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Sample records for tryptophan synthase beta

  1. Alpha-tryptophan synthase of Isatis tinctoria: gene cloning and expression.

    Science.gov (United States)

    Salvini, M; Boccardi, T M; Sani, E; Bernardi, R; Tozzi, S; Pugliesi, C; Durante, M

    2008-07-01

    Indole producing reaction is a crux in the regulation of metabolite flow through the pathways and the coordination of primary and secondary product biosynthesis in plants. Indole is yielded transiently from indole-3-glycerol phosphate and immediately condensed with serine to give tryptophan, by the enzyme tryptophan synthase (TS). There is evidence that plant TS, like the bacterial complex, functions as an alpha beta heteromer. In few species, e.g. maize, are known enzymes, related with the TS alpha-subunit (TSA), able to catalyse reaction producing indole, which is free to enter the secondary metabolite pathways. In this contest, we searched for TSA and TSA related genes in Isatis tinctoria, a species producing the natural blue dye indigo. The It-TSA cDNA and the full-length exons/introns genomic region were isolated. The phylogenetic analysis indicates that It-TSA is more closely related to Arabidopsis thaliana At-T14E10.210 TSA (95.7% identity at the amino acid level) with respect to A. thaliana At-T10P11.11 TSA1-like (63%), Zea mays indole-3-glycerol phosphate lyase (54%), Z. mays TSA (53%), and Z. mays indole synthase (50%). The It-TSA cDNA was also able to complement an Escherichia coli trpA mutant. To examine the involvement of It-TSA in the biosynthesis of secondary metabolism compounds, It-TSA expression was tested in seedling grown under different light conditions. Semi-quantitative RT-PCR showed an increase in the steady-state level of It-TSA mRNA, paralleled by an increase of indigo and its precursor isatan B. Our results appear to indicate an involvement for It-TSA in indigo precursor synthesis and/or tryptophan biosynthesis.

  2. Cloning and characterization of indole synthase (INS) and a putative tryptophan synthase α-subunit (TSA) genes from Polygonum tinctorium.

    Science.gov (United States)

    Jin, Zhehao; Kim, Jin-Hee; Park, Sang Un; Kim, Soo-Un

    2016-12-01

    Two cDNAs for indole-3-glycerol phosphate lyase homolog were cloned from Polygonum tinctorium. One encoded cytosolic indole synthase possibly in indigoid synthesis, whereas the other encoded a putative tryptophan synthase α-subunit. Indigo is an old natural blue dye produced by plants such as Polygonum tinctorium. Key step in plant indigoid biosynthesis is production of indole by indole-3-glycerol phosphate lyase (IGL). Two tryptophan synthase α-subunit (TSA) homologs, PtIGL-short and -long, were isolated by RACE PCR from P. tinctorium. The genome of the plant contained two genes coding for IGL. The short and the long forms, respectively, encoded 273 and 316 amino acid residue-long proteins. The short form complemented E. coli ΔtnaA ΔtrpA mutant on tryptophan-depleted agar plate signifying production of free indole, and thus was named indole synthase gene (PtINS). The long form, either intact or without the transit peptide sequence, did not complement the mutant and was tentatively named PtTSA. PtTSA was delivered into chloroplast as predicted by 42-residue-long targeting sequence, whereas PtINS was localized in cytosol. Genomic structure analysis suggested that a TSA duplicate acquired splicing sites during the course of evolution toward PtINS so that the targeting sequence-containing pre-mRNA segment was deleted as an intron. PtINS had about two to fivefolds higher transcript level than that of PtTSA, and treatment of 2,1,3-benzothiadiazole caused the relative transcript level of PtINS over PtTSA was significantly enhanced in the plant. The results indicate participation of PtINS in indigoid production.

  3. Enzymatic synthesis of S-phenyl-L-cysteine from keratin hydrolysis industries wastewater with tryptophan synthase.

    Science.gov (United States)

    Xu, Lisheng; Wang, Zhiyuan; Mao, Pingting; Liu, Junzhong; Zhang, Hongjuan; Liu, Qian; Jiao, Qing-Cai

    2013-04-01

    An economical method for production of S-phenyl-L-cysteine from keratin acid hydrolysis wastewater (KHW) containing L-serine was developed by recombinant tryptophan synthase. This study provides us with an alternative KHW utilization strategy to synthesize S-phenyl-L-cysteine. Tryptophan synthase could efficiently convert L-serine contained in KHW to S-phenyl-L-cysteine at pH 9.0, 40°C and Trion X-100 of 0.02%. In a scale up study, L-serine conversion rate reach 97.1% with a final S-phenyl-L-cysteine concentration of 38.6 g l(-1). Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Stochastic thermodynamics of a chemical nanomachine: The channeling enzyme tryptophan synthase.

