dependent activation of NADPH oxidase.

    Science.gov (United States)

    White, Caroline N; Figtree, Gemma A; Liu, Chia-Chi; Garcia, Alvaro; Hamilton, Elisha J; Chia, Karin K M; Rasmussen, Helge H

    2009-04-01

    The sarcolemmal Na(+)-K(+) pump, pivotal in cardiac myocyte function, is inhibited by angiotensin II (ANG II). Since ANG II activates NADPH oxidase, we tested the hypothesis that NADPH oxidase mediates the pump inhibition. Exposure to 100 nmol/l ANG II increased superoxide-sensitive fluorescence of isolated rabbit ventricular myocytes. The increase was abolished by pegylated superoxide dismutase (SOD), by the NADPH oxidase inhibitor apocynin, and by myristolated inhibitory peptide to epsilon-protein kinase C (epsilonPKC), previously implicated in ANG II-induced Na(+)-K(+) pump inhibition. A role for epsilonPKC was also supported by an ANG II-induced increase in coimmunoprecipitation of epsilonPKC with the receptor for the activated kinase and with the cytosolic p47(phox) subunit of NADPH oxidase. ANG II decreased electrogenic Na(+)-K(+) pump current in voltage-clamped myocytes. The decrease was abolished by SOD, by the gp91ds inhibitory peptide that blocks assembly and activation of NADPH oxidase, and by epsilonPKC inhibitory peptide. Since colocalization should facilitate NADPH oxidase-dependent regulation of the Na(+)-K(+) pump, we examined whether there is physical association between the pump subunits and NADPH oxidase. The alpha(1)-subunit coimmunoprecipitated with caveolin 3 and with membrane-associated p22(phox) and cytosolic p47(phox) NADPH oxidase subunits at baseline. ANG II had no effect on alpha(1)/caveolin 3 or alpha(1)/p22(phox) interaction, but it increased alpha(1)/p47(phox) coimmunoprecipitation. We conclude that ANG II inhibits the Na(+)-K(+) pump via PKC-dependent NADPH oxidase activation.

  8. Cooperative Bacterial Foraging Optimization

    Directory of Open Access Journals (Sweden)

    Hanning Chen

    2009-01-01

    Full Text Available Bacterial Foraging Optimization (BFO is a novel optimization algorithm based on the social foraging behavior of E. coli bacteria. This paper presents a variation on the original BFO algorithm, namely, the Cooperative Bacterial Foraging Optimization (CBFO, which significantly improve the original BFO in solving complex optimization problems. This significant improvement is achieved by applying two cooperative approaches to the original BFO, namely, the serial heterogeneous cooperation on the implicit space decomposition level and the serial heterogeneous cooperation on the hybrid space decomposition level. The experiments compare the performance of two CBFO variants with the original BFO, the standard PSO and a real-coded GA on four widely used benchmark functions. The new method shows a marked improvement in performance over the original BFO and appears to be comparable with the PSO and GA.

  9. Calculation of site affinity constants and cooperativity coefficients for binding of ligands and/or protons to macromolecules. II. Relationships between chemical model and partition function algorithm.

    Science.gov (United States)

    Fisicaro, E; Braibanti, A; Lamb, J D; Oscarson, J L

    1990-05-01

    The relationships between the chemical properties of a system and the partition function algorithm as applied to the description of multiple equilibria in solution are explained. The partition functions ZM, ZA, and ZH are obtained from powers of the binary generating functions Jj = (1 + kappa j gamma j,i[Y])i tau j, where i tau j = p tau j, q tau j, or r tau j represent the maximum number of sites in sites in class j, for Y = M, A, or H, respectively. Each term of the generating function can be considered an element (ij) of a vector Jj and each power of the cooperativity factor gamma ij,i can be considered an element of a diagonal cooperativity matrix gamma j. The vectors Jj are combined in tensor product matrices L tau = (J1) [J2]...[Jj]..., thus representing different receptor-ligand combinations. The partition functions are obtained by summing elements of the tensor matrices. The relationship of the partition functions with the total chemical amounts TM, TA, and TH has been found. The aim is to describe the total chemical amounts TM, TA, and TH as functions of the site affinity constants kappa j and cooperativity coefficients bj. The total amounts are calculated from the sum of elements of tensor matrices Ll. Each set of indices (pj..., qj..., rj...) represents one element of a tensor matrix L tau and defines each term of the summation. Each term corresponds to the concentration of a chemical microspecies. The distinction between microspecies MpjAqjHrj with ligands bound on specific sites and macrospecies MpAqHR corresponding to a chemical stoichiometric composition is shown. The translation of the properties of chemical model schemes into the algorithms for the generation of partition functions is illustrated with reference to a series of examples of gradually increasing complexity. The equilibria examined concern: (1) a unique class of sites; (2) the protonation of a base with two classes of sites; (3) the simultaneous binding of ligand A and proton H to a

  10. Multiple origins of the phenol reaction negative phenotype in foxtail millet, Setaria italica (L.) P. Beauv., were caused by independent loss-of-function mutations of the polyphenol oxidase (Si7PPO) gene during domestication.

    Science.gov (United States)

    Inoue, Takahiko; Yuo, Takahisa; Ohta, Takeshi; Hitomi, Eriko; Ichitani, Katsuyuki; Kawase, Makoto; Taketa, Shin; Fukunaga, Kenji

    2015-08-01

    Foxtail millet shows variation in positive phenol color reaction (Phr) and negative Phr in grains, but predominant accessions of this crop are negative reaction type, and the molecular genetic basis of the Phr reaction remains unresolved. In this article, we isolated polyphenol oxidase (PPO) gene responsible for Phr using genome sequence information and investigated molecular genetic basis of negative Phr and crop evolution of foxtail millet. First of all, we searched for PPO gene homologs in a foxtail millet genome database using a rice PPO gene as a query and successfully found three copies of the PPO gene. One of the PPO gene homologs on chromosome 7 showed the highest similarity with PPO genes expressed in hulls (grains) of other cereal species including rice, wheat, and barley and was designated as Si7PPO. Phr phenotypes and Si7PPO genotypes completely co-segregated in a segregating population. We also analyzed the genetic variation conferring negative Phr reaction. Of 480 accessions of the landraces investigated, 87 (18.1 %) showed positive Phr and 393 (81.9 %) showed negative Phr. In the 393 Phr negative accessions, three types of loss-of-function Si7PPO gene were predominant and independently found in various locations. One of them has an SNP in exon 1 resulting in a premature stop codon and was designated as stop codon type, another has an insertion of a transposon (Si7PPO-TE1) in intron 2 and was designated as TE1-insertion type, and the other has a 6-bp duplication in exon 3 resulting in the duplication of 2 amino acids and was designated as 6-bp duplication type. As a rare variant of the stop codon type, one accession additionally has an insertion of a transposon, Si7PPO-TE2, in intron 2 and was designated as "stop codon +TE2 insertion type". The geographical distribution of accessions with positive Phr and those with three major types of negative Phr was also investigated. Accessions with positive Phr were found in subtropical and tropical regions at

  11. [The X+ chronic granulomatous disease as a fabulous model to study the NADPH oxidase complex activation].

    Science.gov (United States)

    Stasia, Marie-José

    2007-05-01

    Chronic granulomatous disease (CGD) is a rare inherited disorder in which phagocytes lack NADPH oxidase activity. Patients with CGD suffer from recurrent bacterial and fungal infections because of the absence of superoxide anions (O2- degrees ) generatingsystem. The NADPH oxidase complex is composed of a membranous cytochrome b558, cytosolic proteins p67phox, p47phox, p40phox and two small GTPases Rac2 and Rap1A. Cytochrome b558 consists of two sub-units gp91phox and p22phox. The most common form of CGD is due to mutations in CYBB gene encoding gp91phox. In some rare cases, the mutated gp91phox is normally expressed but is devoided of oxidase activity. These variants called X+ CGD, have provided interesting informations about oxidase activation mechanisms. However modelization of such variants is necessary to obtain enough biological material for studies at the molecular level. A cellular model (knock-out PLB-985 cells) has been developed for expressing recombinant mutated gp91phox for functional analysis of the oxidase complex. Recent works demonstrated that this cell line genetically deficient in gp91phox is a powerful tool for functional analysis of the NADPH oxidase complex activation.

  12. Involvement of NADH Oxidase in Biofilm Formation in Streptococcus sanguinis.

    Directory of Open Access Journals (Sweden)

    Xiuchun Ge

    Full Text Available Biofilms play important roles in microbial communities and are related to infectious diseases. Here, we report direct evidence that a bacterial nox gene encoding NADH oxidase is involved in biofilm formation. A dramatic reduction in biofilm formation was observed in a Streptococcus sanguinis nox mutant under anaerobic conditions without any decrease in growth. The membrane fluidity of the mutant bacterial cells was found to be decreased and the fatty acid composition altered, with increased palmitic acid and decreased stearic acid and vaccenic acid. Extracellular DNA of the mutant was reduced in abundance and bacterial competence was suppressed. Gene expression analysis in the mutant identified two genes with altered expression, gtfP and Idh, which were found to be related to biofilm formation through examination of their deletion mutants. NADH oxidase-related metabolic pathways were analyzed, further clarifying the function of this enzyme in biofilm formation.

  13. Immobilization of oxidases and their analytical applications

    International Nuclear Information System (INIS)

    Yasinzai, M.

    2007-01-01

    Immobilized enzymes are replacing their soluble counter-parts in nearly every field of application. These enzyme modifications have evolved from a research curiosity into an entire branch of Biotechnology. An immobilization method for flavin containing oxidases and their use in flow injection system is described. An electrochemical detector for H/sub 2/O/sub 2/ is assembled which is used effectively for the determination of glucose using more common glucose oxidase and the simultaneous determination of sugars. The combination of oxidases with hydrolases have been used for the determination of maltose and starch. (author)

  14. Alteration of structure and function of ATP synthase and cytochrome c oxidase by lack of F-o-a and Cox3 subunits caused by mitochondrial DNA 9205delTA mutation

    Czech Academy of Sciences Publication Activity Database

    Hejzlarová, Kateřina; Kaplanová, Vilma; Nůsková, Hana; Kovářová, Nikola; Ješina, Pavel; Drahota, Zdeněk; Mráček, Tomáš; Seneca, S.; Houštěk, Josef

    2015-01-01

    Roč. 466, č. 3 (2015), s. 601-611 ISSN 0264-6021 R&D Projects: GA ČR(CZ) GAP303/11/0970; GA ČR(CZ) GB14-36804G; GA MŠk(CZ) LL1204; GA ČR(CZ) GAP303/12/1363 Institutional support: RVO:67985823 Keywords : ATP synthase * cytochrome c oxidase * mitochondrial diseases * mtDNA MT-ATP6 mutation * oxidative phosphorylation * threshold effect Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.562, year: 2015

  15. Similarities and differences between the brain networks underlying allocentric and egocentric spatial learning in rat revealed by cytochrome oxidase histochemistry.

    Science.gov (United States)

    Rubio, S; Begega, A; Méndez, M; Méndez-López, M; Arias, J L

    2012-10-25

    The involvement of different brain regions in place- and response-learning was examined using a water cross-maze. Rats were trained to find the goal from the initial arm by turning left at the choice point (egocentric strategy) or by using environmental cues (allocentric strategy). Although different strategies were required, the same maze and learning conditions were used. Using cytochrome oxidase histochemistry as a marker of cellular activity, the function of the 13 diverse cortical and subcortical regions was assessed in rats performing these two tasks. Our results show that allocentric learning depends on the recruitment of a large functional network, which includes the hippocampal CA3, dentate gyrus, medial mammillary nucleus and supramammillary nucleus. Along with the striatum, these last three structures are also related to egocentric spatial learning. The present study provides evidence for the contribution of these regions to spatial navigation and supports a possible functional interaction between the two memory systems, as their structural convergence may facilitate functional cooperation in the behaviours guided by more than one strategy. In summary, it can be argued that spatial learning is based on dynamic functional systems in which the interaction of brain regions is modulated by task requirements. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  16. The antioxidant properties, cytotoxicity and monoamine oxidase ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-28

    Nov 28, 2011 ... Department of Pharmaceutical Chemistry, North-West University, Private Bag X6001, Potchefstroom 2520, ..... on the inhibition of the catabolism of serotonin, .... Structure of human monoamine oxidase B, a drug target for.

  17. Vanillyl-alcohol oxidase, a tasteful biocatalyst

    NARCIS (Netherlands)

    Heuvel, van den R.H.H.; Fraaije, M.W.; Mattevi, A.; Laane, C.; Berkel, van W.J.H.

    2001-01-01

    The covalent flavoenzyme vanillyl-alcohol oxidase (VAO) is a versatile biocatalyst. It converts a wide range of phenolic compounds by catalysing oxidation, deamination, demethylation, dehydrogenation and hydroxylation reactions. The production of natural vanillin, 4-hydroxybenzaldehyde, coniferyl

  18. Polyphenol Oxidase Enzyme and Inactivation Methods

    Directory of Open Access Journals (Sweden)

    Leman Yılmaz

    2018-03-01

    Full Text Available Polyphenol oxidase enzyme is found in vegetables and fruits, as well as in some animal organs and microorganisms. Polyphenol oxidase enzyme responsible for enzymatic browning is a group of copper proteins that catalyses the oxidation of phenolic compounds to quinones, which produce brown pigments, commonly found in fruits and vegetables. During the industrial preparation of fruits and vegetables, results of catalytic effect of polyphenol oxidase causes enzymatic browning. Enzymatic browning impairs the appearance of products containing phenolic compounds along with undesirable colour, odor and taste formation and significant loss of nutritional value of the products. This affects the acceptability of the products by the consumers and causes economic losses. In this review, some characteristics of polyphenol oxidase enzyme in different fruits and vegetables have been reviewed and information about chemical antibrowning agents, thermal applications, irradiation applications and alternative methods such as high pressure processing, pulse electric field, supercritical carbon dioxide and ultrasound applications to inactivate this enzyme has been presented.

  19. Genetics Home Reference: isolated sulfite oxidase deficiency

    Science.gov (United States)

    ... and Management Resources (1 link) GeneReview: Isolated Sulfite Oxidase Deficiency General Information from MedlinePlus (5 links) Diagnostic Tests Drug Therapy Genetic Counseling Palliative Care Surgery and ...

  20. Construction of Mutant Glucose Oxidases with Increased Dye-Mediated Dehydrogenase Activity

    Science.gov (United States)

    Horaguchi, Yohei; Saito, Shoko; Kojima, Katsuhiro; Tsugawa, Wakako; Ferri, Stefano; Sode, Koji

    2012-01-01

    Mutagenesis studies on glucose oxidases (GOxs) were conducted to construct GOxs with reduced oxidase activity and increased dehydrogenase activity. We focused on two representative GOxs, of which crystal structures have already been reported—Penicillium amagasakiense GOx (PDB ID; 1gpe) and Aspergillus niger GOx (PDB ID; 1cf3). We constructed oxygen-interacting structural models for GOxs, and predicted the residues responsible for oxidative half reaction with oxygen on the basis of the crystal structure of cholesterol oxidase as well as on the fact that both enzymes are members of the glucose/methanol/choline (GMC) oxidoreductase family. Rational amino acid substitution resulted in the construction of an engineered GOx with drastically decreased oxidase activity and increased dehydrogenase activity, which was higher than that of the wild-type enzyme. As a result, the dehydrogenase/oxidase ratio of the engineered enzyme was more than 11-fold greater than that of the wild-type enzyme. These results indicate that alteration of the dehydrogenase/oxidase activity ratio of GOxs is possible by introducing a mutation into the putative functional residues responsible for oxidative half reaction with oxygen of these enzymes, resulting in a further increased dehydrogenase activity. This is the first study reporting the alteration of GOx electron acceptor preference from oxygen to an artificial electron acceptor. PMID:23203056

  1. Construction of Mutant Glucose Oxidases with Increased Dye-Mediated Dehydrogenase Activity

    Directory of Open Access Journals (Sweden)

    Koji Sode

    2012-11-01

    Full Text Available Mutagenesis studies on glucose oxidases (GOxs were conducted to construct GOxs with reduced oxidase activity and increased dehydrogenase activity. We focused on two representative GOxs, of which crystal structures have already been reported—Penicillium amagasakiense GOx (PDB ID; 1gpe and Aspergillus niger GOx (PDB ID; 1cf3. We constructed oxygen-interacting structural models for GOxs, and predicted the residues responsible for oxidative half reaction with oxygen on the basis of the crystal structure of cholesterol oxidase as well as on the fact that both enzymes are members of the glucose/methanol/choline (GMC oxidoreductase family. Rational amino acid substitution resulted in the construction of an engineered GOx with drastically decreased oxidase activity and increased dehydrogenase activity, which was higher than that of the wild-type enzyme. As a result, the dehydrogenase/oxidase ratio of the engineered enzyme was more than 11-fold greater than that of the wild-type enzyme. These results indicate that alteration of the dehydrogenase/oxidase activity ratio of GOxs is possible by introducing a mutation into the putative functional residues responsible for oxidative half reaction with oxygen of these enzymes, resulting in a further increased dehydrogenase activity. This is the first study reporting the alteration of GOx electron acceptor preference from oxygen to an artificial electron acceptor.

  2. Construction of mutant glucose oxidases with increased dye-mediated dehydrogenase activity.

    Science.gov (United States)

    Horaguchi, Yohei; Saito, Shoko; Kojima, Katsuhiro; Tsugawa, Wakako; Ferri, Stefano; Sode, Koji

    2012-11-02

    Mutagenesis studies on glucose oxidases (GOxs) were conducted to construct GOxs with reduced oxidase activity and increased dehydrogenase activity. We focused on two representative GOxs, of which crystal structures have already been reported—Penicillium amagasakiense GOx (PDB ID; 1gpe) and Aspergillus niger GOx (PDB ID; 1cf3). We constructed oxygen-interacting structural models for GOxs, and predicted the residues responsible for oxidative half reaction with oxygen on the basis of the crystal structure of cholesterol oxidase as well as on the fact that both enzymes are members of the glucose/methanol/choline (GMC) oxidoreductase family. Rational amino acid substitution resulted in the construction of an engineered GOx with drastically decreased oxidase activity and increased dehydrogenase activity, which was higher than that of the wild-type enzyme. As a result, the dehydrogenase/oxidase ratio of the engineered enzyme was more than 11-fold greater than that of the wild-type enzyme. These results indicate that alteration of the dehydrogenase/oxidase activity ratio of GOxs is possible by introducing a mutation into the putative functional residues responsible for oxidative half reaction with oxygen of these enzymes, resulting in a further increased dehydrogenase activity. This is the first study reporting the alteration of GOx electron acceptor preference from oxygen to an artificial electron acceptor.

  3. A functional MRI study on how oxytocin affects decision making in social dilemmas: Cooperate as long as it pays off, aggress only when you think you can win.

    Science.gov (United States)

    Lambert, Bruno; Declerck, Carolyn H; Boone, Christophe; Parizel, Paul M

    2017-08-01

    We investigate if the neuropeptide oxytocin (OT), known to moderate social behaviour, influences strategic decision making in social dilemmas by facilitating the integration of incentives and social cues. Participants (N=29) played two economic games with different incentive structures in the fMRI scanner after receiving OT or placebo (following a double blind, within-subject design). Pictures of angry or neutral faces (the social cues) were displayed alongside the game matrices. Consistent with a priori hypotheses based on the modulatory role of OT in mesolimbic dopaminergic brain regions, the results indicate that, compared to placebo, OT significantly increases the activation of the nucleus accumbens during an assurance (coordination) game that rewards mutual cooperation. This increases appetitive motivation so that cooperative behaviour is facilitated for risk averse individuals. OT also significantly attenuates the amygdala, thereby reducing the orienting response to social cues. The corresponding change in behaviour is only apparent in the chicken (or anti-coordination) game, where aggression is incentivized but fatal if the partner also aggresses. Because of this ambiguity, decision making can be improved by additional information, and OT steers decisions in the chicken game in accordance with the valence of the facial cue: aggress when face is neutral; retreat when it is angry. Through its combined influence on amygdala and nucleus accumbens, OT improves the selection of a cooperative or aggressive strategy in function of the best match between the incentives of the game and the social cues present in the decision environment. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Multi-Copper Oxidases and Human Iron Metabolism

    Science.gov (United States)

    Vashchenko, Ganna; MacGillivray, Ross T. A.

    2013-01-01

    Multi-copper oxidases (MCOs) are a small group of enzymes that oxidize their substrate with the concomitant reduction of dioxygen to two water molecules. Generally, multi-copper oxidases are promiscuous with regards to their reducing substrates and are capable of performing various functions in different species. To date, three multi-copper oxidases have been detected in humans—ceruloplasmin, hephaestin and zyklopen. Each of these enzymes has a high specificity towards iron with the resulting ferroxidase activity being associated with ferroportin, the only known iron exporter protein in humans. Ferroportin exports iron as Fe2+, but transferrin, the major iron transporter protein of blood, can bind only Fe3+ effectively. Iron oxidation in enterocytes is mediated mainly by hephaestin thus allowing dietary iron to enter the bloodstream. Zyklopen is involved in iron efflux from placental trophoblasts during iron transfer from mother to fetus. Release of iron from the liver relies on ferroportin and the ferroxidase activity of ceruloplasmin which is found in blood in a soluble form. Ceruloplasmin, hephaestin and zyklopen show distinctive expression patterns and have unique mechanisms for regulating their expression. These features of human multi-copper ferroxidases can serve as a basis for the precise control of iron efflux in different tissues. In this manuscript, we review the biochemical and biological properties of the three human MCOs and discuss their potential roles in human iron homeostasis. PMID:23807651

  5. Biocompatibility selenium nanoparticles with an intrinsic oxidase-like activity

    Science.gov (United States)

    Guo, Leilei; Huang, Kaixun; Liu, Hongmei

    2016-03-01

    Selenium nanoparticles (SeNPs) are considered to be the new selenium supplement forms with high biological activity and low toxicity; however, the molecular mechanism by which SeNPs exert the biological function is unclear. Here, we reported that biocompatibility SeNPs possessed intrinsic oxidase-like activity. Using Na2SeO3 as a precursor and glutathione as a reductant, biocompatibility SeNPs were synthesized by the wet chemical reduction method in the presence of bovine serum albumin (BSA). The results of structure characterization revealed that synthesized SeNPs were amorphous red elementary selenium with spherical morphology, and ranged in size from 25 to 70 nm size with a narrow distribution (41.4 ± 6.7 nm). The oxidase-like activity of the as-synthesized SeNPs was tested with 3,3',5,5'-tetramethylbenzidine (TMB) as a substrate. The results indicated that SeNPs could catalyze the oxidization of TMB by dissolved oxygen. These SeNPs showed an optimum catalytic activity at pH 4 and 30 °C, and the oxidase-like activity was higher as the concentration of SeNPs increased and the size of SeNPs decreased. The Michaelis constant ( K m) values and maximal reaction velocity ( V max) of the SeNPs for TMB oxidation were 0.0083 mol/L and 3.042 μmol/L min, respectively.

  6. Interorganizational Cooperation

    Science.gov (United States)

    2016-10-12

    Administrative Services Officer , Office of Congressional and Intergovernmental Affairs, Office of the Chief Financial Officer , Office of the Chief ...Nations. • Clarifies the role of the United States Agency for International Development (USAID) Office of Transition Initiatives and its relationship...Centralize interorganizational cooperation within the command group. Under this model, the chief of staff or a special staff officer within the command

  7. Multiple controls affect arsenite oxidase gene expression in Herminiimonas arsenicoxydans

    Directory of Open Access Journals (Sweden)

    Coppée Jean-Yves

    2010-02-01

    Full Text Available Abstract Background Both the speciation and toxicity of arsenic are affected by bacterial transformations, i.e. oxidation, reduction or methylation. These transformations have a major impact on environmental contamination and more particularly on arsenic contamination of drinking water. Herminiimonas arsenicoxydans has been isolated from an arsenic- contaminated environment and has developed various mechanisms for coping with arsenic, including the oxidation of As(III to As(V as a detoxification mechanism. Results In the present study, a differential transcriptome analysis was used to identify genes, including arsenite oxidase encoding genes, involved in the response of H. arsenicoxydans to As(III. To get insight into the molecular mechanisms of this enzyme activity, a Tn5 transposon mutagenesis was performed. Transposon insertions resulting in a lack of arsenite oxidase activity disrupted aoxR and aoxS genes, showing that the aox operon transcription is regulated by the AoxRS two-component system. Remarkably, transposon insertions were also identified in rpoN coding for the alternative N sigma factor (σ54 of RNA polymerase and in dnaJ coding for the Hsp70 co-chaperone. Western blotting with anti-AoxB antibodies and quantitative RT-PCR experiments allowed us to demonstrate that the rpoN and dnaJ gene products are involved in the control of arsenite oxidase gene expression. Finally, the transcriptional start site of the aoxAB operon was determined using rapid amplification of cDNA ends (RACE and a putative -12/-24 σ54-dependent promoter motif was identified upstream of aoxAB coding sequences. Conclusion These results reveal the existence of novel molecular regulatory processes governing arsenite oxidase expression in H. arsenicoxydans. These data are summarized in a model that functionally integrates arsenite oxidation in the adaptive response to As(III in this microorganism.

  8. Sulfur K-edge X-ray absorption spectroscopy and density functional theory calculations on monooxo Mo(IV) and bisoxo Mo(VI) bis-dithiolenes: insights into the mechanism of oxo transfer in sulfite oxidase and its relation to the mechanism of DMSO reductase.

    Science.gov (United States)

    Ha, Yang; Tenderholt, Adam L; Holm, Richard H; Hedman, Britt; Hodgson, Keith O; Solomon, Edward I

    2014-06-25

    Sulfur K-edge X-ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations have been used to determine the electronic structures of two complexes [Mo(IV)O(bdt)2](2-) and [Mo(VI)O2(bdt)2](2-) (bdt = benzene-1,2-dithiolate(2-)) that relate to the reduced and oxidized forms of sulfite oxidase (SO). These are compared with those of previously studied dimethyl sulfoxide reductase (DMSOr) models. DFT calculations supported by the data are extended to evaluate the reaction coordinate for oxo transfer to a phosphite ester substrate. Three possible transition states are found with the one at lowest energy, stabilized by a P-S interaction, in good agreement with experimental kinetics data. Comparison of both oxo transfer reactions shows that in DMSOr, where the oxo is transferred from the substrate to the metal ion, the oxo transfer induces electron transfer, while in SO, where the oxo transfer is from the metal site to the substrate, the electron transfer initiates oxo transfer. This difference in reactivity is related to the difference in frontier molecular orbitals (FMO) of the metal-oxo and substrate-oxo bonds. Finally, these experimentally related calculations are extended to oxo transfer by sulfite oxidase. The presence of only one dithiolene at the enzyme active site selectively activates the equatorial oxo for transfer, and allows facile structural reorganization during turnover.

  9. Direct comparison of gluco-oligosaccharide oxidase variants and glucose oxidase: substrate range and H2O2 stability.

    Science.gov (United States)

    Vuong, Thu V; Foumani, Maryam; MacCormick, Benjamin; Kwan, Rachel; Master, Emma R

    2016-11-21

    Glucose oxidase (GO) activity is generally restricted to glucose and is susceptible to inactivation by H 2 O 2 . By comparison, the Y300A variant of gluco-oligosaccharide oxidase (GOOX) from Sarocladium strictum showed broader substrate range and higher H 2 O 2 stability. Specifically, Y300A exhibited up to 40 times higher activity on all tested sugars except glucose, compared to GO. Moreover, fusion of the Y300A variant to a family 22 carbohydrate binding module from Clostridium thermocellum (CtCBM22A) nearly doubled its catalytic efficiency on glucose, while retaining significant activity on oligosaccharides. In the presence of 200 mM of H 2 O 2 , the recombinant CtCBM22A_Y300A retained 80% of activity on glucose and 100% of activity on cellobiose, the preferred substrate for this enzyme. By contrast, a commercial glucose oxidase reported to contain ≤0.1 units catalase/ mg protein, retained 60% activity on glucose under the same conditions. GOOX variants appear to undergo a different mechanism of inactivation, as a loss of histidine instead of methionine was observed after H 2 O 2 incubation. The addition of CtCBM22A also promoted functional binding of the fusion enzyme to xylan, facilitating its simultaneous purification and immobilization using edible oat spelt xylan, which might benefit the usage of this enzyme preparation in food and baking applications.

  10. Cooperation in Construction:

    DEFF Research Database (Denmark)

    Vogelius, Peter; Storgaard, Kresten

    2016-01-01

    The study presents a building project executed by a major Danish construction company, where cooperation and its staging were essential for achieving high productivity and competitiveness. The form of this cooperation is the main theme for the article. The contractor actively changed the communic......The study presents a building project executed by a major Danish construction company, where cooperation and its staging were essential for achieving high productivity and competitiveness. The form of this cooperation is the main theme for the article. The contractor actively changed...... the companies in the case can be understood as possessing a social capital which is enforced and united by initiatives of the main contractor. The social capital was built up and maintained through the actual constitution of cooperation already in the initial phase of bidding before the building process....... The management logic of the main contractor is interpreted as based on a sociology-inspired understanding focusing on norms and social values rather than on contractual (law) and functional (engineering) logic, which had hitherto been prevalent in Danish construction management....

  11. Molecular evolution of the polyamine oxidase gene family in Metazoa

    Directory of Open Access Journals (Sweden)

    Polticelli Fabio

    2012-06-01

    Full Text Available Abstract Background Polyamine oxidase enzymes catalyze the oxidation of polyamines and acetylpolyamines. Since polyamines are basic regulators of cell growth and proliferation, their homeostasis is crucial for cell life. Members of the polyamine oxidase gene family have been identified in a wide variety of animals, including vertebrates, arthropodes, nematodes, placozoa, as well as in plants and fungi. Polyamine oxidases (PAOs from yeast can oxidize spermine, N1-acetylspermine, and N1-acetylspermidine, however, in vertebrates two different enzymes, namely spermine oxidase (SMO and acetylpolyamine oxidase (APAO, specifically catalyze the oxidation of spermine, and N1-acetylspermine/N1-acetylspermidine, respectively. Little is known about the molecular evolutionary history of these enzymes. However, since the yeast PAO is able to catalyze the oxidation of both acetylated and non acetylated polyamines, and in vertebrates these functions are addressed by two specialized polyamine oxidase subfamilies (APAO and SMO, it can be hypothesized an ancestral reference for the former enzyme from which the latter would have been derived. Results We analysed 36 SMO, 26 APAO, and 14 PAO homologue protein sequences from 54 taxa including various vertebrates and invertebrates. The analysis of the full-length sequences and the principal domains of vertebrate and invertebrate PAOs yielded consensus primary protein sequences for vertebrate SMOs and APAOs, and invertebrate PAOs. This analysis, coupled to molecular modeling techniques, also unveiled sequence regions that confer specific structural and functional properties, including substrate specificity, by the different PAO subfamilies. Molecular phylogenetic trees revealed a basal position of all the invertebrates PAO enzymes relative to vertebrate SMOs and APAOs. PAOs from insects constitute a monophyletic clade. Two PAO variants sampled in the amphioxus are basal to the dichotomy between two well supported

  12. Comparative study between dimethyl sulfoxide (dmso), allopurinol and urate oxidase administration in nephrotoxic rats induced with

    International Nuclear Information System (INIS)

    Heibashy, M.I.A.; El-Nahla, A.M.; Ibrahim, A.I.; Saleh, Sh.Y.A.

    2010-01-01

    This study was conducted to show whether DMSO, allopurinol and urate oxidase could offer ameliorating effects against abnormal alterations in kidney function tests in gentamicin (GM) induced nephrotoxic rats . Two experiments were carried out, the first one showed that daily injection of 80 mg GM/kg b. wt interapertonealy (I.P) for two weeks induced acute renal failure indicated by significant elevation in serum urea, creatinine, uric acid, potassium, inorganic phosphorus, TBARS and PTH and a significant decline in serum sodium, total and ionized calcium when compared with their corresponding values in saline injected rats. In the second experiment, comparisons were made between GM induced nephrotoxic rats and other nephrotoxic groups received daily pf I.P injection of DMSO (4 ml/kg b.wt), allopurinol (1.5 mg/100 g b.wt) and urate oxidase (10 mg/100 g b.wt) for 30 days after the incidence of nephrotoxicity. At all intervals, 10,20 and 30 days; serum urea, creatinine, uric acid, potassium, inorganic phosphorus, TBARS and PTH in DMSO, allopurinol and urate oxidase treated groups exhibited significant reduction than nephrotoxic untreated rats. During the same intervals, the levels of serum total and ionized calcium showed an opposite trend. serum sodium level did not show any significant difference between all treated groups except after 20 days , it was increased significantly in urate oxidase treated group and after 30 days in both allopurinol and urate oxidase treated groups. in term time intervals, a significant correction was recorded on the level of most measured parameters. in nephritic rats, the administration of DMSO, allopurinol or urate oxidase led to a significant amelioration effects in the kidney function tests and urate oxidase was the best protective.

  13. EJERCICIO DE LAS FUNCIONES EMPRESARIALES POR PARTE DE LOS SOCIOS EN LAS COOPERATIVAS AGRARIAS / THE EXECUTION OF MANAGERIAL FUNCTIONS BY THE MEMBERS OF AGRARIAN COOPERATIVES

    Directory of Open Access Journals (Sweden)

    Carmen GALVE GÓRRIZ

    2010-01-01

    Full Text Available El objetivo de este trabajo es analizar cómo es efectuada por parte de los socios la coordinación de la empresa cooperativa agraria. Dicha coordinación ha sido analizada a través del análisis de las funciones que deben desarrollar los socios como empresarios. Estas funciones son enumeradas, descritas teóricamente y analizadas a partir de una muestra de cooperativas agrarias pertenecientes a la Denominación de Origen Calificada Rioja. Entre los principales resultados obtenidos cabe destacar que, en la mayoría de los casos analizados, la función de inversor es realizada sin que exista separación con la desempeñada como proveedor; el control formal es ejercido bajo el principio democrático de un hombre un voto; existe poca delegación de las actividades de gestión en una gerencia profesionalizada y cuando esta delegación se produce, no se obtiene niveles de eficiencia significativamente superiores; la organización de actividades muestra una clara especialización en las primeras fases del ciclo productivo y una alta concentración de ventas; por último, la selección de personal es realizada exigiendo unos niveles de cualificación adecuados en cada departamento. / The aim of this work is to analyse how the coordination of the agrarian cooperative firm is brought about by the members. Said coordination has been analysed by means of a study of the functions which members have to develop in their role as managers. These functions have been numbered; theoretically described, and analysed by using a sample of agrarian cooperatives belonging to the Domination of Origin Qualified Rioja. From the principal results obtained, we can highlight the fact that, in most cases analysed, formal control is exercised under the democratic principle, “one-man-one-vote”; where little delegation of management activities exists in professional management and when this delegation occurs, the cooperative does not obtain higher efficiency levels. The

  14. Pseudo-bi-enzyme glucose sensor: ZnS hollow spheres and glucose oxidase concerted catalysis glucose.

    Science.gov (United States)

    Shuai, Ying; Liu, Changhua; Wang, Jia; Cui, Xiaoyan; Nie, Ling

    2013-06-07

    This work creatively uses peroxidase-like ZnS hollow spheres (ZnS HSs) to cooperate with glucose oxidase (GOx) for glucose determinations. This approach is that the ZnS HSs electrocatalytically oxidate the enzymatically generated H2O2 to O2, and then the O2 circularly participates in the previous glucose oxidation by glucose oxidase. Au nanoparticles (AuNPs) and carbon nanotubes (CNTs) are used as electron transfer and enzyme immobilization matrices, respectively. The biosensor of glucose oxidase-carbon nanotubes-Au nanoparticles-ZnS hollow spheres-gold electrode (GOx-CNT-AuNPs-ZnS HSs-GE) exhibits a rapid response, a low detection limit (10 μM), a wide linear range (20 μM to 7 mM) as well as good anti-interference, long-term longevity and reproducibility.

  15. Substrate specificity and copper loading of the manganese-oxidizing multicopper oxidase Mnx from Bacillus sp. PL-12.

    Science.gov (United States)

    Butterfield, Cristina N; Tebo, Bradley M

    2017-02-22

    Manganese(ii) oxidation in the environment is thought to be driven by bacteria because enzymatic catalysis is many orders of magnitude faster than the abiotic processes. The heterologously purified Mn oxidase (Mnx) from marine Bacillus sp. PL-12 is made up of the multicopper oxidase (MCO) MnxG and two small Cu and heme-binding proteins of unknown function, MnxE and MnxF. Mnx binds Cu and oxidizes both Mn(ii) and Mn(iii), generating Mn(iv) oxide minerals that resemble those found on the Bacillus spore surface. Spectroscopic techniques have illuminated details about the metallo-cofactors of Mnx, but very little is known about their requirement for catalytic activity, and even less is known about the substrate specificity of Mnx. Here we quantify the canonical MCO Cu and persistent peripheral Cu bound to Mnx, and test Mnx oxidizing ability toward different substrates at varying pH. Mn(ii) appears to be the best substrate in terms of k cat , but its oxidation does not follow Michaelis-Menten kinetics, instead showing a sigmoidal cooperative behavior. Mnx also oxidizes Fe(ii) substrate, but in a Michaelis-Menten manner and with a decreased activity, as well as organic substrates. The reduced metals are more rapidly consumed than the larger organic substrates, suggesting the hypothesis that the Mnx substrate site is small and tuned for metal oxidation. Of biological relevance is the result that Mnx has the highest catalytic efficiency for Mn(ii) at the pH of sea water, especially when the protein is loaded with greater than the requisite four MCO copper atoms, suggesting that the protein has evolved specifically for Mn oxidation.

  16. Cytochrome oxidase assembly does not require catalytically active cytochrome C.

    Science.gov (United States)

    Barrientos, Antoni; Pierre, Danielle; Lee, Johnson; Tzagoloff, Alexander

    2003-03-14

    Cytochrome c oxidase (COX), the terminal enzyme of the mitochondrial respiratory chain, catalyzes the transfer of electrons from reduced cytochrome c to molecular oxygen. COX assembly requires the coming together of nuclear- and mitochondrial-encoded subunits and the assistance of a large number of nuclear gene products acting at different stages of maturation of the enzyme. In Saccharomyces cerevisiae, expression of cytochrome c, encoded by CYC1 and CYC7, is required not only for electron transfer but also for COX assembly through a still unknown mechanism. We have attempted to distinguish between a functional and structural requirement of cytochrome c in COX assembly. A cyc1/cyc7 double null mutant strain was transformed with the cyc1-166 mutant gene (Schweingruber, M. E., Stewart, J. W., and Sherman, F. (1979) J. Biol. Chem. 254, 4132-4143) that expresses stable but catalytically inactive iso-1-cytochrome c. The COX content of the cyc1/cyc7 double mutant strain harboring non-functional iso-1-cytochrome c has been characterized spectrally, functionally, and immunochemically. The results of these studies demonstrate that cytochrome c plays a structural rather than functional role in assembly of cytochrome c oxidase. In addition to its requirement for COX assembly, cytochrome c also affects turnover of the enzyme. Mutants containing wild type apocytochrome c in mitochondria lack COX, suggesting that only the folded and mature protein is able to promote COX assembly.

  17. Treatment of capital in Brasilian cooperative societies

    Directory of Open Access Journals (Sweden)

    Vergílio Frederico Perius

    2005-12-01

    Full Text Available The early history of the cooperative system never taxed much importance to capital formation in cooperatives. The first German consumer cooperative had no equity in their accounting records. We want to analyze, even though the capital was not essential, what is its function actually.

  18. Agricultural Co-Operatives in Ethiopia

    NARCIS (Netherlands)

    Tefera, Delelegne A.; Bijman, Jos; Slingerland, Maja A.

    2017-01-01

    To what extent can co-operatives strengthen rural development in sub-Saharan Africa? This paper explores the development of agricultural co-operatives in Ethiopia, particularly the changes in economic functions. Co-operative development in Ethiopia has been strongly influenced by various political

  19. Plant species and soil type cooperatively shape the structure and function of microbial communities in the rhizosphere.

    Science.gov (United States)

    Berg, Gabriele; Smalla, Kornelia

    2009-04-01

    The rhizosphere is of central importance not only for plant nutrition, health and quality but also for microorganism-driven carbon sequestration, ecosystem functioning and nutrient cycling in terrestrial ecosystems. A multitude of biotic and abiotic factors are assumed to influence the structural and functional diversity of microbial communities in the rhizosphere. In this review, recent studies on the influence of the two factors, plant species and soil type, on rhizosphere-associated microbial communities are discussed. Root exudates and the response of microorganisms to the latter as well as to root morphology were shown to shape rhizosphere microbial communities. All studies revealed that soil is the main reservoir for rhizosphere microorganisms. Many secrets of microbial life in the rhizosphere were recently uncovered due to the enormous progress in molecular and microscopic tools. Physiological and molecular data on the factors that drive selection processes in the rhizosphere are presented here. Furthermore, implications for agriculture, nature conservation and biotechnology will also be discussed.

  20. Mediation of glycosylated and partially-deglycosylated glucose oxidase of Aspergillus niger by a ferrocene-derivatised detergent.

    Science.gov (United States)

    Fraser, D M; Zakeeruddin, S M; Grätzel, M

    1992-01-30

    A ferrocene-derivatised detergent, (11-ferrocenylundecyl) trimethylammonium bromide (FTMAB), when oxidised to the corresponding ferricinium ion, was found by electrochemical studies to be an effective electron acceptor for reduced glucose oxidase of Aspergillus niger (EC 1.13.4) and thus acts as a electron-transfer mediator between glucose oxidase and a working electrode held at a potential sufficiently positive to reoxidise reduced FTMAB. An increase in mediating activity was produced when FTMAB was present in concentrations above its critical micelle concentration. An 'enzyme electrode' was formed by adsorption of glucose oxidase and FTMAB surfactant on a graphite rod. The electrode functioned as an amperometric biosensor for glucose in phosphate-buffered saline solution. A mixed micelle of glucose oxidase and FTMAB, probably adsorbed on the electrode surface, appears to be advantageous for the amperometric determination of glucose. Additionally, glucose oxidase was treated with alpha-mannosidase. When this partially-deglycosylated glucose oxidase was incorporated in an enzyme electrode, a 100-fold increase in the second-order rate constant (k) for electron transfer between the enzyme and FTMAB was observed, together with increased current densities, with respect to the equivalent values for FTMAB and commercial glucose oxidase. The use of deglycosylated enzymes in biosensors is suggested.

  1. Combined effect of loss of the caa3 oxidase and Crp regulation drives Shewanella to thrive in redox-stratified environments.

    Science.gov (United States)

    Zhou, Guangqi; Yin, Jianhua; Chen, Haijiang; Hua, Yijie; Sun, Linlin; Gao, Haichun

    2013-09-01

    Shewanella species are a group of facultative Gram-negative microorganisms with remarkable respiration abilities that allow the use of a diverse array of terminal electron acceptors (EA). Like most bacteria, S. oneidensis possesses multiple terminal oxidases, including two heme-copper oxidases (caa3- and cbb3-type) and a bd-type quinol oxidase. As aerobic respiration is energetically favored, mechanisms underlying the fact that these microorganisms thrive in redox-stratified environments remain vastly unexplored. In this work, we discovered that the cbb3-type oxidase is the predominant system for respiration of oxygen (O2), especially when O2 is abundant. Under microaerobic conditions, the bd-type quinol oxidase has a significant role in addition to the cbb3-type oxidase. In contrast, multiple lines of evidence suggest that under test conditions the caa3-type oxidase, an analog to the mitochondrial enzyme, has no physiological significance, likely because of its extremely low expression. In addition, expression of both cbb3- and bd-type oxidases is under direct control of Crp (cAMP receptor protein) but not the well-established redox regulator Fnr (fumarate nitrate regulator) of canonical systems typified in Escherichia coli. These data, collectively, suggest that adaptation of S. oneidensis to redox-stratified environments is likely due to functional loss of the caa3-type oxidase and switch of the regulatory system for respiration.