    Science.gov (United States)

    Loutchko, Dimitri; Eisbach, Maximilian; Mikhailov, Alexander S

    2017-01-14

    The enzyme tryptophan synthase is characterized by a complex pattern of allosteric interactions that regulate the catalytic activity of its two subunits and opening or closing of their ligand gates. As a single macromolecule, it implements 13 different reaction steps, with an intermediate product directly channeled from one subunit to another. Based on experimental data, a stochastic model for the operation of tryptophan synthase has been earlier constructed [D. Loutchko, D. Gonze, and A. S. Mikhailov, J. Phys. Chem. B 120, 2179 (2016)]. Here, this model is used to consider stochastic thermodynamics of such a chemical nanomachine. The Gibbs energy landscape of the internal molecular states is determined, the production of entropy and its flow within the enzyme are analyzed, and the information exchange between the subunits resulting from allosteric cross-regulations and channeling is discussed.

  5. Homocystinuria due to cystathionine beta synthase deficiency

    Directory of Open Access Journals (Sweden)

    Rao T

    2008-01-01

    Full Text Available A two year-old male child presented with cutis marmorata congenita universalis, brittle hair, mild mental retardation, and finger spasms. Biochemical findings include increased levels of homocysteine in the blood-106.62 µmol/L (normal levels: 5.90-16µmol/L. Biochemical tests such as the silver nitroprusside and nitroprusside tests were positive suggesting homocystinuria. The patient was treated with oral pyridoxine therapy for three months. The child responded well to this therapy and the muscle spasms as well as skin manifestations such as cutis marmorata subsided. The treatment is being continued; the case is reported here because of its rarity. Homocysteinuria arising due to cystathionine beta-synthase (CBS deficiency is an autosomal recessive disorder of methionine metabolism that produces increased levels of urinary homocysteine and methionine It manifests itself in vascular, central nervous system, cutaneous, and connective tissue disturbances and phenotypically resembles Marfan′s syndrome. Skin manifestations include malar flush, thin hair, and cutis reticulata / marmorata.

  6. Biocatalytic production of psilocybin and derivatives in tryptophan synthase-enhanced reactions.

    Science.gov (United States)

    Blei, Felix; Baldeweg, Florian; Fricke, Janis; Hoffmeister, Dirk

    2018-05-11

    Psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine) is the main alkaloid of the fungal genus Psilocybe, the so-called "magic mushrooms". The pharmaceutical interest in this psychotropic natural product as a future medication to treat depression and anxiety is strongly re-emerging. Here, we present an enhanced enzymatic route of psilocybin production by adding TrpB, the tryptophan synthase of the mushroom Psilocybe cubensis, to the reaction. We capitalized on its substrate flexibility and show psilocybin formation from 4-hydroxyindole and L-serine, which are less cost-intensive substrates, compared to the previous method. Further, we show enzymatic production of 7-phosphoryloxytryptamine (isonorbaeocystin), a non-natural congener of the Psilocybe alkaloid norbaeocystin (4-phosphoryloxytryptamine), and of serotonin (5-hydroxytryptamine) via the same in vitro approach. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. 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.

  8. Beta-Glucan Synthase Gene Expression in Pleurotus sp

    International Nuclear Information System (INIS)

    Azhar Mohamad; Nie, H.J.

    2016-01-01

    Pleurotus sp. is a popular edible mushroom, containing various functional component, in particular, Beta-glucan. Beta-glucans is a part of glucan family of polysaccharides and supposedly contribute to medicinal and nutritional value of Pleurotus.sp. In order to understand the distribution of Beta-glucan in Pleurotus.sp, the Beta-glucan synthase gene expression was determined and compared in different part of Pleurotus, namely mycelium, stripe and cap. The Pleurotus.sp RNA was extracted using commercial kit, employing Tissuelyser ll (Qiagen, USA) to disrupt the cell walls. Then the RNA was quantified by Nano drop (Thermo Fisher, USA) and visualized using denaturing agarose gel. RNA with good OD 260.280 reading (∼2.0) was chosen and converted to cDNA. Using Laccase synthase gene as home keeping gene, Beta-glucan synthase gene expression was quantified using CFX 96 Real Time PCR detection system (Biorad, USA). Preliminary result shows that Beta-glucan synthase was relatively expressed the most in stripe, followed by mycelium and barely in cap. (author)

  9. A small-molecule allosteric inhibitor of Mycobacterium tuberculosis tryptophan synthase

    Energy Technology Data Exchange (ETDEWEB)

    Wellington, Samantha; Nag, Partha P.; Michalska, Karolina; Johnston, Stephen E.; Jedrzejczak, Robert P.; Kaushik, Virendar K.; Clatworthy, Anne E.; Siddiqi, Noman; McCarren, Patrick; Bajrami, Besnik; Maltseva, Natalia I.; Combs, Senya; Fisher, Stewart L.; Joachimiak, Andrzej; Schreiber, Stuart L.; Hung, Deborah T.

    2017-07-03

    New antibiotics with novel targets are greatly needed. Bacteria have numerous essential functions, but only a small fraction of such processes—primarily those involved in macromolecular synthesis—are inhibited by current drugs. Targeting metabolic enzymes has been the focus of recent interest, but effective inhibitors have been difficult to identify. We describe a synthetic azetidine derivative, BRD4592, that kills Mycobacterium tuberculosis (Mtb) through allosteric inhibition of tryptophan synthase (TrpAB), a previously untargeted, highly allosterically regulated enzyme. BRD4592 binds at the TrpAB a–b-subunit interface and affects multiple steps in the enzyme’s overall reaction, resulting in inhibition not easily overcome by changes in metabolic environment. We show that TrpAB is required for the survival of Mtb and Mycobacterium marinum in vivo and that this requirement may be independent of an adaptive immune response. This work highlights the effectiveness of allosteric inhibition for targeting proteins that are naturally highly dynamic and that are essential in vivo, despite their apparent dispensability under in vitro conditions, and suggests a framework for the discovery of a next generation of allosteric inhibitors.

  10. A small-molecule allosteric inhibitor of Mycobacterium tuberculosis tryptophan synthase

    Energy Technology Data Exchange (ETDEWEB)

    Wellington, Samantha; Nag, Partha P.; Michalska, Karolina; Johnston, Stephen E.; Jedrzejczak, Robert P.; Kaushik, Virendar K.; Clatworthy, Anne E.; Siddiqi, Noman; McCarren, Patrick; Bajrami, Besnik; Maltseva, Natalia I.; Combs, Senya; Fisher, Stewart L.; Joachimiak, Andrzej; Schreiber, Stuart L.; Hung, Deborah T.

    2017-07-03

    New antibiotics with novel targets are greatly needed. Bacteria have numerous essential functions, but only a small fraction of such processes—primarily those involved in macromolecular synthesis—are inhibited by current drugs. Targeting metabolic enzymes has been the focus of recent interest, but effective inhibitors have been difficult to identify. We describe a synthetic azetidine derivative, BRD4592, that kills Mycobacterium tuberculosis (Mtb) through allosteric inhibition of tryptophan synthase (TrpAB), a previously untargeted, highly allosterically regulated enzyme. BRD4592 binds at the TrpAB α–β-subunit interface and affects multiple steps in the enzyme's overall reaction, resulting in inhibition not easily overcome by changes in metabolic environment. We show that TrpAB is required for the survival of Mtb and Mycobacterium marinum in vivo and that this requirement may be independent of an adaptive immune response. This work highlights the effectiveness of allosteric inhibition for targeting proteins that are naturally highly dynamic and that are essential in vivo, despite their apparent dispensability under in vitro conditions, and suggests a framework for the discovery of a next generation of allosteric inhibitors.

  11. Site-directed Mutagenesis Switching a Dimethylallyl Tryptophan Synthase to a Specific Tyrosine C3-Prenylating Enzyme*

    Science.gov (United States)

    Fan, Aili; Zocher, Georg; Stec, Edyta; Stehle, Thilo; Li, Shu-Ming

    2015-01-01

    The tryptophan prenyltransferases FgaPT2 and 7-DMATS (7-dimethylallyl tryptophan synthase) from Aspergillus fumigatus catalyze C4- and C7-prenylation of the indole ring, respectively. 7-DMATS was found to accept l-tyrosine as substrate as well and converted it to an O-prenylated derivative. An acceptance of l-tyrosine by FgaPT2 was also observed in this study. Interestingly, isolation and structure elucidation revealed the identification of a C3-prenylated l-tyrosine as enzyme product. Molecular modeling and site-directed mutagenesis led to creation of a mutant FgaPT2_K174F, which showed much higher specificity toward l-tyrosine than l-tryptophan. Its catalytic efficiency toward l-tyrosine was found to be 4.9-fold in comparison with that of non-mutated FgaPT2, whereas the activity toward l-tryptophan was less than 0.4% of that of the wild-type. To the best of our knowledge, this is the first report on an enzymatic C-prenylation of l-tyrosine as free amino acid and altering the substrate preference of a prenyltransferase by mutagenesis. PMID:25477507