  2. Targeting NADPH oxidase decreases oxidative stress in the transgenic sickle cell mouse penis.

    Science.gov (United States)

    Musicki, Biljana; Liu, Tongyun; Sezen, Sena F; Burnett, Arthur L

    2012-08-01

    Sickle cell disease (SCD) is a state of chronic vasculopathy characterized by endothelial dysfunction and increased oxidative stress, but the sources and mechanisms responsible for reactive oxygen species (ROS) production in the penis are unknown. We evaluated whether SCD activates NADPH oxidase, induces endothelial nitric oxide synthase (eNOS) uncoupling, and decreases antioxidants in the SCD mouse penis. We further tested the hypothesis that targeting NADPH oxidase decreases oxidative stress in the SCD mouse penis. SCD transgenic (sickle) mice were used as an animal model of SCD. Hemizygous (hemi) mice served as controls. Mice received an NADPH oxidase inhibitor apocynin (10 mM in drinking water) or vehicle. Penes were excised at baseline for molecular studies. Markers of oxidative stress (4-hydroxy-2-nonenal [HNE]), sources of ROS (eNOS uncoupling and NADPH oxidase subunits p67(phox) , p47(phox) , and gp91(phox) ), and enzymatic antioxidants (superoxide dismutase [SOD]1, SOD2, catalase, and glutathione peroxidase-1 [GPx1]) were measured by Western blot in penes. Sources of ROS, oxidative stress, and enzymatic antioxidants in the SCD penis. Relative to hemi mice, SCD increased (Ppenis. Apocynin treatment of sickle mice reversed (P0.05) prevented eNOS uncoupling in the penis. Apocynin treatment of hemi mice did not affect any of these parameters. NADPH oxidase and eNOS uncoupling are sources of oxidative stress in the SCD penis; decreased GPx1 further contributes to oxidative stress. Inhibition of NADPH oxidase upregulation decreases oxidative stress, implying a major role for NADPH oxidase as a ROS source and a potential target for improving vascular function in the SCD mouse penis. © 2012 International Society for Sexual Medicine.

  3. Intracellular lysyl oxidase: Effect of a specific inhibitor on nuclear mass in proliferating cells

    Energy Technology Data Exchange (ETDEWEB)

    Saad, Fawzy A. [Laboratory for the Study of Skeletal Disorders and Rehabilitation, Department of Orthopedics, Children' s Hospital Boston, 300 Longwood Avenue EN926, Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States); Torres, Marie [Laboratory for the Study of Skeletal Disorders and Rehabilitation, Department of Orthopedics, Children' s Hospital Boston, 300 Longwood Avenue EN926, Boston, MA 02115 (United States); Wang, Hao [Laboratory for the Study of Skeletal Disorders and Rehabilitation, Department of Orthopedics, Children' s Hospital Boston, 300 Longwood Avenue EN926, Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States); Graham, Lila, E-mail: lilagraham@cs.com [Laboratory for the Study of Skeletal Disorders and Rehabilitation, Department of Orthopedics, Children' s Hospital Boston, 300 Longwood Avenue EN926, Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States)

    2010-06-11

    LOX, the principal enzyme involved in crosslinking of collagen, was the first of several lysyl oxidase isotypes to be characterized. Its active form was believed to be exclusively extracellular. Active LOX was later reported to be present in cell nuclei; its function there is unknown. LOX expression opposes the effect of mutationally activated Ras, which is present in about 30% of human cancers. The mechanism of LOX in countering the action of Ras is also unknown. In the present work, assessment of nuclear protein for possible effects of lysyl oxidase activity led to the discovery that proliferating cells dramatically increase their nuclear protein content when exposed to BAPN ({beta}-aminopropionitrile), a highly specific lysyl oxidase inhibitor that reportedly blocks LOX inhibition of Ras-induced oocyte maturation. In three cell types (PC12 cells, A7r5 smooth muscle cells, and NIH 3T3 fibroblasts), BAPN caused a 1.8-, 1.7-, and 2.1-fold increase in total nuclear protein per cell, respectively, affecting all major components in both nuclear matrix and chromatin fractions. Since nuclear size is correlated with proliferative status, enzyme activity restricting nuclear growth may be involved in the lysyl oxidase tumor suppressive effect. Evidence is also presented for the presence of apparent lysyl oxidase isotype(s) containing a highly conserved LOX active site sequence in the nuclei of PC12 cells, which do not manufacture extracellular lysyl oxidase substrates. Results reported here support the hypothesis that nuclear lysyl oxidase regulates nuclear growth, and thereby modulates cell proliferation.

  4. Monoamine Oxidase B Inhibitors in Parkinson's Disease.

    Science.gov (United States)

    Dezsi, Livia; Vecsei, Laszlo

    2017-01-01

    Parkinson's disease (PD) is a neurodegenerative disorder with a prevalence increasing with age. Oxidative stress and glutamate toxicity are involved in its pathomechanism. There are still many unmet needs of PD patients, including the alleviation of motor fluctuations and dyskinesias, and the development of therapies with neuroprotective potential. To give an overview of the pharmacological properties, the efficacy and safety of the monoamine oxidase B (MAO-B) inhibitors in the treatment of PD, with special focus on the results of randomized clinical trials. A literature search was conducted in PubMed for 'PD treatment', 'MAO-B inhibitors', 'selegiline', 'rasagiline', 'safinamide' and 'clinical trials' with 'MAO-B inhibitors' in 'Parkinson' disease'. MAO-B inhibitors have a favorable pharmacokinetic profile, improve the dopamine deficient state and may have neuroprotective properties. Safinamide exhibits an anti-glutamatergic effect as well. When applied as monotherapy, MAO-B inhibitors provide a modest, but significant improvement of motor function and delay the need for levodopa. Rasagiline and safinamide were proven safe and effective when added to a dopamine agonist in early PD. As add-on to levodopa, MAO-B inhibitors significantly reduced off-time and were comparable in efficacy to COMT inhibitors. Improvements were achieved as regards certain non-motor symptoms as well. Due to the efficacy shown in clinical trials and their favorable side-effect profile, MAO-B inhibitors are valuable drugs in the treatment of PD. They are recommended as monotherapy in the early stages of the disease and as add-on therapy to levodopa in advanced PD. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  5. Transboundary cooperation

    International Nuclear Information System (INIS)

    Rauber, D.

    2006-01-01

    The operation of nuclear power plants near national borders requires a close bilateral co-operation to cope with accidents having off-site radiological impacts. For example in 1978 such an agreement was signed by the German and Swiss government. The accident at the Chernobyl NPP changed the international co-operation in the framework of international consequence management. International conventions were agreed to insure a timely notification and international assistance in case of an accident with transboundary effects. In order to fulfill these conventions several procedures were introduced. In addition, bilateral agreements were signed also with countries which are not operating nuclear power plants near national borders. Since then no accident took place that would have required any notification. However, following the experience the expectations to these networks have changed considerably and hence sustainable development is required to cope with new challenges such as long term consequences management, new radiological threats, faster international assistance, media and public concerns, and technical evolution of communications systems. (author)

  6. Mit1 Transcription Factor Mediates Methanol Signaling and Regulates the Alcohol Oxidase 1 (AOX1) Promoter in Pichia pastoris*

    Science.gov (United States)

    Wang, Xiaolong; Wang, Qi; Wang, Jinjia; Bai, Peng; Shi, Lei; Shen, Wei; Zhou, Mian; Zhou, Xiangshan; Zhang, Yuanxing; Cai, Menghao

    2016-01-01

    The alcohol oxidase 1 (AOX1) promoter (PAOX1) of Pichia pastoris is the most powerful and commonly used promoter for driving protein expression. However, mechanisms regulating its transcriptional activity are unclear. Here, we identified a Zn(II)2Cys6-type methanol-induced transcription factor 1 (Mit1) and elucidated its roles in regulating PAOX1 activity in response to glycerol and methanol. Mit1 regulated the expression of many genes involved in methanol utilization pathway, including AOX1, but did not participate in peroxisome proliferation and transportation of peroxisomal proteins during methanol metabolism. Structural analysis of Mit1 by performing domain deletions confirmed its specific and critical role in the strict repression of PAOX1 in glycerol medium. Importantly, Mit1, Mxr1, and Prm1, which positively regulated PAOX1 in response to methanol, were bound to PAOX1 at different sites and did not interact with each other. However, these factors cooperatively activated PAOX1 through a cascade. Mxr1 mainly functioned during carbon derepression, whereas Mit1 and Prm1 functioned during methanol induction, with Prm1 transmitting methanol signal to Mit1 by binding to the MIT1 promoter (PMIT1), thus increasingly expressing Mit1 and subsequently activating PAOX1. PMID:26828066

  7. Mit1 Transcription Factor Mediates Methanol Signaling and Regulates the Alcohol Oxidase 1 (AOX1) Promoter in Pichia pastoris.

    Science.gov (United States)

    Wang, Xiaolong; Wang, Qi; Wang, Jinjia; Bai, Peng; Shi, Lei; Shen, Wei; Zhou, Mian; Zhou, Xiangshan; Zhang, Yuanxing; Cai, Menghao

    2016-03-18

    The alcohol oxidase 1 (AOX1) promoter (P AOX1) of Pichia pastoris is the most powerful and commonly used promoter for driving protein expression. However, mechanisms regulating its transcriptional activity are unclear. Here, we identified a Zn(II)2Cys6-type methanol-induced transcription factor 1 (Mit1) and elucidated its roles in regulating PAOX1 activity in response to glycerol and methanol. Mit1 regulated the expression of many genes involved in methanol utilization pathway, including AOX1, but did not participate in peroxisome proliferation and transportation of peroxisomal proteins during methanol metabolism. Structural analysis of Mit1 by performing domain deletions confirmed its specific and critical role in the strict repression of P AOX1 in glycerol medium. Importantly, Mit1, Mxr1, and Prm1, which positively regulated P AOX1 in response to methanol, were bound to P AOX1 at different sites and did not interact with each other. However, these factors cooperatively activated P AOX1 through a cascade. Mxr1 mainly functioned during carbon derepression, whereas Mit1 and Prm1 functioned during methanol induction, with Prm1 transmitting methanol signal to Mit1 by binding to the MIT1 promoter (P MIT1), thus increasingly expressing Mit1 and subsequently activating P AOX1. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. A new methodology for the determination of enzyme activity based on carbon nanotubes and glucose oxidase.

    Science.gov (United States)

    Yeşiller, Gülden; Sezgintürk, Mustafa Kemal

    2015-11-10

    In this research, a novel enzyme activity analysis methodology is introduced as a new perspective for this area. The activity of elastase enzyme, which is a digestive enzyme mostly of found in the digestive system of vertebrates, was determined by an electrochemical device composed of carbon nanotubes and a second enzyme, glucose oxidase, which was used as a signal generator enzyme. In this novel methodology, a complex bioactive layer was constructed by using carbon nanotubes, glucose oxidase and a supporting protein, gelatin on a solid, conductive substrate. The activity of elastase was determined by monitoring the hydrolysis rate of elastase enzyme in the bioactive layer. As a result of this hydrolysis of elastase, glucose oxidase was dissociated from the bioactive layer, and following this the electrochemical signal due to glucose oxidase was decreased. The progressive elastase-catalyzed digestion of the bioactive layer containing glucose oxidase decreased the layer's enzymatic efficiency, resulting in a decrease of the glucose oxidation current as a function of the enzyme activity. The ratio of the decrease was correlated to elastase activity level. In this study, optimization experiments of bioactive components and characterization of the resulting new electrochemical device were carried out. A linear calibration range from 0.0303U/mL to 0.0729U/mL of elastase was reported. Real sample analyses were also carried out by the new electrochemical device. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. The ASK1 gene regulates B function gene expression in cooperation with UFO and LEAFY in Arabidopsis.

    Science.gov (United States)

    Zhao, D; Yu, Q; Chen, M; Ma, H

    2001-07-01

    The Arabidopsis floral regulatory genes APETALA3 (AP3) and PISTILLATA (PI) are required for the B function according to the ABC model for floral organ identity. AP3 and PI expression are positively regulated by the LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) genes. UFO encodes an F-box protein, and we have shown previously that UFO genetically interacts with the ASK1 gene encoding a SKP1 homologue; both the F-box containing protein and SKP1 are subunits of ubiquitin ligases. We show here that the ask1-1 mutation can enhance the floral phenotypes of weak lfy and ap3 mutants; therefore, like UFO, ASK1 also interacts with LFY and AP3 genetically. Furthermore, our results from RNA in situ hybridizations indicate that ASK1 regulates early AP3 and PI expression. These results support the idea that UFO and ASK1 together positively regulate AP3 and PI expression. We propose that the UFO and ASK1 proteins are components of a ubiquitin ligase that mediates the proteolysis of a repressor of AP3 and PI expression. Our genetic studies also indicate that ASK1 and UFO play a role in regulating the number of floral organ primordia, and we discuss possible mechanisms for such a regulation.

  10. Crystallization of carbohydrate oxidase from Microdochium nivale

    Czech Academy of Sciences Publication Activity Database

    Dušková, Jarmila; Dohnálek, Jan; Skálová, Tereza; Ostergaard, L. H.; Fuglsang, C. C.; Kolenko, Petr; Štěpánková, Andrea; Hašek, Jindřich

    2009-01-01

    Roč. 65, č. 6 (2009), s. 638-640 ISSN 1744-3091 R&D Projects: GA AV ČR IAA500500701; GA ČR GA305/07/1073 Institutional research plan: CEZ:AV0Z40500505 Keywords : carbohydrate oxidase * crystallization * data processing Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.551, year: 2009

  11. Investigation of antihemolytic, xanthine oxidase inhibition ...

    African Journals Online (AJOL)

    Abbreviations: SVEs: Salvia Verbenaca L. aerial part Extracts; CrE: Crud Extract; ChE: Chloroform Extract ; EAE: Ethyl Acetate Extract; AqE : Aqueous Extract ; ROS: Reactive Oxygen Spices; AAPH : 2,2, -Azobis (2-AmidinoPropane) Dihydrochloride ; DPPH: DiPhenyl- Picryl-Hydrazyl; XO: Xanthine Oxidase; Gen: Gentamicin ...

  12. Genetic defects of cytochrome c oxidase assembly

    Czech Academy of Sciences Publication Activity Database

    Pecina, Petr; Houšťková, H.; Hansíková, H.; Zeman, J.; Houštěk, Josef

    2004-01-01

    Roč. 53, Suppl. 1 (2004), s. S213-S223 ISSN 0862-8408 R&D Projects: GA ČR GA303/03/0749 Institutional research plan: CEZ:AV0Z5011922 Keywords : cytochrome c oxidase * mitochondrial disorders Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition Impact factor: 1.140, year: 2004

  13. The antioxidant properties, cytotoxicity and monoamine oxidase ...

    African Journals Online (AJOL)

    Tarchonanthus camphoratus (camphor bush) has been widely used for numerous medicinal purposes. The aim of the present study was to evaluate the antioxidant properties, cytotoxicity and monoamine oxidase inhibition activities of the crude dichloromethane leaf extract of T. camphoratus. The antioxidant activities were ...

  14. Regulation of the NADPH Oxidase RBOHD During Plant Immunity.

    Science.gov (United States)

    Kadota, Yasuhiro; Shirasu, Ken; Zipfel, Cyril

    2015-08-01

    Pathogen recognition induces the production of reactive oxygen species (ROS) by NADPH oxidases in both plants and animals. ROS have direct antimicrobial properties, but also serve as signaling molecules to activate further immune outputs. However, ROS production has to be tightly controlled to avoid detrimental effects on host cells, but yet must be produced in the right amount, at the right place and at the right time upon pathogen perception. Plant NADPH oxidases belong to the respiratory burst oxidase homolog (RBOH) family, which contains 10 members in the model plant Arabidopsis thaliana. The perception of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs) leads to a rapid, specific and strong production of ROS, which is dependent on RBOHD. RBOHD is mainly controlled by Ca(2+) via direct binding to EF-hand motifs and phosphorylation by Ca(2+)-dependent protein kinases. Recent studies have, however, revealed a critical role for a Ca(2+)-independent regulation of RBOHD. The plasma membrane-associated cytoplasmic kinase BIK1 (BOTRYTIS-INDUCED KINASE1), which is a direct substrate of the PRR complex, directly interacts with and phosphorylates RBOHD upon PAMP perception. Impairment of these phosphorylation events completely abolishes the function of RBOHD in immunity. These results suggest that RBOHD activity is tightly controlled by multilayered regulations. In this review, we summarize recent advances in our understanding of the regulatory mechanisms controlling RBOHD activation. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  15. Biocompatibility selenium nanoparticles with an intrinsic oxidase-like activity

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Leilei; Huang, Kaixun; Liu, Hongmei, E-mail: hmliu2004@126.com [Huazhong University of Science and Technology, School of Chemistry and Chemical Engineering (China)

    2016-03-15

    Selenium nanoparticles (SeNPs) are considered to be the new selenium supplement forms with high biological activity and low toxicity; however, the molecular mechanism by which SeNPs exert the biological function is unclear. Here, we reported that biocompatibility SeNPs possessed intrinsic oxidase-like activity. Using Na{sub 2}SeO{sub 3} as a precursor and glutathione as a reductant, biocompatibility SeNPs were synthesized by the wet chemical reduction method in the presence of bovine serum albumin (BSA). The results of structure characterization revealed that synthesized SeNPs were amorphous red elementary selenium with spherical morphology, and ranged in size from 25 to 70 nm size with a narrow distribution (41.4 ± 6.7 nm). The oxidase-like activity of the as-synthesized SeNPs was tested with 3,3′,5,5′-tetramethylbenzidine (TMB) as a substrate. The results indicated that SeNPs could catalyze the oxidization of TMB by dissolved oxygen. These SeNPs showed an optimum catalytic activity at pH 4 and 30 °C, and the oxidase-like activity was higher as the concentration of SeNPs increased and the size of SeNPs decreased. The Michaelis constant (K{sub m}) values and maximal reaction velocity (V{sub max}) of the SeNPs for TMB oxidation were 0.0083 mol/L and 3.042 μmol/L min, respectively.

  16. Biocompatibility selenium nanoparticles with an intrinsic oxidase-like activity

    International Nuclear Information System (INIS)

    Guo, Leilei; Huang, Kaixun; Liu, Hongmei

    2016-01-01

    Selenium nanoparticles (SeNPs) are considered to be the new selenium supplement forms with high biological activity and low toxicity; however, the molecular mechanism by which SeNPs exert the biological function is unclear. Here, we reported that biocompatibility SeNPs possessed intrinsic oxidase-like activity. Using Na 2 SeO 3 as a precursor and glutathione as a reductant, biocompatibility SeNPs were synthesized by the wet chemical reduction method in the presence of bovine serum albumin (BSA). The results of structure characterization revealed that synthesized SeNPs were amorphous red elementary selenium with spherical morphology, and ranged in size from 25 to 70 nm size with a narrow distribution (41.4 ± 6.7 nm). The oxidase-like activity of the as-synthesized SeNPs was tested with 3,3′,5,5′-tetramethylbenzidine (TMB) as a substrate. The results indicated that SeNPs could catalyze the oxidization of TMB by dissolved oxygen. These SeNPs showed an optimum catalytic activity at pH 4 and 30 °C, and the oxidase-like activity was higher as the concentration of SeNPs increased and the size of SeNPs decreased. The Michaelis constant (K m ) values and maximal reaction velocity (V max ) of the SeNPs for TMB oxidation were 0.0083 mol/L and 3.042 μmol/L min, respectively.

  17. Covalent immobilization of glucose oxidase on amino MOFs via post-synthetic modification

    NARCIS (Netherlands)

    Tudisco, C.G.; Zolubas, G.; Seoane de la Cuesta, B.; Zafarani, H.; Kazemzad Asiabi, M.; Gascon Sabate, J.; Hagedoorn, P.L.; Rassaei, L.

    2016-01-01

    The post-synthetic modification (PSM) of two amino-MOFs with glucose oxidase is reported in this study. The multi-step approach preserved the MOFs' structure and allowed the production of enzyme-functionalized MOFs (MOFs@GOx), which retained the enzymatic activity and showed selective properties

  18. Pyruvate Oxidase Influences the Sugar Utilization Pattern and Capsule Production in Streptococcus pneumoniae

    NARCIS (Netherlands)

    Carvalho, Sandra M.; Farshchi Andisi, Vahid; Gradstedt, Henrik; Neef, Jolanda; Kuipers, Oscar P.; Neves, Ana R.; Bijlsma, Jetta J. E.

    2013-01-01

    Pyruvate oxidase is a key function in the metabolism and lifestyle of many lactic acid bacteria and its activity depends on the presence of environmental oxygen. In Streptococcus pneumoniae the protein has been suggested to play a major role in metabolism and has been implicated in virulence,

  19. The role of double covalent flavin binding in chito-oligosaccharide oxidase from Fusarium graminearum

    NARCIS (Netherlands)

    Heuts, Dominic P. H. M.; Winter, Remko T.; Damsma, Gerke E.; Janssen, Dick B.; Fraaije, Marco W.

    2008-01-01

    ChitO (chito-oligosaccharide oxidase) from Fusarium graminearum catalyses the regioselective oxidation of N-acetylated oligosaccharides. The enzyme harbours an FAD cofactor that is covalently attached to His(94) and Cys(154). The functional role of this unusual bi-covalent flavin-protein linkage was

  20. Tie2 signaling cooperates with TNF to promote the pro-inflammatory activation of human macrophages independently of macrophage functional phenotype.

    Science.gov (United States)

    García, Samuel; Krausz, Sarah; Ambarus, Carmen A; Fernández, Beatriz Malvar; Hartkamp, Linda M; van Es, Inge E; Hamann, Jörg; Baeten, Dominique L; Tak, Paul P; Reedquist, Kris A

    2014-01-01

    Angiopoietin (Ang) -1 and -2 and their receptor Tie2 play critical roles in regulating angiogenic processes during development, homeostasis, tumorigenesis, inflammation and tissue repair. Tie2 signaling is best characterized in endothelial cells, but a subset of human and murine circulating monocytes/macrophages essential to solid tumor formation express Tie2 and display immunosuppressive properties consistent with M2 macrophage polarization. However, we have recently shown that Tie2 is strongly activated in pro-inflammatory macrophages present in rheumatoid arthritis patient synovial tissue. Here we examined the relationship between Tie2 expression and function during human macrophage polarization. Tie2 expression was observed under all polarization conditions, but was highest in IFN-γ and IL-10 -differentiated macrophages. While TNF enhanced expression of a common restricted set of genes involved in angiogenesis and inflammation in GM-CSF, IFN-γ and IL-10 -differentiated macrophages, expression of multiple chemokines and cytokines, including CXCL3, CXCL5, CXCL8, IL6, and IL12B was further augmented in the presence of Ang-1 and Ang-2, via Tie2 activation of JAK/STAT signaling. Conditioned medium from macrophages stimulated with Ang-1 or Ang-2 in combination with TNF, sustained monocyte recruitment. Our findings suggest a general role for Tie2 in cooperatively promoting the inflammatory activation of macrophages, independently of polarization conditions.

  1. Plasma amine oxidase activities in Norrie disease patients with an X-chromosomal deletion affecting monoamine oxidase.

    Science.gov (United States)

    Murphy, D L; Sims, K B; Karoum, F; Garrick, N A; de la Chapelle, A; Sankila, E M; Norio, R; Breakefield, X O

    1991-01-01

    Two individuals with an X-chromosomal deletion were recently found to lack the genes encoding monoamine oxidase type A (MAO-A) and MAO-B. This abnormality was associated with almost total (90%) reductions in the oxidatively deaminated urinary metabolites of the MAO-A substrate, norepinephrine, and with marked (100-fold) increases in an MAO-B substrate, phenylethylamine, confirming systemic functional consequences of the genetic enzyme deficiency. However, urinary concentrations of the deaminated metabolites of dopamine and serotonin (5-HT) were essentially normal. To investigate other deaminating systems besides MAO-A and MAO-B that might produce these metabolites of dopamine and 5-HT, we examined plasma amine oxidase (AO) activity in these two patients and two additional patients with the same X-chromosomal deletion. Normal plasma AO activity was found in all four Norrie disease-deletion patients, in four patients with classic Norrie disease without a chromosomal deletion, and in family members of patients from both groups. Marked plasma amine metabolite abnormalities and essentially absent platelet MAO-B activity were found in all four Norrie disease-deletion patients, but in none of the other subjects in the two comparison groups. These results indicate that plasma AO is encoded by gene(s) independent of those for MAO-A and MAO-B, and raise the possibility that plasma AO, and perhaps the closely related tissue AO, benzylamine oxidase, as well as other atypical AOs or MAOs encoded independently from MAO-A and MAO-B may contribute to the oxidative deamination of dopamine and 5-HT in humans.

  2. Functional cooperation between HIF-1α and c-Jun in mediating primary and acquired resistance to gefitinib in NSCLC cells with activating mutation of EGFR.

    Science.gov (United States)

    Meng, Shuyan; Wang, Guorui; Lu, Yang; Fan, Zhen

    2018-07-01

    Hypoxia-inducible factor 1 (HIF-1) and activator protein 1 (AP-1) are important transcription factors regulating expression of genes involved in cell survival. HIF-1α and c-Jun are key components of HIF-1 and AP-1, respectively, and are regulated by epidermal growth factor receptor (EGFR)-mediated cell signaling and tumor microenvironmental cues. The roles of HIF-1α and c-Jun in development of resistance to EGFR tyrosine kinase inhibitor (TKI) in non-small cell lung cancer (NSCLC) with activating mutation of EGFR have not been explored. In this study, we investigated the roles of HIF-1α and c-Jun in mediating primary and acquired resistance to gefitinib in NSCLC cells with activating mutation of EGFR. Changes in HIF-1α protein and in total and phosphorylated c-Jun levels in relation to changes in total and phosphorylated EGFR levels before and after gefitinib treatment were measured using Western blot analysis in NSCLC cells sensitive or resistant to gefitinib. The impact of overexpression of a constitutively expressed HIF-1α (HIF-1α/ΔODD) or a constitutively active c-Jun upstream regulator (SEK1 S220E/T224D mutant) on cell response to gefitinib was also examined. The effect of pharmacological inhibition of SEK1-JNK-c-Jun pathway on cell response to gefitinib was evaluated. Downregulation of HIF-1α and total and phosphorylated c-Jun levels correlated with cell inhibitory response to gefitinib better than decrease in phosphorylated EGFR did in NSCLC cells with intrinsic or acquired resistance to gefitinib. Overexpression of HIF-1α/ΔODD or SEK1 S220E/T224D mutant conferred resistance to gefitinib. There exists a positive feed-forward regulation loop between HIF-1 and c-Jun. The JNK inhibitor SP600125 sensitized gefitinib-resistant NSCLC cells to gefitinib. HIF-1α and c-Jun functionally cooperate in development of resistance to gefitinib in NSCLC cells. The translational value of inhibiting HIF-1α/c-Jun cooperation in overcoming resistance to EGFR TKI

  3. Acupuncture elicits neuroprotective effect by inhibiting NAPDH oxidase-mediated reactive oxygen species production in cerebral ischaemia.

    Science.gov (United States)

    Shi, Guang-Xia; Wang, Xue-Rui; Yan, Chao-Qun; He, Tian; Yang, Jing-Wen; Zeng, Xiang-Hong; Xu, Qian; Zhu, Wen; Du, Si-Qi; Liu, Cun-Zhi

    2015-12-10

    In the current study, we aimed to investigate whether NADPH oxidase, a major ROS-producing enzyme, was involved in the antioxidant effect of acupuncture on cognitive impairment after cerebral ischaemia. The cognitive function, infract size, neuron cell loss, level of superoxide anion and expression of NADPH oxidase subunit in hippocampus of two-vessel occlusion (2VO) rats were determined after 2-week acupuncture. Furthermore, the cognitive function and production of O2(-) were determined in the presence and absence of NADPH oxidase agonist (TBCA) and antagonist (Apocynin). The effect of acupuncture on cognitive function after cerebral ischaemia in gp91phox-KO mice was evaluated by Morris water maze. Acupuncture reduced infarct size, attenuated overproduction of O2(-), and reversed consequential cognitive impairment and neuron cell loss in 2VO rats. The elevations of gp91phox and p47phox after 2VO were significantly decreased after acupuncture treatment. However, no differences of gp91phox mRNA were found among any experimental groups. Furthermore, these beneficial effects were reversed by TBCA, whereas apocynin mimicked the effect of acupuncture by improving cognitive function and decreasing O2(-) generation. Acupuncture failed to improve the memory impairment in gp91phox KO mice. Full function of the NADPH oxidase enzyme plays an important role in neuroprotective effects against cognitive impairment via inhibition of NAPDH oxidase-mediated oxidative stress.

  4. A broad distribution of the alternative oxidase in microsporidian parasites.

    Directory of Open Access Journals (Sweden)

    Bryony A P Williams

    2010-02-01

    Full Text Available Microsporidia are a group of obligate intracellular parasitic eukaryotes that were considered to be amitochondriate until the recent discovery of highly reduced mitochondrial organelles called mitosomes. Analysis of the complete genome of Encephalitozoon cuniculi revealed a highly reduced set of proteins in the organelle, mostly related to the assembly of iron-sulphur clusters. Oxidative phosphorylation and the Krebs cycle proteins were absent, in keeping with the notion that the microsporidia and their mitosomes are anaerobic, as is the case for other mitosome bearing eukaryotes, such as Giardia. Here we provide evidence opening the possibility that mitosomes in a number of microsporidian lineages are not completely anaerobic. Specifically, we have identified and characterized a gene encoding the alternative oxidase (AOX, a typically mitochondrial terminal oxidase in eukaryotes, in the genomes of several distantly related microsporidian species, even though this gene is absent from the complete genome of E. cuniculi. In order to confirm that these genes encode functional proteins, AOX genes from both A. locustae and T. hominis were over-expressed in E. coli and AOX activity measured spectrophotometrically using ubiquinol-1 (UQ-1 as substrate. Both A. locustae and T. hominis AOX proteins reduced UQ-1 in a cyanide and antimycin-resistant manner that was sensitive to ascofuranone, a potent inhibitor of the trypanosomal AOX. The physiological role of AOX microsporidia may be to reoxidise reducing equivalents produced by glycolysis, in a manner comparable to that observed in trypanosomes.

  5. Oxidase catalysis via aerobically generated hypervalent iodine intermediates

    Science.gov (United States)

    Maity, Asim; Hyun, Sung-Min; Powers, David C.

    2018-02-01

    The development of sustainable oxidation chemistry demands strategies to harness O2 as a terminal oxidant. Oxidase catalysis, in which O2 serves as a chemical oxidant without necessitating incorporation of oxygen into reaction products, would allow diverse substrate functionalization chemistry to be coupled to O2 reduction. Direct O2 utilization suffers from intrinsic challenges imposed by the triplet ground state of O2 and the disparate electron inventories of four-electron O2 reduction and two-electron substrate oxidation. Here, we generate hypervalent iodine reagents—a broadly useful class of selective two-electron oxidants—from O2. This is achieved by intercepting reactive intermediates of aldehyde autoxidation to aerobically generate hypervalent iodine reagents for a broad array of substrate oxidation reactions. The use of aryl iodides as mediators of aerobic oxidation underpins an oxidase catalysis platform that couples substrate oxidation directly to O2 reduction. We anticipate that aerobically generated hypervalent iodine reagents will expand the scope of aerobic oxidation chemistry in chemical synthesis.

  6. Role of pH in oxidase variability of Aeromonas hydrophila.

    OpenAIRE

    Hunt, L K; Overman, T L; Otero, R B

    1981-01-01

    Some strains of Aeromonas hydrophila may be oxidase negative or only weakly oxidase positive by the Kovacs method taken from the surface of a differential medium, such as MacConkey agar. Six strains of A. hydrophila, two oxidase variable, one oxidase constant, and three weakly oxidase positive on MacConkey agar, were studied to determine the cause of oxidase variability. The bacteriostatic dyes in MacConkey agar were considered possible inhibitors of the oxidase reaction. The concentration of...

  7. The Membrane Modulates Internal Proton Transfer in Cytochrome c Oxidase

    DEFF Research Database (Denmark)

    Öjemyr, Linda Nasvik; Ballmoos, Christoph von; Faxén, Kristina

    2012-01-01

    The functionality of membrane proteins is often modulated by the surrounding membrane. Here, we investigated the effect of membrane reconstitution of purified cytochrome c oxidase (CytcO) on the kinetics and thermodynamics of internal electron and proton-transfer reactions during O-2 reduction...... DOPC lipids. In conclusion, the data show that the membrane significantly modulates internal charge-transfer reactions and thereby the function of the membrane-bound enzyme.......-glycerol) (DOPG). In addition, a small Change in the internal Cu-A-heme a electron equilibrium constant was observed. This effect was lipid-dependent and explained in terms of a lower electrostatic potential within the membrane-spanning part of the protein with the anionic DOPG lipids than with the zwitterionic...

  8. Plasma diamine oxidase activity in asthmatic children

    Directory of Open Access Journals (Sweden)

    Kyoichiro Toyoshima

    1996-01-01

    Full Text Available Histamine plays an important role in the development of asthmatic symptoms. Diamine oxidase (DAO histaminase, which inactivates histamine, is located in the intestine and kidney and is released into plasma. Plasma DAO activity in asthmatic children was measured by a recently developed high performance liquid chromatographic method using histamine as the DAO substrate. Diamine oxidase activity was higher in severely asthmatic children than in those with mild asthma. A time course study during the acute exacerbation phase revealed that DAO activity rose during acute asthmatic attacks and then decreased gradually over several days. Although the mechanisms of plasma DAO activity increase during acute asthmatic attacks could not be explained, data showed that plasma DAO activity is an important index of histamine metabolism in asthmatics and may relate to some mechanisms of acute exacerbation of airway inflammation. Consequently, fluctuations in plasma DAO can be used as one of various indices of instability in management of asthma.

  9. Lysyl Oxidase and the Tumor Microenvironment

    Directory of Open Access Journals (Sweden)

    Tong-Hong Wang

    2016-12-01

    Full Text Available The lysyl oxidase (LOX family of oxidases contains a group of extracellular copper-dependent enzymes that catalyze the cross-linking of collagen and elastin by oxidation, thus maintaining the rigidity and structural stability of the extracellular matrix (ECM. Aberrant expression or activation of LOX alters the cellular microenvironment, leading to many diseases, including atherosclerosis, tissue fibrosis, and cancer. Recently, a number of studies have shown that LOX is overexpressed in most cancers and that it is involved in the regulation of tumor progression and metastasis. In contrast, a few reports have also indicated the tumor-suppressing role of LOX. In this short review, we discuss recent research on the correlations between LOX and cancer. Further, the role of LOX in tumor microenvironment remodeling, tumorigenesis, and metastasis and the underlying mechanisms have also been elucidated.

  10. How feeling betrayed affects cooperation.

    Science.gov (United States)

    Ramazi, Pouria; Hessel, Jop; Cao, Ming

    2015-01-01

    For a population of interacting self-interested agents, we study how the average cooperation level is affected by some individuals' feelings of being betrayed and guilt. We quantify these feelings as adjusted payoffs in asymmetric games, where for different emotions, the payoff matrix takes the structure of that of either a prisoner's dilemma or a snowdrift game. Then we analyze the evolution of cooperation in a well-mixed population of agents, each of whom is associated with such a payoff matrix. At each time-step, an agent is randomly chosen from the population to update her strategy based on the myopic best-response update rule. According to the simulations, decreasing the feeling of being betrayed in a portion of agents does not necessarily increase the level of cooperation in the population. However, this resistance of the population against low-betrayal-level agents is effective only up to some extend that is explicitly determined by the payoff matrices and the number of agents associated with these matrices. Two other models are also considered where the betrayal factor of an agent fluctuates as a function of the number of cooperators and defectors that she encounters. Unstable behaviors are observed for the level of cooperation in these cases; however, we show that one can tune the parameters in the function to make the whole population become cooperative or defective.

  11. How feeling betrayed affects cooperation.

    Directory of Open Access Journals (Sweden)

    Pouria Ramazi

    Full Text Available For a population of interacting self-interested agents, we study how the average cooperation level is affected by some individuals' feelings of being betrayed and guilt. We quantify these feelings as adjusted payoffs in asymmetric games, where for different emotions, the payoff matrix takes the structure of that of either a prisoner's dilemma or a snowdrift game. Then we analyze the evolution of cooperation in a well-mixed population of agents, each of whom is associated with such a payoff matrix. At each time-step, an agent is randomly chosen from the population to update her strategy based on the myopic best-response update rule. According to the simulations, decreasing the feeling of being betrayed in a portion of agents does not necessarily increase the level of cooperation in the population. However, this resistance of the population against low-betrayal-level agents is effective only up to some extend that is explicitly determined by the payoff matrices and the number of agents associated with these matrices. Two other models are also considered where the betrayal factor of an agent fluctuates as a function of the number of cooperators and defectors that she encounters. Unstable behaviors are observed for the level of cooperation in these cases; however, we show that one can tune the parameters in the function to make the whole population become cooperative or defective.

  12. Monoamine oxidase inhibitors from Gentiana lutea.

    Science.gov (United States)

    Haraguchi, Hiroyuki; Tanaka, Yasumasa; Kabbash, Amal; Fujioka, Toshihiro; Ishizu, Takashi; Yagi, Akira

    2004-08-01

    Three monoamine oxidase (MAO) inhibitors were isolated from Gentiana lutea. Their structures were elucidated to be 3-3''linked-(2'-hydroxy-4-O-isoprenylchalcone)-(2'''-hydroxy-4''-O-isoprenyldihydrochalcone) (1), 2-methoxy-3-(1,1'-dimethylallyl)-6a,10a-dihydrobenzo(1,2-c)chroman-6-one and 5-hydroxyflavanone. These compounds, and the hydrolysis product of 1, displayed competitive inhibitory properties against MAO-B which was more effective than MAO-A.

  13. Imaging Monoamine Oxidase in the Human Brain

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J. S.; Volkow, N. D.; Wang, G-J.; Logan, Jean

    1999-11-10

    Positron emission tomography (PET) studies mapping monoamine oxidase in the human brain have been used to measure the turnover rate for MAO B; to determine the minimum effective dose of a new MAO inhibitor drug lazabemide and to document MAO inhibition by cigarette smoke. These studies illustrate the power of PET and radiotracer chemistry to measure normal biochemical processes and to provide information on the effect of drug exposure on specific molecular targets.

  14. Imaging Monoamine Oxidase in the Human Brain

    International Nuclear Information System (INIS)

    Fowler, J. S.; Volkow, N. D.; Wang, G-J.; Logan, Jean

    1999-01-01

    Positron emission tomography (PET) studies mapping monoamine oxidase in the human brain have been used to measure the turnover rate for MAO B; to determine the minimum effective dose of a new MAO inhibitor drug lazabemide and to document MAO inhibition by cigarette smoke. These studies illustrate the power of PET and radiotracer chemistry to measure normal biochemical processes and to provide information on the effect of drug exposure on specific molecular targets

  15. Modulation of NADPH oxidase activity by known uraemic retention solutes

    DEFF Research Database (Denmark)

    Schulz, Anna Marta; Terne, Cindy; Jankowski, Vera

    2014-01-01

    chloride (DPI), an inhibitor of NADPH oxidase. The effect on enzymatic activity of NADPH oxidase was quantified within an incubation time of 120 min. RESULTS: Thirty-nine of the 48 uraemic retention solutes tested had a significant decreasing effect on NADPH oxidase activity. Oxalate has been characterized......BACKGROUND: Uraemia and cardiovascular disease appear to be associated with an increased oxidative burden. One of the key players in the genesis of reactive oxygen species (ROS) is nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Based on initial experiments demonstrating a decreased...... inhibitory effect on NADPH oxidase activity in the presence of plasma from patients with CKD-5D after dialysis compared with before dialysis, we investigated the effect of 48 known and commercially available uraemic retention solutes on the enzymatic activity of NADPH oxidase. METHODS: Mononuclear leucocytes...

  16. International co-operation

    International Nuclear Information System (INIS)

    1998-01-01

    In this part the are reviewed: Co-operation with IAEA; Participation of the Slovakia on the 41 st session of the General Conference; The comprehensive Nuclear-Test-Ban Treaty Organization; Co-operation with the Organization for Economic Co-operation and Development; co-operation with the European Commission; Fulfillment of obligations resulting from the international contracting documents

  17. Sorting and sustaining cooperation

    DEFF Research Database (Denmark)

    Vikander, Nick

    2013-01-01

    This paper looks at cooperation in teams where some people are selfish and others are conditional cooperators, and where lay-offs will occur at a fixed future date. I show that the best way to sustain cooperation prior to the lay-offs is often in a sorting equilibrium, where conditional cooperators...... can identify and then work with one another. Changes to parameters that would seem to make cooperation more attractive, such as an increase in the discount factor or the fraction of conditional cooperators, can reduce equilibrium cooperation if they decrease a selfish player's incentive to sort....

  18. Chemoenzymatic combination of glucose oxidase with titanium silicalite -1

    DEFF Research Database (Denmark)

    Vennestrøm, Peter Nicolai Ravnborg; Taarning, Esben; Christensen, Claus H.

    2010-01-01

    Zeozymes: A proof-of-concept is presented for the chemoenzymatic combination of titanium silicalite-1 zeolite with glucose oxidase. In this combination, glucose is oxidized to gluconic acid and the H2O2 byproduct formed in situ is used for the simultaneous oxidation of chemical substrates. Both...... a soluble glucose oxidase and a truly integrated heterogeneous combination whereby the oxidase enzyme is anchored onto the zeolite surface are reported....

  19. Plasma diamine oxidase levels in pregnancy complicated by threatened abortion.

    Science.gov (United States)

    Legge, M; Duff, G B

    1981-02-01

    Plasma diamine oxidase levels were assayed in 66 patients who presented with pregnancy complicated by threatened abortion. Levels within the normal range were associated with continuing pregnancies, whereas levels below the normal range were associated with subsequent abortion. Among those patients in whom gestation was greater than eight weeks, 66.6% of diamine oxidase levels correctly predicted the pregnancy outcome. Assay of the diamine oxidase levels at eight weeks of gestation or less gave little useful information.

  20. Plasma diamine oxidase levels in pregnancy complicated by threatened abortion.

    OpenAIRE

    Legge, M; Duff, G B

    1981-01-01

    Plasma diamine oxidase levels were assayed in 66 patients who presented with pregnancy complicated by threatened abortion. Levels within the normal range were associated with continuing pregnancies, whereas levels below the normal range were associated with subsequent abortion. Among those patients in whom gestation was greater than eight weeks, 66.6% of diamine oxidase levels correctly predicted the pregnancy outcome. Assay of the diamine oxidase levels at eight weeks of gestation or less ga...