  12. Regulation of glycogen synthase kinase-3{beta} (GSK-3{beta}) after ionizing radiation; Regulation der Glykogen Synthase Kinase-3{beta} (GSK-3{beta}) nach ionisierender Strahlung

    Energy Technology Data Exchange (ETDEWEB)

    Boehme, K.A.

    2006-12-15

    Glycogen Synthase Kinase-3{beta} (GSK-3{beta}) phosphorylates the Mdm2 protein in the central domain. This phosphorylation is absolutely required for p53 degradation. Ionizing radiation inactivates GSK-3{beta} by phosphorylation at serine 9 and in consequence prevents Mdm2 mediated p53 degradation. During the work for my PhD I identified Akt/PKB as the kinase that phosphorylates GSK-3{beta} at serine 9 after ionizing radiation. Ionizing radiation leads to phosphorylation of Akt/PKB at threonine 308 and serine 473. The PI3 Kinase inhibitor LY294002 completely abolished Akt/PKB serine 473 phosphorylation and prevented the induction of GSK-3{beta} serine 9 phosphorylation after ionizing radiation. Interestingly, the most significant activation of Akt/PKB after ionizing radiation occurred in the nucleus while cytoplasmic Akt/PKB was only weakly activated after radiation. By using siRNA, I showed that Akt1/PKBa, but not Akt2/PKB{beta}, is required for phosphorylation of GSK- 3{beta} at serine 9 after ionizing radiation. Phosphorylation and activation of Akt/PKB after ionizing radiation depends on the DNA dependent protein kinase (DNA-PK), a member of the PI3 Kinase family, that is activated by free DNA ends. Both, in cells from SCID mice and after knockdown of the catalytic subunit of DNA-PK by siRNA in osteosarcoma cells, phosphorylation of Akt/PKB at serine 473 and of GSK-3{beta} at serine 9 was completely abolished. Consistent with the principle that phosphorylation of GSK-3 at serine 9 contributes to p53 stabilization after radiation, the accumulation of p53 in response to ionizing radiation was largely prevented by downregulation of DNA-PK. From these results I conclude, that ionizing radiation induces a signaling cascade that leads to Akt1/PKBa activation mediated by DNA-PK dependent phosphorylation of serine 473. After activation Akt1/PKBa phosphorylates and inhibits GSK-3{beta} in the nucleus. The resulting hypophosphorylated form of Mdm2 protein is no longer

  13. Neurospora tryptophan synthase: N-terminal analysis and the sequence of the pyridoxal phosphate active site peptide

    International Nuclear Information System (INIS)

    Pratt, M.L.; Hsu, P.Y.; DeMoss, J.A.

    1986-01-01

    Tryptophan synthase (TS), which catalyzes the final step of tryptophan biosynthesis, is a multifunctional protein requiring pyridoxal phosphate (B6P) for two of its three distinct enzyme activities. TS from Neurospora has a blocked N-terminal, is a homodimer of 150 KDa and binds one mole of B6P per mole of subunit. The authors shown the N-terminal residue to be acyl-serine. The B6P-active site of holoenzyme was labelled by reduction of the B6P-Schiff base with [ 3 H]-NaBH 4 , and resulted in a proportionate loss of activity in the two B6P-requiring reactions. SDS-polyacrylamide gel electrophoresis of CNBr-generated peptides showed the labelled, active site peptide to be 6 KDa. The sequence of this peptide, purified to apparent homogeneity by a combination of C-18 reversed phase and TSK gel filtration HPLC is: gly-arg-pro-gly-gln-leu-his-lys-ala-glu-arg-leu-thr-glu-tyr-ala-gly-gly-ala-gln-ile-xxx-leu-lys-arg-glu-asp-leu-asn-his-xxx-gly-xxx-his-/sub ***/-ile-asn-asn-ala-leu. Although four residues (xxx, /sub ***/) are unidentified, this peptide is minimally 78% homologous with the corresponding peptide from yeast TS, in which residue (/sub ***/) is the lysine that binds B6P