  1. Gravity Responsive NADH Oxidase of the Plasma Membrane

    Science.gov (United States)

    Morre, D. James (Inventor)

    2002-01-01

    A method and apparatus for sensing gravity using an NADH oxidase of the plasma membrane which has been found to respond to unit gravity and low centrifugal g forces. The oxidation rate of NADH supplied to the NADH oxidase is measured and translated to represent the relative gravitational force exerted on the protein. The NADH oxidase of the plasma membrane may be obtained from plant or animal sources or may be produced recombinantly.

  2. Polyphenol Oxidases in Crops: Biochemical, Physiological and Genetic Aspects

    Directory of Open Access Journals (Sweden)

    Francesca Taranto

    2017-02-01

    Full Text Available Enzymatic browning is a colour reaction occurring in plants, including cereals, fruit and horticultural crops, due to oxidation during postharvest processing and storage. This has a negative impact on the colour, flavour, nutritional properties and shelf life of food products. Browning is usually caused by polyphenol oxidases (PPOs, following cell damage caused by senescence, wounding and the attack of pests and pathogens. Several studies indicated that PPOs play a role in plant immunity, and emerging evidence suggested that PPOs might also be involved in other physiological processes. Genomic investigations ultimately led to the isolation of PPO homologs in several crops, which will be possibly characterized at the functional level in the near future. Here, focusing on the botanic families of Poaceae and Solanaceae, we provide an overview on available scientific literature on PPOs, resulting in useful information on biochemical, physiological and genetic aspects.

  3. A multicopper oxidase-related protein is essential for insect viability, longevity and ovary development.

    Science.gov (United States)

    Peng, Zeyu; Green, Peter G; Arakane, Yasuyuki; Kanost, Michael R; Gorman, Maureen J

    2014-01-01

    Typical multicopper oxidases (MCOs) have ten conserved histidines and one conserved cysteine that coordinate four copper atoms. These copper ions are required for oxidase activity. During our studies of insect MCOs, we discovered a gene that we named multicopper oxidase-related protein (MCORP). MCORPs share sequence similarity with MCOs, but lack many of the copper-coordinating residues. We identified MCORP orthologs in many insect species, but not in other invertebrates or vertebrates. We predicted that MCORPs would lack oxidase activity due to the absence of copper-coordinating residues. To test this prediction, we purified recombinant Tribolium castaneum (red flour beetle) MCORP and analyzed its enzymatic activity using a variety of substrates. As expected, no oxidase activity was detected. To study MCORP function in vivo, we analyzed expression profiles of TcMCORP and Anopheles gambiae (African malaria mosquito) MCORP, and assessed RNAi-mediated knockdown phenotypes. We found that both MCORPs are constitutively expressed at a low level in all of the tissues we analyzed. Injection of TcMCORP dsRNA into larvae resulted in 100% mortality prior to adult eclosion, with death occurring mainly during the pharate pupal stage or late pharate adult stage. Injection of TcMCORP dsRNA into pharate pupae resulted in the death of approximately 20% of the treated insects during the pupal to adult transition and a greatly shortened life span for the remaining insects. In addition, knockdown of TcMCORP in females prevented oocyte maturation and, thus, greatly decreased the number of eggs laid. These results indicate that TcMCORP is an essential gene and that its function is required for reproduction. An understanding of the role MCORP plays in insect physiology may help to develop new strategies for controlling insect pests.

  4. To cooperate or not to cooperate

    DEFF Research Database (Denmark)

    Wessels, Josepha Ivanka

    To Cooperate or not to Cooperate...? discusses results of a research project to study the rehabilitation of 1500-year old water tunnels, so called "qanats", in Syria. Communities all over the world are using traditional technologies to extract drinkingwater, irrigate their lands and feed...... their livestock. But these often sustainable and ancient ways to make use of groundwater are in rapid decline worldwide. A research project started in 1999 to study the rehabilitation of 1500-year old water tunnels called "qanats"in Syria. To Cooperate or not to Cooperate...? discusses results and outcomes...

  5. Modern aspects of cross-border cooperation on the example of the functioning of Euroregion «Upper Prut»

    Directory of Open Access Journals (Sweden)

    O. O. Hrushko

    2015-07-01

    Full Text Available In the article the current aspects of cross­border cooperation between regions of Ukraine in the framework of the EU Eastern Partnership and in the frame of «Upper Prut» in particular are discussed. The retrospective of the establishment of cross­border ties of Chernivtsi oblast with the regions of Moldova and Romania and evolution of this cooperation (from Euroregion to implementation of the projects funded by EU programs is given. Also the efficiency of the Joint Operational Programme «Romania­Ukraine­Republic of Moldova 2007­2013» for the Ukrainian side border is analyzed. The research of public opinion on influence of the European integration process and its cross­border cooperation was. It was determined that the CBC projects implementation not only positively affects on the development of the region, but also is an effective mechanism for the formation of public opinion on the movement of Ukraine towards the EU. It is concluded that trans­regional cooperation today is looking for new models of national infrastructures, which includes power systems, transportation and communication network. The development of a common policy on technogenic and ecological safety, prevention of pollution of river basins, and the development of tourism and recreational activities also must be included in such new model. The implementation of joint strategies must be established and have to include the equalization of socio­economic and political development of border regions.

  6. Theoretical Outline about Cooperative Entrepreneurial Management System

    Directory of Open Access Journals (Sweden)

    Angie Fernández Lorenzo

    2015-12-01

    Full Text Available The essence of Cooperativism prints some particular characters to the cooperatives management process, especially the need to integrate the technical, economic and social edges in shaping and improving its. Considering that documented precedent studies have not led to analyze the whole process of cooperative management, but only to solve problems in specific subsystems, in this paper we the theoretical fundaments of Cooperatives Business Management System, under the criteria of integrity and balance between these edges, which is the basis for the proposal of functional subsystems to ensure the whole cooperatives performance.

  7. 21 CFR 56.114 - Cooperative research.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Cooperative research. 56.114 Section 56.114 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL INSTITUTIONAL REVIEW BOARDS IRB Functions and Operations § 56.114 Cooperative research. In complying with these...

  8. Myeloperoxidase amplified high glucose-induced endothelial dysfunction in vasculature: Role of NADPH oxidase and hypochlorous acid.

    Science.gov (United States)

    Tian, Rong; Ding, Yun; Peng, Yi-Yuan; Lu, Naihao

    2017-03-11

    Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-derived reactive oxygen species (ROS) such as superoxide and hydrogen peroxide (H 2 O 2 ), have emerged as important molecules in the pathogenesis of diabetic endothelial dysfunction. Additionally, neutrophils-derived myeloperoxidase (MPO) and MPO-catalyzed hypochlorous acid (HOCl) play important roles in the vascular injury. However, it is unknown whether MPO can use vascular-derived ROS to induce diabetic endothelial dysfunction. In the present study, we demonstrated that NADPH oxidase was the main source of ROS formation in high glucose-cultured human umbilical vein endothelial cells (HUVECs), and played a critical role in high glucose-induced endothelial dysfunction such as cell apoptosis, loss of cell viability and reduction of nitric oxide (NO). However, the addition of MPO could amplify the high glucose-induced endothelial dysfunction which was inhibited by the presence of apocynin (NADPH oxidase inhibitor), catalase (H 2 O 2 scavenger), or methionine (HOCl scavenger), demonstrating the contribution of NADPH oxidase-H 2 O 2 -MPO-HOCl pathway in the MPO/high glucose-induced vascular injury. In high glucose-incubated rat aortas, MPO also exacerbated the NADPH oxidase-induced impairment of endothelium-dependent relaxation. Consistent with these in vitro data, in diabetic rat aortas, both MPO expresion and NADPH oxidase activity were increased while the endothelial function was simultaneously impaired. The results suggested that vascular-bound MPO could amplify high glucose-induced vascular injury in diabetes. MPO-NADPH oxidase-HOCl may represent an important pathogenic pathway in diabetic vascular diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Crystallization of carbohydrate oxidase from Microdochium nivale

    International Nuclear Information System (INIS)

    Dušková, Jarmila; Dohnálek, Jan; Skálová, Tereza; Østergaard, Lars Henrik; Fuglsang, Claus Crone; Kolenko, Petr; Štěpánková, Andrea; Hašek, Jindřich

    2009-01-01

    Industrially used carbohydrate oxidase was successfully crystallized in several forms, diffraction data suitable for structural analysis were collected. Microdochium nivale carbohydrate oxidase was produced by heterologous recombinant expression in Aspergillus oryzae, purified and crystallized. The enzyme crystallizes with varying crystal morphologies depending on the crystallization conditions. Several different crystal forms were obtained using the hanging-drop vapour-diffusion method, two of which were used for diffraction measurements. Hexagon-shaped crystals (form I) diffracted to 2.66 Å resolution, with unit-cell parameters a = b = 55.7, c = 610.4 Å and apparent space group P6 2 22. Analysis of the data quality showed almost perfect twinning of the crystals. Attempts to solve the structure by molecular replacement did not give satisfactory results. Recently, clusters of rod-shaped crystals (form II) were grown in a solution containing PEG MME 550. These crystals belonged to the monoclinic system C2, with unit-cell parameters a = 132.9, b = 56.6, c = 86.5 Å, β = 95.7°. Data sets were collected to a resolution of 2.4 Å. The structure was solved by the molecular-replacement method. Model refinement is currently in progress

  10. Cytochemical Localization of Glucose Oxidase in Peroxisomes of Aspergillus niger

    NARCIS (Netherlands)

    Veenhuis, Marten; Dijken, Johannes Pieter van

    1980-01-01

    The subcellular localization of glucose oxidase (E.C. 1.1.3.4) in mycelia of Aspergillus niger has been investigated using cytochemical staining techniques. Mycelia from fermenter cultures, which produced gluconic acid from glucose, contained elevated levels of glucose oxidase and catalase. Both

  11. Xanthine oxidase in human skeletal muscle following eccentric exercise

    DEFF Research Database (Denmark)

    Hellsten, Ylva; Frandsen, Ulrik; Orthenblad, N.

    1997-01-01

    the increase in xanthine oxidase in the muscle there were no detectable changes in the levels of muscle malondialdehyde or in plasma antioxidant capacity up to 4 days post-exercise. 5. It is concluded that eccentric exercise leads to an increased level of xanthine oxidase in human muscle and that the increase...

  12. Laboratory-evolved vanillyl-alcohol oxidase produces natural vanillin

    NARCIS (Netherlands)

    Heuvel, van den R.H.H.; Berg, van den W.A.M.; Rovida, S.; Berkel, van W.J.H.

    2004-01-01

    The flavoenzyme vanillyl-alcohol oxidase was subjected to random mutagenesis to generate mutants with enhanced reactivity to creosol (2-methoxy-4-methylphenol). The vanillyl-alcohol oxidase-mediated conversion of creosol proceeds via a two-step process in which the initially formed vanillyl alcohol

  13. Optimization of glucose oxidase production by Aspergillus niger

    African Journals Online (AJOL)

    user

    2011-02-28

    Feb 28, 2011 ... manganese, cobalt, thioglycolic acid, and gluconic acid according to (Liu et al., .... In this experiment duplicate media of glucose 10% were adjusted at different ... Glucose oxidase as a pharmaceutical anti oxidant Drug. Devt. ... Plush KS, Hellmuth K, Rinas U (1996). kinetics of glucose oxidase excretion by ...

  14. 21 CFR 866.2420 - Oxidase screening test for gonorrhea.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Oxidase screening test for gonorrhea. 866.2420... screening test for gonorrhea. (a) Identification. An oxidase screening test for gonorrhea is an in vitro... of gonorrhea. (b) Classification. Class III (premarket approval) (transitional device). (c) Date PMA...

  15. Lysyl oxidase: properties, specificity, and biological roles inside and outside of the cell.

    Science.gov (United States)

    Kagan, Herbert M; Li, Wande

    2003-03-01

    Lysyl oxidase (LO) plays a critical role in the formation and repair of the extracellular matrix (ECM) by oxidizing lysine residues in elastin and collagen, thereby initiating the formation of covalent crosslinkages which stabilize these fibrous proteins. Its catalytic activity depends upon both its copper cofactor and a unique carbonyl cofactor and has been shown to extend to a variety of basic globular proteins, including histone H1. Although the three-dimensional structure of LO has yet to be determined, the present treatise offers hypotheses based upon its primary sequence, which may underlie the prominent electrostatic component of its unusual substrate specificity as well as the catalysis-suppressing function of the propeptide domain of prolysyl oxidase. Recent studies have demonstrated that LO appears to function within the cell in a manner, which strongly modifies cellular activity. Newly discovered LO-like proteins also likely play unique roles in biology. Copyright 2002 Wiley-Liss, Inc.

  16. Cooperation, trust and confidence

    NARCIS (Netherlands)

    Korver, T.; Oeij, P.R.A.; Urze, P.C.G.D.

    2007-01-01

    Environmental complexity may strain cooperative relationships, both within and beyond organizations, for two reasons. First, when complexity implies uncertainty the predictability of change disappears. Secondly, change may and often will entail different estimates of the cooperating partners on the

  17. Cooperative Tagging Center (CTC)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Cooperative Tagging Center (CTC) began as the Cooperative Game Fish Tagging Program (GTP) at Woods Hole Oceanographic Institute (WHOI) in 1954. The GTP was...

  18. Cooperatives as Entrants

    OpenAIRE

    Richard J. Sexton; Terri A. Sexton

    1987-01-01

    A potential shortcoming of game-theoretic models in industrial organization is their failure to consider consumers as players. We introduce a customer coalition --- a cooperative -- as a potential entrant and compare the cooperative entry threat with that posed by the usual for-profit entrant. We identify four fundamental distinctions between cooperative and for-profit entrants and demonstrate that the strategic interplay between a cooperative and an incumbent firm may differ markedly from th...

  19. Choosing the cooperative option

    Energy Technology Data Exchange (ETDEWEB)

    English, G. (National Rural Electric Cooperative Association (United States))

    1999-06-01

    Cooperatives do not ask to be exempted from the law. They do ask that laws and regulations be designed to allow them to meet the needs of their consumer-owners in accordance with cooperative principles, at a time that the marginal consumers being abandoned by for-profit utilities may be ready to gravitate toward cooperatives. The cooperative principles are worth reviewing because they explain the focus on the consumer and the cooperative concept of service: cooperatives are voluntary organizations, open to all persons able to use their services and willing to accept the responsibilities of membership; cooperatives are democratic organizations controlled by their members, who actively participate in setting policies and making decisions, the elected representatives are accountable to the membership; members contribute equitably to, and democratically control, the capital of their cooperative; cooperatives are autonomous, self-help organizations controlled by their members, if they enter into agreements with other organizations, including governments, they do so on terms that ensure democratic control by their members and maintain their cooperative autonomy; cooperatives provide education and training for their members, elected representatives, managers, and employees so they can contribute effectively to the development of their cooperatives, they inform the general public, particularly young people and opinion leaders, about the nature and benefits of cooperation; cooperatives serve their members most effectively and strength the cooperative movement by working together through local, national, regional, and international structures; and while focusing on member needs, cooperatives work for the sustainable development of their communities through policies accepted by their members.

  20. Inertia in Cooperative Remodeling

    OpenAIRE

    Nilsson, Jerker

    1997-01-01

    Which organization model is appropriate for a cooperative enterprise depends on the prerequisites in its business environment. When conditions are changing, the firm must adapt itself. The entry of Sweden, Finland, and Austria into the European Union led to radical changes for agricultural cooperation, especially for Swedish cooperatives since agricultural policy was not allowed a transitional period. After two years, Swedish cooperatives have still not adapted their organization model despit...

  1. Thermodynamics of cooperative binding of FAD to human NQO1: Implications to understanding cofactor-dependent function and stability of the flavoproteome.

    Science.gov (United States)

    Clavería-Gimeno, Rafael; Velazquez-Campoy, Adrian; Pey, Angel Luis

    2017-12-15

    The stability of human flavoproteins strongly depends on flavin levels, although the structural and energetic basis of this relationship is poorly understood. Here, we report an in-depth analysis on the thermodynamics of FAD binding to one of the most representative examples of such relationship, NAD(P)H:quinone oxidoreductase 1 (NQO1). NQO1 is a dimeric enzyme that tightly binds FAD, which triggers large structural changes upon binding. A common cancer-associated polymorphism (P187S) severely compromises FAD binding. We show that FAD binding is described well by a thermodynamic model explicitly incorporating binding cooperativity when applied to different sets of calorimetric analyses and NQO1 variants, thus providing insight on the effects in vitro and in cells of cancer-associated P187S, its suppressor mutation H80R and the role of NQO1 C-terminal domain to modulate binding cooperativity and energetics. Furthermore, we show that FAD binding to NQO1 is very sensitive to physiologically relevant environmental conditions, such as the presence of phosphate buffer and salts. Overall, our results contribute to understanding at the molecular level the link between NQO1 stability and fluctuations of FAD levels intracellularly, and supports the notion that FAD binding energetics and cooperativity are fundamentally linked with the dynamic nature of apo-NQO1 conformational ensemble. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Modulation of NADPH oxidase activity by known uraemic retention solutes.

    Science.gov (United States)

    Schulz, Anna Marta; Terne, Cindy; Jankowski, Vera; Cohen, Gerald; Schaefer, Mandy; Boehringer, Falko; Tepel, Martin; Kunkel, Desiree; Zidek, Walter; Jankowski, Joachim

    2014-08-01

    Uraemia and cardiovascular disease appear to be associated with an increased oxidative burden. One of the key players in the genesis of reactive oxygen species (ROS) is nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. Based on initial experiments demonstrating a decreased inhibitory effect on NADPH oxidase activity in the presence of plasma from patients with CKD-5D after dialysis compared with before dialysis, we investigated the effect of 48 known and commercially available uraemic retention solutes on the enzymatic activity of NADPH oxidase. Mononuclear leucocytes isolated from buffy coats of healthy volunteers were isolated, lysed and incubated with NADH in the presence of plasma from healthy controls and patients with CKD-5D. Furthermore, the leucocytes were lysed and incubated in the presence of uraemic retention solute of interest and diphenyleneiodonium chloride (DPI), an inhibitor of NADPH oxidase. The effect on enzymatic activity of NADPH oxidase was quantified within an incubation time of 120 min. Thirty-nine of the 48 uraemic retention solutes tested had a significant decreasing effect on NADPH oxidase activity. Oxalate has been characterized as the strongest inhibitor of NADPH oxidase (90% of DPI inhibition). Surprisingly, none of the uraemic retention solutes we investigated was found to increase NADPH oxidase activity. Furthermore, plasma from patients with CKD-5D before dialysis caused significantly higher inhibitory effect on NADPH oxidase activity compared with plasma from healthy subjects. However, this effect was significantly decreased in plasma from patients with CKD-5D after dialysis. The results of this study show that uraemic retention solutes modulated the activity of the NADPH oxidase. The results of this study might be the basis for the development of inhibitors applicable as drug in the situation of increased oxidative stress. © 2014 Stichting European Society for Clinical Investigation Journal Foundation.

  3. H2O2 and NADPH oxidases involve in regulation of 2-(2-phenylethyl)chromones accumulation during salt stress in Aquilaria sinensis calli.

    Science.gov (United States)

    Wang, Xiaohui; Dong, Xianjuan; Feng, Yingying; Liu, Xiao; Wang, Jinling; Zhang, Zhongxiu; Li, Jun; Zhao, Yunfang; Shi, Shepo; Tu, Pengfei

    2018-04-01

    2-(2-Phenylethyl)chromones are the main compounds responsible for the quality of agarwood, which is widely used in traditional medicines, incenses and perfumes. H 2 O 2 and NADPH oxidases (also known as respiratory burst oxidase homologs, Rbohs) mediate diverse physiological and biochemical processes in environmental stress responses. However, little is known about the function of H 2 O 2 and NADPH oxidases in 2-(2-phenylethyl)chromones accumulation. In this study, we found that salt stress induced a transient increase in content of H 2 O 2 and 2-(2-phenylethyl)chromones accumulation in Aquilaria sinensis calli. Exogenous H 2 O 2 remarkably decreased the production of 2-(2-phenylethyl)chromones, while dimethylthiourea (DMTU), a scavenger of H 2 O 2 , significantly increased 2-(2-phenylethyl)chromones accumulation in salt treated calli. Three new H 2 O 2 -generating genes, named AsRbohA-C, were isolated and characterized from A. sinensis. Salt stress also induced a transient increase in AsRbohA-C expression and NADPH oxidase activity. Furthermore, exogenous H 2 O 2 increased AsRbohA-C expression and NADPH oxidase activity, while DMTU inhibited AsRbohA-C expression and NADPH oxidase activity under salt stress. Moreover, diphenylene iodonium (DPI), the inhibitor of NADPH oxidases, reduced AsRbohA-C expression and NADPH oxidase activity, but significantly induced 2-(2-phenylethyl)chromones accumulation during salt stress. These results clearly demonstrated the central role of H 2 O 2 and NADPH oxidases in regulation of salt-induced 2-(2-phenylethyl)chromones accumulation in A. sinensis calli. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. What is a cooperative?

    Science.gov (United States)

    Kimberly Zeuli

    2006-01-01

    Groups of individuals throughout time have worked together in pursuit of common goals. The earliest forms of hunting and agriculture required a great deal of cooperation among humans. Although the word "cooperative" can be applied to many different types of group activities, in this publication it refers to a formal business model. Cooperative businesses are...

  5. Designing for cooperation - cooperating in design

    DEFF Research Database (Denmark)

    Kyng, Morten

    1991-01-01

    This article will discuss how to design computer applications that enhance the quality of work and products, and will relate the discussion to current themes in the field of Computer-Supported Cooperative Work (CSCW). Cooperation is a key element of computer use and work practice, yet here...... a specific "CSCW approach is not taken." Instead the focus is cooperation as an important aspect of work that should be integrated into most computer support efforts in order to develop successful computer support, however, other aspects such as power, conflict and control must also be considered....

  6. Researches on Agricultural Cooperative Economic Organization Promoting Agricultural Insurance Development

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The advantages of cooperative economic organization being the effective carrier of agricultural insurance development are analyzed. Firstly, cooperative economic organization promotes scale management and solves the problem of decentralized operation of small households. Secondly, cooperative economic organization can settle the problem of peasants’ low systematization. Thirdly, cooperative economic organization can largely reduce the costs of agricultural insurance operation. Fourthly, cooperative organization decreases moral risks as well as adverse selection to some extent. Lastly, cooperative organization, to a certain degree, reduces the risks of agricultural production and increases the insurability of agricultural risks. Meanwhile, limitations of agricultural cooperative economic organization being the carrier of agricultural insurance operation are pointed out. Firstly, cooperative economic organization has limited coverage and small size of organization, which is harmful to the diversification of agricultural risks. Secondly, cooperative economic organization lacks capital funds and its development is not standard, which is not perfect for the function exertion as a carrier. Lastly, members of professional cooperative organization have low cultural qualities, which restrict the implementation of agricultural insurance. The modes of farmers’ cooperative economic organization promoting agricultural insurance development are proposed, including mode of agricultural insurance cooperative ( mutual corporation), mode of "leading enterprises (companies) + professional cooperative organization (planting majors) + insurance" and mode of professional cooperatives serving as agricultural insurance agent. Last of all, the promoting role of agricultural insurance in agricultural cooperative economic organization is briefly illustrated.

  7. Cooperative strategies European perspectives

    CERN Document Server

    Killing, J Peter

    1997-01-01

    Cooperative Strategies: European Perspectives is one of three geographically targeted volumes in which the contributors present the most current research on topics such as advances in theories of cooperative strategies, the formation of cooperative alliances, the dynamics of partner relationships, and the role of information and knowledge in cooperative alliances. Blending conceptual insights with empirical analyses, the contributors highlight commonalities and differences across national, cultural, and trade zones. The chapters in this volume are anchored in a wide set of theoretical approaches, conceptual frameworks, and models, illustrating how rich the area of cooperative strategies is for scholarly inquiry.

  8. In Situ Enzymatically Generated Photoswitchable Oxidase Mimetics and Their Application for Colorimetric Detection of Glucose Oxidase.

    Science.gov (United States)

    Cao, Gen-Xia; Wu, Xiu-Ming; Dong, Yu-Ming; Li, Zai-Jun; Wang, Guang-Li

    2016-07-09

    In this study, a simple and amplified colorimetric assay is developed for the detection of the enzymatic activity of glucose oxidase (GOx) based on in situ formation of a photoswitchable oxidase mimetic of PO₄(3-)-capped CdS quantum dots (QDs). GOx catalyzes the oxidation of 1-thio-β-d-glucose to give 1-thio-β-d-gluconic acid which spontaneously hydrolyzes to β-d-gluconic acid and H₂S; the generated H₂S instantly reacts with Cd(2+) in the presence of Na₃PO₄ to give PO₄(3-)-stabilized CdS QDs in situ. Under visible-light (λ ≥ 400 nm) stimulation, the PO₄(3-)-capped CdS QDs are a new style of oxidase mimic derived by producing some active species, such as h⁺, (•)OH, O₂(•-) and a little H₂O₂, which can oxidize the typical substrate (3,3,5,5-tetramethylbenzydine (TMB)) with a color change. Based on the GOx-triggered growth of the oxidase mimetics of PO₄(3-)-capped CdS QDs in situ, we developed a simple and amplified colorimetric assay to probe the enzymatic activity of GOx. The proposed method allowed the detection of the enzymatic activity of GOx over the range from 25 μg/L to 50 mg/L with a low detection limit of 6.6 μg/L. We believe the PO₄(3-)-capped CdS QDs generated in situ with photo-stimulated enzyme-mimicking activity may find wide potential applications in biosensors.

  9. Characterization of the in vitro binding and inhibition kinetics of primary amine oxidase/vascular adhesion protein-1 by glucosamine.

    LENUS (Irish Health Repository)

    Olivieri, Aldo

    2012-04-01

    Primary-amine oxidase (PrAO) catalyzes the oxidative deamination of endogenous and exogenous primary amines and also functions, in some tissues, as an inflammation-inducible endothelial factor, known as vascular adhesion protein-1. VAP-1 mediates the slow rolling and adhesion of lymphocytes to endothelial cells in a number of inflammatory conditions, including inflammation of the synovium.

  10. Intracellular expression of reactive oxygen species-generating NADPH oxidase NOX4 in normal and cancer thyroid tissues

    NARCIS (Netherlands)

    Weyemi, Urbain; Caillou, Bernard; Talbot, Monique; Ameziane-El-Hassani, Rabii; Lacroix, Ludovic; Lagent-Chevallier, Odile; Al Ghuzlan, Abir; Roos, Dirk; Bidart, Jean-Michel; Virion, Alain; Schlumberger, Martin; Dupuy, Corinne

    2010-01-01

    NADPH oxidase 4 (NOX4) belongs to the NOX family that generates reactive oxygen species (ROS). Function and tissue distribution of NOX4 have not yet been entirely clarified. To date, in the thyroid gland, only DUOX1/2 NOX systems have been described. NOX4 mRNA expression, as shown by real-time PCR,

  11. Effects of F/G-actin ratio and actin turn-over rate on NADPH oxidase activity in microglia

    DEFF Research Database (Denmark)

    Rasmussen, Izabela; Pedersen, Line Hjortshøj; Byg, Luise

    2010-01-01

    Most in vivo studies that have addressed the role of actin dynamics in NADPH oxidase function in phagocytes have used toxins to modulate the polymerization state of actin and mostly effects on actin has been evaluated by end point measurements of filamentous actin, which says little about actin d...... dynamics, and without consideration for the subcellular distribution of the perturbed actin cytoskeleton....

  12. Visualization of monoamine oxidase in human brain

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, J.S.; Volkow, N.D.; Wang, G.J.; Pappas, N.; Shea, C.; MacGregor, R.R.; Logan, J.

    1996-12-31

    Monoamine oxidase is a flavin enzyme which exists in two subtypes, MAO A and MAO B. In human brain MAO B predominates and is largely compartmentalized in cell bodies of serotonergic neurons and glia. Regional distribution of MAO B was determined by positron computed tomography with volunteers after the administration of deuterium substituted [11C]L-deprenyl. The basal ganglia and thalamus exhibited the greatest concentrations of MAO B with intermediate levels in the frontal cortex and cingulate gyrus while lowest levels were observed in the parietal and temporal cortices and cerebellum. We observed that brain MAO B increases with are in health normal subjects, however the increases were generally smaller than those revealed with post-mortem studies.

  13. An ultrafiltration assay for lysyl oxidase

    International Nuclear Information System (INIS)

    Shackleton, D.R.; Hulmes, D.J.

    1990-01-01

    A modification of the original microdistillation assay for lysyl oxidase is described in which Amicon C-10 microconcentrators are used to separate, by ultrafiltration, the 3H-labeled products released from a [4,5-3H]-lysine-labeled elastin substrate. Enzyme activity is determined by scintillation counting of the ultrafiltrate, after subtraction of radioactivity released in the presence of beta-aminopropionitrile, a specific inhibitor of the enzyme. Conditions are described which optimize both the sensitivity and the efficient use of substrate. The assay shows linear inhibition of activity in up to 1 M urea; hence, as the enzyme is normally diluted in the assay, samples in 6 M urea can be assayed directly, without prior dialysis, and corrected for partial inhibition. Comparable results are obtained when enzyme activity is assayed by ultrafiltration or microdistillation. The assay is simple and convenient and, by using disposable containers throughout, it eliminates the need for time-consuming decontamination of radioactive glassware

  14. Evaluation of oxalate decarboxylase and oxalate oxidase for industrial applications.

    Science.gov (United States)

    Cassland, Pierre; Sjöde, Anders; Winestrand, Sandra; Jönsson, Leif J; Nilvebrant, Nils-Olof

    2010-05-01

    Increased recirculation of process water has given rise to problems with formation of calcium oxalate incrusts (scaling) in the pulp and paper industry and in forest biorefineries. The potential in using oxalate decarboxylase from Aspergillus niger for oxalic acid removal in industrial bleaching plant filtrates containing oxalic acid was examined and compared with barley oxalate oxidase. Ten different filtrates from chemical pulping were selected for the evaluation. Oxalate decarboxylase degraded oxalic acid faster than oxalate oxidase in eight of the filtrates, while oxalate oxidase performed better in one filtrate. One of the filtrates inhibited both enzymes. The potential inhibitory effect of selected compounds on the enzymatic activity was tested. Oxalate decarboxylase was more sensitive than oxalate oxidase to hydrogen peroxide. Oxalate decarboxylase was not as sensitive to chlorate and chlorite as oxalate oxidase. Up to 4 mM chlorate ions, the highest concentration tested, had no inhibitory effect on oxalate decarboxylase. Analysis of the filtrates suggests that high concentrations of chlorate present in some of the filtrates were responsible for the higher sensitivity of oxalate oxidase in these filtrates. Oxalate decarboxylase was thus a better choice than oxalate oxidase for treatment of filtrates from chlorine dioxide bleaching.

  15. Quantitation of immunoadsorbed flavoprotein oxidases by luminol-mediated chemiluminescence.

    Science.gov (United States)

    Hinkkanen, A; Maly, F E; Decker, K

    1983-04-01

    The detection of the flavoenzymes 6-hydroxy-L-nicotine oxidase and 6-hydroxy-D-nicotine oxidase at the sub-femtomol level was achieved by coupling the reaction of the immunoadsorbed proteins to the peroxidase-catalysed oxidation of luminol. The H2O2-producing oxidases retained their full activity when bound to the respective immobilized antibodies. This fact allowed the concentration of the enzymes from very dilute solutions and the quantitative assay of their activities in the microU range. Due to strict stereoselectivity and the absence of immunological cross-reactivity, the two flavoproteins could be determined in the same solution. This method was used to measure the 6-hydroxy-D-nicotine oxidase and 6-hydroxy-L-nicotine oxidase activities in Escherichia coli RR1 and different Arthrobacter strains cultured under non-inducing conditions. The same activity ratio of 6-hydroxy-L-nicotine oxidase/6-hydroxy-D-nicotine oxidase as in D L-nicotine-induced cells of A. oxidans was observed in non-induced wild type and in riboflavin-requiring (rf-) mutant cells of this aerob.

  16. Implementing Cooperative Learning in Australian Primary Schools: Generalist Teachers' Perspectives

    Science.gov (United States)

    Hennessey, Angela; Dionigi, Rylee A.

    2013-01-01

    To implement cooperative learning successfully in practice, teachers require knowledge of cooperative learning, its features and terms, and how it functions in classrooms. This qualitative study examined 12 Australian generalist primary teachers', understandings of cooperative learning and perceived factors affecting its implementation. Using…

  17. Platelet monoamine oxidase: specific activity and turnover number in headache

    International Nuclear Information System (INIS)

    Summers, K.M.; Brown, G.K.; Craig, I.W.; Peatfield, R.; Rose, F.C.

    1982-01-01

    Monoamine oxidase turnover numbers (molecules of substrate converted to product per minute per active site) have been calculated for the human platelet enzyme using [ 3 H]pargyline. Headache patients with high and low monoamine oxidase specific activities relative to controls were found to have turnover numbers very close to those for controls. This finding suggests that their specific activities vary because of differences in the concentration of active monoamine oxidase molecules, rather than differences in the ability of those enzyme molecules to catalyse the deamination reaction. (Auth.)

  18. The sound of cooperation: Musical influences on cooperative behavior.

    Science.gov (United States)

    Kniffin, Kevin M; Yan, Jubo; Wansink, Brian; Schulze, William D

    2017-03-01

    Music as an environmental aspect of professional workplaces has been closely studied with respect to consumer behavior while sparse attention has been given to its relevance for employee behavior. In this article, we focus on the influence of music upon cooperative behavior within decision-making groups. Based on results from two extended 20-round public goods experiments, we find that happy music significantly and positively influences cooperative behavior. We also find a significant positive association between mood and cooperative behavior. Consequently, while our studies provide partial support for the relevance of affect in relation to cooperation within groups, we also show an independently important function of happy music that fits with a theory of synchronous and rhythmic activity as a social lubricant. More generally, our findings indicate that music and perhaps other atmospheric variables that are designed to prime consumer behavior might have comparably important effects for employees and consequently warrant closer investigation. Copyright © 2016 The Authors Journal of Organizational Behavior Published by John Wiley & Sons Ltd.

  19. The principle of cooperation in environmental law

    International Nuclear Information System (INIS)

    Rengeling, H.W.

    1988-01-01

    The study prepared by order of the Federal Office for Environmental Protection describes the cooperation principle in German environmental policy. It presents examples from various areas of environmental protection, i.a. the participation of third-parties in government decisions. The functions, advantages, problems and risks of cooperation are dealt with. The study focuses on the constitutional and administrative fundamentals for the evaluation of the admissibility and limits of cooperation. On the one hand, there has to be cooperation between State and Society, on the other, there is a normative separation of the two in accordance with constitutional law. The study points out scopes of action for cooperation between State and Society. (RST) [de

  20. Effect of a heme oxygenase-1 inducer on NADPH oxidase ...

    African Journals Online (AJOL)

    Effect of a heme oxygenase-1 inducer on NADPH oxidase expression in ... and immunohistochemistry of hepatic NOX1 and NOX4 were investigated in week 4. ... (HO-1 inhibitor) administration caused upregulation of NOX gene expression ...

  1. Effects of glucose oxidase on the growth performance, serum ...

    African Journals Online (AJOL)

    Martina

    2016-02-06

    Feb 6, 2016 ... The experiment was conducted to investigate the effects of diets supplemented with ... Keywords: Glucose oxidase, intestinal health, performance, swine ..... This work was supported by the National High-Tech Research and ...

  2. Structure and activity of Aspergillus nidulans copper amine oxidase

    DEFF Research Database (Denmark)

    McGrath, Aaron P; Mithieux, Suzanne M; Collyer, Charles A

    2011-01-01

    Aspergillus nidulans amine oxidase (ANAO) has the unusual ability among the family of copper and trihydroxyphenylalanine quinone-containing amine oxidases of being able to oxidize the amine side chains of lysine residues in large peptides and proteins. We show here that in common with the related...... enzyme from the yeast Pichia pastoris, ANAO can promote the cross-linking of tropoelastin and oxidize the lysine residues in α-casein proteins and tropoelastin. The crystal structure of ANAO, the first for a fungal enzyme in this family, has been determined to a resolution of 2.4 Å. The enzyme is a dimer...... with the archetypal fold of a copper-containing amine oxidase. The active site is the most open of any of those of the structurally characterized enzymes in the family and provides a ready explanation for its lysine oxidase-like activity....

  3. Gene cloning and characterization of NADH oxidase from ...

    African Journals Online (AJOL)

    use

    2011-12-07

    Dec 7, 2011 ... potent inhibitors of NADH oxidases, silver nitrate and potassium cyanide did not show any significant ... anaerobes, a class of organisms that have not been ... DNA and amino acid sequence analyses were performed using.

  4. Allelic variations of functional markers for polyphenol oxidase (PPO)

    Indian Academy of Sciences (India)

    genes in Indian bread wheat (Triticum aestivum L.) cultivars. Rajender Singh, Umesh Goutam, R. K. Gupta, G. C. Pandey, Jag Shoran and Ratan Tiwari. J. Genet. 88, 325–329. Figure 1. Phenol colour reaction of kernels. Kernels without treatment by phenol solution are shown as controls. Phenol colour reaction of kernels; ...

  5. Function, mechanism and structure of vanillyl-alcohol oxidase

    NARCIS (Netherlands)

    Fraaije, M.W.

    1998-01-01

    Lignin is a heterogeneous aromatic polymer formed by all higher plants. As the biopolymer lignin is a major constituent of wood, it is highly abundant. Lignin biodegradation, an essential process to complete the Earth's carbon cycle, is initiated by action of several oxidoreductases

  6. International co-operation

    International Nuclear Information System (INIS)

    Klinda, J.; Lieskovska, Z.

    1998-01-01

    Within the Union Nations (UN) framework, the Slovak Republic participated in following activities on environment protection co-operation: UN European Economic Commission, UN Industrial Development Organization, UN Development Programme, UN Human Habitat Organization, UN Environment Programme, and UN Commission on Sustainable Development. Relevant activities of the Slovak Republic in these co-operations as well as in European Union and OECD activities are reviewed. International conventions and other forms of multilateral co-operation, bilateral co-operation, and international programmes and projects in which the Slovak Republic took participate are presented

  7. Cooperative Station History Forms

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Various forms, photographs and correspondence documenting the history of Cooperative station instrumentation, location changes, inspections, and...

  8. Production of rabbit antibodies against purified Glucose oxidase

    OpenAIRE

    Zia,Muhammad Anjum; Ain,Qurat-ul; Iftikhar,Tehreema; Abbas,Rao Zahid; Rahman,Khalil-ur

    2012-01-01

    Glucose oxidase is an active oxygen species generating enzyme produced from Aspergillus niger grown in submerged fermentation. Disintegration of the mycelium resulted in high glucose oxidase activity that was subjected to ammonium sulfate precipitation at 60-85% saturation rates that resulted to 6.14 U mg -1 specific activity. Purification of enzyme by anion exchange column (DEAE-Cellulose) resulted into 22.53 U mg-1 specific activity and 10.27 fold purification. This was applied to sephadex ...

  9. Effect of retinal impulse blockage on cytochrome oxidase-poor interpuffs in the macaque striate cortex: quantitative EM analysis of neurons.

    Science.gov (United States)

    Wong-Riley, M T; Trusk, T C; Kaboord, W; Huang, Z

    1994-09-01

    One of the hallmarks of the primate striate cortex is the presence of cytochrome oxidase-rich puffs in its supragranular layers. Neurons in puffs have been classified as type A, B, and C in ascending order of cytochrome oxidase content, with type C cells being the most vulnerable to retinal impulse blockade. The present study aimed at analysing cytochrome oxidase-poor interpuffs with reference to their metabolic cell types and the effect of intraretinal tetrodotoxin treatment. The same three metabolic types were found in interpuffs, except that type B and C neurons were smaller and less cytochrome oxidase-reactive in interpuffs than in puffs. Type A neurons had small perikarya, low levels of cytochrome oxidase, and received exclusively symmetric axosomatic synapses. The largest neurons were pyramidal, type B cells with moderate cytochrome oxidase activity and were also contacted exclusively by symmetric axosomatic synapses. Type C cells medium-sized with a rich supply of large, darkly reactive mitochondria and possessed all the characteristics of GABAergic neurons. They were the only cell type that received both symmetric and asymmetric axosomatic synapses. Two weeks of monocular tetrodotoxin blockade in adult monkeys caused all three major cell types in deprived interpuffs to suffer a significant downward shift in the size and cytochrome oxidase reactivity of their mitochondria, but the effects were more severe in type B and C neurons. In nondeprived interpuffs, all three cell types gained both in size and absolute number of mitochondria, and type A cells also had an elevated level of cytochrome oxidase, indicating that they might be functioning at a competitive advantage over cells in deprived columns. However, type B and C neurons showed a net loss of darkly reactive mitochondria, indicating that these cells became less active. Thus, mature interpuff neurons remained vulnerable to retinal impulse blockade and the metabolic capacity of these cells remains tightly

  10. Confirmation of a blocked amino terminus of sulfhydryl oxidase

    International Nuclear Information System (INIS)

    Janolino, V.G.; Morrison-Rowe, S.J.; Swaisgood, H.E.

    1990-01-01

    The isolation of sulfhydryl oxidase from bovine milk in a suitably pure form for sequencing was carried out by transient covalent affinity chromatography of diafiltered whey using cysteinylsuccinamidopropyl-glass as matrix. The glutathione-eluted proteins were separated by SDS-PAGE. By radiolabeling the affinity chromatography-purified enzyme with [ 14 C]iodoacetate before subjecting to SDS-PAGE, the sulfhydryl oxidase band was identified, because sulfhydryl oxidase is known to be inactivated by alkylation of one sulfhydryl group per mole. The results confirmed that sulfhydryl oxidase corresponds to the 85 (± 5)-kDa band observed on SDS-PAGE. The protein band corresponding to radiolabeled sulfhydryl oxidase was recovered from SDS-PAGE gels by electrophoretic elution and by electroblotting on polyvinylidene difluoride membrane and subjected to gas phase sequencing. Precautions were taken during electrophoretic elution to prevent reactions that result in N-terminal blocking. Both methods of protein recovery yielded negative results when subjected to sequence analysis indicating that the N-terminus of sulfhydryl oxidase is blocked

  11. Characterization of three bioenergetically active respiratory terminal oxidases in the cyanobacterium Synechocystis sp. strain PCC 6803.

    Science.gov (United States)

    Pils, D; Schmetterer, G

    2001-09-25

    Synechocystis sp. PCC 6803 contains three respiratory terminal oxidases (RTOs): cytochrome c oxidase (Cox), quinol oxidase (Cyd), and alternate RTO (ARTO). Mutants lacking combinations of the RTOs were used to characterize these key enzymes of respiration. Pentachlorophenol and 2-heptyl-4-hydroxy-quinoline-N-oxide inhibited Cyd completely, but had little effect on electron transport to the other RTOs. KCN inhibited all three RTOs but the in vivo K(I) for Cox and Cyd was quite different (7 vs. 27 microM), as was their affinity for oxygen (K(M) 1.0 vs. 0.35 microM). ARTO has a very low respiratory activity. However, when uptake of 3-O-methylglucose, an active H+ co-transport, was used to monitor energization of the cytoplasmic membrane, ARTO was similarly effective as the other RTOs. As removal of the gene for cytochrome c(553) had the same effects as removal of ARTO genes, we propose that the ARTO might be a second Cox. The possible functions, localization and regulation of the RTOs are discussed.

  12. A Plastid Terminal Oxidase Associated with Carotenoid Desaturation during Chromoplast Differentiation1

    Science.gov (United States)

    Josse, Eve-Marie; Simkin, Andrew J.; Gaffé, Joël; Labouré, Anne-Marie; Kuntz, Marcel; Carol, Pierre

    2000-01-01

    The Arabidopsis IMMUTANS gene encodes a plastid homolog of the mitochondrial alternative oxidase, which is associated with phytoene desaturation. Upon expression in Escherichia coli, this protein confers a detectable cyanide-resistant electron transport to isolated membranes. In this assay this activity is sensitive to n-propyl-gallate, an inhibitor of the alternative oxidase. This protein appears to be a plastid terminal oxidase (PTOX) that is functionally equivalent to a quinol:oxygen oxidoreductase. This protein was immunodetected in achlorophyllous pepper (Capsicum annuum) chromoplast membranes, and a corresponding cDNA was cloned from pepper and tomato (Lycopersicum esculentum) fruits. Genomic analysis suggests the presence of a single gene in these organisms, the expression of which parallels phytoene desaturase and ζ-carotene desaturase gene expression during fruit ripening. Furthermore, this PTOX gene is impaired in the tomato ghost mutant, which accumulates phytoene in leaves and fruits. These data show that PTOX also participates in carotenoid desaturation in chromoplasts in addition to its role during early chloroplast development. PMID:10938359

  13. Improving Glyphosate Oxidation Activity of Glycine Oxidase from Bacillus cereus by Directed Evolution

    Science.gov (United States)

    Zhan, Tao; Zhang, Kai; Chen, Yangyan; Lin, Yongjun; Wu, Gaobing; Zhang, Lili; Yao, Pei; Shao, Zongze; Liu, Ziduo

    2013-01-01

    Glyphosate, a broad spectrum herbicide widely used in agriculture all over the world, inhibits 5-enolpyruvylshikimate-3-phosphate synthase in the shikimate pathway, and glycine oxidase (GO) has been reported to be able to catalyze the oxidative deamination of various amines and cleave the C-N bond in glyphosate. Here, in an effort to improve the catalytic activity of the glycine oxidase that was cloned from a glyphosate-degrading marine strain of Bacillus cereus (BceGO), we used a bacteriophage T7 lysis-based method for high-throughput screening of oxidase activity and engineered the gene encoding BceGO by directed evolution. Six mutants exhibiting enhanced activity toward glyphosate were screened from two rounds of error-prone PCR combined with site directed mutagenesis, and the beneficial mutations of the six evolved variants were recombined by DNA shuffling. Four recombinants were generated and, when compared with the wild-type BceGO, the most active mutant B3S1 showed the highest activity, exhibiting a 160-fold increase in substrate affinity, a 326-fold enhancement in catalytic efficiency against glyphosate, with little difference between their pH and temperature stabilities. The role of these mutations was explored through structure modeling and molecular docking, revealing that the Arg51 mutation is near the active site and could be an important residue contributing to the stabilization of glyphosate binding, while the role of the remaining mutations is unclear. These results provide insight into the application of directed evolution in optimizing glycine oxidase function and have laid a foundation for the development of glyphosate-tolerant crops. PMID:24223901

  14. Improving glyphosate oxidation activity of glycine oxidase from Bacillus cereus by directed evolution.

    Directory of Open Access Journals (Sweden)

    Tao Zhan

    Full Text Available Glyphosate, a broad spectrum herbicide widely used in agriculture all over the world, inhibits 5-enolpyruvylshikimate-3-phosphate synthase in the shikimate pathway, and glycine oxidase (GO has been reported to be able to catalyze the oxidative deamination of various amines and cleave the C-N bond in glyphosate. Here, in an effort to improve the catalytic activity of the glycine oxidase that was cloned from a glyphosate-degrading marine strain of Bacillus cereus (BceGO, we used a bacteriophage T7 lysis-based method for high-throughput screening of oxidase activity and engineered the gene encoding BceGO by directed evolution. Six mutants exhibiting enhanced activity toward glyphosate were screened from two rounds of error-prone PCR combined with site directed mutagenesis, and the beneficial mutations of the six evolved variants were recombined by DNA shuffling. Four recombinants were generated and, when compared with the wild-type BceGO, the most active mutant B3S1 showed the highest activity, exhibiting a 160-fold increase in substrate affinity, a 326-fold enhancement in catalytic efficiency against glyphosate, with little difference between their pH and temperature stabilities. The role of these mutations was explored through structure modeling and molecular docking, revealing that the Arg(51 mutation is near the active site and could be an important residue contributing to the stabilization of glyphosate binding, while the role of the remaining mutations is unclear. These results provide insight into the application of directed evolution in optimizing glycine oxidase function and have laid a foundation for the development of glyphosate-tolerant crops.

  15. Effect of gamma irradiation on aspergillus niger for enhanced production of glucose oxidase

    International Nuclear Information System (INIS)

    Zia, M.A.; Rasul, S.

    2012-01-01

    Developing countries have a high prevalence of diabetes and their populations are suffering from associated adverse factors. Such a frequency requires more effective diagnosis, mostly achieved by glucose diagnostic kits. Although high priced kits are available in market but local production of such kits can be highly cost effective and may confer the decline in incidence of the disease. Glucose oxidase is the key enzyme for the determination of glucose in such analytical tools. Enhanced production of glucose oxidase was performed by mutagenesis of Aspergillus niger by gamma irradiation. A dose of 80 krad was found as optimum for derivation of positive mutant strains. Following the screening by triton X-100 and 2-deoxy-D-glucose, the selected strains A. niger G-80-A, A. niger G-80-B and A. niger G-80-C showed 27.5, 23.20 and 20.55 UmL/sub -1/ glucose oxidase activity in enzyme diffusion zone test; which is much higher to parental strain (7.5 UmL/sup -1/). A. niger G-80-A was subjected to submerged fermentation and obtained highest yields after 36 h, at CSL 2%, pH 6.5, 30 degree C, KH/sub 2/PO/sub 4/ 0.8% and urea 0.3%. Partial purification by ammonium sulfate resulted in 175 UmL/sup -1/ of glucose oxidase activity after dialysis. Kinetic parameters like optimum pH, temperature, K/sub m/ and V/sub max/ were found to be 6.0 (180 +- 2 UmL/sup -1/), 30 degree C (185 +- 0.5 UmL/sup -1/), 5.26 mM and 400 U mL/sup -1/, respectively. Active inhibition of the enzyme by increasing concentration of PLP in reaction mixture confirmed the presence of functional lysyl residue on the active site of enzyme. (author)

  16. MONOAMINE OXIDASE: RADIOTRACER DEVELOPMENT AND HUMAN STUDIES.

    Energy Technology Data Exchange (ETDEWEB)

    FOWLER,J.S.; LOGAN,J.; VOLKOW,N.D.; WANG,G.J.; MACGREGOR,R.R.; DING,Y.S.

    2000-09-28

    PET is uniquely capable of providing information on biochemical transformations in the living human body. Although most of the studies of monoamine oxidase (MAO) have focused on measurements in the brain, the role of peripheral MAO as a phase 1 enzyme for the metabolism of drugs and xenobiotics is gaining attention (Strolin Benedetti and Tipton, 1998; Castagnoli et al., 1997.). MAO is well suited for this role because its concentration in organs such as kidneys, liver and digestive organs is high sometimes exceeding that in the brain. Knowledge of the distribution of the MAO subtypes within different organs and different cells is important in determining which substrates (and which drugs and xenobiotics) have access to which MAO subtypes. The highly variable subtype distribution with different species makes human studies even more important. In addition, the deleterious side effects of combining MAO inhibitors with other drugs and with foodstuffs makes it important to know the MAO inhibitory potency of different drugs both in the brain and in peripheral organs (Ulus et al., 2000). Clearly PET can play a role in answering these questions, in drug research and development and in discovering some of the factors which contribute to the highly variable MAO levels in different individuals.

  17. When Reputation Enforces Evolutionary Cooperation in Unreliable MANETs.

    Science.gov (United States)

    Tang, Changbing; Li, Ang; Li, Xiang

    2015-10-01

    In self-organized mobile ad hoc networks (MANETs), network functions rely on cooperation of self-interested nodes, where a challenge is to enforce their mutual cooperation. In this paper, we study cooperative packet forwarding in a one-hop unreliable channel which results from loss of packets and noisy observation of transmissions. We propose an indirect reciprocity framework based on evolutionary game theory, and enforce cooperation of packet forwarding strategies in both structured and unstructured MANETs. Furthermore, we analyze the evolutionary dynamics of cooperative strategies and derive the threshold of benefit-to-cost ratio to guarantee the convergence of cooperation. The numerical simulations verify that the proposed evolutionary game theoretic solution enforces cooperation when the benefit-to-cost ratio of the altruistic exceeds the critical condition. In addition, the network throughput performance of our proposed strategy in structured MANETs is measured, which is in close agreement with that of the full cooperative strategy.

  18. Cooperation of a university with business practice

    Directory of Open Access Journals (Sweden)

    Sojkin Bogdan

    2016-12-01

    Full Text Available The article presents forms of cooperation and social benefits resulting from cooperation between universities and business practice. Basic kinds and directions of mutual relations arising from common areas of interest, possibilities, needs and conditions for the functioning of each side, have been presented. Solutions carried out by universities with the participation of business practice have been discussed. In case of business practice, potential areas of cooperation with schools and joint ventures in the area of R&D have been discussed.

  19. Monoamine oxidase A (MAO A) inhibitors decrease glioma progression

    Science.gov (United States)

    Vaikari, Vijaya Pooja; Kota, Rajesh; Chen, Kevin; Yeh, Tzu-Shao; Jhaveri, Niyati; Groshen, Susan L.; Olenyuk, Bogdan Z.; Chen, Thomas C.; Hofman, Florence M.; Shih, Jean C.

    2016-01-01

    Glioblastoma (GBM) is an aggressive brain tumor which is currently treated with temozolomide (TMZ). Tumors usually become resistant to TMZ and recur; no effective therapy is then available. Monoamine Oxidase A (MAO A) oxidizes monoamine neurotransmitters resulting in reactive oxygen species which cause cancer. This study shows that MAO A expression is increased in human glioma tissues and cell lines. MAO A inhibitors, clorgyline or the near-infrared-dye MHI-148 conjugated to clorgyline (NMI), were cytotoxic for glioma and decreased invasion in vitro. Using the intracranial TMZ-resistant glioma model, clorgyline or NMI alone or in combination with low-dose TMZ reduced tumor growth and increased animal survival. NMI was localized specifically to the tumor. Immunocytochemistry studies showed that the MAO A inhibitor reduced proliferation, microvessel density and invasion, and increased macrophage infiltration. In conclusion, we have identified MAO A inhibitors as potential novel stand-alone drugs or as combination therapy with low dose TMZ for drug-resistant gliomas. NMI can also be used as a non-invasive imaging tool. Thus has a dual function for both therapy and diagnosis. PMID:26871599

  20. Spermine oxidase promotes bile canalicular lumen formation through acrolein production.

    Science.gov (United States)

    Uemura, Takeshi; Takasaka, Tomokazu; Igarashi, Kazuei; Ikegaya, Hiroshi

    2017-11-01

    Spermine oxidase (SMOX) catalyzes oxidation of spermine to generate spermidine, hydrogen peroxide (H 2 O 2 ) and 3-aminopropanal, which is spontaneously converted to acrolein. SMOX is induced by a variety of stimuli including bacterial infection, polyamine analogues and acetaldehyde exposure. However, the physiological functions of SMOX are not yet fully understood. We investigated the physiological role of SMOX in liver cells using human hepatocellular carcinoma cell line HepG2. SMOX localized to the bile canalicular lumen, as determined by F-actin staining. Knockdown of SMOX reduced the formation of bile canalicular lumen. We also found that phospho-Akt (phosphorylated protein kinase B) was localized to canalicular lumen. Treatment with Akt inhibitor significantly reduced the formation of bile canalicular lumen. Acrolein scavenger also inhibited the formation of bile canalicular lumen. PTEN, phosphatase and tensin homolog and an inhibitor of Akt, was alkylated in a SMOX-dependent manner. Our results suggest that SMOX plays a central role in the formation of bile canalicular lumen in liver cells by activating Akt pathway through acrolein production.

  1. Assays of D-Amino Acid Oxidase Activity

    Directory of Open Access Journals (Sweden)

    Elena Rosini

    2018-01-01

    Full Text Available D-amino acid oxidase (DAAO is a well-known flavoenzyme that catalyzes the oxidative FAD-dependent deamination of D-amino acids. As a result of the absolute stereoselectivity and broad substrate specificity, microbial DAAOs have been employed as industrial biocatalysts in the production of semi-synthetic cephalosporins and enantiomerically pure amino acids. Moreover, in mammals, DAAO is present in specific brain areas and degrades D-serine, an endogenous coagonist of the N-methyl-D-aspartate receptors (NMDARs. Dysregulation of D-serine metabolism due to an altered DAAO functionality is related to pathological NMDARs dysfunctions such as in amyotrophic lateral sclerosis and schizophrenia. In this protocol paper, we describe a variety of direct assays based on the determination of molecular oxygen consumption, reduction of alternative electron acceptors, or α-keto acid production, of coupled assays to detect the hydrogen peroxide or the ammonium production, and an indirect assay of the α-keto acid production based on a chemical derivatization. These analytical assays allow the determination of DAAO activity both on recombinant enzyme preparations, in cells, and in tissue samples.

  2. Predisposed to cooperate

    Directory of Open Access Journals (Sweden)

    Cathryn Costello

    2013-09-01

    Full Text Available Recent research in Toronto and Geneva indicates that asylum seekers and refugees are predisposed to be cooperative with the refugee status determination system and other immigration procedures, and that the design of alternatives to detention can create, foster and support this cooperative predisposition – or can undermine or even demolish it.

  3. Proto-cooperation

    DEFF Research Database (Denmark)

    Herbert-Read, James E; Romanczuk, Pawel; Krause, Stefan

    2016-01-01

    beneficial if the cost of attacking is high, and only then when waiting times are short. Our findings provide evidence that cooperative benefits can be realized through the facilitative effects of individuals' hunting actions without spatial coordination of attacks. Such 'proto-cooperation' may be the pre...

  4. Cooperation, compensation and transition

    NARCIS (Netherlands)

    Ju, Y.

    2004-01-01

    Cooperation and compensation are two important and well-linked issues in economics. The central question in cooperation is how to share the joint gains among participating players. Compensation is a specific aspect of surplus sharing problems providing incentives for agents to sacrifice their own

  5. Scandinavian Cooperative Advantage

    DEFF Research Database (Denmark)

    Strand, Robert; Freeman, R. Edward

    2015-01-01

    . We conclude by endorsing the expression “Scandinavian cooperative advantage” in an effort to draw attention to the Scandinavian context and encourage the field of strategic management to shift its focus from achieving a competitive advantage toward achieving a cooperative advantage....

  6. Helping Children Cooperate

    Science.gov (United States)

    Pica, Rae

    2011-01-01

    There are occasions in life when the competitive process is appropriate. But when people consider the relationships in their lives--with friends, family members, coworkers, and the larger community--they realize the value of cooperation. When adults give children the chance to cooperate, to work together toward a solution or a common goal like…

  7. Efficiency in Microfinance Cooperatives

    Directory of Open Access Journals (Sweden)

    HARTARSKA, Valentina

    2012-12-01

    Full Text Available In recognition of cooperatives’ contribution to the socio-economic well-being of their participants, the United Nations has declared 2012 as the International Year of Cooperatives. Microfinance cooperatives make a large part of the microfinance industry. We study efficiency of microfinance cooperatives and provide estimates of the optimal size of such organizations. We employ the classical efficiency analysis consisting of estimating a system of equations and identify the optimal size of microfinance cooperatives in terms of their number of clients (outreach efficiency, as well as dollar value of lending and deposits (sustainability. We find that microfinance cooperatives have increasing returns to scale which means that the vast majority can lower cost if they become larger. We calculate that the optimal size is around $100 million in lending and half of that in deposits. We find less robust estimates in terms of reaching many clients with a range from 40,000 to 180,000 borrowers.

  8. Cytochemical localization of catalase and several hydrogen peroxide-producing oxidases in the nucleoids and matrix of rat liver peroxisomes

    NARCIS (Netherlands)

    Veenhuis, M.; Wendelaar Bonga, S.E.

    1979-01-01

    The distribution of catalase, amino acid oxidase, α-hydroxy acid oxidase, urate oxidase and alcohol oxidase was studied cytochemically in rat hepatocytes. The presence of catalase was demonstrated with the conventional diaminobenzidine technique. Oxidase activities were visualized with methods based

  9. Serum diamine oxidase activity in patients with histamine intolerance.

    Science.gov (United States)

    Manzotti, G; Breda, D; Di Gioacchino, M; Burastero, S E

    2016-03-01

    Intolerance to various foods, excluding bona fide coeliac disease and lactose intolerance, represents a growing cause of patient visits to allergy clinics.Histamine intolerance is a long-known, multifaceted clinical condition triggered by histamine-rich foods and alcohol and/or by drugs that liberate histamine or block diamine oxidase (DAO), the main enzyme involved in the metabolism of ingested histamine. Histamine limitation diets impose complex, non-standardized restrictions that may severely impact the quality of life of patients. We retrospectively evaluated 14 patients who visited allergy outpatient facilities in northern Italy with a negative diagnosis for IgE-mediated food hypersensitivity, coeliac disease, conditions related to gastric hypersecretion, and systemic nickel hypersensitivity, and who previously underwent a histamine limitation diet with benefits for their main symptoms. Serum diamine oxidase levels and the clinical response to diamine oxidase supplementation were investigated. We found that 10 out of 14 patients had serum DAO activityintolerance. Moreover, 13 out of 14 patients subjectively reported a benefit in at least one of the disturbances related to food intolerances following diamine oxidase supplementation. The mean value (±SD) of diamine oxidase activity in the cohort of patients with histamine intolerance symptoms was 7.04±6.90 U/mL compared to 39.50±18.16 U/mL in 34 healthy controls (P=0.0031). In patients with symptoms triggered by histamine-rich food, measuring the serum diamine oxidase activity can help identify subjects who can benefit from a histamine limitation diet and/or diamine oxidase supplementation.Properly designed, controlled studies investigating histamine intolerance that include histamine provocation are indispensable for providing insights into the area of food intolerances, which are currently primarily managed with non-scientific approaches in Italy. © The Author(s) 2015.

  10. Cooperative epidemics on multiplex networks

    Science.gov (United States)

    Azimi-Tafreshi, N.

    2016-04-01

    The spread of one disease, in some cases, can stimulate the spreading of another infectious disease. Here, we treat analytically a symmetric coinfection model for spreading of two diseases on a two-layer multiplex network. We allow layer overlapping, but we assume that each layer is random and locally loopless. Infection with one of the diseases increases the probability of getting infected with the other. Using the generating function method, we calculate exactly the fraction of individuals infected with both diseases (so-called coinfected clusters) in the stationary state, as well as the epidemic spreading thresholds and the phase diagram of the model. With increasing cooperation, we observe a tricritical point and the type of transition changes from continuous to hybrid. Finally, we compare the coinfected clusters in the case of cooperating diseases with the so-called "viable" clusters in networks with dependencies.

  11. Assessment of a cooperative workstation.

    Science.gov (United States)

    Beuscart, R J; Molenda, S; Souf, N; Foucher, C; Beuscart-Zephir, M C

    1996-01-01

    Groupware and new Information Technologies have now made it possible for people in different places to work together in synchronous cooperation. Very often, designers of this new type of software are not provided with a model of the common workspace, which is prejudicial to software development and its acceptance by potential users. The authors take the example of a task of medical co-diagnosis, using a multi-media communication workstation. Synchronous cooperative work is made possible by using local ETHERNET or public ISDN Networks. A detailed ergonomic task analysis studies the cognitive functioning of the physicians involved, compares their behaviour in the normal and the mediatized situations, and leads to an interpretation of the likely causes for success or failure of CSCW tools.

  12. Forage Polyphenol Oxidase and Ruminant Livestock Nutrition

    Directory of Open Access Journals (Sweden)

    Michael Richard F. Lee

    2014-12-01

    Full Text Available Polyphenol oxidase (PPO is associated with the detrimental effect of browning fruit and vegetables, however interest within PPO containing forage crops has grown since the brownng reaction was associated with reduced nitrogen (N losses in silo and the rumen. The reduction in protein breakdown in silo of red clover (high PPO forage increased the quality of protein, improving N-use efficiency (NUE when fed to ruminants. A further benefit of red clover silage feeding is a significant reduction in lipolysis in silo and an increase in the deposition of beneficial C18 polyunsaturated fatty acid (PUFA in animal products, which has also been linked to PPO activity. PPOs protection of plant protein and glycerol based-PUFA in silo is related to the deactivation of plant proteases and lipases. This deactivation occurs through PPO catalysing the conversion of diphenols to quinones which bind with cellular nucleophiles such as protein reforming a protein-bound phenol (PBP. If the protein is an enzyme the complexing denatures the enzyme. However, PPO is inactive in the anaerobic rumen and therefore any subsequent protection of plant protein and glycerol based-PUFA in the rumen must be as a result of events that occurred to the forage pre-ingestion. Reduced activity of plant proteases and lipases would have little effect on NUE and glycerol based-PUFA in the rumen due to the greater concentration of rumen microbial proteases and lipases. The mechanism for PPOs protection of plant protein in the rumen is a consequence of complexing plant protein, rather than protease deactivation per se. These complexed proteins reduce protein digestibility in the rumen and subsequently increase un-degraded dietary protein flow to the small intestine. The mechanism for protecting glycerol-based PUFA has yet to be fully elucidated but may be associated with entrapment within PBP reducing access to microbial lipases or differences in rumen digestion kinetics of red clover.

  13. Monoamine oxidase and agitation in psychiatric patients.

    Science.gov (United States)

    Nikolac Perkovic, Matea; Svob Strac, Dubravka; Nedic Erjavec, Gordana; Uzun, Suzana; Podobnik, Josip; Kozumplik, Oliver; Vlatkovic, Suzana; Pivac, Nela

    2016-08-01

    Subjects with schizophrenia or conduct disorder display a lifelong pattern of antisocial, aggressive and violent behavior and agitation. Monoamine oxidase (MAO) is an enzyme involved in the degradation of various monoamine neurotransmitters and neuromodulators and therefore has a role in various psychiatric and neurodegenerative disorders and pathological behaviors. Platelet MAO-B activity has been associated with psychopathy- and aggression-related personality traits, while variants of the MAOA and MAOB genes have been associated with diverse clinical phenotypes, including aggressiveness, antisocial problems and violent delinquency. The aim of the study was to evaluate the association of platelet MAO-B activity, MAOB rs1799836 polymorphism and MAOA uVNTR polymorphism with severe agitation in 363 subjects with schizophrenia and conduct disorder. The results demonstrated significant association of severe agitation and smoking, but not diagnosis or age, with platelet MAO-B activity. Higher platelet MAO-B activity was found in subjects with severe agitation compared to non-agitated subjects. Platelet MAO-B activity was not associated with MAOB rs1799836 polymorphism. These results suggested the association between increased platelet MAO-B activity and severe agitation. No significant association was found between severe agitation and MAOA uVNTR or MAOB rs1799836 polymorphism, revealing that these individual polymorphisms in MAO genes are not related to severe agitation in subjects with schizophrenia and conduct disorder. As our study included 363 homogenous Caucasian male subjects, our data showing this negative genetic association will be a useful addition to future meta-analyses. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. [Effect of Kaixinsan on monoamine oxidase activity].

    Science.gov (United States)

    Wang, Shi; Dong, Xian-Zhe; Tan, Xiao; Wang, Yu-Ning; Liu, Ping

    2016-05-01

    To observe the effect of antidepressant medicine prescription, Kaixinsan (KXS) on monoamine oxidase (MAO) activity, and explore the mechanism of KXS in elevating the levels of monoamine neurotransmitter from the perspective of metabolism, in vitro enzyme reaction system and C6 neuroglial cells, the effect of KXS at different concentrations on MAO-A and MAO-B activity was observed. In animal studies, the effect of KXS at different concentrations on MAO-A and MAO-B activities of brain mitochondrialin normal rats and solitary chronic unpredictable moderate stress (CMS) model rats after intragastric administration for 1, 2, 3 weeks. Results showed that 10 g•L⁻¹ KXS could significantly reduce the activity of MAO-A and MAO-B in enzyme reaction system; and in C6 cells, KXS within 0.625-10 g•L⁻¹ concentration range had no significant effect on the activity of MAO-A, but had obvious inhibitory effect on the activity of MAO-B in a dose dependent manner. KXS had no significant effect on the activity of MAO-A and MAO-B in brains of normal rats after action for 1, 2, 3 weeks. After 2 and 3 weeks treatment with 338 mg•kg⁻¹ dose KXS, MAO-A activity in the brain of CMS rats was decreased as compared with the model group (PMAO-B activity after 1, 2, 3 weeks of treatment. The results indicated that KXS had certain effect on in vitro MAO-A and MAO-B activity, had no effect on brain MAO-A and MAO-B activity in vivo in normal rats, and had certain inhibitory effect on MAO-A activity in brains of CMS rats. Copyright© by the Chinese Pharmaceutical Association.

  15. Lysyl oxidase and adipose tissue dysfunction.

    Science.gov (United States)

    Pastel, Emilie; Price, Emily; Sjöholm, Kajsa; McCulloch, Laura J; Rittig, Nikolaj; Liversedge, Neil; Knight, Bridget; Møller, Niels; Svensson, Per-Arne; Kos, Katarina

    2018-01-01

    Lysyl oxidase (LOX) is an enzyme crucial for collagen fibre crosslinking and thus for fibrosis development. Fibrosis is characterised by a surplus of collagen fibre accumulation and is amongst others also a feature of obesity-associated dysfunctional adipose tissue (AT) which has been linked with type 2 diabetes. We hypothesised that in type 2 diabetes and obesity LOX expression and activity will be increased as a consequence of worsening AT dysfunction. This study aimed to provide a comprehensive characterisation of LOX in human AT. LOX mRNA expression was analysed in omental and abdominal subcutaneous AT obtained during elective surgery from subjects with a wide range of BMI, with and without diabetes. In addition, LOX expression was studied in subcutaneous AT before and 9.5months after bariatric surgery. To study the mechanism of LOX changes, its expression and activity were assessed after either hypoxia, recombinant human leptin or glucose treatment of AT explants. In addition, LOX response to acute inflammation was tested after stimulation by a single injection of lipopolysaccharide versus saline solution (control) in healthy men, in vivo. Quantity of mRNA was measured by RT-qPCR. LOX expression was higher in obesity and correlated with BMI whilst, in vitro, leptin at high concentrations, as a potential feedback mechanism, suppressed its expression. Neither diabetes status, nor hyperglycaemia affected LOX. Hypoxia and lipopolysaccharide-induced acute inflammation increased LOX AT expression, latter was independent of macrophage infiltration. Whilst LOX may not be affected by obesity-associated complications such as diabetes, our results confirm that LOX is increased by hypoxia and inflammation as underlying mechanism for its upregulation in adipose tissue with obesity. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. What drives cooperative breeding?

    Directory of Open Access Journals (Sweden)

    Walter D Koenig

    2017-06-01

    Full Text Available Cooperative breeding, in which more than a pair of conspecifics cooperate to raise young at a single nest or brood, is widespread among vertebrates but highly variable in its geographic distribution. Particularly vexing has been identifying the ecological correlates of this phenomenon, which has been suggested to be favored in populations inhabiting both relatively stable, productive environments and in populations living under highly variable and unpredictable conditions. Griesser et al. provide a novel approach to this problem, performing a phylogenetic analysis indicating that family living is an intermediate step between nonsocial and cooperative breeding birds. They then examine the ecological and climatic conditions associated with these different social systems, concluding that cooperative breeding emerges when family living is favored in highly productive environments, followed secondarily by selection for cooperative breeding when environmental conditions deteriorate and within-year variability increases. Combined with recent work addressing the fitness consequences of cooperative breeding, Griesser et al.'s contribution stands to move the field forward by demonstrating that the evolution of complex adaptations such as cooperative breeding may only be understood when each of the steps leading to it are identified and carefully integrated.

  17. Characterization of a Flavoprotein Oxidase from Opium Poppy Catalyzing the Final Steps in Sanguinarine and Papaverine Biosynthesis*

    Science.gov (United States)

    Hagel, Jillian M.; Beaudoin, Guillaume A. W.; Fossati, Elena; Ekins, Andrew; Martin, Vincent J. J.; Facchini, Peter J.

    2012-01-01

    Benzylisoquinoline alkaloids are a diverse class of plant specialized metabolites that includes the analgesic morphine, the antimicrobials sanguinarine and berberine, and the vasodilator papaverine. The two-electron oxidation of dihydrosanguinarine catalyzed by dihydrobenzophenanthridine oxidase (DBOX) is the final step in sanguinarine biosynthesis. The formation of the fully conjugated ring system in sanguinarine is similar to the four-electron oxidations of (S)-canadine to berberine and (S)-tetrahydropapaverine to papaverine. We report the isolation and functional characterization of an opium poppy (Papaver somniferum) cDNA encoding DBOX, a flavoprotein oxidase with homology to (S)-tetrahydroprotoberberine oxidase and the berberine bridge enzyme. A query of translated opium poppy stem transcriptome databases using berberine bridge enzyme yielded several candidate genes, including an (S)-tetrahydroprotoberberine oxidase-like sequence selected for heterologous expression in Pichia pastoris. The recombinant enzyme preferentially catalyzed the oxidation of dihydrosanguinarine to sanguinarine but also converted (RS)-tetrahydropapaverine to papaverine and several protoberberine alkaloids to oxidized forms, including (RS)-canadine to berberine. The Km values of 201 and 146 μm for dihydrosanguinarine and the protoberberine alkaloid (S)-scoulerine, respectively, suggested high concentrations of these substrates in the plant. Virus-induced gene silencing to reduce DBOX transcript levels resulted in a corresponding reduction in sanguinarine, dihydrosanguinarine, and papaverine accumulation in opium poppy roots in support of DBOX as a multifunctional oxidative enzyme in BIA metabolism. PMID:23118227

  18. Characterization of a flavoprotein oxidase from opium poppy catalyzing the final steps in sanguinarine and papaverine biosynthesis.

    Science.gov (United States)

    Hagel, Jillian M; Beaudoin, Guillaume A W; Fossati, Elena; Ekins, Andrew; Martin, Vincent J J; Facchini, Peter J

    2012-12-14

    Benzylisoquinoline alkaloids are a diverse class of plant specialized metabolites that includes the analgesic morphine, the antimicrobials sanguinarine and berberine, and the vasodilator papaverine. The two-electron oxidation of dihydrosanguinarine catalyzed by dihydrobenzophenanthridine oxidase (DBOX) is the final step in sanguinarine biosynthesis. The formation of the fully conjugated ring system in sanguinarine is similar to the four-electron oxidations of (S)-canadine to berberine and (S)-tetrahydropapaverine to papaverine. We report the isolation and functional characterization of an opium poppy (Papaver somniferum) cDNA encoding DBOX, a flavoprotein oxidase with homology to (S)-tetrahydroprotoberberine oxidase and the berberine bridge enzyme. A query of translated opium poppy stem transcriptome databases using berberine bridge enzyme yielded several candidate genes, including an (S)-tetrahydroprotoberberine oxidase-like sequence selected for heterologous expression in Pichia pastoris. The recombinant enzyme preferentially catalyzed the oxidation of dihydrosanguinarine to sanguinarine but also converted (RS)-tetrahydropapaverine to papaverine and several protoberberine alkaloids to oxidized forms, including (RS)-canadine to berberine. The K(m) values of 201 and 146 μm for dihydrosanguinarine and the protoberberine alkaloid (S)-scoulerine, respectively, suggested high concentrations of these substrates in the plant. Virus-induced gene silencing to reduce DBOX transcript levels resulted in a corresponding reduction in sanguinarine, dihydrosanguinarine, and papaverine accumulation in opium poppy roots in support of DBOX as a multifunctional oxidative enzyme in BIA metabolism.

  19. HUMAN MACHINE COOPERATIVE TELEROBOTICS

    International Nuclear Information System (INIS)

    William R. Hamel; Spivey Douglass; Sewoong Kim; Pamela Murray; Yang Shou; Sriram Sridharan; Ge Zhang; Scott Thayer; Rajiv V. Dubey

    2003-01-01

    The remediation and deactivation and decommissioning (D and D) of nuclear waste storage tanks using telerobotics is one of the most challenging tasks faced in environmental cleanup. Since a number of tanks have reached the end of their design life and some of them have leaks, the unstructured, uncertain and radioactive environment makes the work inefficient and expensive. However, the execution time of teleoperation consumes ten to hundred times that of direct contact with an associated loss in quality. Thus, a considerable effort has been expended to improve the quality and efficiency of telerobotics by incorporating into teleoperation and robotic control functions such as planning, trajectory generation, vision, and 3-D modeling. One example is the Robot Task Space Analyzer (RTSA), which has been developed at the Robotics and Electromechanical Systems Laboratory (REMSL) at the University of Tennessee in support of the D and D robotic work at the Oak Ridge National Laboratory and the National Energy Technology Laboratory. This system builds 3-D models of the area of interest in task space through automatic image processing and/or human interactive manual modeling. The RTSA generates a task plan file, which describes the execution of a task including manipulator and tooling motions. The high level controller of the manipulator interprets the task plan file and executes the task automatically. Thus, if the environment is not highly unstructured, a tooling task, which interacts with environment, will be executed in the autonomous mode. Therefore, the RTSA not only increases the system efficiency, but also improves the system reliability because the operator will act as backstop for safe operation after the 3-D models and task plan files are generated. However, unstructured conditions of environment and tasks necessitate that the telerobot operates in the teleoperation mode for successful execution of task. The inefficiency in the teleoperation mode led to the

  20. HUMAN MACHINE COOPERATIVE TELEROBOTICS

    Energy Technology Data Exchange (ETDEWEB)

    William R. Hamel; Spivey Douglass; Sewoong Kim; Pamela Murray; Yang Shou; Sriram Sridharan; Ge Zhang; Scott Thayer; Rajiv V. Dubey

    2003-06-30

    The remediation and deactivation and decommissioning (D&D) of nuclear waste storage tanks using telerobotics is one of the most challenging tasks faced in environmental cleanup. Since a number of tanks have reached the end of their design life and some of them have leaks, the unstructured, uncertain and radioactive environment makes the work inefficient and expensive. However, the execution time of teleoperation consumes ten to hundred times that of direct contact with an associated loss in quality. Thus, a considerable effort has been expended to improve the quality and efficiency of telerobotics by incorporating into teleoperation and robotic control functions such as planning, trajectory generation, vision, and 3-D modeling. One example is the Robot Task Space Analyzer (RTSA), which has been developed at the Robotics and Electromechanical Systems Laboratory (REMSL) at the University of Tennessee in support of the D&D robotic work at the Oak Ridge National Laboratory and the National Energy Technology Laboratory. This system builds 3-D models of the area of interest in task space through automatic image processing and/or human interactive manual modeling. The RTSA generates a task plan file, which describes the execution of a task including manipulator and tooling motions. The high level controller of the manipulator interprets the task plan file and executes the task automatically. Thus, if the environment is not highly unstructured, a tooling task, which interacts with environment, will be executed in the autonomous mode. Therefore, the RTSA not only increases the system efficiency, but also improves the system reliability because the operator will act as backstop for safe operation after the 3-D models and task plan files are generated. However, unstructured conditions of environment and tasks necessitate that the telerobot operates in the teleoperation mode for successful execution of task. The inefficiency in the teleoperation mode led to the research

  1. Defining the Interactions of Cellobiohydrolase with Substrate through Structure Function Studies: Cooperative Research and Development Final Report, CRADA Number CRD-10-409

    Energy Technology Data Exchange (ETDEWEB)

    Beckham, G. T.; Himmel, M. E.

    2013-07-01

    NREL researchers will use their expertise and skilled resources in numerical computational modeling to generate structure-function relationships for improved cellulase variant enzymes to support the development of cellulases with improved performance in biomass conversion.

  2. The evolution of cooperation on geographical networks

    Science.gov (United States)

    Li, Yixiao; Wang, Yi; Sheng, Jichuan

    2017-11-01

    We study evolutionary public goods game on geographical networks, i.e., complex networks which are located on a geographical plane. The geographical feature effects in two ways: In one way, the geographically-induced network structure influences the overall evolutionary dynamics, and, in the other way, the geographical length of an edge influences the cost when the two players at the two ends interact. For the latter effect, we design a new cost function of cooperators, which simply assumes that the longer the distance between two players, the higher cost the cooperator(s) of them have to pay. In this study, network substrates are generated by a previous spatial network model with a cost-benefit parameter controlling the network topology. Our simulations show that the greatest promotion of cooperation is achieved in the intermediate regime of the parameter, in which empirical estimates of various railway networks fall. Further, we investigate how the distribution of edges' geographical costs influences the evolutionary dynamics and consider three patterns of the distribution: an approximately-equal distribution, a diverse distribution, and a polarized distribution. For normal geographical networks which are generated using intermediate values of the cost-benefit parameter, a diverse distribution hinders the evolution of cooperation, whereas a polarized distribution lowers the threshold value of the amplification factor for cooperation in public goods game. These results are helpful for understanding the evolution of cooperation on real-world geographical networks.

  3. Cognitive Load and Cooperation

    DEFF Research Database (Denmark)

    Døssing, Felix Sebastian; Piovesan, Marco; Wengström, Erik Roland

    2017-01-01

    We study the effect of intuitive and reflective processes on cooperation using cognitive load. Compared with time constraint, which has been used in the previous literature, cognitive load is a more direct way to block reflective processes, and thus a more suitable way to study the link between...... intuition and cooperation. Using a repeated public goods game, we study the effect of different levels of cognitive load on contributions. We show that a higher cognitive load increases the initial level of cooperation. In particular, subjects are significantly less likely to fully free ride under high...... cognitive load....

  4. Nordic Energy Policy Cooperation

    DEFF Research Database (Denmark)

    Jørgensen, Birte Holst

    2016-01-01

    Brundtland Commission Report, and climate change became a common concern. Energy technology cooperation was an integral part of Nordic energy policy cooperation from the very beginning. The Nordic Energy Research Programme was established with funding from each of the Nordic countries, and was earmarked...... by a committee of senior officials and a secretariat. This was characterised by an incremental development of the cooperation based on consensus, mutual understanding and trust facilitated through exchange of experiences, work groups, seminars, educational activities and mobility schemes for energy policy...

  5. Cooperative Mobile Web Browsing

    DEFF Research Database (Denmark)

    Perrucci, GP; Fitzek, FHP; Zhang, Qi

    2009-01-01

    This paper advocates a novel approach for mobile web browsing based on cooperation among wireless devices within close proximity operating in a cellular environment. In the actual state of the art, mobile phones can access the web using different cellular technologies. However, the supported data......-range links can then be used for cooperative mobile web browsing. By implementing the cooperative web browsing on commercial mobile phones, it will be shown that better performance is achieved in terms of increased data rate and therefore reduced access times, resulting in a significantly enhanced web...

  6. Production of rabbit antibodies against purified Glucose oxidase

    Directory of Open Access Journals (Sweden)

    Muhammad Anjum Zia

    2012-02-01

    Full Text Available Glucose oxidase is an active oxygen species generating enzyme produced from Aspergillus niger grown in submerged fermentation. Disintegration of the mycelium resulted in high glucose oxidase activity that was subjected to ammonium sulfate precipitation at 60-85% saturation rates that resulted to 6.14 U mg -1 specific activity. Purification of enzyme by anion exchange column (DEAE-Cellulose resulted into 22.53 U mg-1 specific activity and 10.27 fold purification. This was applied to sephadex G-200 column for gel filtration chromatography. It was observed that enzyme achieved 59.37 U mg-1of specific activity with 27.08 fold purity and 64.36% recovery. Purified glucose oxidase was injected into rabbits through intravenous route, to raise the glucose oxidase antibodies. After 30 days incubation period, the rabbits were slaughtered and serum was separated from blood. The antibodies were isolated by ammonium sulfate precipitation and confirmed by agar gel precipitation test. This could be a convenient and low cost alternate assay for the estimation of glucose oxidase in biological fluids. Moreover, such antibodies against the said enzyme could be used in various therapeutic and diagnostic applications.

  7. Calcium transport in vesicles energized by cytochrome oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Rosier, Randy N. [Univ. of Rochester, NY (United States)

    1979-01-01

    Experiments on the reconstitution of cytochrome oxidase into phospholipid vesicles were carried out using techniques of selectivity energizing the suspensions with ascorbate and cytochrome c or ascorbate, PMS, and internally trapped cytochrome c. It was found that the K+ selective ionophore valinomycin stimulated the rate of respiration of cytochrome oxidase vesicles regardless of the direction of the K+ flux across the vesicle membranes. The stimulation occurred in the presence of protonophoric uncouplers and in the complete absence of potassium or in detergent-lysed suspensions. Gramicidin had similar effects and it was determined that the ionophores acted by specific interaction with cytochrome oxidase rather than by the previously assumed collapse of membrane potentials. When hydrophobic proteins and appropriate coupling factors were incorporated into the cytochrome oxidase, vesicles phosphorylation of ADP could be coupled to the oxidation reaction of cytochrome oxidase. Relatively low P:O, representing poor coupling of the system, were problematical and precluded measurements of protonmotive force. However the system was used to study ion translocation.

  8. Immobilization of xanthine oxidase on a polyaniline silicone support.

    Science.gov (United States)

    Nadruz, W; Marques, E T; Azevedo, W M; Lima-Filho, J L; Carvalho, L B

    1996-03-01

    A polyaniline silicone support to immobilize xanthine oxidase is proposed as a reactor coil to monitor the action of xanthine oxidase on hypoxanthine, xanthine and 6-mercaptopurine. A purified xanthine oxidase immobilized on this support lost 80% of the initial activity after 12 min of use. Co-immobilization of superoxide dismutase and catalase increased the stability of immobilized xanthine oxidase so that the derivative maintained 79% of its initial activity after 4.6 h of continuous use in which 1.5 mumol purine bases were converted by the immobilized enzyme system. There is no evidence of either polyaniline or protein leaching from the coil during 3 h of continuous use. When solutions (10 ml) of hypoxanthine, xanthine and 6-mercaptopurine were circulated individually through the xanthine oxidase-superoxide dismutase-catalase-polyaniline coil (1 mm internal diameter and 3 m in length, 3 ml internal volume) activities of 8.12, 11.17 and 1.09 nmol min-1 coil-1, respectively, were obtained. The advantages of the reactor configuration and the redox properties of the polymer, particularly with respect to immobilized oxidoreductases, make this methodology attractive for similar enzyme systems. This immobilized enzyme system using polyaniline-silicone as support converted 6-mercaptopurine to 6-thiouric acid with equal efficiency as resins based on polyacrylamide and polyamide 11.

  9. Cooperation with the charges’ families as a component of functionality of re-socialization institutions for minors [Współpraca z rodzinami wychowanków jako element funkcjonalności instytucji resocjalizacyjnej dla nieletnich

    Directory of Open Access Journals (Sweden)

    Barbara JEZIERSKA

    2016-01-01

    Full Text Available Efficient functioning of a re-socialization institution is a condition of its growth and key factor of appropriate course of the community life that within its structure. Its efficiency relies on explicitly, clearly acknowledged objectives, its internal organization and division of workload as well as the independence of the professional tasks from the personal interests of the staff. Moreover, it tackles the conformity of the staff aspirations with aims and assignments for the accomplishment of which such a structure has been established, entailing high internal integrity, productive cooperation with other facilities and the external environment. It enables the achievement of the projected and socially desired outcomes as well as the accomplishment of common goals upon arrangements of various activities. Cooperation with the family environment of the charges constitutes a key element of the functionality of every re-socialization institution. It must be remembered that parents of the juvenile delinquents manifest features disabling the appropriate course of the upbringing, which consequently can lead to the children’s criminogenic lifestyle. Such features concern structural properties of the families, qualities related to the emotional attitude to their child, parental competences and last but not least – upbringing methods. Non-structural features can be subject to modification in given circumstances. Nonetheless, it is a challenging task particularly when institutions do not participate in the process of family support. Inclusion of the charges’ parents in the process of its correctional activities can condition the quality of educational measures accomplished within, becoming a key indicator of a rational organization and correction of behavior, reforming socially maladjusted behaviors of children and teenagers.

  10. The Cooperative Education as central axis for the integral Formation in the cooperative sector

    Directory of Open Access Journals (Sweden)

    Iriadna Marín de León

    2013-06-01

    Full Text Available The cooperative constitutes one of the most important sectors in the economy in any economic formation - social, its fundamental cell is the man's integral development who should be capable for, from a reflexive and creative position, to assume the challenges that it implies an efficient and effective administration in function of the cooperative company. It is the educational dimension in cooperative values the key for the future, conceived in a systematic way and assuming an appropriate methodological conception. In this perspective, leaving of the theoretical foundation of the administration of the human resources in general, he intends to be carried out an integral analysis of the formation processes and education for the cooperative with the purpose of valuing the central aspects of this thematic one, leaving of the fact that the education constitutes the medullary element that leads to a true cooperative formation.

  11. O-Fucose Monosaccharide of Drosophila Notch Has a Temperature-sensitive Function and Cooperates with O-Glucose Glycan in Notch Transport and Notch Signaling Activation*

    Science.gov (United States)

    Ishio, Akira; Sasamura, Takeshi; Ayukawa, Tomonori; Kuroda, Junpei; Ishikawa, Hiroyuki O.; Aoyama, Naoki; Matsumoto, Kenjiroo; Gushiken, Takuma; Okajima, Tetsuya; Yamakawa, Tomoko; Matsuno, Kenji

    2015-01-01

    Notch (N) is a transmembrane receptor that mediates the cell-cell interactions necessary for many cell fate decisions. N has many epidermal growth factor-like repeats that are O-fucosylated by the protein O-fucosyltransferase 1 (O-Fut1), and the O-fut1 gene is essential for N signaling. However, the role of the monosaccharide O-fucose on N is unclear, because O-Fut1 also appears to have O-fucosyltransferase activity-independent functions, including as an N-specific chaperon. Such an enzymatic activity-independent function could account for the essential role of O-fut1 in N signaling. To evaluate the role of the monosaccharide O-fucose modification in N signaling, here we generated a knock-in mutant of O-fut1 (O-fut1R245A knock-in), which expresses a mutant protein that lacks O-fucosyltransferase activity but maintains the N-specific chaperon activity. Using O-fut1R245A knock-in and other gene mutations that abolish the O-fucosylation of N, we found that the monosaccharide O-fucose modification of N has a temperature-sensitive function that is essential for N signaling. The O-fucose monosaccharide and O-glucose glycan modification, catalyzed by Rumi, function redundantly in the activation of N signaling. We also showed that the redundant function of these two modifications is responsible for the presence of N at the cell surface. Our findings elucidate how different forms of glycosylation on a protein can influence the protein's functions. PMID:25378397

  12. Mutual cooperation with Brazil

    International Nuclear Information System (INIS)

    Orstein, Roberto M.

    1998-01-01

    The history of the nuclear cooperation between Brazil and Argentina is outlined in the framework of the changing political circumstances. Reference is made to the agreements between both countries and to its implementation

  13. Cooperative Hurricane Network Obs

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Observations from the Cooperative Hurricane Reporting Network (CHURN), a special network of stations that provided observations when tropical cyclones approached the...

  14. From cooperation to globalization

    Directory of Open Access Journals (Sweden)

    Gabriela UNGUREANU

    2010-09-01

    Full Text Available Globalization is seen as a consequence of cross-border business. This complex and irreversible process can be seen as an extension of capitalist relations of production or increased interdependence in the economic system. Globalization has given rise to more and more fields of activity worldwide. To meet the challenges of business globalization, many companies form strategic alliances, cooperate or merge with other companies. Cooperation is seen by many companies as an alternative path to success. In recent years joint international associations, licensing, co-production agreements, joint research programs, exploration of consortia and other cooperative relationships between two or more corporations with potential have increased. We notice a cooperation tendency among small-sized companies, especially among those from the developing countries.

  15. Globalization and economic cooperation

    Directory of Open Access Journals (Sweden)

    Javier Divar

    2006-12-01

    Full Text Available Economic globalization is nothing, really, that the universality of capitalism. Not globalized culture, and economic participation, and human rights, ... has only globalized market. We must react by substituting those materialistic values with cooperative economy.

  16. Cooperative processing data bases

    Science.gov (United States)

    Hasta, Juzar

    1991-01-01

    Cooperative processing for the 1990's using client-server technology is addressed. The main theme is concepts of downsizing from mainframes and minicomputers to workstations on a local area network (LAN). This document is presented in view graph form.

  17. 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.

  18. On Cooper's Nonparametric Test.

    Science.gov (United States)

    Schmeidler, James

    1978-01-01

    The basic assumption of Cooper's nonparametric test for trend (EJ 125 069) is questioned. It is contended that the proper assumption alters the distribution of the statistic and reduces its usefulness. (JKS)

  19. Regional National Cooperative Observer

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA publication dedicated to issues, news and recognition of observers in the National Weather Service Cooperative Observer program. Issues published regionally...

  20. Cooperative Weather Observations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Monthly logs include a daily account of temperature extremes and precipitation, along with snow data at some locations. U.S. Cooperative Observer Program (COOP)...

  1. Nuclear cooperation agreements

    International Nuclear Information System (INIS)

    Nuclear cooperation agreements are reviewed in tabular form, especially agreements with developing countries. The reporting countries are the USA, the Federal Republic of Germany, Canada, Australia, Japan, and France. A separate EURATOM list is annexed

  2. Attraction and cooperative behavior

    OpenAIRE

    Donja Darai; Silvia Grätz

    2012-01-01

    Being good-looking seems to generate substantial benefits in many social interactions, making the "beauty premium" a not to be underrated economic factor. This paper investigates how physical attractiveness enables people to generate these benefits in the case of cooperation, using field data from a modified one-shot prisoner's dilemma played in a high-stakes television game show. While attractive contestants are not more or less cooperative than less attractive ones, facial attractiveness pr...

  3. Fluorescent Probes for Analysis and Imaging of Monoamine Oxidase Activity

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dokyoung; Jun, Yong Woong; Ahn, Kyo Han [POSTECH, Pohang (Korea, Republic of)

    2014-05-15

    Monoamine oxidases catalyze the oxidative deamination of dietary amines and amine neurotransmitters, and assist in maintaining the homeostasis of the amine neurotransmitters in the brain. Dysfunctions of these enzymes can cause neurological and behavioral disorders including Parkinson's and Alzheimer's diseases. To understand their physiological roles, efficient assay methods for monoamine oxidases are essential. Reviewed in this Perspective are the recent progress in the development of fluorescent probes for monoamine oxidases and their applications to enzyme assays in cells and tissues. It is evident that still there is strong need for a fluorescent probe with desirable substrate selectivity and photophysical properties to challenge the much unsolved issues associated with the enzymes and the diseases.

  4. Characterization of wheat germin (oxalate oxidase) expressed by Pichia pastoris

    International Nuclear Information System (INIS)

    Pan, Heng-Yen; Whittaker, Mei M.; Bouveret, Romaric; Berna, Anne; Bernier, Francois; Whittaker, James W.

    2007-01-01

    High-level secretory expression of wheat (Triticum aestivum) germin/oxalate oxidase was achieved in Pichia pastoris fermentation cultures as an α-mating factor signal peptide fusion, based on the native wheat cDNA coding sequence. The oxalate oxidase activity of the recombinant enzyme is substantially increased (7-fold) by treatment with sodium periodate, followed by ascorbate reduction. Using these methods, approximately 1 g (4 x 10 4 U) of purified, activated enzyme was obtained following eight days of induction of a high density Pichia fermentation culture, demonstrating suitability for large-scale production of oxalate oxidase for biotechnological applications. Characterization of the recombinant protein shows that it is glycosylated, with N-linked glycan attached at Asn47. For potential biomedical applications, a nonglycosylated (S49A) variant was also prepared which retains essentially full enzyme activity, but exhibits altered protein-protein interactions

  5. The use of galactose oxidase in lipid labeling

    International Nuclear Information System (INIS)

    Radin, N.S.; Evangelatos, G.P.

    1981-01-01

    Galactose oxidase can be used to oxidize the terminal carbon atom of lipids containing galactose or N-acetylgalactosamine, and the resultant aldehyde group can be reduced back to the original carbinol with radioactive borohydride. The efficiency of the first reaction has been investigated systematically by using [6- 3 H]galactosyl ceramide as substrate and measuring the amount of radioactive water formed. This enabled us to establish that the addition of catalase and peroxidase greatly speeded the oxidation, that phosphate and PIPES buffers were the best among those tested, that the reaction continued for 24 hr without a second addition of galactose oxidase, and that the optimum concentration of organic solvent (tetrahydrofuran) was 50%. The suggestion if made that a similar set of variables be studied for each lipid or nonlipid by the same basic technique: labeling by the oxidase/borohydride method and use of the resultant compound as substrate

  6. Increased xanthine oxidase during labour--implications for oxidative stress.

    Science.gov (United States)

    Many, A; Roberts, J M

    1997-11-01

    Xanthine dehydrogenase/oxidase (XDH/XO) produces uric acid. When in the oxidase form, this production is coupled with the generation of free radicals. Hypoxia-reperfusion enhances conversion of XDH to XO. Since the placenta is exposed to short periods of hypoxia reperfusion during labour, 17 placentae of pregnancy terminated by elective caesarean section and five placentae of pregnancies terminated by caesarean section during labour were examined for XDH/XO activity. It was found that XO activity was higher in the placentae of labouring women (P = 0.003), which suggests that labour enhances conversion of XDH to XO, facilitating free radical production.

  7. Two X-linked chronic granulomatous disease patients with unusual NADPH oxidase properties

    NARCIS (Netherlands)

    Wolach, Baruch; Broides, Arnon; Zeeli, Tal; Gavrieli, Ronit; de Boer, Martin; van Leeuwen, Karin; Levy, Jacov; Roos, Dirk

    2011-01-01

    Chronic granulomatous disease (CGD) is an immune deficiency syndrome caused by defects in the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, the enzyme that generates reactive oxygen species (ROS) in phagocytizing leukocytes. This study evaluates the NADPH oxidase capacity in two

  8. Catalytic aspects of a copper(II) complex: biological oxidase to ...

    Indian Academy of Sciences (India)

    BISWAJIT CHOWDHURY

    2017-10-03

    Oct 3, 2017 ... made with a Jasco model V-730 UV-Vis spectrophotometer. ..... Ligand-induced coordination changes ... Fet3 protein from yeast, a multinuclear copper oxidase ... of mutants of the multicopper oxidase Fet3p Biochem-.

  9. Heterologous expression of the Crassostrea gigas (Pacific oyster) alternative oxidase in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Robertson, Aaron; Schaltz, Kyle; Neimanis, Karina; Staples, James F; McDonald, Allison E

    2016-10-01

    Alternative oxidase (AOX) is a terminal oxidase within the inner mitochondrial membrane (IMM) present in many organisms where it functions in the electron transport system (ETS). AOX directly accepts electrons from ubiquinol and is therefore capable of bypassing ETS Complexes III and IV. The human genome does not contain a gene coding for AOX, so AOX expression has been suggested as a gene therapy for a range of human mitochondrial diseases caused by genetic mutations that render Complex III and/or IV dysfunctional. An effective means of screening mutations amenable to AOX treatment remains to be devised. We have generated such a tool by heterologously expressing AOX from the Pacific oyster (Crassostrea gigas) in the yeast Saccharomyces cerevisiae under the control of a galactose promoter. Our results show that this animal AOX is monomeric and is correctly targeted to yeast mitochondria. Moreover, when expressed in yeast, Pacific oyster AOX is a functional quinol oxidase, conferring cyanide-resistant growth and myxothiazol-resistant oxygen consumption to yeast cells and isolated mitochondria. This system represents a high-throughput screening tool for determining which Complex III and IV genetic mutations in yeast will be amenable to AOX gene therapy. As many human genes are orthologous to those found in yeast, our invention represents an efficient and cost-effective way to evaluate viable research avenues. In addition, this system provides the opportunity to learn more about the localization, structure, and regulation of AOXs from animals that are not easily reared or manipulated in the lab.

  10. Divergence and adaptive evolution of the gibberellin oxidase genes in plants.

    Science.gov (United States)

    Huang, Yuan; Wang, Xi; Ge, Song; Rao, Guang-Yuan

    2015-09-29

    The important phytohormone gibberellins (GAs) play key roles in various developmental processes. GA oxidases (GAoxs) are critical enzymes in GA synthesis pathway, but their classification, evolutionary history and the forces driving the evolution of plant GAox genes remain poorly understood. This study provides the first large-scale evolutionary analysis of GAox genes in plants by using an extensive whole-genome dataset of 41 species, representing green algae, bryophytes, pteridophyte, and seed plants. We defined eight subfamilies under the GAox family, namely C19-GA2ox, C20-GA2ox, GA20ox,GA3ox, GAox-A, GAox-B, GAox-C and GAox-D. Of these, subfamilies GAox-A, GAox-B, GAox-C and GAox-D are described for the first time. On the basis of phylogenetic analyses and characteristic motifs of GAox genes, we demonstrated a rapid expansion and functional divergence of the GAox genes during the diversification of land plants. We also detected the subfamily-specific motifs and potential sites of some GAox genes, which might have evolved under positive selection. GAox genes originated very early-before the divergence of bryophytes and the vascular plants and the diversification of GAox genes is associated with the functional divergence and could be driven by positive selection. Our study not only provides information on the classification of GAox genes, but also facilitates the further functional characterization and analysis of GA oxidases.

  11. Insomnia, platelet serotonin and platelet monoamine oxidase in chronic alcoholism.

    Science.gov (United States)

    Nenadic Sviglin, Korona; Nedic, Gordana; Nikolac, Matea; Mustapic, Maja; Muck-Seler, Dorotea; Borovecki, Fran; Pivac, Nela

    2011-08-18

    Insomnia is a common sleep disorder frequently occurring in chronic alcoholic patients. Neurobiological basis of insomnia, as well as of alcoholism, is associated with disrupted functions of the main neurotransmitter systems, including the serotonin (5-hydroxytryptamine, 5-HT) system. Blood platelets are considered a limited peripheral model for the central 5-HT neurons, since both platelets and central 5-HT synaptosomes have similar dynamics of 5-HT. Platelet 5-HT concentration and platelet monoamine oxidase type B (MAO-B) are assumed to represent biomarkers for particular symptoms and behaviors in psychiatric disorders. The hypothesis of this study was that platelet 5-HT concentration and platelet MAO-B activity will be altered in chronic alcoholic patients with insomnia compared to comparable values in patients without insomnia. The study included 498 subjects: 395 male and 103 female medication-free patients with alcohol dependence and 502 healthy control subjects: 325 men and 177 women. The effects of early, middle and late insomnia (evaluated using the Hamilton Depression Rating Scale), as well as sex, age and smoking on platelet 5-HT concentration and platelet MAO-B activity were evaluated using one-way ANOVA and multiple regression analysis by the stepwise method. Platelet 5-HT concentration, but not platelet MAO-B activity, was significantly reduced in alcoholic patients with insomnia compared to patients without insomnia. Multiple regression analysis revealed that platelet 5-HT concentration was affected by middle insomnia, smoking and sex, while platelet MAO activity was affected only by sex and age. The present and previous data suggest that platelet 5-HT concentration might be used, after controlling for sex and smoking, as a biomarker for insomnia in alcoholism, PTSD and in rotating shift workers. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  12. Cooperative games and network structures

    NARCIS (Netherlands)

    Musegaas, Marieke

    2017-01-01

    This thesis covers various research topics involving cooperative game theory, a mathematical tool to analyze the cooperative behavior within a group of players. The focus is mainly on interrelations between operations research and cooperative game theory by analyzing specific types of cooperative

  13. Does intuition cause cooperation?

    Science.gov (United States)

    Verkoeijen, Peter P J L; Bouwmeester, Samantha

    2014-01-01

    Recently, researchers claimed that people are intuitively inclined to cooperate with reflection causing them to behave selfishly. Empirical support for this claim came from experiments using a 4-player public goods game with a marginal return of 0.5 showing that people contributed more money to a common project when they had to decide quickly (i.e., a decision based on intuition) than when they were instructed to reflect and decide slowly. This intuitive-cooperation effect is of high scientific and practical importance because it argues against a central assumption of traditional economic and evolutionary models. The first experiment of present study was set up to examine the generality of the intuitive-cooperation effect and to further validate the experimental task producing the effect. In Experiment 1, we investigated Amazon Mechanical Turk (AMT) workers' contributions to a 4-player public goods game with a marginal return of 0.5 while we manipulated the knowledge about the other players' contribution to the public goods game (contribution known vs. contribution unknown), the identity of the other players (humans vs. computers randomly generating contributions) and the time constraint (time pressure/intuition vs. forced delay/reflection). However, the results of Experiment 1 failed to reveal an intuitive-cooperation effect. Furthermore, four subsequent direct replications attempts with AMT workers (Experiments 2a, 2b, 2c and Experiment 3, which was conducted with naïve/inexperienced participants) also failed to demonstrate intuitive-cooperation effects. Taken together, the results of the present study could not corroborate the idea that people are intuitively cooperative, hence suggesting that the theoretical relationship between intuition and cooperation should be further scrutinized.

  14. Does intuition cause cooperation?

    Directory of Open Access Journals (Sweden)

    Peter P J L Verkoeijen

    Full Text Available Recently, researchers claimed that people are intuitively inclined to cooperate with reflection causing them to behave selfishly. Empirical support for this claim came from experiments using a 4-player public goods game with a marginal return of 0.5 showing that people contributed more money to a common project when they had to decide quickly (i.e., a decision based on intuition than when they were instructed to reflect and decide slowly. This intuitive-cooperation effect is of high scientific and practical importance because it argues against a central assumption of traditional economic and evolutionary models. The first experiment of present study was set up to examine the generality of the intuitive-cooperation effect and to further validate the experimental task producing the effect. In Experiment 1, we investigated Amazon Mechanical Turk (AMT workers' contributions to a 4-player public goods game with a marginal return of 0.5 while we manipulated the knowledge about the other players' contribution to the public goods game (contribution known vs. contribution unknown, the identity of the other players (humans vs. computers randomly generating contributions and the time constraint (time pressure/intuition vs. forced delay/reflection. However, the results of Experiment 1 failed to reveal an intuitive-cooperation effect. Furthermore, four subsequent direct replications attempts with AMT workers (Experiments 2a, 2b, 2c and Experiment 3, which was conducted with naïve/inexperienced participants also failed to demonstrate intuitive-cooperation effects. Taken together, the results of the present study could not corroborate the idea that people are intuitively cooperative, hence suggesting that the theoretical relationship between intuition and cooperation should be further scrutinized.

  15. Cytochrome cbb3 of Thioalkalivibrio is a Na+-pumping cytochrome oxidase

    NARCIS (Netherlands)

    Muntyan, M.S.; Cherepanov, D.A.; Malinen, A.M.; Bloch, D.A.; Sorokin, D.Y.; Severina, I.I.; Ivashina, T.V.; Lahti, R.; Muyzer, G.; Skulachev, V.P.

    2015-01-01

    Cytochrome c oxidases (Coxs) are the basic energy transducers in the respiratory chain of the majority of aerobic organisms. Coxs studied to date are redox-driven proton-pumping enzymes belonging to one of three subfamilies: A-, B-, and C-type oxidases. The C-type oxidases (cbb3 cytochromes), which

  16. Functionally deregulated AML1/RUNX1 cooperates with BCR-ABL to induce a blastic phase-like phenotype of chronic myelogenous leukemia in mice.

    Directory of Open Access Journals (Sweden)

    Kiyoko Yamamoto

    Full Text Available Patients in the chronic phase (CP of chronic myelogenous leukemia (CML have been treated successfully following the advent of ABL kinase inhibitors, but once they progress to the blast crisis (BC phase the prognosis becomes dismal. Although mechanisms underlying the progression are largely unknown, recent studies revealed the presence of alterations of key molecules for hematopoiesis, such as AML1/RUNX1. Our analysis of 13 BC cases revealed that three cases had AML1 mutations and the transcript levels of wild-type (wt. AML1 were elevated in BC compared with CP. Functional analysis of representative AML1 mutants using mouse hematopoietic cells revealed the possible contribution of some, but not all, mutants for the BC-phenotype. Specifically, K83Q and R139G, but neither R80C nor D171N mutants, conferred upon BCR-ABL-expressing cells a growth advantage over BCR-ABL-alone control cells in cytokine-free culture, and the cells thus grown killed mice upon intravenous transfer. Unexpectedly, wt.AML1 behaved similarly to K83Q and R139G mutants. In a bone marrow transplantation assay, K83Q and wt.AML1s induced the emergence of blast-like cells. The overall findings suggest the roles of altered functions of AML1 imposed by some, but not all, mutants, and the elevated expression of wt.AML1 for the disease progression of CML.

  17. Study on dioxygen reduction by mutational modifications of the hydrogen bond network leading from bulk water to the trinuclear copper center in bilirubin oxidase

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, Hirotoshi; Kurita, Daisuke; Kataoka, Kunishige; Sakurai, Takeshi, E-mail: tsakurai@se.kanazawa-u.ac.jp

    2014-07-18

    Highlights: • Proton transport pathway in bilirubin oxidase was mutated. • Two intermediates in the dioxygen reduction steps were trapped and characterized. • A specific glutamate for dioxygen reduction by multicopper oxidases was identified. - Abstract: The hydrogen bond network leading from bulk water to the trinuclear copper center in bilirubin oxidase is constructed with Glu463 and water molecules to transport protons for the four-electron reduction of dioxygen. Substitutions of Glu463 with Gln or Ala were attributed to virtually complete loss or significant reduction in enzymatic activities due to an inhibition of the proton transfer steps to dioxygen. The single turnover reaction of the Glu463Gln mutant afforded the highly magnetically interacted intermediate II (native intermediate) with a broad g = 1.96 electron paramagnetic resonance signal detectable at cryogenic temperatures. Reactions of the double mutants, Cys457Ser/Glu463Gln and Cys457Ser/Glu463Ala afforded the intermediate I (peroxide intermediate) because the type I copper center to donate the fourth electron to dioxygen was vacant in addition to the interference of proton transport due to the mutation at Glu463. The intermediate I gave no electron paramagnetic resonance signal, but the type II copper signal became detectable with the decay of the intermediate I. Structural and functional similarities between multicopper oxidases are discussed based on the present mutation at Glu463 in bilirubin oxidase.

  18. Study on dioxygen reduction by mutational modifications of the hydrogen bond network leading from bulk water to the trinuclear copper center in bilirubin oxidase

    International Nuclear Information System (INIS)

    Morishita, Hirotoshi; Kurita, Daisuke; Kataoka, Kunishige; Sakurai, Takeshi

    2014-01-01

    Highlights: • Proton transport pathway in bilirubin oxidase was mutated. • Two intermediates in the dioxygen reduction steps were trapped and characterized. • A specific glutamate for dioxygen reduction by multicopper oxidases was identified. - Abstract: The hydrogen bond network leading from bulk water to the trinuclear copper center in bilirubin oxidase is constructed with Glu463 and water molecules to transport protons for the four-electron reduction of dioxygen. Substitutions of Glu463 with Gln or Ala were attributed to virtually complete loss or significant reduction in enzymatic activities due to an inhibition of the proton transfer steps to dioxygen. The single turnover reaction of the Glu463Gln mutant afforded the highly magnetically interacted intermediate II (native intermediate) with a broad g = 1.96 electron paramagnetic resonance signal detectable at cryogenic temperatures. Reactions of the double mutants, Cys457Ser/Glu463Gln and Cys457Ser/Glu463Ala afforded the intermediate I (peroxide intermediate) because the type I copper center to donate the fourth electron to dioxygen was vacant in addition to the interference of proton transport due to the mutation at Glu463. The intermediate I gave no electron paramagnetic resonance signal, but the type II copper signal became detectable with the decay of the intermediate I. Structural and functional similarities between multicopper oxidases are discussed based on the present mutation at Glu463 in bilirubin oxidase

  19. Depletion of rat cortical norepinephrine and the inhibition of [3H]norepinephrine uptake by xylamine does not require monoamine oxidase activity

    International Nuclear Information System (INIS)

    Dudley, M.W.

    1988-01-01

    Inhibition of monoamine oxidase A through pretreatment of rats with clorgyline or the pro-drug MDL 72,394 did not block the amine-depleting action of xylamine. Xylamine treatment resulted in a loss of approximately 60% of the control level of norepinephrine in the cerebral cortex. A 1-hr pretreatment, but not a 24-hr pretreatment, with the monoamine oxidase B inhibitor, L-deprenyl, prevented the depletion of norepinephrine by xylamine. In addition, pretreatment with MDL 72,974, a monoamine oxidase B inhibitor without amine-releasing or uptake - inhibiting effects, did not prevent cortical norepinephrine levels. Inhibition of monoamine oxidase by either MDL 72,974 or MDL 72,394 did not prevent the inhibition of [ 3 H]norepinephrine uptake into rat cortical synaptosomes by xylamine. These data indicate that monoamine oxidase does not mediate the amine-releasing or uptake inhibiting properties of xylamine. The protection afforded by L-deprenyl following a 1-hr pretreatment most probably was due to accumulation of its metabolite, L-amphetamine, which would inhibit the uptake carrier. A functional carrier is required for depletion since desipramine administered 1 hr prior to xylamine, was also able to prevent depletion of norepinephrine

  20. The story of technical cooperation

    International Nuclear Information System (INIS)

    Park, Yang Taek

    1989-09-01

    This book gives descriptions of technical cooperation, which is about why does technology transfer?, process of technology transfer with model, decisive cause and cooperation of technology transfer, cost and effect of technology transfer, historical experience of technology transfer, cases of technology transfer by field such as rubber tire, medicine and computer industry and automobile industry, technology transfer process and present condition of technical cooperation, and strategy for rising of technical cooperation : selection of technology for object of cooperation and development of human resources.

  1. Enhanced production of glucose oxidase from UVmutant of ...

    African Journals Online (AJOL)

    UV rays were used as mutagen in wild type strain of Aspergillus niger for enhanced production of glucose oxidase. After mutangenization and selection, mutant A. niger strains, resistant to 2-deoxy-Dglucose were obtained. The mutants showed 1.57 and 1.98 fold increase in activities of extra and intra cellular glucose ...

  2. Localization of Glucose Oxidase and Catalase Activities in Aspergillus niger

    NARCIS (Netherlands)

    Witteveen, Cor F.B.; Veenhuis, Marten; Visser, Jaap

    The subcellular localization of glucose oxidase (EC 1.1.3.4) in Aspergillus niger N400 (CBS 120.49) was investigated by (immuno)cytochemical methods. By these methods, the bulk of the enzyme was found to be localized in the cell wall. In addition, four different catalases (EC 1.11.1.6) were

  3. The glucose oxidase-peroxidase assay for glucose

    Science.gov (United States)

    The glucose oxidase-peroxidase assay for glucose has served as a very specific, sensitive, and repeatable assay for detection of glucose in biological samples. It has been used successfully for analysis of glucose in samples from blood and urine, to analysis of glucose released from starch or glycog...

  4. Nanoporous gold assembly of glucose oxidase for electrochemical biosensing

    DEFF Research Database (Denmark)

    Xiao, Xinxin; Ulstrup, Jens; Li, Hui

    2014-01-01

    Nanoporous gold (NPG) is composed of three-dimensional (3D) bicontinuous nanostructures with large surface area. Nano-channels inside NPG provide an ideal local environment for immobilization of enzyme molecules with expected stabilization of the protein molecules. In this work, glucose oxidase (...

  5. Gene cloning and characterization of NADH oxidase from ...

    African Journals Online (AJOL)

    The genome search of Thermococcus kodakarensis revealed three open reading frames, Tk0304, Tk1299 and Tk1392 annotated as nicotinamide adenine dinucleotide (NADH) oxidases. This study deals with cloning, and characterization of Tk0304. The gene, composed of 1320 nucleotides, encodes a protein of 439 ...

  6. Optimization of cholesterol oxidase production by Brevibacterium sp ...

    African Journals Online (AJOL)

    An ultrasound-assisted emulsification as a pretreatment for cholesterol oxidase production by submerge fermentation using Brevibacterium sp. in a batch system was studied. Medium improvement for the production employing response surface methodology (RSM) was optimized in this paper. The concentration of ...

  7. in Escherichia coli with native cholesterol oxidase expressed

    African Journals Online (AJOL)

    The structure and bio-activity of an endogenous cholesterol oxidase from Brevibacterium sp. was compared to the same enzyme exogenously expressed in Escherichia coli BL21 (DE3) with and without N- or C-terminal his-tags. The different proteins were purified with affinity and subtractive protocols. The specific activity of ...

  8. Cytokinin oxidase or dehydrogenase? Mechanism of cytokinin degradation in cereals

    DEFF Research Database (Denmark)

    Galuszka, P.; Frebort, I.; Sebela, M.

    2001-01-01

    An enzyme degrading cytokinins with isoprenoid side chain, previously named cytokinin oxidase, was purified to near homogeneity from wheat and barley grains. New techniques were developed for the enzyme activity assay and staining on native electrophoretic gels to identify the protein. The purifi...

  9. Effect of heat treatment on polyphenol oxidase and peroxidase ...

    African Journals Online (AJOL)

    Effect of heat treatment (55°C/20 min) on polyphenol oxidase (PPO) and peroxidase (POD) activities and total phenolic compounds was investigated in Algerian dates (Deglet Nour variety) at Tamar (fully ripe) stage and in dates stored for 5 months at ambient temperature and in cold storage (10°C). Results obtained ...

  10. Lysyl oxidases regulate fibrillar collagen remodelling in idiopathic pulmonary fibrosis

    NARCIS (Netherlands)

    Tjin, Gavin; White, Eric S; Faiz, Alen; Sicard, Delphine; Tschumperlin, Daniel J; Mahar, Annabelle; Kable, Eleanor P W; Burgess, Janette K

    2017-01-01

    Idiopathic pulmonary fibrosis (IPF) is a progressive scarring disease of the lung with feweffective therapeutic options. Structural remodelling of the extracellular matrix [i.e. collagen cross-linkingmediated by the lysyl oxidase (LO) family of enzymes (LOX, LOXL1-4)] might contribute to disease

  11. Novel thidiazuron-derived inhibitors of cytokinin oxidase/dehydrogenase

    Czech Academy of Sciences Publication Activity Database

    Nisler, Jaroslav; Kopečný, D.; Končitíková, R.; Zatloukal, Marek; Bazgier, Václav; Berka, K.; Zalabák, D.; Briozzo, P.; Strnad, Miroslav; Spíchal, Lukáš

    2016-01-01

    Roč. 92, 1-2 (2016), s. 235-248 ISSN 0167-4412 R&D Projects: GA MŠk(CZ) LO1204; GA ČR GA15-22322S Institutional support: RVO:61389030 Keywords : Cytokinin oxidase/dehydrogenase * Crystal structure * Molecular docking Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.356, year: 2016

  12. DNA damage and decrease of cellular oxidase activity in piglet ...

    African Journals Online (AJOL)

    DNA damage and decrease of cellular oxidase activity in piglet sertoli cells exposed to gossypol. Ming Zhang, Hui Yuan, Zuping He, Liyun Yuan, Jine Yi, Sijun Deng, Li Zhu, Chengzhi Guo, Yin Lu, Jing Wu, Lixin Wen, Qiang Wei, Liqun Xue ...

  13. Cooper Pairs in Insulators?

    International Nuclear Information System (INIS)

    Valles, James

    2008-01-01

    Nearly 50 years elapsed between the discovery of superconductivity and the emergence of the microscopic theory describing this zero resistance state. The explanation required a novel phase of matter in which conduction electrons joined in weakly bound pairs and condensed with other pairs into a single quantum state. Surprisingly, this Cooper pair formation has also been invoked to account for recently uncovered high-resistance or insulating phases of matter. To address this possibility, we have used nanotechnology to create an insulating system that we can probe directly for Cooper pairs. I will present the evidence that Cooper pairs exist and dominate the electrical transport in these insulators and I will discuss how these findings provide new insight into superconductor to insulator quantum phase transitions.

  14. Evolution, epigenetics and cooperation.

    Science.gov (United States)

    Bateson, Patrick

    2014-04-01

    Explanations for biological evolution in terms of changes in gene frequencies refer to outcomes rather than process. Integrating epigenetic studies with older evolutionary theories has drawn attention to the ways in which evolution occurs. Adaptation at the level of the gene is givingway to adaptation at the level of the organism and higher-order assemblages of organisms. These ideas impact on the theories of how cooperation might have evolved. Two of the theories, i.e. that cooperating individuals are genetically related or that they cooperate for self-interested reasons, have been accepted for a long time. The idea that adaptation takes place at the level of groups is much more controversial. However, bringing together studies of development with those of evolution is taking away much of the heat in the debate about the evolution of group behaviour.

  15. Cooperative Prototyping Experiments

    DEFF Research Database (Denmark)

    Bødker, Susanne; Grønbæk, Kaj

    1989-01-01

    This paper describes experiments with a design technique that we denote cooperative prototyping. The experiments consider design of a patient case record system for municipal dental clinics in which we used HyperCard, an off the shelf programming environment for the Macintosh. In the ecperiments we...... tried to achieve a fluent work-like evaluation of prototypes where users envisioned future work with a computer tool, at the same time as we made on-line modifications of prototypes in cooperation with the users when breakdown occur in their work-like evaluation. The experiments showed...... that it was possible to make a number of direct manipulation changes of prototypes in cooperation with the users, in interplay with their fluent work-like evaluation of these. However, breakdown occurred in the prototyping process when we reached the limits of the direct manipulation support for modification. From...

  16. International co-operation

    International Nuclear Information System (INIS)

    1997-01-01

    In 1996, Nuclear Regulatory Authority of the Slovak Republic (NRA SR) ensured the Slovak Republic (SR) obligations with relation to the international agreements and with the SR membership in the IAEA.International co-operation has been ensured on the basis of the bilateral international agreements. With the Ministry of Foreign Affairs co-operation, the SR fulfilled its financial obligations to this organization in due time and in the full scope. Representing Central and Eastern Europe interest in the Board of Governors, the SR participation in the highest executive in the highest executive authority was finished in 1996.The Board of Governors Vice-chairman position was executed by NRA SR Chairman. 5 national and 6 regional technical co-operation and assistance projects were realized in 1996. 12 organizations participated in these projects and accordingly 104 experts took part in training programmes, scientific visits or as the mission members abroad. Besides, Slovak experts participated at work of technical advisory and consultation groups with the significant assistance. In the framework of IAEA co-operation, the SR was visited by 11 expert missions formed by 28 experts from 19 countries including IAEA. Slovak organizations, namely institutes of the Academy of Sciences, Slovak research centres and universities participated in IAEA scientific and research activities through NRA SR. 15 scientific contracts in total were approved and realized and these contracts are utilized as supplementary financing of the own scientific and research projects. Other international co-operation and regional co-operation activities of the NRA SR in 1996 are reviewed

  17. Identification, expression, and taxonomic distribution of alternative oxidases in non-angiosperm plants.

    Science.gov (United States)

    Neimanis, Karina; Staples, James F; Hüner, Norman P A; McDonald, Allison E

    2013-09-10

    Alternative oxidase (AOX) is a terminal ubiquinol oxidase present in the respiratory chain of all angiosperms investigated to date, but AOX distribution in other members of the Viridiplantae is less clear. We assessed the taxonomic distribution of AOX using bioinformatics. Multiple sequence alignments compared AOX proteins and examined amino acid residues involved in AOX catalytic function and post-translational regulation. Novel AOX sequences were found in both Chlorophytes and Streptophytes and we conclude that AOX is widespread in the Viridiplantae. AOX multigene families are common in non-angiosperm plants and the appearance of AOX1 and AOX2 subtypes pre-dates the divergence of the Coniferophyta and Magnoliophyta. Residues involved in AOX catalytic function are highly conserved between Chlorophytes and Streptophytes, while AOX post-translational regulation likely differs in these two lineages. We demonstrate experimentally that an AOX gene is present in the moss Physcomitrella patens and that the gene is transcribed. Our findings suggest that AOX will likely exert an influence on plant respiration and carbon metabolism in non-angiosperms such as green algae, bryophytes, liverworts, lycopods, ferns, gnetophytes, and gymnosperms and that further research in these systems is required. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Nuclear expression of lysyl oxidase enzyme is an independent prognostic factor in rectal cancer patients

    DEFF Research Database (Denmark)

    Liu, Na; Cox, Thomas R; Cui, Weiyingqi

    2017-01-01

    Emerging evidence has implicated a pivotal role for lysyl oxidase (LOX) in cancer progression and metastasis. Whilst the majority of work has focused on the extracellular matrix cross-linking role of LOX, the exact function of intracellular LOX localisation remains unclear. In this study, we anal...... the nucleus of colon cancer cell lines by confocal microscopy and Western blot. Our results show a powerful link between nuclear LOX expression in tumours and patient survival, and offer a promising prognostic biomarker for rectal cancer patients....... analysed the LOX expression patterns in the nuclei of rectal cancer patient samples and determined the clinical significance of this expression. Nuclear LOX expression was significantly increased in patient lymph node metastases compared to their primary tumours. High nuclear LOX expression in tumours......Emerging evidence has implicated a pivotal role for lysyl oxidase (LOX) in cancer progression and metastasis. Whilst the majority of work has focused on the extracellular matrix cross-linking role of LOX, the exact function of intracellular LOX localisation remains unclear. In this study, we...

  19. Membership in cooperative societies

    Directory of Open Access Journals (Sweden)

    Eba Gaminde Egia

    2017-12-01

    Full Text Available In this work we will analyze the practical application of one of the cooperative principles, «voluntary and free membership», referring to the entering of members in cooperative societies. We will first explain the meaning of this principle, and then bring up its normative regulation, with special emphasis on those aspects in which our autonomic laws differ, and ending with a brief reference to the economic aspect and the different ways to make contributions and their consequences.Received: 31 May 2017Accepted: 14 October 2017Published online: 22 December 2017

  20. Introduction: cooperative learning

    Directory of Open Access Journals (Sweden)

    José-Manuel Serrano

    2014-10-01

    Full Text Available The principal objective of this revision is the recognition of cooperative learning as a highly effective strategy for the accomplishment of the general goals in learning. The different investigations assessed validate the potential that a cooperative organization of the classroom could entail for academic achievement, self-esteem, interpersonal attraction or social support. The solidity of the existing research contributes to its external and internal validity and, thus, to conclude that the results are consistent and can be extrapolated to different cultures, ethnic groups or countries.

  1. Excited cooper pairs

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Arrietea, M. G.; Solis, M. A.; De Llano, M. [Universidad Nacional Autonoma de Mexico, Mexico, D.F (Mexico)

    2001-02-01

    Excited cooper pairs formed in a many-fermion system are those with nonzero total center-of mass momentum (CMM). They are normally neglected in the standard Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity for being too few compared with zero CMM pairs. However, a Bose-Einstein condensation picture requires both zero and nonzero CMM pairs. Assuming a BCS model interaction between fermions we determine the populations for all CMM values of Cooper pairs by actually calculating the number of nonzero-CMM pairs relative to that of zero-CMM ones in both 2D and 3D. Although this ratio decreases rapidly with CMM, the number of Cooper pairs for any specific CMM less than the maximum (or breakup of the pair) momentum turns out to be typically larger than about 95% of those with zero-CMM at zero temperature T. Even at T {approx}100 K this fraction en 2D is still as large as about 70% for typical quasi-2D cuprate superconductor parameters. [Spanish] Los pares de cooper excitados formados en un sistema de muchos electrones, son aquellos con momentos de centro de masa (CMM) diferente de cero. Normalmente estos no son tomados en cuenta en la teoria estandar de la superconductividad de Bardeen-Cooper-Schrieffer (BCS) al suponer que su numero es muy pequeno comparados con los pares de centro de masa igual a cero. Sin embargo, un esquema de condensacion Bose-Einstein requiere de ambos pares, con CMM cero y diferente de cero. Asumiendo una interaccion modelo BCS entre los fermiones, determinamos la poblacion de pares cooper con cada uno de todos los posibles valores del CMM calculando el numero de pares con momentos de centro de masa diferente de cero relativo a los pares de CMM igual a cero, en 2D y 3D. Aunque esta razon decrece rapidamente con el CMM, el numero de pares de cooper para cualquier CMM especifico menor que el momento maximo (o rompimiento de par) es tipicamente mas grande que el 95% de aquellos con CMM cero. Aun a T {approx}100 K esta fraccion en 2D es

  2. Distinguishing the Roles of Thylakoid Respiratory Terminal Oxidases in the Cyanobacterium Synechocystis sp. PCC 6803.

    Science.gov (United States)

    Ermakova, Maria; Huokko, Tuomas; Richaud, Pierre; Bersanini, Luca; Howe, Christopher J; Lea-Smith, David J; Peltier, Gilles; Allahverdiyeva, Yagut

    2016-06-01

    Various oxygen-utilizing electron sinks, including the soluble flavodiiron proteins (Flv1/3), and the membrane-localized respiratory terminal oxidases (RTOs), cytochrome c oxidase (Cox) and cytochrome bd quinol oxidase (Cyd), are present in the photosynthetic electron transfer chain of Synechocystis sp. PCC 6803. However, the role of individual RTOs and their relative importance compared with other electron sinks are poorly understood, particularly under light. Via membrane inlet mass spectrometry gas exchange, chlorophyll a fluorescence, P700 analysis, and inhibitor treatment of the wild type and various mutants deficient in RTOs, Flv1/3, and photosystem I, we investigated the contribution of these complexes to the alleviation of excess electrons in the photosynthetic chain. To our knowledge, for the first time, we demonstrated the activity of Cyd in oxygen uptake under light, although it was detected only upon inhibition of electron transfer at the cytochrome b6f site and in ∆flv1/3 under fluctuating light conditions, where linear electron transfer was drastically inhibited due to impaired photosystem I activity. Cox is mostly responsible for dark respiration and competes with P700 for electrons under high light. Only the ∆cox/cyd double mutant, but not single mutants, demonstrated a highly reduced plastoquinone pool in darkness and impaired gross oxygen evolution under light, indicating that thylakoid-based RTOs are able to compensate partially for each other. Thus, both electron sinks contribute to the alleviation of excess electrons under illumination: RTOs continue to function under light, operating on slower time ranges and on a limited scale, whereas Flv1/3 responds rapidly as a light-induced component and has greater capacity. © 2016 American Society of Plant Biologists. All Rights Reserved.

  3. Mitochondrial terminal alternative oxidase and its enhancement by thermal stress in the coral symbiont Symbiodinium

    Science.gov (United States)

    Oakley, Clinton A.; Hopkinson, Brian M.; Schmidt, Gregory W.

    2014-06-01

    A terminal electron acceptor alternative to mitochondrial cytochrome c oxidase (COX), mitochondrial alternative oxidase (AOX), is ubiquitous in higher plants and represented in nearly every algal taxon but is poorly documented in dinoflagellates. AOX competes for electrons with the conventional COX and has been hypothesized to function as a means of reducing oxidative stress in mitochondria, as well as a potential mechanism for ameliorating thermal and other physiological stressors. Here, the presence of an active AOX in cultured Symbiodinium was assayed by the response of oxygen consumption to the AOX inhibitor salicylhydroxamic acid (SHAM) and the COX inhibitor cyanide (CN). CN-insensitive, SHAM-sensitive oxygen consumption was found to account for a large portion (26 %) of Symbiodinium dark respiration and is consistent with high levels of AOX activity. This experimental evidence of the existence of a previously unreported terminal oxidase was further corroborated by analysis of publicly available Symbiodinium transcriptome data. The potential for enhanced AOX expression to play a compensatory role in mediating thermal stress was supported by inhibitor assays of cultured Symbiodinium at low (18 °C), moderate (26 °C), and high (32 °C) temperature conditions. Maximum capacity of the putative AOX pathway as a proportion of total dark oxygen consumption was found to increase from 26 % at 26 °C to 45 % and 53 % at 18 °C and 32 °C, respectively, when cells were acclimated to the treatment temperatures. Cells assayed at 18 and 32 °C without acclimation exhibited either the same or lower AOX capacity as controls, suggesting that the AOX protein is upregulated under temperature stress. The physiological implications for the presence of AOX in the coral/algal symbiosis and its potential role in response to many forms of biotic and abiotic stress, particularly oxidative stress, are discussed.

  4. Isolated cytochrome c oxidase deficiency in G93A SOD1 mice overexpressing CCS protein.

    Science.gov (United States)

    Son, Marjatta; Leary, Scot C; Romain, Nadine; Pierrel, Fabien; Winge, Dennis R; Haller, Ronald G; Elliott, Jeffrey L

    2008-05-02

    G93A SOD1 transgenic mice overexpressing CCS protein develop an accelerated disease course that is associated with enhanced mitochondrial pathology and increased mitochondrial localization of mutant SOD1. Because these results suggest an effect of mutant SOD1 on mitochondrial function, we assessed the enzymatic activities of mitochondrial respiratory chain complexes in the spinal cords of CCS/G93A SOD1 and control mice. CCS/G93A SOD1 mouse spinal cord demonstrates a 55% loss of complex IV (cytochrome c oxidase) activity compared with spinal cord from age-matched non-transgenic or G93A SOD1 mice. In contrast, CCS/G93A SOD1 spinal cord shows no reduction in the activities of complex I, II, or III. Blue native gel analysis further demonstrates a marked reduction in the levels of complex IV but not of complex I, II, III, or V in spinal cords of CCS/G93A SOD1 mice compared with non-transgenic, G93A SOD1, or CCS/WT SOD1 controls. With SDS-PAGE analysis, spinal cords from CCS/G93A SOD1 mice showed significant decreases in the levels of two structural subunits of cytochrome c oxidase, COX1 and COX5b, relative to controls. In contrast, CCS/G93A SOD1 mouse spinal cord showed no reduction in levels of selected subunits from complexes I, II, III, or V. Heme A analyses of spinal cord further support the existence of cytochrome c oxidase deficiency in CCS/G93A SOD1 mice. Collectively, these results establish that CCS/G93A SOD1 mice manifest an isolated complex IV deficiency which may underlie a substantial part of mutant SOD1-induced mitochondrial cytopathy.

  5. Genomic sequencing of uric acid metabolizing and clearing genes in relationship to xanthine oxidase inhibitor dose.

    Science.gov (United States)

    Carroll, Matthew B; Smith, Derek M; Shaak, Thomas L

    2017-03-01

    It remains unclear why the dose of xanthine oxidase inhibitors (XOI) allopurinol or febuxostat varies among patients though they reach similar serum uric acid (SUA) goal. We pursued genomic sequencing of XOI metabolism and clearance genes to identify single-nucleotide polymorphisms (SNPs) relate to differences in XOI dose. Subjects with a diagnosis of Gout based on the 1977 American College of Rheumatology Classification Criteria for the disorder, who were on stable doses of a XOI, and who were at their goal SUA level, were enrolled. The primary outcome was relationship between SNPs in any of these genes to XOI dose. The secondary outcome was relationship between SNPs and change in pre- and post-treatment SUA. We enrolled 100 subjects. The average patient age was 68.6 ± 10.6 years old. Over 80% were men and 77% were Caucasian. One SNP was associated with a higher XOI dose: rs75995567 (p = 0.031). Two SNPs were associated with 300 mg daily of allopurinol: rs11678615 (p = 0.022) and rs3731722 on Aldehyde Oxidase (AO) (His1297Arg) (p = 0.001). Two SNPs were associated with a lower dose of allopurinol: rs1884725 (p = 0.033) and rs34650714 (p = 0.006). For the secondary outcome, rs13415401 was the only SNP related to a smaller mean SUA change. Ten SNPs were identified with a larger change in SUA. Though multiple SNPs were identified in the primary and secondary outcomes of this study, rs3731722 is known to alter catalytic function for some aldehyde oxidase substrates.

  6. Identification and characterization of an antennae-specific aldehyde oxidase from the navel orangeworm.

    Directory of Open Access Journals (Sweden)

    Young-Moo Choo

    Full Text Available Antennae-specific odorant-degrading enzymes (ODEs are postulated to inactivate odorant molecules after they convey their signal. Different classes of insect ODEs are specific to esters, alcohols, and aldehydes--the major functional groups of female-produced, hydrophobic sex pheromones from moth species. Esterases that rapidly inactive acetate and other esters have been well-studied, but less is known about aldehyde oxidases (AOXs. Here we report cloning of an aldehyde oxidase, AtraAOX2, from the antennae of the navel orangeworm (NOW, Amyelois transitella, and the first activity characterization of a recombinant insect AOX. AtraAOX2 gene spans 3,813 bp and encodes a protein with 1,270 amino acid residues. AtraAOX2 cDNA was expressed in baculovirus-infected insect Sf21 cells as a ≈280 kDa homodimer with 140 kDa subunits. Recombinant AtraAOX2 degraded Z11Z13-16Ald and plant volatile aldehydes as substrates. However, as expected for aldehyde oxidases, recombinant AtraAOX2 did not show specificity for Z11Z13-16Ald, the main constituent of the sex pheromone, but showed high activity for plant volatile aldehydes. Our data suggest AtraAOX2 might be involved in degradation of a diversity of aldehydes including sex pheromones, plant-derived semiochemicals, and chemical cues for oviposition sites. Additionally, AtraAOX2 could protect the insect's olfactory system from xenobiotics, including pesticides that might reach the sensillar lymph surrounding the olfactory receptor neurons.

  7. Inactivation of 1-aminocyclopropane-1-carboxylate oxidase involves oxidative modifications.

    Science.gov (United States)

    Barlow, J N; Zhang, Z; John, P; Baldwin, J E; Schofield, C J

    1997-03-25

    1-Aminocyclopropane-1-carboxylate (ACC) oxidase catalyzes the final step in the biosynthesis of the plant signaling molecule ethylene. It is a member of the ferrous iron dependent family of oxidases and dioxygenases and is unusual in that it displays a very short half-life under catalytic conditions, typically less than 20 min, and a requirement for CO2 as an activator. The rates of inactivation of purified, recombinant ACC oxidase from tomato under various combinations of substrates and cofactors were measured. Inactivation was relatively slow in the presence of buffer alone (t1/2 > 1 h), but fast in the presence of ferrous iron and ascorbate (t1/2 approximately 10 min). The rate of iron/ascorbate-mediated inactivation was increased by the addition of ACC, unaffected by the addition of CO2 at saturation (supplied as bicarbonate) but decreased by the addition of catalase or ACC + CO2 at saturation (supplied as bicarbonate). Iron/ascorbate-mediated inactivation was accompanied by partial proteolysis as observed by SDS-PAGE analysis. The fragmentation pattern was altered when ACC was also included, suggesting that ACC can bind to ACC oxidase in the absence of bicarbonate. N-terminal sequencing of fragments resulted in identification of an internal cleavage site which we propose is proximate to active-site bound iron. Thus, ACC oxidase inactivates via relatively slow partial unfolding of the catalytically active conformation, oxidative damage mediated via hydrogen peroxide which is catalase protectable and oxidative damage to the active site which results in partial proteolysis and is not catalase protectable.

  8. Expression Studies of Gibberellin Oxidases in Developing Pumpkin Seeds1

    Science.gov (United States)

    Frisse, Andrea; Pimenta, Maria João; Lange, Theo

    2003-01-01

    Two cDNA clones, 3-ox and 2-ox, have been isolated from developing pumpkin (Cucurbita maxima) embryos that show significant amino acid homology to gibberellin (GA) 3-oxidases and 2-oxidases, respectively. Recombinant fusion protein of clone 3-ox converted GA12-aldehyde, GA12, GA15, GA24, GA25, and GA9 to GA14-aldehyde, GA14, GA37, GA36, GA13, and GA4, respectively. Recombinant 2-ox protein oxidized GA9, GA4, and GA1 to GA51, GA34, and GA8, respectively. Previously cloned GA 7-oxidase revealed additional 3β-hydroxylation activity of GA12. Transcripts of this gene were identified in endosperm and embryo of the developing seed by quantitative reverse transcriptase-polymerase chain reaction and localized in protoderm, root apical meristem, and quiescent center by in situ hybridization. mRNA of the previously cloned GA 20-oxidase from pumpkin seeds was localized in endosperm and in tissues of protoderm, ground meristem, and cotyledons of the embryo. However, transcripts of the recently cloned GA 20-oxidase from pumpkin seedlings were found all over the embryo, and in tissues of the inner seed coat at the micropylar end. Previously cloned GA 2β,3β-hydroxylase mRNA molecules were specifically identified in endosperm tissue. Finally, mRNA molecules of the 3-ox and 2-ox genes were found in the embryo only. 3-ox transcripts were localized in tissues of cotyledons, protoderm, and inner cell layers of the root apical meristem, and 2-ox transcripts were found in all tissues of the embryo except the root tips. These results indicate tissue-specific GA-biosynthetic pathways operating within the developing seed. PMID:12644672

  9. Cooperatives between truth and validity

    Directory of Open Access Journals (Sweden)

    Guilherme Krueger

    2014-12-01

    Full Text Available The current declaration of the International Cooperative Alliance on cooperative identity since its 1995 Centennial Conference (which was held in Manchester makes no distinction between cooperation and cooperative. The lack of distinction between cooperation and cooperative has caused the Decennial Cooperative Action Plan to define cooperatives as a form, while their materiality is regarded as managerial: a business (activity under a cooperative form. An identity that is close to us cannot be reduced to form, without this being a problem. Therefore, the value underlying this identity —cooperation— must have a substantial basis, even if it is idealised, if it is to affect us.Received: 27.03.2014Accepted: 12.05.2014

  10. Cyanobacterial lactate oxidases serve as essential partners in N2-fixation and evolved into photorespiratory glycolate oxidases in plants.

    NARCIS (Netherlands)

    Hackenberg, C.; Kern, R.; Hüge, J; Stal, L.J.; Tsuji, Y.; Kopka, J.; Shiraiwa, Y.; Bauwe, H.; Hagemann, M.

    2011-01-01

    Glycolate oxidase (GOX) is an essential enzyme involved in photorespiratory metabolism in plants. In cyanobacteria and green algae, the corresponding reaction is catalyzed by glycolate dehydrogenases (GlcD). The genomes of N2-fixing cyanobacteria, such as Nostoc PCC 7120 and green algae, appear to

  11. Cyanobacterial lactate oxidases serve as essential partners of N2-fixation and evolved to photorespiratory glycolate oxidases in plants

    NARCIS (Netherlands)

    Hackenberg, C.; Kern, R.; Hüge, J.; Stal, L.J.; Tsuji, Y.; Kopka, J.; Shiraiwa, Y.; Bauwe, H.; Hagemann, M.

    2011-01-01

    Glycolate oxidase (GOX) is an essential enzyme involved in photorespiratory metabolism in plants. In cyanobacteria and green algae, the corresponding reaction is catalyzed by glycolate dehydrogenases (GlcD). The genomes of N2-fixing cyanobacteria, such as Nostoc PCC 7120 and green algae, appear to

  12. Social penalty promotes cooperation in a cooperative society.

    Science.gov (United States)

    Ito, Hiromu; Yoshimura, Jin

    2015-08-04

    Why cooperation is well developed in human society is an unsolved question in biological and human sciences. Vast studies in game theory have revealed that in non-cooperative games selfish behavior generally dominates over cooperation and cooperation can be evolved only under very limited conditions. These studies ask the origin of cooperation; whether cooperation can evolve in a group of selfish individuals. In this paper, instead of asking the origin of cooperation, we consider the enhancement of cooperation in a small already cooperative society. We ask whether cooperative behavior is further promoted in a small cooperative society in which social penalty is devised. We analyze hawk-dove game and prisoner's dilemma introducing social penalty. We then expand it for non-cooperative games in general. The results indicate that cooperation is universally favored if penalty is further imposed. We discuss the current result in terms of the moral, laws, rules and regulations in a society, e.g., criminology and traffic violation.

  13. D-amino acid oxidase activator gene (DAOA) variation affects cerebrospinal fluid homovanillic acid concentrations in healthy Caucasians

    DEFF Research Database (Denmark)

    Andreou, Dimitrios; Saetre, Peter; Werge, Thomas

    2012-01-01

    The D-amino acid oxidase activator (DAOA) protein regulates the function of D-amino oxidase (DAO), an enzyme that catalyzes the oxidative deamination of D-3,4-dihydroxyphenylalanine (D-DOPA) and D-serine. D-DOPA is converted to L-3,4-DOPA, a precursor of dopamine, whereas D-serine participates...... in glutamatergic transmission. We hypothesized that DAOA polymorphisms are associated with dopamine, serotonin and noradrenaline turnover in the human brain. Four single-nucleotide polymorphisms, previously reported to be associated with schizophrenia, were genotyped. Cerebrospinal fluid (CSF) samples were drawn...... by lumbar puncture, and the concentrations of the major dopamine metabolite homovanillic acid (HVA), the major serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) and the major noradrenaline metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) were measured. Two of the investigated polymorphisms, rs...

  14. Crystallization and preliminary X-ray analysis of a bifunctional catalase-phenol oxidase from Scytalidium thermophilum

    International Nuclear Information System (INIS)

    Sutay Kocabas, Didem; Pearson, Arwen R.; Phillips, Simon E. V.; Bakir, Ufuk; Ogel, Zumrut B.; McPherson, Michael J.; Trinh, Chi H.

    2009-01-01

    The bifunctional enzyme catalase-phenol oxidase from S. thermophilum was crystallized by the hanging-drop vapour-diffusion method in space group P2 1 and diffraction data were collected to 2.8 Å resolution. Catalase-phenol oxidase from Scytalidium thermophilum is a bifunctional enzyme: its major activity is the catalase-mediated decomposition of hydrogen peroxide, but it also catalyzes phenol oxidation. To understand the structural basis of this dual functionality, the enzyme, which has been shown to be a tetramer in solution, has been purified by anion-exchange and gel-filtration chromatography and has been crystallized using the hanging-drop vapour-diffusion technique. Streak-seeding was used to obtain larger crystals suitable for X-ray analysis. Diffraction data were collected to 2.8 Å resolution at the Daresbury Synchrotron Radiation Source. The crystals belonged to space group P2 1 and contained one tetramer per asymmetric unit

  15. Cooperative heuristic multi-agent planning

    NARCIS (Netherlands)

    De Weerdt, M.M.; Tonino, J.F.M.; Witteveen, C.

    2001-01-01

    In this paper we will use the framework to study cooperative heuristic multi-agent planning. During the construction of their plans, the agents use a heuristic function inspired by the FF planner (l3l). At any time in the process of planning the agents may exchange available resources, or they may

  16. Cooperative social capital

    Directory of Open Access Journals (Sweden)

    Oscar Acera Manero

    2005-12-01

    Full Text Available Social capital consists of the contributions of members and associates, both mandatory and voluntary. From an accounting point of view, it is a liability figure that expresses the value of a portion of the equity of the cooperative. Its inclusion in the liability is not the fact that it is a debt but by its nature unenforceable.

  17. Supranational Cooperation in Europe

    NARCIS (Netherlands)

    de Deugd, Nienke; Stamm, Katharina; Westerman, Wim

    The sovereign debt crisis and the euro crisis have prompted heads of state and government in Europe to intensify supranational cooperation. However, some political leaders and policy makers aim for more. They propose the introduction of a common European economic government that would prevent Europe

  18. Systematic, Cooperative Evaluation.

    Science.gov (United States)

    Nassif, Paula M.

    Evaluation procedures based on a systematic evaluation methodology, decision-maker validity, new measurement and design techniques, low cost, and a high level of cooperation on the part of the school staff were used in the assessment of a public school mathematics program for grades 3-8. The mathematics curriculum was organized into Spirals which…

  19. Non-Cooperative Games

    NARCIS (Netherlands)

    van Damme, E.E.C.

    2014-01-01

    We describe non-cooperative game models and discuss game theoretic solution concepts. Some applications are also noted. Conventional theory focuses on the question ‘how will rational players play?’, and has the Nash equilibrium at its core. We discuss this concept and its interpretations, as well as

  20. Cooperative Technolgy Deployed

    NARCIS (Netherlands)

    Koenders, E.; Velt, R. in 't

    2011-01-01

    After the successful demonstrations of cooperative technology by the CVIS and Safespot projects the question remains how this technology can be successfully deployed. This question is explored by the Field Operational Test project FREILOT, which aims to provide fuel economy applications that must be

  1. Cooper's Hawk (Accipiter cooperii)

    Science.gov (United States)

    Jean-Luc E. Cartron; Patricia L. Kennedy; Rob Yaksich; Scott H. Stoleson

    2010-01-01

    The Cooper's Hawk (Accipiter cooperii) is intermediate in size between the Northern Goshawk (Accipiter gentilis) and the Sharp-shinned Hawk (A. striatus), northern North America's other two accipiters. The two sexes are almost alike in plumage, but as in both of the other species, the female is noticeably larger. According to Wheeler and Clark (1995), a...

  2. Cooperative courseware authoring support

    NARCIS (Netherlands)

    Dicheva, D.; Aroyo, L.M.; Cristea, A.I.

    2003-01-01

    We refined our knowledge classification and indexing approach applied in our previously developed system AIMS (Agentbased Information Management System) by introducing ontology-oriented support for cooperative courseware authoring. In order to provide a basis for formal semantics and reasoning in

  3. Can war foster cooperation?

    Czech Academy of Sciences Publication Activity Database

    Bauer, Michal; Blattman, C.; Chytilová, Julie; Henrich, J.; Miguel, E.; Mitts, T.

    2016-01-01

    Roč. 30, č. 3 (2016), s. 249-274 ISSN 0895-3309 R&D Projects: GA ČR(CZ) GBP402/12/G130 Institutional support: RVO:67985998 Keywords : war * conflict * cooperation Subject RIV: AH - Economics Impact factor: 5.727, year: 2016

  4. Robust Dynamic Cooperative Games

    NARCIS (Netherlands)

    Bauso, D.; Timmer, Judith B.

    2006-01-01

    Classical cooperative game theory is no longer a suitable tool for those situations where the values of coalitions are not known with certainty. Recent works address situations where the values of coalitions are modelled by random variables. In this work we still consider the values of coalitions as

  5. Does intuition cause cooperation?

    NARCIS (Netherlands)

    P.P.J.L. Verkoeijen (Peter); S. Bouwmeester (Samantha)

    2014-01-01

    textabstractRecently, researchers claimed that people are intuitively inclined to cooperate with reflection causing them to behave selfishly. Empirical support for this claim came from experiments using a 4-player public goods game with a marginal return of 0.5 showing that people contributed more

  6. Indian Ocean Rim Cooperation

    DEFF Research Database (Denmark)

    Wippel, Steffen

    Since the mid-1990s, the Indian Ocean has been experiencing increasing economic cooperation among its rim states. Middle Eastern countries, too, participate in the work of the Indian Ocean Rim Association, which received new impetus in the course of the current decade. Notably Oman is a very active...

  7. Predicting Human Cooperation.

    Directory of Open Access Journals (Sweden)

    John J Nay

    Full Text Available The Prisoner's Dilemma has been a subject of extensive research due to its importance in understanding the ever-present tension between individual self-interest and social benefit. A strictly dominant strategy in a Prisoner's Dilemma (defection, when played by both players, is mutually harmful. Repetition of the Prisoner's Dilemma can give rise to cooperation as an equilibrium, but defection is as well, and this ambiguity is difficult to resolve. The numerous behavioral experiments investigating the Prisoner's Dilemma highlight that players often cooperate, but the level of cooperation varies significantly with the specifics of the experimental predicament. We present the first computational model of human behavior in repeated Prisoner's Dilemma games that unifies the diversity of experimental observations in a systematic and quantitatively reliable manner. Our model relies on data we integrated from many experiments, comprising 168,386 individual decisions. The model is composed of two pieces: the first predicts the first-period action using solely the structural game parameters, while the second predicts dynamic actions using both game parameters and history of play. Our model is successful not merely at fitting the data, but in predicting behavior at multiple scales in experimental designs not used for calibration, using only information about the game structure. We demonstrate the power of our approach through a simulation analysis revealing how to best promote human cooperation.

  8. Discover new cooperation forms

    International Nuclear Information System (INIS)

    Anon.

    2000-01-01

    In spite of the good forecasts concerning the supply and demand, the gas market is full of uncertainties because of the competition and the industrial reorganizing. Producers and operators try to define new forms of cooperation allowing the attainments protection and at the same time allowing to take advantage of the market opportunities with a shared risk. (A.L.B.)

  9. International co-operation

    International Nuclear Information System (INIS)

    1998-01-01

    A brief account of activities in international co-operation carried out by the Nuclear power plants Jaslovske Bohunice in 1997 is presented. Professionality of the Bohunice NPPs staff was highly appreciated by inviting them to be the OSART team members

  10. Marketing co-operatives

    NARCIS (Netherlands)

    G.W.J. Hendrikse (George); C.P. Veerman (Cees)

    2000-01-01

    textabstractMarketing co-operatives (MCs) are analysed from an incomplete contracting perspective. The requirement of the domination of control by the members of a MC is a threat to the survival of a MC in markets where the level of asset specificity at the processing stage of production is

  11. Safe Cooperating Cyber-Physical Systems using Wireless Communication

    DEFF Research Database (Denmark)

    Pop, Paul; Scholle, Detlef; Sljivo, Irfan

    2017-01-01

    This paper presents an overview of the ECSEL project entitled ―Safe Cooperating Cyber-Physical Systems using Wireless Communication‖ (SafeCOP), which runs during the period 2016–2019. SafeCOP targets safety-related Cooperating Cyber-Physical Systems (CO-CPS) characterised by use of wireless...... detection of abnormal behaviour, triggering if needed a safe degraded mode. SafeCOP will also develop methods and tools, which will be used to produce safety assurance evidence needed to certify cooperative functions. SafeCOP will extend current wireless technologies to ensure safe and secure cooperation...

  12. Practicing What We Preach: Teacher Reflection Groups on Cooperative Learning

    Science.gov (United States)

    Farrell, Thomas S. C.; Jacobs, George M.

    2016-01-01

    This article discusses the use of teacher reflection groups to aid teachers in their efforts to facilitate cooperative learning among their students. It is argued that these teacher reflection groups function best when they are organized with reference to eight cooperative learning principles. Furthermore, it is suggested that these reflective…

  13. [Social cooperatives in Italy].

    Science.gov (United States)

    Villotti, P; Zaniboni, S; Fraccaroli, F

    2014-06-01

    This paper describes the role of social cooperatives in Italy as a type of economic, non-profit organization and their role in contributing to the economic and social growth of the country. The purpose of this paper is to learn more about the experience of the Italian social cooperatives in promoting the work integration process of disadvantaged workers, especially those suffering from mental disorders, from a theoretical and an empirical point of view. Social enterprise is the most popular and consolidated legal and organizational model for social enterprises in Italy, introduced by Law 381/91. Developed during the early 1980s, and formally recognized by law in the early 1990s, social cooperatives aim at pursuing the general interest of the community to promote the human needs and social inclusion of citizens. They are orientated towards aims that go beyond the interest of the business owners, the primary beneficiary of their activities is the community, or groups of disadvantaged people. In Italy, Law 381/91 distinguishes between two categories of social cooperatives, those producing goods of social utility, such as culture, welfare and educational services (A-type), and those providing economic activities for the integration of disadvantaged people into employment (B-type). The main purpose of B-type social cooperatives is to integrate disadvantaged people into the open labour market. This goal is reached after a period of training and working experience inside the firm, during which the staff works to improve both the social and professional abilities of disadvantaged people. During the years, B-type social co-ops acquired a particular relevance in the care of people with mental disorders by offering them with job opportunities. Having a job is central in the recovery process of people suffering from mental diseases, meaning that B-type social co-ops in Italy play an important rehabilitative and integrative role for this vulnerable population of workers. The

  14. The increased risk of joint venture promotes social cooperation.

    Directory of Open Access Journals (Sweden)

    Te Wu

    Full Text Available The joint venture of many members is common both in animal world and human society. In these public enterprizes, highly cooperative groups are more likely to while low cooperative groups are still possible but not probable to succeed. Existent literature mostly focuses on the traditional public goods game, in which cooperators create public wealth unconditionally and benefit all group members unbiasedly. We here institute a model addressing this public goods dilemma with incorporating the public resource foraging failure risk. Risk-averse individuals tend to lead a autarkic life, while risk-preferential ones tend to participate in the risky public goods game. For participants, group's success relies on its cooperativeness, with increasing contribution leading to increasing success likelihood. We introduce a function with one tunable parameter to describe the risk removal pattern and study in detail three representative classes. Analytical results show that the widely replicated population dynamics of cyclical dominance of loner, cooperator and defector disappear, while most of the time loners act as savors while eventually they also disappear. Depending on the way that group's success relies on its cooperativeness, either cooperators pervade the entire population or they coexist with defectors. Even in the later case, cooperators still hold salient superiority in number as some defectors also survive by parasitizing. The harder the joint venture succeeds, the higher level of cooperation once cooperators can win the evolutionary race. Our work may enrich the literature concerning the risky public goods games.

  15. The increased risk of joint venture promotes social cooperation.

    Science.gov (United States)

    Wu, Te; Fu, Feng; Zhang, Yanling; Wang, Long

    2013-01-01

    The joint venture of many members is common both in animal world and human society. In these public enterprizes, highly cooperative groups are more likely to while low cooperative groups are still possible but not probable to succeed. Existent literature mostly focuses on the traditional public goods game, in which cooperators create public wealth unconditionally and benefit all group members unbiasedly. We here institute a model addressing this public goods dilemma with incorporating the public resource foraging failure risk. Risk-averse individuals tend to lead a autarkic life, while risk-preferential ones tend to participate in the risky public goods game. For participants, group's success relies on its cooperativeness, with increasing contribution leading to increasing success likelihood. We introduce a function with one tunable parameter to describe the risk removal pattern and study in detail three representative classes. Analytical results show that the widely replicated population dynamics of cyclical dominance of loner, cooperator and defector disappear, while most of the time loners act as savors while eventually they also disappear. Depending on the way that group's success relies on its cooperativeness, either cooperators pervade the entire population or they coexist with defectors. Even in the later case, cooperators still hold salient superiority in number as some defectors also survive by parasitizing. The harder the joint venture succeeds, the higher level of cooperation once cooperators can win the evolutionary race. Our work may enrich the literature concerning the risky public goods games.

  16. A User Cooperation Stimulating Strategy Based on Cooperative Game Theory in Cooperative Relay Networks

    Directory of Open Access Journals (Sweden)

    Ping Zhang

    2009-01-01

    Full Text Available This paper proposes a user cooperation stimulating strategy among rational users. The strategy is based on cooperative game theory and enacted in the context of cooperative relay networks. Using the pricing-based mechanism, the system is modeled initially with two nodes and a Base Station (BS. Within this framework, each node is treated as a rational decision maker. To this end, each node can decide whether to cooperate and how to cooperate. Cooperative game theory assists in providing an optimal system utility and provides fairness among users. Under different cooperative forwarding modes, certain questions are carefully investigated, including “what is each node's best reaction to maximize its utility?” and “what is the optimal reimbursement to encourage cooperation?” Simulation results show that the nodes benefit from the proposed cooperation stimulating strategy in terms of utility and thus justify the fairness between each user.

  17. A User Cooperation Stimulating Strategy Based on Cooperative Game Theory in Cooperative Relay Networks

    Directory of Open Access Journals (Sweden)

    Jiang Fan

    2009-01-01

    Full Text Available This paper proposes a user cooperation stimulating strategy among rational users. The strategy is based on cooperative game theory and enacted in the context of cooperative relay networks. Using the pricing-based mechanism, the system is modeled initially with two nodes and a Base Station (BS. Within this framework, each node is treated as a rational decision maker. To this end, each node can decide whether to cooperate and how to cooperate. Cooperative game theory assists in providing an optimal system utility and provides fairness among users. Under different cooperative forwarding modes, certain questions are carefully investigated, including "what is each node's best reaction to maximize its utility?" and "what is the optimal reimbursement to encourage cooperation?" Simulation results show that the nodes benefit from the proposed cooperation stimulating strategy in terms of utility and thus justify the fairness between each user.

  18. Sildenafil promotes eNOS activation and inhibits NADPH oxidase in the transgenic sickle cell mouse penis.

    Science.gov (United States)

    Musicki, Biljana; Bivalacqua, Trinity J; Champion, Hunter C; Burnett, Arthur L

    2014-02-01

    Sickle cell disease (SCD)-associated vasculopathy in the penis is characterized by aberrant nitric oxide and phosphodiesterase (PDE) 5 signaling, and by increased oxidative stress. Preliminary clinical trials show that continuous treatment with PDE5 inhibitor sildenafil unassociated with sexual activity decreases priapic activity in patients with SCD. However, the mechanism of its vasculoprotective effect in the penis remains unclear. We evaluated whether continuous administration of PDE5 inhibitor sildenafil promotes eNOS function at posttranslational levels and decreases superoxide-producing enzyme NADPH oxidase activity in the sickle cell mouse penis. SCD transgenic mice were used as an animal model of SCD. WT mice served as controls. Mice received treatment with the PDE5 inhibitor sildenafil (100 mg/kg/day) or vehicle for 3 weeks. eNOS phosphorylation on Ser-1177 (positive regulatory site), eNOS interactions with heat-shock protein 90 (HSP90) (positive regulator), phosphorylated AKT (upstream mediator of eNOS phosphorylation on Ser-1177), an NADPH oxidase catalytic subunit gp91(phox), and a marker of oxidative stress (4-hydroxy-2-nonenal [HNE]) were measured by Western blot. Effect of continuous sildenafil treatment on eNOS posttranslational activation, NADPH oxidase catalytic subunit, and oxidative stress in the penis of the sickle cell mouse. Continuous treatment with sildenafil reversed (P penis. Sildenafil treatment of WT mice did not affect any of these parameters. Our findings that sildenafil enhances eNOS activation and inhibits NADPH oxidase function in the sickle cell mouse penis offers a vasculoprotective molecular basis for the therapeutic effect of sildenafil in the penis in association with SCD. © 2013 International Society for Sexual Medicine.

  19. Spatial modes of cooperation based on bounded rationality

    Science.gov (United States)

    Pan, Qiuhui; Wang, Lingxiao; Shi, Rongrong; Wang, Huan; He, Mingfeng

    2014-12-01

    Social factors, such as public opinion, values, ethics, moral standards, could guide people’s behavior to some degree. In this paper, we introduce social orientation as a motivator factor into the Nowak model, and discuss the variation of cooperation proportion under the function of motivator factor and betrayal temptation. Results show that motivator factors can promote cooperation proportion, and there is a motivator factor threshold. And a jump point is present in the value, on each side of which cooperation proportion has a small change. Reduction of betrayal temptation can also promote cooperation proportion, and there is a betrayal temptation threshold. And the value is corresponding with a jump point. And cooperation proportion changes very little on each side of the value. In addition, when betrayal temptation and motivator factor both play a role in a system, there are always cooperators and defectors in coexistence.

  20. Computational Aspects of Cooperative Game Theory

    CERN Document Server

    Chalkiadakis, Georgios; Wooldridge, Michael

    2011-01-01

    Cooperative game theory is a branch of (micro-)economics that studies the behavior of self-interested agents in strategic settings where binding agreements among agents are possible. Our aim in this book is to present a survey of work on the computational aspects of cooperative game theory. We begin by formally defining transferable utility games in characteristic function form, and introducing key solution concepts such as the core and the Shapley value. We then discuss two major issues that arise when considering such games from a computational perspective: identifying compact representation

  1. Energy and cooperation among the Scandinavian countries

    Energy Technology Data Exchange (ETDEWEB)

    Milas, R

    1984-11-01

    The Scandinavian countries have a long experience of functional cooperation in the field of energy. The oil crisis has been largely attenuated for Norway since the exploitation of the North Sea oil deposits. The future will be oil or nuclear, this is the characteristic of energy cooperation on the Scandinavian, European and international levels. In this connection, no level excludes another and the Scandinavian countries are going to patiently attempt to benefit from their Scandinavian dimension over the short range, their European vocation for research and development and their free trade ideology for the surveillance of markets on the level of international agencies.

  2. Calcineurin Aβ regulates NADPH oxidase (Nox) expression and activity via nuclear factor of activated T cells (NFAT) in response to high glucose.

    Science.gov (United States)

    Williams, Clintoria R; Gooch, Jennifer L

    2014-02-21

    Hypertrophy is an adaptive response that enables organs to appropriately meet increased functional demands. Previously, we reported that calcineurin (Cn) is required for glomerular and whole kidney hypertrophy in diabetic rodents (Gooch, J. L., Barnes, J. L., Garcia, S., and Abboud, H. E. (2003). Calcineurin is activated in diabetes and is required for glomerular hypertrophy and ECM accumulation. Am. J. Physiol. Renal Physiol. 284, F144-F154; Reddy, R. N., Knotts, T. L., Roberts, B. R., Molkentin, J. D., Price, S. R., and Gooch, J. L. (2011). Calcineurin Aβ is required for hypertrophy but not matrix expansion in the diabetic kidney. J. Cell Mol. Med. 15, 414-422). Because studies have also implicated the reactive oxygen species-generating enzymes NADPH oxidases (Nox) in diabetic kidney responses, we tested the hypothesis that Nox and Cn cooperate in a common signaling pathway. First, we examined the role of the two main isoforms of Cn in hypertrophic signaling. Using primary kidney cells lacking a catalytic subunit of Cn (CnAα(-/-) or CnAβ(-/-)), we found that high glucose selectively activates CnAβ, whereas CnAα is constitutively active. Furthermore, CnAβ but not CnAα mediates hypertrophy. Next, we found that chronic reactive oxygen species generation in response to high glucose is attenuated in CnAβ(-/-) cells, suggesting that Cn is upstream of Nox. Consistent with this, loss of CnAβ reduces basal expression and blocks high glucose induction of Nox2 and Nox4. Inhibition of nuclear factor of activated T cells (NFAT), a CnAβ-regulated transcription factor, decreases Nox2 and Nox4 expression, whereas NFAT overexpression increases Nox2 and Nox4, indicating that the CnAβ/NFAT pathway modulates Nox. These data reveal that the CnAβ/NFAT pathway regulates Nox and plays an important role in high glucose-mediated hypertrophic responses in the kidney.

  3. Cooperating for assisting intelligently operators

    International Nuclear Information System (INIS)

    Brezillon, P.; Cases, E.; CEA Centre d'Etudes de la Vallee du Rhone, 30 - Marcoule

    1995-01-01

    We are in the process of an intelligent cooperative system in a nuclear plant application. The system must cooperate with an operator who accomplishes a task of supervision of a real-world process. We point out in the paper that a cooperation between a cooperative system and an operator has two modes: a waking state and a participating state. During the waking state, the system observes the operator's behavior and the consequences on the process. During the participation state, the cooperative system builds jointly with the user a solution to the problem. In our approach, the cooperation depends on the system capabilities to explain, to incrementally acquire knowledge and to make explicit the context of the cooperation. We develop these ideas in the framework of the design of the cooperative system in the nuclear plant. (authors). 22 refs., 1 fig

  4. Cooperation and cheating in microbes

    Science.gov (United States)

    Gore, Jeff

    2011-03-01

    Understanding the cooperative and competitive dynamics within and between species is a central challenge in evolutionary biology. Microbial model systems represent a unique opportunity to experimentally test fundamental theories regarding the evolution of cooperative behaviors. In this talk I will describe our experiments probing cooperation in microbes. In particular, I will compare the cooperative growth of yeast in sucrose and the cooperative inactivation of antibiotics by bacteria. In both cases we find that cheater strains---which don't contribute to the public welfare---are able to take advantage of the cooperator strains. However, this ability of cheaters to out-compete cooperators occurs only when cheaters are present at low frequency, thus leading to steady-state coexistence. These microbial experiments provide fresh insight into the evolutionary origin of cooperation.

  5. Glucose oxidase probe as a surface-enhanced Raman scattering sensor for glucose.

    Science.gov (United States)

    Qi, Guohua; Wang, Yi; Zhang, Biying; Sun, Dan; Fu, Cuicui; Xu, Weiqing; Xu, Shuping

    2016-10-01

    Glucose oxidase (GOx) possessing a Raman-active chromophore (flavin adenine dinucleotide) is used as a signal reporter for constructing a highly specific "turn off" surface-enhanced Raman scattering (SERS) sensor for glucose. This sensing chip is made by the electrostatic assembly of GOx over silver nanoparticle (Ag NP)-functionalized SERS substrate through a positively charged polyelectrolyte linker under the pH of 6.86. To trace glucose in blood serum, owing to the reduced pH value caused by the production of gluconic acid in the GOx-catalyzed oxidation reaction, the bonding force between GOx and polyelectrolyte weakens, making GOx drop off from the sensing chip. As a result, the SERS intensity of GOx on the chip decreases along with the concentration of glucose. This glucose SERS sensor exhibits excellent selectivity based on the specific GOx/glucose catalysis reaction and high sensitivity to 1.0 μM. The linear sensing range is 2.0-14.0 mM, which also meets the requirement on the working range of the human blood glucose detection. Using GOx as a probe shows superiority over other organic probes because GOx almost has no toxicity to the biological system. This sensing mechanism can be applied for intracellular in vivo SERS monitoring of glucose in the future. Graphical abstract Glucose oxidase is used as a Raman signal reporter for constructing a highly specific glucose surface-enhanced Raman scattering (SERS) sensor.

  6. Pyruvate oxidase influences the sugar utilization pattern and capsule production in Streptococcus pneumoniae.

    Directory of Open Access Journals (Sweden)

    Sandra M Carvalho

    Full Text Available Pyruvate oxidase is a key function in the metabolism and lifestyle of many lactic acid bacteria and its activity depends on the presence of environmental oxygen. In Streptococcus pneumoniae the protein has been suggested to play a major role in metabolism and has been implicated in virulence, oxidative stress survival and death in stationary phase. Under semi-aerobic conditions, transcriptomic and metabolite profiling analysis of a spxB mutant grown on glucose showed minor changes compared to the wild type, apart from the significant induction of two operons involved in carbohydrate uptake and processing. This induction leads to a change in the sugar utilization capabilities of the bacterium, as indicated by the analysis of the growth profiles of the D39 parent and spxB mutant on alternative carbohydrates. Metabolic analysis and growth experiments showed that inactivation of SpxB has no effect on the glucose fermentation pattern, except under aerobic conditions. More importantly, we show that mutation of spxB results in the production of increased amounts of capsule, the major virulence factor of S. pneumoniae. Part of this increase can be attributed to induction of capsule operon (cps transcription. Therefore, we propose that S. pneumoniae utilizes pyruvate oxidase as an indirect sensor of the oxygenation of the environment, resulting in the adaption of its nutritional capability and the amount of capsule to survive in the host.

  7. Localization of ascorbic acid, ascorbic acid oxidase, and glutathione in roots of Cucurbita maxima L.

    Science.gov (United States)

    Liso, Rosalia; De Tullio, Mario C; Ciraci, Samantha; Balestrini, Raffaella; La Rocca, Nicoletta; Bruno, Leonardo; Chiappetta, Adriana; Bitonti, Maria Beatrice; Bonfante, Paola; Arrigoni, Oreste

    2004-12-01

    To understand the function of ascorbic acid (ASC) in root development, the distribution of ASC, ASC oxidase, and glutathione (GSH) were investigated in cells and tissues of the root apex of Cucubita maxima. ASC was regularly distributed in the cytosol of almost all root cells, with the exception of quiescent centre (QC) cells. ASC also occurred at the surface of the nuclear membrane and correspondingly in the nucleoli. No ASC could be observed in vacuoles. ASC oxidase was detected by immunolocalization mainly in cell walls and vacuoles. This enzyme was particularly abundant in the QC and in differentiating vascular tissues and was absent in lateral root primordia. Administration of the ASC precursor L-galactono-gamma-lactone markedly increased ASC content in all root cells, including the QC. Root treatment with the ASC oxidized product, dehydroascorbic acid (DHA), also increased ASC content, but caused ASC accumulation only in peripheral tissues, where DHA was apparently reduced at the expense of GSH. The different pattern of distribution of ASC in different tissues and cell compartments reflects its possible role in cell metabolism and root morphogenesis.

  8. Immobilization of Glucose Oxidase on Modified-Carbon-Paste-Electrodes for Microfuel Cell

    Directory of Open Access Journals (Sweden)

    Laksmi Ambarsari

    2016-03-01

    Full Text Available Glucose oxidase (GOx is being developed for many applications such as an implantable fuel cell, due to its attractive property of operating under physiological conditions. This study reports the functional immobilization of glucose oxidase onto polyaniline-nanofiber-modified-carbon-paste-electrodes (GOx/MCPE as bioanodes in fuel cell applications. In particular, GOx is immobilized onto the electrode surface via a linker molecule (glutaraldehyde. Polyaniline, synthesized by the interfacial polymerization method, produces a morphological form of nanofibers (100-120 nm which have good conductivity. The performance of the polyaniline-modified-carbon-paste-electrode (MCPE was better than the carbon- paste-electrode (CPE alone. The optimal pH and temperature of the GOx/MCPE were 4.5 (in 100 mM acetate buffer and 65 °C, respectively. The GOx/MCPE exhibit high catalytic performances (activation energy 16.4 kJ mol-1, have a high affinity for glucose (Km value 37.79 µM and can have a maximum current (Imax of 3.95 mA. The sensitivity of the bioelectrode also was high at 57.79 mA mM-1 cm-2.

  9. Structure-Activity Relationship Analysis of 3-phenylcoumarin-Based Monoamine Oxidase B Inhibitors

    Science.gov (United States)

    Rauhamäki, Sanna; Postila, Pekka A.; Niinivehmas, Sanna; Kortet, Sami; Schildt, Emmi; Pasanen, Mira; Manivannan, Elangovan; Ahinko, Mira; Koskimies, Pasi; Nyberg, Niina; Huuskonen, Pasi; Multamäki, Elina; Pasanen, Markku; Juvonen, Risto O.; Raunio, Hannu; Huuskonen, Juhani; Pentikäinen, Olli T.

    2018-03-01

    Monoamine oxidase B (MAO-B) catalyzes deamination of monoamines such as neurotransmitters dopamine and norepinephrine. Accordingly, small-molecule MAO-B inhibitors potentially alleviate the symptoms of dopamine-linked neuropathologies such as depression or Parkinson’s disease. Coumarin with a functionalized 3-phenyl ring system is a promising scaffold for building potent MAO-B inhibitors. Here, a vast set of 3-phenylcoumarin derivatives was designed using virtual combinatorial chemistry or rationally de novo and synthesized using microwave chemistry. The derivatives inhibited the MAO-B at 100 nM - 1 µM. The IC50 value of the most potent derivative 1 was 56 nM. A docking-based structure-activity relationship analysis summarizes the atom-level determinants of the MAO-B inhibition by the derivatives. Finally, the cross-reactivity of the derivatives was tested against monoamine oxidase A and a specific subset of enzymes linked to estradiol metabolism, known to have coumarin-based inhibitors. Overall, the results indicate that the 3-phenylcoumarins, especially derivative 1, present unique pharmacological features worth considering in future drug development.

  10. Cox1 mutation abrogates need for Cox23 in cytochrome c oxidase biogenesis

    Directory of Open Access Journals (Sweden)

    Richard Dela Cruz

    2016-06-01

    Full Text Available Cox23 is a known conserved assembly factor for cytochrome c oxidase, although its role in cytochrome c oxidase (CcO biogenesis remains unresolved. To gain additional insights into its role, we isolated spontaneous suppressors of the respiratory growth defect in cox23∆ yeast cells. We recovered independent colonies that propagated on glycerol/lactate medium for cox23∆ cells at 37°C. We mapped these mutations to the mitochondrial genome and specifically to COX1 yielding an I101F substitution. The I101F Cox1 allele is a gain-of-function mutation enabling yeast to respire in the absence of Cox23. CcO subunit steady-state levels were restored with the I101F Cox1 suppressor mutation and oxygen consumption and CcO activity were likewise restored. Cells harboring the mitochondrial genome encoding I101F Cox1 were used to delete genes for other CcO assembly factors to test the specificity of the Cox1 mutation as a suppressor of cox23∆ cells. The Cox1 mutant allele fails to support respiratory growth in yeast lacking Cox17, Cox19, Coa1, Coa2, Cox14 or Shy1, demonstrating its specific suppressor activity for cox23∆ cells.

  11. Pyruvate oxidase influences the sugar utilization pattern and capsule production in Streptococcus pneumoniae.

    Science.gov (United States)

    Carvalho, Sandra M; Farshchi Andisi, Vahid; Gradstedt, Henrik; Neef, Jolanda; Kuipers, Oscar P; Neves, Ana R; Bijlsma, Jetta J E

    2013-01-01

    Pyruvate oxidase is a key function in the metabolism and lifestyle of many lactic acid bacteria and its activity depends on the presence of environmental oxygen. In Streptococcus pneumoniae the protein has been suggested to play a major role in metabolism and has been implicated in virulence, oxidative stress survival and death in stationary phase. Under semi-aerobic conditions, transcriptomic and metabolite profiling analysis of a spxB mutant grown on glucose showed minor changes compared to the wild type, apart from the significant induction of two operons involved in carbohydrate uptake and processing. This induction leads to a change in the sugar utilization capabilities of the bacterium, as indicated by the analysis of the growth profiles of the D39 parent and spxB mutant on alternative carbohydrates. Metabolic analysis and growth experiments showed that inactivation of SpxB has no effect on the glucose fermentation pattern, except under aerobic conditions. More importantly, we show that mutation of spxB results in the production of increased amounts of capsule, the major virulence factor of S. pneumoniae. Part of this increase can be attributed to induction of capsule operon (cps) transcription. Therefore, we propose that S. pneumoniae utilizes pyruvate oxidase as an indirect sensor of the oxygenation of the environment, resulting in the adaption of its nutritional capability and the amount of capsule to survive in the host.

  12. Crystallization and preliminary crystallographic analysis of a flavoprotein NADH oxidase from Lactobacillus brevis

    International Nuclear Information System (INIS)

    Kuzu, Mutlu; Niefind, Karsten; Hummel, Werner; Schomburg, Dietmar

    2005-01-01

    The water-forming flavoenzyme NADH oxidase was crystallized successfully for the first time. The crystals diffract X-rays to at least 4.0 Å resolution. NADH oxidase (NOX) from Lactobacillus brevis is a homotetrameric flavoenzyme composed of 450 amino acids per subunit. The molecular weight of each monomer is 48.8 kDa. The enzyme catalyzes the oxidation of two equivalents of NADH and reduces one equivalent of oxygen to yield two equivalents of water, without releasing hydrogen peroxide after the reduction of the first equivalent of NADH. Crystals of this protein were grown in the presence of 34% polyethylene glycol monomethyl ether 2000, 0.1 M sodium acetate and 0.2 M ammonium sulfate at pH 5.4. They belong to the tetragonal space group P4 3 2 1 2, with unit-cell parameters a = 74.8, b = 95.7, c = 116.9 Å, α = γ = 90, β = 103.8°. The current diffraction limit is 4.0 Å. The self-rotation function of the native data set is consistent with a NOX tetramer in the asymmetric unit

  13. CTBTO international cooperation workshop

    International Nuclear Information System (INIS)

    1999-01-01

    The International Cooperation Workshop took place in Vienna, Austria, on 16 and 17 November 1998, with the participation of 104 policy/decision makers, Research and Development managers and diplomatic representatives from 58 States Signatories to the Comprehensive Nuclear-Test Ban Treaty (CTBT). The Workshop attempted to develop Treaty stipulations to: promote cooperation to facilitate and participate in the fullest possible exchange relating to technologies used in the verification of the Treaty; enable member states to strengthen national implementation of verification measures, and to benefit from the application of such technologies for peaceful purposes. The potential benefits arising from the CTBT monitoring, analysis and data communication systems are multifaceted, and as yet unknown. This Workshop provided the opportunity to examine some of these possibilities. An overview of the CTBT verification regime on the general aspects of the four monitoring technologies (seismic, hydro-acoustic, infrasound and radionuclides), including some of the elements that are the subject of international cooperation, were presented and discussed. Questions were raised on the potential benefits that can be derived by participating in the CTBT regime and broad-based discussions took place. Several concrete proposals on ways and means to facilitate and promote cooperation among States Signatories were suggested. The main points discussed by the participants can be summarized as follows: the purpose of the CTBT Organization is to assist member states to monitor Treaty compliance; the CTBT can be a highly effective technological tool which can generate wide-ranging data, which can be used for peaceful purposes; there are differences in the levels of technology development in the member states that is why peaceful applications should be supported by the Prep Com for the benefit of all member states, whether developed or developing, training being a key element to optimize the CTBT

  14. Health data cooperatives - citizen empowerment.

    Science.gov (United States)

    Hafen, E; Kossmann, D; Brand, A

    2014-01-01

    functional Health Data Cooperatives exist yet. The relative success of health data repositories such as 23andme and PatientsLikeMe indicates that citizens are willing to participate in research even if - and in contrast to the cooperative model - the commercial value of these data does not go back to the collective of users. In the Health Data Cooperative model, the citizens with their data would take the center stage in the healthcare system and society would benefit from the health-related and financial benefits that aggregation of these data brings.

  15. Statistical fluctuations in cooperative cyclotron radiation

    Science.gov (United States)

    Anishchenko, S. V.; Baryshevsky, V. G.

    2018-01-01

    Shot noise is the cause of statistical fluctuations in cooperative cyclotron radiation generated by an ensemble of electrons oscillating in magnetic field. Autophasing time - the time required for the cooperative cyclotron radiation power to peak - is the critical parameter characterizing the dynamics of electron-oscillators interacting via the radiation field. It is shown that premodulation of charged particles leads to a considerable narrowing of the autophasing time distribution function for which the analytic expression is obtained. When the number of particles Ne exceeds a certain value that depends on the degree to which the particles have been premodulated, the relative root-mean-square deviation (RMSD) of the autophasing time δT changes from a logarithmic dependence on Ne (δT ∼ 1 / lnNe) to square-root (δT ∼ 1 /√{Ne }). A slight energy spread (∼4%) results in a twofold drop of the maximum attainable power of cooperative cyclotron radiation.

  16. International cooperation for operating safety

    International Nuclear Information System (INIS)

    Dupuis, M.C.

    1989-03-01

    The international-cooperation organization in nuclear safety domain is discussed. The nuclear energy Direction Committee is helped by the Security Committee for Nuclear Power Plants in the cooperation between security organizations of member countries and in the safety and nuclear activity regulations. The importance of the cooperation between experts in human being and engine problems is underlined. The applied methods, exchange activities and activity analysis, and the cooperation of the Nuclear Energy Agency and international organizations is analysed [fr

  17. Cooperation in regional nuclear training

    International Nuclear Information System (INIS)

    Newstead, C.M.; Lee, D.S.; Spitalnik, J.

    1985-01-01

    This paper presents an overview of the nuclear training currently being undertaken in the countries of the co-authors, and considers the degree to which training problems are amenable to common solutions such as cooperative regional training programs. Different types of cooperation are discussed including the development of regional and international training centers, cooperative bilateral and multilateral training, and the proposed US International Nuclear Safety Training Academy. The paper provides suggestions of ways for enhancing regional cooperation

  18. Internal control in non - agricultural cooperatives

    Directory of Open Access Journals (Sweden)

    Yolanda García Castro

    2014-12-01

    Full Text Available The process of formation of non-agricultural cooperatives in Cuba, has been a step forward for the Cuban economy, provide primary care represents economic sustainability for the country. A necessary tool for achieving quality in the provision of services and products, it represents the audit process. In this sense the present work was aimed in the Council of the Provincial Administration, in order to strengthen the functioning of non-agricultural cooperatives. Theoretical and empirical methods, techniques, surveys and interviews with leaders and workers, aimed to assess the knowledge, applications for the creation of cooperatives, processing, approval, establishment and operation, based on guidelines established in internal control were applied; and descriptive statistics for processing information, which identified the important work that developed the organization, which was able to promote the operation of non-agricultural cooperatives, as well as the tools necessary for the production of income and consequently improve the quality of services. The diagnosis made it possible to identify the point in the process, so disruption to the operation. Undoubtedly, every experiment needs time to mature and gain experience, besides confirming Waste Disposal workers cooperatives and agencies to jump-start this process. Improvement measures were implemented in order to increase the economic efficiency of each process, in response to various guidelines of Economic and Social Policy of the Party and the Revolution, adopted at the Sixth Party Congress and Conference Objectives.

  19. Tax cooperation among member states of European Union and Directive on administrative cooperation in the field of taxation

    Directory of Open Access Journals (Sweden)

    Josimovski Aleksandar G.

    2013-01-01

    Full Text Available Countries have possibility to choose between several alternatives for cooperation in international tax matters at global level. They can decide not to cooperate or provide some form of tax cooperation. Because of harmful tax competition among countries and efforts of international organizations, all countries in the world are oblidged to comply with one of multiple alternatives for tax cooperation. Situation in European Union (hereinafter EU is specific. EU is not country or classic international organization. By the reason of its successful functioning, EU has need for tax cooperation. EU has attempted to harmonise tax policies of member states, but member states did not approve that. Only indirect taxes are harmonized on EU level, direct taxes are harmonized only to the point necessarily for functioning of single market. That is why tax cooperation instruments are so important. Object of this paper are procedures and measures, stipulated by the most important instrument in the field of tax cooperation enacted by institutions of EU, its development and status in international tax law. Regulatives and directives in field of tax cooperation in the EU are 'pioneers' in tax matters. EU instruments provide standards which are subsequently accepted by several international organizations - Organisation for Economic Co-operation and Development (OECD and United Nations (UN. Our purpose is to present positive and negative aspects of tax cooperation in the EU. In time of crisis efficient tax cooperation provides higher revenues for the member states, on the other hand, taxpayers and tax administrations have increased expenses as result of tax cooperation which are not fairly distributed.

  20. Cooperative Learning: Developments in Research

    Science.gov (United States)

    Gillies, Robyn M.

    2014-01-01

    Cooperative learning is widely recognized as a pedagogical practice that promotes socialization and learning among students from kindergarten through to college level and across different subject areas. Cooperative learning involves students working together to achieve common goals or complete group tasks. Interest in cooperative learning has…

  1. Conditional cooperation on three continents

    NARCIS (Netherlands)

    Kocher, M.G.; Cherry, T.; Kroll, S.; Netzer, R.; Sutter, M.

    2007-01-01

    We show in a public goods experiment on three continents that conditional cooperation is a universal behavioral regularity. Yet, the number of conditional cooperators and the extent of conditional cooperation are much higher in the U.S.A. than anywhere else.

  2. The governance of cooperative societies

    Directory of Open Access Journals (Sweden)

    Yaiza Juanes Sobradillo

    2005-12-01

    Full Text Available The present work aims to expose the appropriate legislation for cooperative societies to which Article 129 of the Spanish Constitution refers, deepen the analysis of the organs of management and control based on the Spanish and Basque Laws on Cooperatives and the Statute for the European Cooperative Societies.

  3. Cooperative Learning in Elementary Schools

    Science.gov (United States)

    Slavin, Robert E.

    2015-01-01

    Cooperative learning refers to instructional methods in which students work in small groups to help each other learn. Although cooperative learning methods are used for different age groups, they are particularly popular in elementary (primary) schools. This article discusses methods and theoretical perspectives on cooperative learning for the…

  4. Forestry cooperatives: past and present

    Science.gov (United States)

    Mark G. Rickenbach

    2006-01-01

    Forest landowner cooperatives are not a new phenomenon, but past efforts to create and sustain these businesses have been largely unsuccessful in the U.S. Before and just after World War II saw significant investment in cooperative development that failed to create durable business. The purpose of this chapter is to briefly describe the history of forestry cooperatives...

  5. Lactate Biosensor Based on Cellulose Acetate Membrane Bound Lactate Oxidase

    Directory of Open Access Journals (Sweden)

    Suman

    2007-05-01

    Full Text Available Lactate biosensor was fabricated by immobilizing lactate oxidase in cellulose acetate membrane and by mounting over the sensing part of Pt electrode (working and connected to Ag/AgCl electrode (reference along with auxillary electrode through potentiostat. The enzyme electrode was anodically polarized at +400 mV to generate electrons from H2O2, which was formed from oxidation of serum lactate by immobilized lactate oxidase. The minimum detection limit of the electrode was 0.1mmoles/L and sensitivity of the sensor was 0.008 mA/mM/L lactate. Assay coefficients of variation were < 2% .A good correlation (r=0.99 was found between lactate values obtained by colorimetric method and lactate biosensor. The self-life of the biosensor was 18 days at 4ºC and enzyme electrode can be re-used 150 times without any significant loss in enzyme activity.

  6. Dual inhibitors of cholinesterases and monoamine oxidases for Alzheimer's disease.

    Science.gov (United States)

    Knez, Damijan; Sova, Matej; Košak, Urban; Gobec, Stanislav

    2017-05-01

    Accumulating evidence indicates a solid relationship between several enzymes and Alzheimer's disease. Cholinesterases and monoamine oxidases are closely associated with the disease symptomatology and progression and have been tackled simultaneously using several multifunctional ligands. This design strategy offers great chances to alter the course of Alzheimer's disease, in addition to alleviation of the symptoms. More than 15 years of research has led to the identification of various dual cholinesterase/monoamine oxidase inhibitors, while some showing positive outcomes in clinical trials, thus giving rise to additional research efforts in the field. The aim of this review is to provide an update on the novel dual inhibitors identified recently and to shed light on their therapeutic potential.

  7. Variations in epidermal cytochrome oxidase activity after local irradiation

    International Nuclear Information System (INIS)

    Itoiz, M.E.; Rey, B.M. de; Cabrini, R.L.

    1982-01-01

    Cytochrome oxidase activity was evaluated histochemically as an index of mitochondrial damage after local irradiation with X-rays. It was determined by microphotometry on the tail skin of newly born Wistar rats four days after irradiation with doses ranging from 2 to 16krad. The enzyme activity of the whole epidermis increased after irradiation, the increases being related to the increase in thickness of the epithelium which was observed as a response to irradiation injury. Within the dose range tested, the enzyme concentration (expressed per unit volume of tissue) decreased in relation to the dose applied. At the electron microscopy level, the cytochemical demonstration of cytochrome oxidase revealed an irregular reaction over the cristae, intramitochondrial vacuolization and partial homogenization of the matrix. Positive membrane fragments were seen around lipid droplets. This reaction confirms the mitochondrial origin of these previously observed radiation-induced vacuoles. (author)

  8. Cooperate or Free Ride?

    DEFF Research Database (Denmark)

    Hansen, Per H.

    2012-01-01

    of international cooperation. On the other hand, the evidence seems to confirm Kindleberger's hypothesis that small countries were free riding during the international financial crisis of 1931, and that therefore there is a need for some coordinating mechanism, or a hegemon, in such crises....... in the establishment of the BIS and free riders in the Austrian crisis, even though there were marked differences in their attitude to international cooperation. These results run counter to the views of those International Political Economy (IPE) theorists who argue that small states should be in favour......In this article, I discuss the role of the three Scandinavian central banks in the establishment of the Bank for International Settlements (BIS) in 1930, and in the international lender of last resort operation towards Austria in 1931. I argue that small central banks were reluctant supporters...

  9. Junctionless Cooper pair transistor

    Energy Technology Data Exchange (ETDEWEB)

    Arutyunov, K. Yu., E-mail: konstantin.yu.arutyunov@jyu.fi [National Research University Higher School of Economics , Moscow Institute of Electronics and Mathematics, 101000 Moscow (Russian Federation); P.L. Kapitza Institute for Physical Problems RAS , Moscow 119334 (Russian Federation); Lehtinen, J.S. [VTT Technical Research Centre of Finland Ltd., Centre for Metrology MIKES, P.O. Box 1000, FI-02044 VTT (Finland)

    2017-02-15

    Highlights: • Junctionless Cooper pair box. • Quantum phase slips. • Coulomb blockade and gate modulation of the Coulomb gap. - Abstract: Quantum phase slip (QPS) is the topological singularity of the complex order parameter of a quasi-one-dimensional superconductor: momentary zeroing of the modulus and simultaneous 'slip' of the phase by ±2π. The QPS event(s) are the dynamic equivalent of tunneling through a conventional Josephson junction containing static in space and time weak link(s). Here we demonstrate the operation of a superconducting single electron transistor (Cooper pair transistor) without any tunnel junctions. Instead a pair of thin superconducting titanium wires in QPS regime was used. The current–voltage characteristics demonstrate the clear Coulomb blockade with magnitude of the Coulomb gap modulated by the gate potential. The Coulomb blockade disappears above the critical temperature, and at low temperatures can be suppressed by strong magnetic field.

  10. Cooperative Learning i voksenundervisningen

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne

    Nationalt Center for Kompetenceudvikling har evalueret undervisningsmetoden Cooperative Learning i voksenundervisningen og dokumenteret positive effekter på oplevelsen af samarbejde og på lærere og kursisters engagement - men har ikke kunnet påvise systematiske positive effekter af metoden på...... kursisters frafald, fravær og karakterer. Projektet har afprøvet og videreudviklet den pædagogiske metode Cooperative Learning (CL) i en dansk virkelighed og mere specifikt i forhold til VUC'ernes nye kursistgrupper med det overordnede mål at øge gennemførslen markant og målbart ved at anvende og udvikle en...

  11. International cooperative information systems

    International Nuclear Information System (INIS)

    1980-01-01

    Developing countries need mechanisms by which the information they generate themselves and development information from the rest of the world can be retrieved. The international cooperative information system is such a mechanism. Delegates to the Seminar on International Cooperative Information Systems were informed about various existing systems (INIS, AGRIS, INFOTERRA, TCDC/INRES, POPIN, DEVSIS, and INPADROC), some specialized information systems and services (CDS/ISIS and the Cassava Information Centre), and computer programs for information processing (INIS/AGRIS, CDS/ISIS, and MINISIS). The participants suggested some changes that should be made on both the national and the international levels to ensure that these systems meet the needs of developing countries more effectively. (LL)

  12. Cooperative method development

    DEFF Research Database (Denmark)

    Dittrich, Yvonne; Rönkkö, Kari; Eriksson, Jeanette

    2008-01-01

    The development of methods tools and process improvements is best to be based on the understanding of the development practice to be supported. Qualitative research has been proposed as a method for understanding the social and cooperative aspects of software development. However, qualitative...... research is not easily combined with the improvement orientation of an engineering discipline. During the last 6 years, we have applied an approach we call `cooperative method development', which combines qualitative social science fieldwork, with problem-oriented method, technique and process improvement....... The action research based approach focusing on shop floor software development practices allows an understanding of how contextual contingencies influence the deployment and applicability of methods, processes and techniques. This article summarizes the experiences and discusses the further development...

  13. Cooperation or Silent Rivalry?

    DEFF Research Database (Denmark)

    Zank, Wolfgang

    2010-01-01

    a gravitational pull which goes beyond economic problems. Furthermore, the EU has gradually built up a coherent policy on many fields. The EU has become the “reform anchor” and most important cooperation partner for Egypt. The progress towards increasing Egypt’s “Stake in the Internal Market” places cooperation......For decades the US has had a hegemonic position in the Middle East. A key country in this respect has been Egypt. However, in recent decades the EU has made itself increasingly felt in the region. Due to enlargements the EU came geographically much closer, and the Internal Market has generated...... to see the US and EU as rivals. Their roles are rather complementary. The article explores developments in a long-term perspective. Internal and structural developments have had a heavy impact, but at important junctions ideas and strategies for gaining political legitimacy were powerful factors too...

  14. Strategies of inducing cooperation

    International Nuclear Information System (INIS)

    Deutsch, M.

    1986-01-01

    The results of the four experiments described in this paper are very consistent, and they can be summarized as follows: (1) The ''nonpunitive'' strategy was most effective in eliciting cooperative behavior from the subjects and, overall, resulted in the highest joint outcomes as well as the highest outcomes for the accomplice. (2) The effectiveness of the turn-the-other-cheek strategy was very much influenced by the competitiveness of the situation; the more competitive the incentives of the subjects, the more massively they exploited the accomplice who employed this strategy. (3) The punitive deterrent strategy elicited more agressive and self-protective, as well as less cooperative, behavior from the subjects than did the other strategies

  15. Problems of technical cooperation

    International Nuclear Information System (INIS)

    Noramli, M.

    1987-01-01

    The main principles of the IAEA technical co-operation program, which intends to answer the requirements of the member states as regards technical assistance, are presented. IAEA offers its assistance in the supervision and financial support of the projects, which promise direct and quick profit to the member states. Projects related to the satisfaction of the main demands of humanity, industrial use, energy generation, radiation protection and other fields, which can promote the contribution of nuclear power generation to the course of peace, protection of health and thriving of states, are among them. 35 million dollars (USA) was allocated for the IAEA technical assistance and realization of the co-operation program in 1987

  16. Enresa International Cooperation

    International Nuclear Information System (INIS)

    Rodriguez Beceiro, A.

    1998-01-01

    The Empresa Nacional de Residuos Radiactivos, S.A. (ENRESA) was set up in 1984 with the mandate to undertake responsibility for radioactive waste management in Spain. From the very beginning, ENRESA was fully aware of the fact that international cooperation plays a very important role in the development of national programmes. Aspects such as the setting up of international databases, the development and validation of models or site characterization technique such enormous efforts and amounts of resources that they could hardly be undertaken individually. Furthermore, joint participation in research, development and demonstration projects reinforces the level of confidence, not only in the decision-making process but also in the technologies, techniques and practices used. ENRESA's participation in the international contexts is largely defined, on the one hand, by the needs arising from its technical programme, as reflected in the General Radioactive Waste Plan and in the Research and Development Plan, and on the other by the need to support spanish governmental institutions in their participation in inter-governmental institutions in their participation in inter-governmental forums. The formula for cooperation varies according to needs, this cooperation generally being accomplished by means of bilateral agreements with other institutions having similar competence or by participating in the programmes of inter-governmental organizations. In particular, ENRESA has reached cooperation agreements with most of the agencies with similar responsibilities in other countries and participates very actively in the programmes of the European Union, the Nuclear energy Agency (NEA/OECD) and the International Atomic Energy Agency (IAEA). (Author)

  17. Automated Cooperative Trajectories

    Science.gov (United States)

    Hanson, Curt; Pahle, Joseph; Brown, Nelson

    2015-01-01

    This presentation is an overview of the Automated Cooperative Trajectories project. An introduction to the phenomena of wake vortices is given, along with a summary of past research into the possibility of extracting energy from the wake by flying close parallel trajectories. Challenges and barriers to adoption of civilian automatic wake surfing technology are identified. A hardware-in-the-loop simulation is described that will support future research. Finally, a roadmap for future research and technology transition is proposed.

  18. Diversity and Cooperation

    OpenAIRE

    Bruner, Justin Pearce

    2014-01-01

    The present dissertation is an exploration of the effect of diversity on social contract formation and the evolution of cooperation. This work stems from the pioneering efforts of economist Arthur Robson, who first explored the role of costless pre-game communication in strategic interactions. When communication is permitted, individuals playing a game can condition their behavior on the signal received from their counterpart. For my purposes, I interpret these signals as racial markers or cu...

  19. Glucose Oxidase Catalyzed Self-Assembly of Bioelectroactive Gold Nanostructures

    Science.gov (United States)

    2010-01-01

    polymer matrix), however, electrons generated at the FAD/FADH2 active site of glucose oxidase (GOx) must tunnel ca. 15 through the protein shell...described as a surface bound thiolate [33]. Recently, the presence of free thiol groups has been proposed as a mechanism for gold reduction in pure enzymes...simultaneously [38]. The oxidative polymerization of the amines proceeds simulta- neously with the formation of gold nanoparticles such that the polymerized amine

  20. Graphene-glucose oxidase bioanodes for enzymatic biofuel cells

    DEFF Research Database (Denmark)

    Tang, Jing; Werchmeister, Rebecka Maria Larsen; Engelbrekt, Christian

    2017-01-01

    as supporting material, polyethyleneimine (PEI) as linker and glucose oxidase (GOD) as the chosen enzyme. GOD can catalyze oxidation of glucose to gluconolactone, but needs a mediator to assist electron transfer between the enzyme and electrodes. The redox molecule ferrocene carboxylic acid (Fc...... and systematically investigated. The assembled EBFCs show good reproducibility. EBFCs provide maximum output power density 2.47 μW cm-2 at 35 ℃, indicating the optimized activity of EBFCs fed with glucose....

  1. Biochemical Conservation and Evolution of Germacrene A Oxidase in Asteraceae*

    Science.gov (United States)

    Nguyen, Don Trinh; Göpfert, Jens Christian; Ikezawa, Nobuhiro; MacNevin, Gillian; Kathiresan, Meena; Conrad, Jürgen; Spring, Otmar; Ro, Dae-Kyun

    2010-01-01

    Sesquiterpene lactones are characteristic natural products in Asteraceae, which constitutes ∼8% of all plant species. Despite their physiological and pharmaceutical importance, the biochemistry and evolution of sesquiterpene lactones remain unexplored. Here we show that germacrene A oxidase (GAO), evolutionarily conserved in all major subfamilies of Asteraceae, catalyzes three consecutive oxidations of germacrene A to yield germacrene A acid. Furthermore, it is also capable of oxidizing non-natural substrate amorphadiene. Co-expression of lettuce GAO with germacrene synthase in engineered yeast synthesized aberrant products, costic acids and ilicic acid, in an acidic condition. However, cultivation in a neutral condition allowed the de novo synthesis of a single novel compound that was identified as germacrene A acid by gas and liquid chromatography and NMR analyses. To trace the evolutionary lineage of GAO in Asteraceae, homologous genes were further isolated from the representative species of three major subfamilies of Asteraceae (sunflower, chicory, and costus from Asteroideae, Cichorioideae, and Carduoideae, respectively) and also from the phylogenetically basal species, Barnadesia spinosa, from Barnadesioideae. The recombinant GAOs from these genes clearly showed germacrene A oxidase activities, suggesting that GAO activity is widely conserved in Asteraceae including the basal lineage. All GAOs could catalyze the three-step oxidation of non-natural substrate amorphadiene to artemisinic acid, whereas amorphadiene oxidase diverged from GAO displayed negligible activity for germacrene A oxidation. The observed amorphadiene oxidase activity in GAOs suggests that the catalytic plasticity is embedded in ancestral GAO enzymes that may contribute to the chemical and catalytic diversity in nature. PMID:20351109

  2. Hydrazine and hydroxylamine as probes for O2-reduction site of mitochondrial cytochrome c oxidase.

    Science.gov (United States)

    Kubota, T; Yoshikawa, S

    1993-01-01

    Reactions of hydrazine and hydroxylamine with bovine heart cytochrome c oxidase in the fully reduced state were investigated under anaerobic conditions following the visible-Soret spectral change. Hydrazine gave a sharp band at 575 nm with 20% decrease in the alpha band at 603 nm, and hydroxylamine induced a 2 nm blue-shift for the alpha band without any clear splitting. The Soret band at 443 nm was decreased significantly in intensity, with the concomitant appearance of a shoulder with hydrazine or a peak with hydroxylamine, both near 430 nm. The dependence on pH of the affinity of these reagents for the enzyme indicates that only the deprotonated forms of these reagents bind to the enzyme, suggesting a highly hydrophobic environment of the haem ligand-biding site. These spectral changes were largely removed by addition of cyanide or CO. However, detailed analysis of these spectral changes indicates that hydrazine perturbs the shape of the spectral change induced by cyanide and hydroxylamine perturbs that induced by CO. These results suggest that these aldehyde reagents bind to haem a3 iron as well as to a second site which is most likely to be the formyl group on the haem periphery, and that these two sites bind these reagents anti-cooperatively with each other. PMID:8389138

  3. NADPH oxidase is not an essential mediator of oxidative stress or liver injury in murine MCD diet-induced steatohepatitis.

    Science.gov (United States)

    dela Peña, Aileen; Leclercq, Isabelle A; Williams, Jacqueline; Farrell, Geoffrey C

    2007-02-01

    Hepatic oxidative stress is a key feature of metabolic forms of steatohepatitis, but the sources of pro-oxidants are unclear. The NADPH oxidase complex is critical for ROS generation in inflammatory cells; loss of any one component (e.g., gp91phox) renders NADPH oxidase inactive. We tested whether activated inflammatory cells contribute to oxidant stress in steatohepatitis. gp91phox-/- and wildtype (wt) mice were fed a methionine and choline-deficient (MCD) diet. Serum ALT, hepatic triglycerides, histopathology, lipid peroxidation, activation of NF-kappaB, expression of NF-kappaB-regulated genes and macrophage chemokines were measured. After 10 days of MCD dietary feeding, gp91phox-/- and wt mice displayed equivalent hepatocellular injury. After 8 weeks, there were fewer activated macrophages in livers of gp91phox-/- mice than controls, despite similar mRNA levels for MCP and MIP chemokines, but fibrosis was similar. NF-kappaB activation and increased expression of ICAM-1, TNF-alpha and COX-2 mRNA were evident in both genotypes, but in gp91phox-/- mice, expression of these genes was confined to hepatocytes. A functional NADPH oxidase complex does not contribute importantly to oxidative stress in this model and therefore is not obligatory for induction or perpetuation of dietary steatohepatitis.

  4. Characterization of the cytochrome c oxidase in isolated and purified plasma membranes from the cyanobacterium Anacystis nidulans

    International Nuclear Information System (INIS)

    Peschek, G.A.; Wastyn, M.; Trnka, M.; Molitor, V.; Fry, I.V.; Packer, L.

    1989-01-01

    Functionally intact plasma membranes were isolated from the cyanobacterium (blue-green alga) Anacystis nidulans through French pressure cell extrusion of lysozyme/EDTA-treated cells, separated from thylakoid membranes by discontinuous sucrose density gradient centrifugation, and purified by repeated recentrifugation. Origin and identity of the chlorophyll-free plasma membrane fraction were confirmed by labeling of intact cells with impermeant protein markers, [ 35 S]diazobenzenesulfonate and fluorescamine, prior to membrane isolation. Rates of oxidation of reduced horse heart cytochrome c by purified plasma and thylakoid membranes were 90 and 2 nmol min -1 (mg of protein) -1 , respectively. The cytochrome oxidase in isolated plasma membranes was identified as a copper-containing aa 3 -type enzyme from the properties of its redox-active and EDTA-resistant Cu 2+ ESR signal, the characteristic inhibition profile, reduced minus oxidized difference spectra, carbon monoxide difference spectra, photoaction and photodissociation spectra of the CO-inhibited enzyme, and immunological cross-reaction of two subunits of the enzyme with antibodies against subunits I and II, and the holoenzyme, of Paracoccus denitrificans aa 3 -type cytochrome oxidase. The data presented are the first comprehensive evidence for the occurrence of aa 3 -type cytochrome oxidase in the plasma membrane of a cyanobacterium similar to the corresponding mitochondrial enzyme

  5. Crystal structure of human lysyl oxidase-like 2 (hLOXL2) in a precursor state.

    Science.gov (United States)

    Zhang, Xi; Wang, Qifan; Wu, Jianping; Wang, Jiawei; Shi, Yigong; Liu, Minhao

    2018-04-10

    Lysyl oxidases (LOXs), a type of copper- and lysyl tyrosylquinone (LTQ) -dependent amine oxidase, catalyze the oxidative deamination of lysine residues of extracellular matrix (ECM) proteins such as elastins and collagens and generate aldehyde groups. The oxidative deamination of lysine represents the foundational step for the cross-linking of elastin and collagen and thus is crucial for ECM modeling. Despite their physiological significance, the structure of this important family of enzymes remains elusive. Here we report the crystal structure of human lysyl oxidase-like 2 (hLOXL2) at 2.4-Å resolution. Unexpectedly, the copper-binding site of hLOXL2 is occupied by zinc, which blocks LTQ generation and the enzymatic activity of hLOXL2 in our in vitro assay. Biochemical analysis confirms that copper loading robustly activates hLOXL2 and supports LTQ formation. Furthermore, the LTQ precursor residues in the structure are distanced by 16.6 Å, corroborating the notion that the present structure may represent a precursor state and that pronounced conformational rearrangements would be required for protein activation. The structure presented here establishes an important foundation for understanding the structure-function relationship of LOX proteins and will facilitate LOX-targeting drug discovery. Copyright © 2018 the Author(s). Published by PNAS.

  6. A single mutation in the castor Δ9-18:0-desaturase changes reaction partitioning from desaturation to oxidase chemistry

    Science.gov (United States)

    Guy, Jodie E.; Abreu, Isabel A.; Moche, Martin; Lindqvist, Ylva; Whittle, Edward; Shanklin, John

    2006-01-01

    Sequence analysis of the diiron cluster-containing soluble desaturases suggests they are unrelated to other diiron enzymes; however, structural alignment of the core four-helix bundle of desaturases to other diiron enzymes reveals a conserved iron binding motif with similar spacing in all enzymes of this structural class, implying a common evolutionary ancestry. Detailed structural comparison of the castor desaturase with that of a peroxidase, rubrerythrin, shows remarkable conservation of both identity and geometry of residues surrounding the diiron center, with the exception of residue 199. Position 199 is occupied by a threonine in the castor desaturase, but the equivalent position in rubrerythrin contains a glutamic acid. We previously hypothesized that a carboxylate in this location facilitates oxidase chemistry in rubrerythrin by the close apposition of a residue capable of facilitating proton transfer to the activated oxygen (in a hydrophobic cavity adjacent to the diiron center based on the crystal structure of the oxygen-binding mimic azide). Here we report that desaturase mutant T199D binds substrate but its desaturase activity decreases by ≈2 × 103-fold. However, it shows a >31-fold increase in peroxide-dependent oxidase activity with respect to WT desaturase, as monitored by single-turnover stopped-flow spectrometry. A 2.65-Å crystal structure of T199D reveals active-site geometry remarkably similar to that of rubrerythrin, consistent with its enhanced function as an oxidase enzyme. That a single amino acid substitution can switch reactivity from desaturation to oxidation provides experimental support for the hypothesis that the desaturase evolved from an ancestral oxidase enzyme. PMID:17088542

  7. Conditional imitation might promote cooperation under high temptations to defect

    Science.gov (United States)

    Dai, Qionglin; Li, Haihong; Cheng, Hongyan; Qian, Xiaolan; Zhang, Mei; Yang, Junzhong

    2012-07-01

    In this paper we introduce a conditional imitation rule into an evolutionary game, in which the imitation probabilities of individuals are determined by a function of payoff difference and two crucial parameters μ and σ. The parameter μ characterizes the most adequate goal for individuals and the parameter σ characterizes the tolerance of individuals. By using the pair approximation method and numerical simulations, we find an anomalous cooperation enhancement in which the cooperation level shows a nonmonotonic variation with the increase of temptation. The parameter μ affects the regime of the payoff parameter which supports the anomalous cooperation enhancement, whereas the parameter σ plays a decisive role on the appearance of the nonmonotonic variation of the cooperation level. Furthermore, to give explicit implications for the parameters μ and σ we present an alterative form of the conditional imitation rule based on the benefit and the cost incurred to individuals during strategy updates. In this way, we also provide a phenomenological interpretation for the nonmonotonic behavior of cooperation with the increase of temptation. The results give a clue that a higher cooperation level could be obtained under adverse environments for cooperation by applying the conditional imitation rule, which is possible to be manipulated in real life. More generally, the results in this work might point out an efficient way to maintain cooperation in the risky environments to cooperators.

  8. Evaluation of Fluorine-18-Labeled α1(I-N-Telopeptide Analogs as Substrate-Based Radiotracers for PET Imaging of Melanoma-Associated Lysyl Oxidase

    Directory of Open Access Journals (Sweden)

    Manuela Kuchar

    2018-04-01

    Full Text Available Accumulating evidence suggests an unequivocal role of lysyl oxidases as key players of tumor progression and metastasis, which renders this enzyme family highly attractive for targeted non-invasive functional imaging of tumors. Considering their function in matrix remodeling, malignant melanoma appears as particularly interesting neoplasia in this respect. For the development of radiotracers that enable PET imaging of the melanoma-associated lysyl oxidase activity, substrates derived from the type I collagen α1 N-telopeptide were labeled with fluorine-18 using N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB as prosthetic reagent. With regards to potential crosslinking to tumor-associated collagen in vivo, their interaction with triple-helical type I collagen was studied by SPR. A mouse model of human melanoma was established on the basis of the A375 cell line, for which the expression of the oncologically relevant lysyl oxidase isoforms LOX and LOXL2 was demonstrated in Western blot and immunohistochemical experiments. The radiopharmacological profiles of the peptidic radiotracers were evaluated in normal rats and A375 melanoma-bearing mice by ex vivo metabolite analysis, whole-body biodistribution studies and dynamic PET imaging. Out of three 18F-labeled telopeptide analogs, the one with the most favorable substrate properties has shown favorable tumor uptake and tumor-to-muscle ratio. Lysyl oxidase-mediated tumor uptake was proven by pharmacological inhibition using β-aminopropionitrile and by employing negative-control analogs of impeded or abolished targeting capability. The latter were obtained by substituting the lysine residue by ornithine and norleucine, respectively. Comparing the tumor uptake of the lysine-containing peptide with that of the non-functional analogs indicate the feasibility of lysyl oxidase imaging in melanoma using substrate-based radiotracers.

  9. Evaluation of Fluorine-18-Labeled α1(I)-N-Telopeptide Analogs as Substrate-Based Radiotracers for PET Imaging of Melanoma-Associated Lysyl Oxidase.

    Science.gov (United States)

    Kuchar, Manuela; Neuber, Christin; Belter, Birgit; Bergmann, Ralf; Lenk, Jens; Wodtke, Robert; Kniess, Torsten; Steinbach, Jörg; Pietzsch, Jens; Löser, Reik

    2018-01-01

    Accumulating evidence suggests an unequivocal role of lysyl oxidases as key players of tumor progression and metastasis, which renders this enzyme family highly attractive for targeted non-invasive functional imaging of tumors. Considering their function in matrix remodeling, malignant melanoma appears as particularly interesting neoplasia in this respect. For the development of radiotracers that enable PET imaging of the melanoma-associated lysyl oxidase activity, substrates derived from the type I collagen α1 N-telopeptide were labeled with fluorine-18 using N -succinimidyl 4-[ 18 F]fluorobenzoate ([ 18 F]SFB) as prosthetic reagent. With regards to potential crosslinking to tumor-associated collagen in vivo , their interaction with triple-helical type I collagen was studied by SPR. A mouse model of human melanoma was established on the basis of the A375 cell line, for which the expression of the oncologically relevant lysyl oxidase isoforms LOX and LOXL2 was demonstrated in Western blot and immunohistochemical experiments. The radiopharmacological profiles of the peptidic radiotracers were evaluated in normal rats and A375 melanoma-bearing mice by ex vivo metabolite analysis, whole-body biodistribution studies and dynamic PET imaging. Out of three 18 F-labeled telopeptide analogs, the one with the most favorable substrate properties has shown favorable tumor uptake and tumor-to-muscle ratio. Lysyl oxidase-mediated tumor uptake was proven by pharmacological inhibition using β-aminopropionitrile and by employing negative-control analogs of impeded or abolished targeting capability. The latter were obtained by substituting the lysine residue by ornithine and norleucine, respectively. Comparing the tumor uptake of the lysine-containing peptide with that of the non-functional analogs indicate the feasibility of lysyl oxidase imaging in melanoma using substrate-based radiotracers.

  10. On the Possibility of Uphill Intramolecular Electron Transfer in Multicopper Oxidases: Electrochemical and Quantum Chemical Study of Bilirubin Oxidase

    Czech Academy of Sciences Publication Activity Database

    Shleev, S.; Andoralov, V.; Falk, M.; Reimann, C. T.; Ruzgas, T.; Srnec, Martin; Ryde, U.; Rulíšek, Lubomír

    2012-01-01

    Roč. 24, č. 7 (2012), s. 1524-1540 ISSN 1040-0397 Grant - others:7th Framework Program(XE) NMP4-SL-2009-229255 Institutional research plan: CEZ:AV0Z40550506 Keywords : bilirubin oxidase * intramolecular electron transfer * rate-limiting catalytic step * reorganization energy * QM/MM calculations Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.817, year: 2012

  11. Lysyl oxidase overexpression accelerates cardiac remodeling and aggravates angiotensin II-induced hypertrophy.

    Science.gov (United States)

    Galán, María; Varona, Saray; Guadall, Anna; Orriols, Mar; Navas, Miquel; Aguiló, Silvia; de Diego, Alicia; Navarro, María A; García-Dorado, David; Rodríguez-Sinovas, Antonio; Martínez-González, José; Rodriguez, Cristina

    2017-09-01

    Lysyl oxidase (LOX) controls matrix remodeling, a key process that underlies cardiovascular diseases and heart failure; however, a lack of suitable animal models has limited our knowledge with regard to the contribution of LOX to cardiac dysfunction. Here, we assessed the impact of LOX overexpression on ventricular function and cardiac hypertrophy in a transgenic LOX (TgLOX) mouse model with a strong cardiac expression of human LOX. TgLOX mice exhibited high expression of the transgene in cardiomyocytes and cardiofibroblasts, which are associated with enhanced LOX activity and H 2 O 2 production and with cardiofibroblast reprogramming. LOX overexpression promoted an age-associated concentric remodeling of the left ventricle and impaired diastolic function. Furthermore, LOX transgenesis aggravated angiotensin II (Ang II)-induced cardiac hypertrophy and dysfunction, which triggered a greater fibrotic response that was characterized by stronger collagen deposition and cross-linking and high expression of fibrotic markers. In addition, LOX transgenesis increased the Ang II-induced myocardial inflammatory infiltrate, exacerbated expression of proinflammatory markers, and decreased that of cardioprotective factors. Mechanistically, LOX overexpression enhanced oxidative stress and potentiated the Ang II-mediated cardiac activation of p38 MAPK while reducing AMPK activation. Our findings suggest that LOX induces an age-dependent disturbance of diastolic function and aggravates Ang II-induced hypertrophy, which provides novel insights into the role of LOX in cardiac performance.-Galán, M., Varona, S., Guadall, A., Orriols, M., Navas, M., Aguiló, S., de Diego, A., Navarro, M. A., García-Dorado, D., Rodríguez-Sinovas, A., Martínez-González, J., Rodriguez, C. Lysyl oxidase overexpression accelerates cardiac remodeling and aggravates angiotensin II-induced hypertrophy. © FASEB.

  12. Protein structural development of threadfin bream ( Nemipterus spp.) surimi gels induced by glucose oxidase.

    Science.gov (United States)

    Wang, Lei; Fan, Daming; Fu, Lulu; Jiao, Xidong; Huang, Jianlian; Zhao, Jianxin; Yan, Bowen; Zhou, Wenguo; Zhang, Wenhai; Ye, Weijian; Zhang, Hao

    2018-01-01

    This study investigated the effect of glucose oxidase on the gel properties of threadfin bream surimi. The gel strength of surimi increased with the addition of 0.5‰ glucose oxidase after two-step heating. Based on the results of the chemical interactions, the hydrophobic interaction and disulfide bond of glucose oxidase-treated surimi samples increased compared with the control samples at the gelation temperature and gel modori temperature. The surface hydrophobicity of samples with glucose oxidase and glucose increased significantly ( p glucose oxidase induced more α-helixes to turn into a more elongated random and flocculent structure. Glucose oxidase changes the secondary structure of the surimi protein, making more proteins depolarize and stretch and causing actomyosin to accumulate to each other, resulting in the formation of surimi gel.

  13. Amine oxidases as important agents of pathological processes of rhabdomyolysis in rats.

    Science.gov (United States)

    Gudkova, O O; Latyshko, N V; Shandrenko, S G

    2016-01-01

    In this study we have tested an idea on the important role of amine oxidases (semicarbazide-sensitive amine oxidase, diamine oxidase, polyamine oxidase) as an additional source of oxidative/carbonyl stress under glycerol-induced rhabdomyolysis, since the enhanced formation of reactive oxygen species and reactive carbonyl species in a variety of tissues is linked to various diseases. In our experiments we used the sensitive fluorescent method devised for estimation of amine oxidases activity in the rat kidney and thymus as targeted organs under rhabdomyolysis. We have found in vivo the multiple rises in activity of semicarbazide-sensitive amine oxidase, diamine oxidase, polyamine oxidase (2-4.5 times) in the corresponding cell fractions, whole cells or their lysates at the 3-6th day after glycerol injection. Aberrant antioxidant activities depended on rhabdomyolysis stage and had organ specificity. Additional treatment of animals with metal chelator ‘Unithiol’ adjusted only the activity of antioxidant enzymes but not amine oxidases in both organs. Furthermore the in vitro experiment showed that Fenton reaction (hydrogen peroxide in the presence of iron) products alone had no effect on semicarbazide-sensitive amine oxidase activity in rat liver cell fraction whereas supplementation with methylglyoxal resulted in its significant 2.5-fold enhancement. Combined action of the both agents had additive effect on semicarbazide-sensitive amine oxidase activity. We can assume that biogenic amine and polyamine catabolism by amine oxidases is upregulated by oxidative and carbonyl stress factors directly under rhabdomyolysis progression, and the increase in catabolic products concentration contributes to tissue damage in glycerol-induced acute renal failure and apoptosis stimulation in thymus.

  14. Up-Streaming Process for Glucose Oxidase by Thermophilic Penicillium sp. in Shake Flask

    OpenAIRE

    Muhammad Mohsin JAVED; Aroosh SHABIR; Sana ZAHOOR; Ikram UL-HAQ

    2012-01-01

    The present study is concerned with the production of glucose oxidase (GOD) from thermophilic Penicillium sp. in 250 mL shake flask. Fourteen different strains of thermophilic Penicillium sp. were isolated from the soil and were screened for glucose oxidase production. IIBP-13 strain gave maximum extra-cellular glucose oxidase production as compared to other isolates. Effect of submerged fermentation in shaking and static conditions, different carbon sources and incubation period on the produ...

  15. AFRA: Supporting regional cooperation

    International Nuclear Information System (INIS)

    2016-01-01

    The African Regional Cooperative Agreement for Research, Development and Training Related to Nuclear Science and Technology (AFRA) provides a framework for African Member States to intensify their collaboration through programmes and projects focused on the specific shared needs of its members. It is a formal intergovernmental agreement which entered into force in 1990. In the context of AFRA, Regional Designated Centres for training and education in radiation protection (RDCs) are established African institutions able to provide services, such as training of highly qualified specialists or instructors needed at the national level and also to facilitate exchange of experience and information through networks of services operating in the field

  16. Ascorbate oxidase is the potential conductor of a symphony of signaling pathways.

    Science.gov (United States)

    De Tullio, Mario C; Guether, Mike; Balestrini, Raffaella

    2013-03-01

    The functional role of ascorbate oxidase (AO; EC 1.10.3.3) has never been fully explained so far, due to the difficulties in understanding the presence of an enzyme specifically oxidizing ascorbate with no obvious advantage, and the apparent disadvantage of lowering plant stress resistance as a consequence of ascorbate consumption. Here we suggest a complete change of perspective, by proposing an essential role of AO as a modulator of both ascorbate and oxygen content, with relevant implications related to signaling. By affecting the overall redox state, AO is actually involved in redox regulation in the extracellular matrix. In addition, AO can contribute to creating a hypoxic microenvironment, especially relevant in the maintenance of meristem identity and the establishment of mutualistic plant-microbe interactions. We also hypothesize the possible involvement of AO in the activation of a signaling cascade analogous to the mechanism of prolyl hydroxylases/Hypoxia Inducible Factors in animals.

  17. Novel p47phox-related organizers regulate NADPH oxidase 1 (Nox1) activity and localization

    Science.gov (United States)

    Gianni, Davide; Diaz, Begoña; Taulet, Nicolas; Fowler, Bruce; Courtneidge, Sara A.; Bokoch, Gary M.

    2010-01-01

    The mechanisms that determine localized formation of reactive oxygen species (ROS) via NADPH oxidases (Nox) in nonphagocytic cells are unknown. We show that the c-Src substrate proteins Tks4 and Tks5 are functional members of a p47phox-related organizer superfamily. Tks proteins selectively support Nox1 and Nox3 (vs. Nox2 and Nox4) activity in reconstituted cellular systems, and interact with the NoxA1 activator protein through an SH3-mediated interaction. Endogenous Tks4 is required for Rac GTPase-dependent ROS production by DLD1 colon cancer cells. Tks4 recruits Nox1 to invadopodia that form in DLD1 cells in a Tks- and Nox-dependent fashion. We propose that Tks organizers represent novel members of an organizer superfamily that link Nox to localized ROS formation. PMID:19755710

  18. Quantum chemical modeling of the inhibition mechanism of monoamine oxidase by oxazolidinone and analogous heterocyclic compounds.

    Science.gov (United States)

    Erdem, Safiye Sağ; Özpınar, Gül Altınbaş; Boz, Ümüt

    2014-02-01

    Monoamine oxidase (MAO, EC 1.4.3.4) is responsible from the oxidation of a variety of amine neurotransmitters. MAO inhibitors are used for the treatment of depression or Parkinson's disease. They also inhibit the catabolism of dietary amines. According to one hypothesis, inactivation results from the formation of a covalent adduct to a cysteine residue in the enzyme. If the adduct is stable enough, the enzyme is inhibited for a long time. After a while, enzyme can turn to its active form as a result of adduct breakdown by β-elimination. In this study, the proposed inactivation mechanism was modeled and tested by quantum chemical calculations. Eight heterocyclic methylthioamine derivatives were selected to represent the proposed covalent adducts. Activation energies related to their β-elimination reactions were calculated using ab initio and density functional theory methods. Calculated activation energies were in good agreement with the relative stabilities of the hypothetical adducts predicted in the literature by enzyme inactivation measurements.

  19. A benzoxazine derivative induces vascular endothelial cell apoptosis in the presence of fibroblast growth factor-2 by elevating NADPH oxidase activity and reactive oxygen species levels.

    Science.gov (United States)

    Zhao, Jing; He, Qiuxia; Cheng, Yizhe; Zhao, Baoxiang; Zhang, Yun; Zhang, Shangli; Miao, Junying

    2009-09-01

    Previously, we found that 6,8-dichloro-2,3-dihydro-3-hydroxymethyl-1,4-benzoxazine (DBO) promoted apoptosis of human umbilical vascular endothelial cells (HUVECs) deprived of growth factors. In this study, we aimed to investigate the effect of DBO and its mechanism of action on angiogenesis and apoptosis of HUVECs in the presence of fibroblast growth factor-2 (FGF-2), which promotes angiogenesis and inhibits apoptosis in vivo and in vitro. DBO significantly inhibited capillary-like tube formation by promoting apoptosis of HUVECs in the presence of FGF-2 in vitro. Furthermore, DBO elevated the levels of reactive oxygen species (ROS) and nitric oxide (NO) and increased the activity of NADPH oxidase and inducible nitric oxide synthase (iNOS) in promoting apoptosis under this condition. Moreover, when NADPH oxidase was inhibited by its specific inhibitor, dibenziodolium chloride (DPI), DBO could not elevate ROS and NO levels in HUVECs. The data suggest that DBO is a new modulator of apoptosis in vitro, and it might function by increasing the activity of NADPH oxidase and iNOS, subsequently elevating the levels of ROS and NO in HUVECs. The findings of this study provide a new small molecule for investigating the FGF-2/NADPH oxidase/iNOS signaling pathway in apoptosis.

  20. Financial problems and cooperation

    Energy Technology Data Exchange (ETDEWEB)

    Izquierdo, J.

    1994-12-31

    For a Bank, an usual way to attract new clients is by offering better interest rates depending on the amount of money that the client deposits in an account: {open_quotes}The more money you have the higher interest rate you get{close_quotes}. For a company is also a common practice to offer their clients discounts connected with the number of units of the product they order: {open_quotes}The more you order, the lower price per unit you pay{close_quotes}. From these situations arises the possibility to take profit if the clients cooperate and join their money or their orders. Hence, we define a new class of cooperative games called Financial Games. We study basic properties and necessary conditions for a game to belong to this class of games and we define the concept of duality for Financial games. The core is always non-empty and, moreover, Financial games are always totally balanced. We look at some special amputations lying in the Core and we study the reduced game on the j{sup th} player at {rvec x} where x{sub j} = b{sub j} = v(N) {minus} v(N {minus} j).

  1. Precompetitive cooperative research

    International Nuclear Information System (INIS)

    Holton, W.C.

    1991-01-01

    This paper reports that in the current worldwide technology environment, it is essential for the U.S. microelectronics industry, and especially for the integrated circuit portion of that industry, that precompetitive cooperative research alliances be formed and funded at a level that enables them to be effective in rapidly advancing technology. It is important to realize that technology advances with or without our direct participation. If we do not aggressively participate we are quickly left behind. Increasing complexity and miniaturization have been the themes in semiconductor technology. Many are aware that what began in the early 60's with a few masking steps and minimum dimensions measured in mils, has now evolved to a level of sophistication requiring a 100 MIP workstation for IC design and the investment of nearly $400 million dollars in fab cost to produce today's microchips. The leading nations of the world have come to realize that their future well- being is closely tied to their ability to compete in this hi- tech environment. Industry coalitions have been formed to exploit the early ramifications of emerging technologies. Improvements in overseas manufacturing have been made and continue unabated with new products, new processes, and new services being introduced at an increasing rate. Many foreign governments are now actively involved in formulating and conducting industrial and technology policies to aid their hi-tech industry. To meet these challenges, U.S. firms, with U.S. government cooperation, must respond

  2. Teleworking through cooperation

    Directory of Open Access Journals (Sweden)

    Dario Minervini

    2006-07-01

    scheme is strictly connected to new technologies and cooperation is an important dimension of teleworking. In our study, cooperation is found performed both in social relations between employers and employees and in institutionalized relations between managers and unions. Although the two forms of cooperation, here called “social trustee cooperation” and “institutional cooperation”, are often thought as prerequisites of “best practices” of new working arrangements, our case studies demonstrate that cooperation has not always arisen that make possible to implement practices of teleworking. By focusing on cooperative relations, the results of different case studies in industry and in the service sector are discussed, thus intending to contribute to the development of sociological debate on telework.

  3. Social identity and cooperation in cultural evolution.

    Science.gov (United States)

    Smaldino, Paul E

    2017-12-06

    I discuss the function of social identity signaling in facilitating cooperative group formation, and how the nature of that function changes with the structure of social organization. I propose that signals of social identity facilitate assortment for successful coordination in large-scale societies, and that the multidimensional, context-dependent nature of social identity is crucial for successful coordination when individuals have to cooperate in different contexts. Furthermore, the structure of social identity is tied to the structure of society, so that as societies grow larger and more interconnected, the landscape of social identities grows more heterogeneous. This discussion bears directly on the need to articulate the dynamics of emergent, ephemeral groups as a major factor in human cultural evolution. Copyright © 2017 The Author. Published by Elsevier B.V. All rights reserved.

  4. Models in cooperative game theory

    CERN Document Server

    Branzei, Rodica; Tijs, Stef

    2008-01-01

    This book investigates models in cooperative game theory in which the players have the possibility to cooperate partially. In a crisp game the agents are either fully involved or not involved at all in cooperation with some other agents, while in a fuzzy game players are allowed to cooperate with infinite many different participation levels, varying from non-cooperation to full cooperation. A multi-choice game describes the intermediate case in which each player may have a fixed number of activity levels. Different set and one-point solution concepts for these games are presented. The properties of these solution concepts and their interrelations on several classes of crisp, fuzzy, and multi-choice games are studied. Applications of the investigated models to many economic situations are indicated as well. The second edition is highly enlarged and contains new results and additional sections in the different chapters as well as one new chapter.

  5. Political Ideology, Trust, and Cooperation

    Science.gov (United States)

    Balliet, Daniel; Tybur, Joshua M.; Wu, Junhui; Antonellis, Christian; Van Lange, Paul A. M.

    2016-01-01

    Theories suggest that political ideology relates to cooperation, with conservatives being more likely to pursue selfish outcomes, and liberals more likely to pursue egalitarian outcomes. In study 1, we examine how political ideology and political party affiliation (Republican vs. Democrat) predict cooperation with a partner who self-identifies as Republican or Democrat in two samples before (n = 362) and after (n = 366) the 2012 US presidential election. Liberals show slightly more concern for their partners’ outcomes compared to conservatives (study 1), and in study 2 this relation is supported by a meta-analysis (r = .15). However, in study 1, political ideology did not relate to cooperation in general. Both Republicans and Democrats extend more cooperation to their in-group relative to the out-group, and this is explained by expectations of cooperation from in-group versus out-group members. We discuss the relation between political ideology and cooperation within and between groups. PMID:29593363

  6. The Professionalization of Intelligence Cooperation

    DEFF Research Database (Denmark)

    Svendsen, Adam David Morgan

    "Providing an in-depth insight into the subject of intelligence cooperation (officially known as liason), this book explores the complexities of this process. Towards facilitating a general understanding of the professionalization of intelligence cooperation, Svendsen's analysis includes risk...... management and encourages the realisation of greater resilience. Svendsen discusses the controversial, mixed and uneven characterisations of the process of the professionalization of intelligence cooperation and argues for a degree of 'fashioning method out of mayhem' through greater operational...

  7. ITDB Cooperation With International Organizations

    International Nuclear Information System (INIS)

    2010-01-01

    IAEA illicit trafficking database cooperates with many international organizations. Among these organizations are Interpol, Universal Postal Union,and World Customs Organization. Other organizations are Organization for Security and Cooperation in Europe, UN Economic Commission for Europe, UN-Department of Disarmament Affairs and UN office for Drug and Crime. The cooperation with Interpol involves consultations on issues of training and technical assistance and other matters of common interest.

  8. A Cooperative IDS Approach Against MPTCP Attacks

    Science.gov (United States)

    2017-06-01

    physical testbeds in order to present a methodology that allows distributed IDSs (DIDS) to cooperate in a manner that permits effective detection of...reconstruct MPTCP subflows and detect malicious content. Next, we build physical testbeds in order to present a methodology that allows distributed IDSs...It has been proven with measurements performed with smartphones that popular applications function correctly through a SOCKS [10] proxy and MPTCP

  9. NADPH Oxidase Activity in Cerebral Arterioles Is a Key Mediator of Cerebral Small Vessel Disease—Implications for Prevention

    Directory of Open Access Journals (Sweden)

    Mark F. McCarty

    2015-04-01

    Full Text Available Cerebral small vessel disease (SVD, a common feature of brain aging, is characterized by lacunar infarcts, microbleeds, leukoaraiosis, and a leaky blood-brain barrier. Functionally, it is associated with cognitive decline, dementia, depression, gait abnormalities, and increased risk for stroke. Cerebral arterioles in this syndrome tend to hypertrophy and lose their capacity for adaptive vasodilation. Rodent studies strongly suggest that activation of Nox2-dependent NADPH oxidase activity is a crucial driver of these structural and functional derangements of cerebral arterioles, in part owing to impairment of endothelial nitric oxide synthase (eNOS activity. This oxidative stress may also contribute to the breakdown of the blood-brain barrier seen in SVD. Hypertension, aging, metabolic syndrome, smoking, hyperglycemia, and elevated homocysteine may promote activation of NADPH oxidase in cerebral arterioles. Inhibition of NADPH oxidase with phycocyanobilin from spirulina, as well as high-dose statin therapy, may have potential for prevention and control of SVD, and high-potassium diets merit study in this regard. Measures which support effective eNOS activity in other ways—exercise training, supplemental citrulline, certain dietary flavonoids (as in cocoa and green tea, and capsaicin, may also improve the function of cerebral arterioles. Asian epidemiology suggests that increased protein intakes may decrease risk for SVD; conceivably, arginine and/or cysteine—which boosts tissue glutathione synthesis, and can be administered as N-acetylcysteine—mediate this benefit. Ameliorating the risk factors for SVD—including hypertension, metabolic syndrome, hyperglycemia, smoking, and elevated homocysteine—also may help to prevent and control this syndrome, although few clinical trials have addressed this issue to date.

  10. NADPH Oxidase Activity in Cerebral Arterioles Is a Key Mediator of Cerebral Small Vessel Disease-Implications for Prevention.

    Science.gov (United States)

    McCarty, Mark F

    2015-04-15

    Cerebral small vessel disease (SVD), a common feature of brain aging, is characterized by lacunar infarcts, microbleeds, leukoaraiosis, and a leaky blood-brain barrier. Functionally, it is associated with cognitive decline, dementia, depression, gait abnormalities, and increased risk for stroke. Cerebral arterioles in this syndrome tend to hypertrophy and lose their capacity for adaptive vasodilation. Rodent studies strongly suggest that activation of Nox2-dependent NADPH oxidase activity is a crucial driver of these structural and functional derangements of cerebral arterioles, in part owing to impairment of endothelial nitric oxide synthase (eNOS) activity. This oxidative stress may also contribute to the breakdown of the blood-brain barrier seen in SVD. Hypertension, aging, metabolic syndrome, smoking, hyperglycemia, and elevated homocysteine may promote activation of NADPH oxidase in cerebral arterioles. Inhibition of NADPH oxidase with phycocyanobilin from spirulina, as well as high-dose statin therapy, may have potential for prevention and control of SVD, and high-potassium diets merit study in this regard. Measures which support effective eNOS activity in other ways-exercise training, supplemental citrulline, certain dietary flavonoids (as in cocoa and green tea), and capsaicin, may also improve the function of cerebral arterioles. Asian epidemiology suggests that increased protein intakes may decrease risk for SVD; conceivably, arginine and/or cysteine-which boosts tissue glutathione synthesis, and can be administered as N-acetylcysteine-mediate this benefit. Ameliorating the risk factors for SVD-including hypertension, metabolic syndrome, hyperglycemia, smoking, and elevated homocysteine-also may help to prevent and control this syndrome, although few clinical trials have addressed this issue to date.

  11. Evolution of conditional cooperation under multilevel selection.

    Science.gov (United States)

    Zhang, Huanren; Perc, Matjaž

    2016-03-11

    We study the emergence of conditional cooperation in the presence of both intra-group and inter-group selection. Individuals play public goods games within their groups using conditional strategies, which are represented as piecewise linear response functions. Accordingly, groups engage in conflicts with a certain probability. In contrast to previous studies, we consider continuous contribution levels and a rich set of conditional strategies, allowing for a wide range of possible interactions between strategies. We find that the existence of conditional strategies enables the stabilization of cooperation even under strong intra-group selection. The strategy that eventually dominates in the population has two key properties: (i) It is unexploitable with strong intra-group selection; (ii) It can achieve full contribution to outperform other strategies in the inter-group selection. The success of this strategy is robust to initial conditions as well as changes to important parameters. We also investigate the influence of different factors on cooperation levels, including group conflicts, group size, and migration rate. Their effect on cooperation can be attributed to and explained by their influence on the relative strength of intra-group and inter-group selection.

  12. Social heuristics shape intuitive cooperation.

    Science.gov (United States)

    Rand, David G; Peysakhovich, Alexander; Kraft-Todd, Gordon T; Newman, George E; Wurzbacher, Owen; Nowak, Martin A; Greene, Joshua D

    2014-04-22

    Cooperation is central to human societies. Yet relatively little is known about the cognitive underpinnings of cooperative decision making. Does cooperation require deliberate self-restraint? Or is spontaneous prosociality reined in by calculating self-interest? Here we present a theory of why (and for whom) intuition favors cooperation: cooperation is typically advantageous in everyday life, leading to the formation of generalized cooperative intuitions. Deliberation, by contrast, adjusts behaviour towards the optimum for a given situation. Thus, in one-shot anonymous interactions where selfishness is optimal, intuitive responses tend to be more cooperative than deliberative responses. We test this 'social heuristics hypothesis' by aggregating across every cooperation experiment using time pressure that we conducted over a 2-year period (15 studies and 6,910 decisions), as well as performing a novel time pressure experiment. Doing so demonstrates a positive average effect of time pressure on cooperation. We also find substantial variation in this effect, and show that this variation is partly explained by previous experience with one-shot lab experiments.

  13. Regional cooperation in transportation planning.

    Science.gov (United States)

    2012-02-01

    As Floridas urbanized areas grow and merge, : neighboring jurisdictions experience interrelated : problems and opportunities, and regional : cooperation becomes an imperative. In the : transportation sector, Floridas metropolitan : planning org...

  14. Electroconvulsive therapy in patients taking monoamine oxidase inhibitors.

    Science.gov (United States)

    Dolenc, Tamara J; Habl, Samar S; Barnes, Roxann D; Rasmussen, Keith G

    2004-12-01

    Concerns have been expressed regarding the use of general anesthesia for electroconvulsive therapy (ECT) in patients taking monoamine oxidase inhibitors (MAOIs). We review the published literature and present 4 new cases and conclude that there is no evidence of a dangerous interaction between ECT and MAOI use. In general, a cautious approach would be to discontinue MAOIs before ECT if the medication has not been helpful; however, there is no need for a washout interval before starting ECT. Furthermore, if there is otherwise a reason for continuing the MAOI, it can be continued during index ECT or initiated during maintenance ECT.

  15. Lysyl Oxidase, a Targetable Secreted Molecule Involved in Cancer Metastasis

    DEFF Research Database (Denmark)

    Cox, Thomas Robert; Gartland, Alison; Erler, Janine T

    2016-01-01

    to improve the tools available in our arsenal against this disease, both in terms of treatment, but also prevention. Recently, we showed that hypoxic induction of the extracellular matrix modifying enzyme lysyl oxidase (LOX) correlates with metastatic dissemination to the bone in estrogen receptor negative...... of this enzyme as a therapeutic target for metastatic breast cancer. Our work is the latest in an emerging body of work supporting the targeting of LOX and calls for greater efforts in developing therapeutics against this extracellular secreted factor in the prevention of cancer progression across multiple solid...

  16. Evolution of cooperation driven by social-welfare-based migration

    Science.gov (United States)

    Li, Yan; Ye, Hang; Zhang, Hong

    2016-03-01

    Individuals' migration behavior may play a significant role in the evolution of cooperation. In reality, individuals' migration behavior may depend on their perceptions of social welfare. To study the relationship between social-welfare-based migration and the evolution of cooperation, we consider an evolutionary prisoner's dilemma game (PDG) in which an individual's migration depends on social welfare but not on the individual's own payoff. By introducing three important social welfare functions (SWFs) that are commonly studied in social science, we find that social-welfare-based migration can promote cooperation under a wide range of parameter values. In addition, these three SWFs have different effects on cooperation, especially through the different spatial patterns formed by migration. Because the relative efficiency of the three SWFs will change if the parameter values are changed, we cannot determine which SWF is optimal for supporting cooperation. We also show that memory capacity, which is needed to evaluate individual welfare, may affect cooperation levels in opposite directions under different SWFs. Our work should be helpful for understanding the evolution of human cooperation and bridging the chasm between studies of social preferences and studies of social cooperation.

  17. Putting together a plasma membrane NADH oxidase: a tale of three laboratories.

    Science.gov (United States)

    Löw, Hans; Crane, Frederick L; Morré, D James

    2012-11-01

    The observation that high cellular concentrations of NADH were associated with low adenylate cyclase activity led to a search for the mechanism of the effect. Since cyclase is in the plasma membrane, we considered the membrane might have a site for NADH action, and that NADH might be oxidized at that site. A test for NADH oxidase showed very low activity, which could be increased by adding growth factors. The plasma membrane oxidase was not inhibited by inhibitors of mitochondrial NADH oxidase such as cyanide, rotenone or antimycin. Stimulation of the plasma membrane oxidase by iso-proterenol or triiodothyronine was different from lack of stimulation in endoplasmic reticulum. After 25 years of research, three components of a trans membrane NADH oxidase have been discovered. Flavoprotein NADH coenzyme Q reductases (NADH cytochrome b reductase) on the inside, coenzyme Q in the middle, and a coenzyme Q oxidase on the outside as a terminal oxidase. The external oxidase segment is a copper protein with unique properties in timekeeping, protein disulfide isomerase and endogenous NADH oxidase activity, which affords a mechanism for control of cell growth by the overall NADH oxidase and the remarkable inhibition of oxidase activity and growth of cancer cells by a wide range of anti-tumor drugs. A second trans plasma membrane electron transport system has been found in voltage dependent anion channel (VDAC), which has NADH ferricyanide reductase activity. This activity must be considered in relation to ferricyanide stimulation of growth and increased VDAC antibodies in patients with autism. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Convergent evolution of morphogenetic processes in fungi: Role of tetraspanins and NADPH oxidases 2 in plant pathogens and saprobes.

    Science.gov (United States)

    Malagnac, Fabienne; Bidard, Frédérique; Lalucque, Hervé; Brun, Sylvain; Lambou, Karine; Lebrun, Marc-Henri; Silar, Philippe

    2008-01-01

    Convergent evolution of trophic life style and morphological characters are very common in the fungal kingdom. Recently, we have shown that the same molecular machinery containing a tetraspanin and a NADPH oxidase has been recruited in two different fungal species for the same purpose (exiting from a melanized re-enforced cell at a focal weakened point), but at different stages of their development (ascospore germination and appressorium mediated penetration). Although this molecular machinery is required at these key developmental steps, it is also likely involved in specialized cellular functions at other stages of fungal development, as shown here for nutrient acquisition by Podospora anserina.

  19. Engineering co-operation

    Energy Technology Data Exchange (ETDEWEB)

    Hryniszak, W

    1981-06-01

    A purposeful employment policy for human energy is basic to solving the energy dilemma, but a lack of understanding about human behavior has allowed man's exploitive characteristics to dominate during the Inductrial Revolution. England is dependent on trade to survive, but the importance of size in world competition is seen in the trend toward multinational and partnership enterprises. Reflecting this increasing competition, the engineering industries see a need for government policies that acknowledge the importance of technology and the effects of those policies on productivity. Engineering progress requires the creativity of optimistic idealism and the realism of implementing new ideas. The training and nurturing of human resources should begin by broadening the education of engineers to emphasize the concepts of quality and cooperation between government and industry. Engineers and scientists, who work within society, need to understand national demands and to operate in accordance with the highest moral standards. (DCK)

  20. Coaching While Coaching: The Functional Relationship of Elbow Coaching on Cooperating Teacher's "e"Coaching, Pre-Service Teacher's Reading Instruction, and Student Outcomes

    Science.gov (United States)

    Jones, Jennie Leigh

    2017-01-01

    Pre-service teachers (PST) clinical experiences are critical for transfering theory to practice (e.g., Brownell, Ross, Colon, and McCallum, 2005) and these experiences require effective mentoring, coaching, and supervision from university supervisors and cooperating teachers (e.g., Leko, Brownell, Sindelar, & Murphy, 2012). Yet, many special…

  1. The Relationship between Children's Executive Functioning, Theory of Mind, and Verbal Skills with Their Own and Others' Behaviour in a Cooperative Context: Changes in Relations from Early to Middle School-Age

    Science.gov (United States)

    Huyder, Vanessa; Nilsen, Elizabeth S.; Bacso, Sarah A.

    2017-01-01

    Learning to behave in socially competent ways is an essential component of children's development. This study examined the relations between children's social, communicative, and cognitive skills and their behaviours during a cooperative task, as well as how these relationships change at different ages. Early school-age (5-8 years old) and middle…

  2. Capturing cooperative interactions with the PSI-MI format.

    Science.gov (United States)

    Van Roey, Kim; Orchard, Sandra; Kerrien, Samuel; Dumousseau, Marine; Ricard-Blum, Sylvie; Hermjakob, Henning; Gibson, Toby J

    2013-01-01

    The complex biological processes that control cellular function are mediated by intricate networks of molecular interactions. Accumulating evidence indicates that these interactions are often interdependent, thus acting cooperatively. Cooperative interactions are prevalent in and indispensible for reliable and robust control of cell regulation, as they underlie the conditional decision-making capability of large regulatory complexes. Despite an increased focus on experimental elucidation of the molecular details of cooperative binding events, as evidenced by their growing occurrence in literature, they are currently lacking from the main bioinformatics resources. One of the contributing factors to this deficiency is the lack of a computer-readable standard representation and exchange format for cooperative interaction data. To tackle this shortcoming, we added functionality to the widely used PSI-MI interchange format for molecular interaction data by defining new controlled vocabulary terms that allow annotation of different aspects of cooperativity without making structural changes to the underlying XML schema. As a result, we are able to capture cooperative interaction data in a structured format that is backward compatible with PSI-MI-based data and applications. This will facilitate the storage, exchange and analysis of cooperative interaction data, which in turn will advance experimental research on this fundamental principle in biology.

  3. 75 FR 10319 - Cooper Tools-Sumter, Cooper Tools Divisions, a Subsidiary of Cooper Industries, Inc., Including...

    Science.gov (United States)

    2010-03-05

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-71,602] Cooper Tools--Sumter, Cooper Tools Divisions, a Subsidiary of Cooper Industries, Inc., Including On-Site Leased Workers From... January 26, 2010, applicable to workers of Cooper Tools--Sumter, Cooper Tools Division, a subsidiary of...

  4. Hofmeister effects on the glucose oxidase hydrogel-modified electrode

    International Nuclear Information System (INIS)

    Suzuki, Aimi; Tsujimura, Seiya

    2016-01-01

    We describe the consistent effect of salts in the electrolyte solution on glucose oxidation current production in the redox hydrogel-modified electrode containing glucose oxidase as an electrocatalyst and Os complex mediator. The ions affect not only on the electron transfer between the enzyme and the Os complex, but also on the hydrogel structure. This study found that the degree of the effect can be characterized by Hofmeister series. The relative decrease in oxidization current is the lowest in the middle of the Hofmeister series, and increases monotonically on either side. An increase of ionic strength inhibits the electron transfer from the active site of glucose oxidase to Os complex. In addition to this, the kosmotropic anions, which are strongly hydrated, caused hydrogel deswelling (shrinking). The more chaotropic an ion is, the more it adsorbs to uncharged parts of polymer/enzyme with dispersion force, and the swelling of the hydrogel decreases the catalytic current. This study impacts the design of hydrogel electrode and selection of electrolyte ions for bioelectronic applications.

  5. 2-acetylphenol analogs as potent reversible monoamine oxidase inhibitors

    Directory of Open Access Journals (Sweden)

    Legoabe LJ

    2015-07-01

    Full Text Available Lesetja J Legoabe,1 Anél Petzer,1 Jacobus P Petzer1,21Centre of Excellence for Pharmaceutical Sciences, 2Department of Pharmaceutical Chemistry, School of Pharmacy, North-West University, Potchefstroom, South AfricaAbstract: Based on a previous report that substituted 2-acetylphenols may be promising leads for the design of novel monoamine oxidase (MAO inhibitors, a series of C5-substituted 2-acetylphenol analogs (15 and related compounds (two were synthesized and evaluated as inhibitors of human MAO-A and MAO-B. Generally, the study compounds exhibited inhibitory activities against both MAO-A and MAO-B, with selectivity for the B isoform. Among the compounds evaluated, seven compounds exhibited IC50 values <0.01 µM for MAO-B inhibition, with the most selective compound being 17,000-fold selective for MAO-B over the MAO-A isoform. Analyses of the structure–activity relationships for MAO inhibition show that substitution on the C5 position of the 2-acetylphenol moiety is a requirement for MAO-B inhibition, and the benzyloxy substituent is particularly favorable in this regard. This study concludes that C5-substituted 2-acetylphenol analogs are potent and selective MAO-B inhibitors, appropriate for the design of therapies for neurodegenerative disorders such as Parkinson’s disease.Keywords: monoamine oxidase, MAO, inhibition, 2-acetylphenol, structure–activity relationship

  6. Students' views of cooperative learning and group testing.

    Science.gov (United States)

    Hicks, Jay

    2007-01-01

    Today's radiologic technology students must learn to collaborate and communicate to function as part of the health care team. Innovative educational techniques such as cooperative learning (working collectively in small groups) and group testing (collaborating on tests) can foster these skills. Assess students' familiarity with and opinions about cooperative learning and group testing before and after participation in a semester-long course incorporating these methods. Twenty-eight students enrolled in a baccalaureate-level radiologic technology program in Louisiana were surveyed at the beginning and end of the semester. Results showed that students were more knowledgeable about and more accepting of cooperative learning and group testing after participating in the course. However, some students continued to prefer independent learning. Students are open to new learning methods such as cooperative learning and group testing. These techniques can help them develop the skills they will need to function collaboratively in the workplace.

  7. Biodegradation of phenolic compounds with oxidases from sorghum and non-defined mixed bacterium media

    International Nuclear Information System (INIS)

    Obame, C. E. L.; Savadogo, P. W.; Mamoudou, D. H.; Dembele, R. H.; Traore, A. S.

    2009-01-01

    The biodegradation of the phenolic compounds is performed using oxidative enzymes, e. g. polyphenol oxidases (PPOs) and peroxidases (POXs). These oxidases displaying a wide spectrum for the oxidation of phenolic compounds were isolated either from sorghum or mixed bacteria. Spectrophotometric methods were used to assess the monophenolase and diphenolase activities of PPOs as well as the hydrogen-dependant oxidation of POXs. (Author)

  8. Study on the preparation of immobilized glucose oxidase membrane and its application in clinic analysis

    International Nuclear Information System (INIS)

    Yu Ye; Cao Jin; Su Zongxian; Chen Zixiong

    1990-01-01

    The paper deals with the preparation of immobilized glucose oxidase membrane by using two steps irradiation (irradiation gratfting, irradiation entrapping). Some properties of membrane were discussed. The immobilized glucose oxidase membrane with oxygen electrode and oxygen analyser can be satisfied with the clinic analysis for the determination of serum glucose

  9. Switching an O2 sensitive glucose oxidase bioelectrode into an almost insensitive one by cofactor redesign.

    Science.gov (United States)

    Tremey, Emilie; Suraniti, Emmanuel; Courjean, Olivier; Gounel, Sébastien; Stines-Chaumeil, Claire; Louerat, Frédéric; Mano, Nicolas

    2014-06-04

    In the 5-8 mM glucose concentration range, of particular interest for diabetes management, glucose oxidase bioelectrodes are O2 dependent, which decrease their efficiencies. By replacing the natural cofactor of glucose oxidase, we succeeded in turning an O2 sensitive bioelectrode into an almost insensitive one.

  10. Hydroxychavicol: a potent xanthine oxidase inhibitor obtained from the leaves of betel, Piper betle.

    Science.gov (United States)

    Murata, Kazuya; Nakao, Kikuyo; Hirata, Noriko; Namba, Kensuke; Nomi, Takao; Kitamura, Yoshihisa; Moriyama, Kenzo; Shintani, Takahiro; Iinuma, Munekazu; Matsuda, Hideaki

    2009-07-01

    The screening of Piperaceous plants for xanthine oxidase inhibitory activity revealed that the extract of the leaves of Piper betle possesses potent activity. Activity-guided purification led us to obtain hydroxychavicol as an active principle. Hydroxychavicol is a more potent xanthine oxidase inhibitor than allopurinol, which is clinically used for the treatment of hyperuricemia.

  11. Analysis of cellulase and polyphenol oxidase production by southern pine beetle associated fungi

    Science.gov (United States)

    Abduvali Valiev; Zumrut B. Ogel; Dier D. Klepzig

    2009-01-01

    In this study, the production of extracellular enzymes by fungi associated with southern pine beetle was investigated for the first time. Cellulase and polyphenol oxidase production were analyzed for three beetle associated fungi. Only the mutualistic symbiont Entomocorticium sp. A was found to produce cellulases and polyphenol oxidase....

  12. Biocatalytic potential of laccase-like multicopper oxidases from Aspergillus niger

    NARCIS (Netherlands)

    Tamayo Ramos, J.A.; Berkel, van W.J.H.; Graaff, de L.H.

    2012-01-01

    BACKGROUND: Laccase-like multicopper oxidases have been reported in several Aspergillus species but they remain uncharacterized. The biocatalytic potential of the Aspergillus niger fungal pigment multicopper oxidases McoA and McoB and ascomycete laccase McoG was investigated. RESULTS: The

  13. Purification, characterization and decolorization of bilirubin oxidase from Myrothecium verrucaria 3.2190

    Science.gov (United States)

    Myrothecium verrucaria 3.2190 is a nonligninolytic fungus that produces bilirubin oxidase. Both Myrothecium verrucaria and the extracellular bilirubin oxidase were tested for their ability to decolorize indigo carmine. The biosorption and biodegradation of the dye were detected during the process of...

  14. Hot or not? Discovery and characterization of a thermostable alditol oxidase from Acidothermus cellulolyticus 11B

    NARCIS (Netherlands)

    Winter, Remko T.; Heuts, Dominic P. H. M.; Rijpkema, Egon M. A.; van Bloois, Edwin; Wijma, Hein J.; Fraaije, Marco W.

    We describe the discovery, isolation and characterization of a highly thermostable alditol oxidase from Acidothermus cellulolyticus 11B. This protein was identified by searching the genomes of known thermophiles for enzymes homologous to Streptomyces coelicolor A3(2) alditol oxidase (AldO). A gene

  15. Discovery, characterization, and kinetic analysis of an alditol oxidase from streptomyces coelicolor

    NARCIS (Netherlands)

    Heuts, Dominic P. H. M.; van Hellemond, Erik W.; Janssen, Dick B.; Fraaije, Marco W.

    2007-01-01

    A gene encoding an alditol oxidase was found in the genome of Streptomyces coelicolor A3(2). This newly identified oxidase, AldO, was expressed at extremely high levels in Escherichia coli when fused to maltose-binding protein. AldO is a soluble monomeric flavoprotein with subunits of 45.1 kDa, each

  16. Biodegradation of phenolic compounds with oxidases from sorghum and non-defined mixed bacterium media

    Energy Technology Data Exchange (ETDEWEB)

    Obame, C. E. L.; Savadogo, P. W.; Mamoudou, D. H.; Dembele, R. H.; Traore, A. S.

    2009-07-01

    The biodegradation of the phenolic compounds is performed using oxidative enzymes, e. g. polyphenol oxidases (PPOs) and peroxidases (POXs). These oxidases displaying a wide spectrum for the oxidation of phenolic compounds were isolated either from sorghum or mixed bacteria. Spectrophotometric methods were used to assess the monophenolase and diphenolase activities of PPOs as well as the hydrogen-dependant oxidation of POXs. (Author)

  17. Cooperative newsvendor games : a review

    NARCIS (Netherlands)

    Montrucchio, L.; Norde, H.; Ozen, U.; Scarsini, M.; Slikker, M.; Choi, T.-M.

    2012-01-01

    In this survey, we review some of the main contributions to the cooperative approach of newsvendor situations. We show how newsvendor situations with several retailers can be modeled as a transferable-utility cooperative game and we concentrate on one solution concept: the core. First, we examine

  18. Gender and Cooperation in Children

    DEFF Research Database (Denmark)

    Cardenas, Juan-Camilo; Dreber, Anna; Essen, Emma von

    2014-01-01

    In this article we compare cooperation among Colombian and Swedish children aged 9-12. We illustrate the dynamics of the prisoner’s dilemma in a new task that is easily understood by children and performed during a physical education class. We find no robust evidence of a difference in cooperation...

  19. Monitoring emotions and cooperative behavior

    NARCIS (Netherlands)

    Gorbunov, R.D.

    2013-01-01

    Cooperation among people in teams that are bound to perform a common goal is one of the main factors determining success of these teams. Cooperation becomes even more important for small teams performing long-term missions in isolation. Examples of such missions include missions performed on the

  20. Subsidizing R&D cooperatives

    NARCIS (Netherlands)

    Hinloopen, J.

    2001-01-01

    A framework is developed with which the implementation of two commonly used R&D-stimulating policies can be evaluated: providing R&D subsidies and sustaining the formation of R&D cooperatives. Subsidized R&D cooperatives can also be analyzed. The analysis shows that providing R&D subsidies is more