  14. Eukaryotic beta-alanine synthases are functionally related but have a high degree of structural diversity

    DEFF Research Database (Denmark)

    Gojkovic, Zoran; Sandrini, Michael; Piskur, Jure

    2001-01-01

    no pyrimidine catabolic pathway, it enabled growth on N-carbamyl- beta -alanine as the sole nitrogen source. The D. discoideum and D. melanogaster PYD3 gene products are similar to mammalian beta -alanine synthases. In contrast, the S. kluyveri protein is quite different from these and more similar to bacterial......beta -Alanine synthase (EC 3.5.1.6), which catalyzes the final step of pyrimidine catabolism, has only been characterized in mammals. A Saccharomyces kluyveri pyd3 mutant that is unable to grow on N-carbamy-beta -alanine as the sole nitrogen source and exhibits diminished beta -alanine synthase...... N- carbamyl amidohydrolases. All three beta -alanine synthases are to some degree related to various aspartate transcarbamylases, which catalyze the second step of the de novo pyrimidine biosynthetic pathway. PYD3 expression in yeast seems to be inducible by dihydrouracil and N...

  15. Structural basis for substrate activation and regulation by cystathionine beta-synthase (CBS) domains in cystathionine [beta]-synthase

    Energy Technology Data Exchange (ETDEWEB)

    Koutmos, Markos; Kabil, Omer; Smith, Janet L.; Banerjee, Ruma (Michigan-Med)

    2011-08-17

    The catalytic potential for H{sub 2}S biogenesis and homocysteine clearance converge at the active site of cystathionine {beta}-synthase (CBS), a pyridoxal phosphate-dependent enzyme. CBS catalyzes {beta}-replacement reactions of either serine or cysteine by homocysteine to give cystathionine and water or H{sub 2}S, respectively. In this study, high-resolution structures of the full-length enzyme from Drosophila in which a carbanion (1.70 {angstrom}) and an aminoacrylate intermediate (1.55 {angstrom}) have been captured are reported. Electrostatic stabilization of the zwitterionic carbanion intermediate is afforded by the close positioning of an active site lysine residue that is initially used for Schiff base formation in the internal aldimine and later as a general base. Additional stabilizing interactions between active site residues and the catalytic intermediates are observed. Furthermore, the structure of the regulatory 'energy-sensing' CBS domains, named after this protein, suggests a mechanism for allosteric activation by S-adenosylmethionine.

  16. Enantioselective synthesis of the novel chiral sulfoxide derivative as a glycogen synthase kinase 3beta inhibitor.

    Science.gov (United States)

    Saitoh, Morihisa; Kunitomo, Jun; Kimura, Eiji; Yamano, Toru; Itoh, Fumio; Kori, Masakuni

    2010-09-01

    Glycogen synthase kinase 3beta (GSK-3beta) inhibitors are expected to be attractive therapeutic agents for the treatment of Alzheimer's disease (AD). Recently we discovered sulfoxides (S)-1 as a novel GSK-3beta inhibitor having in vivo efficacy. We investigated practical asymmetric preparation methods for the scale-up synthesis of (S)-1. The highly enantioselective synthesis of (S)-1 (94% ee) was achieved by titanium-mediated oxidation with D-(-)-diethyl tartrate on gram scale.

  17. Homocysteine threshold value based on cystathionine beta synthase and paraoxonase 1 activities in mice.

    Science.gov (United States)

    Hamelet, J; Aït-Yahya-Graison, E; Matulewicz, E; Noll, C; Badel-Chagnon, A; Camproux, A-C; Demuth, K; Paul, J-L; Delabar, J M; Janel, N

    2007-12-01

    Hyperhomocysteinaemia is a metabolic disorder associated with the development of premature atherosclerosis. Among the determinants which predispose to premature thromboembolic and atherothrombotic events, serum activity of paraoxonase 1, mainly synthesized in the liver, has been shown to be a predictor of cardiovascular disease and to be negatively correlated with serum homocysteine levels in human. Even though treatments of hyperhomocysteinaemic patients ongoing cardiovascular complications are commonly used, it still remains unclear above which homocysteine level a preventive therapy should be started. In order to establish a threshold of plasma homocysteine concentration we have analyzed the hepatic cystathionine beta synthase and paraoxonase 1 activities in a moderate to intermediate murine model of hyperhomocysteinaemia. Using wild type and heterozygous cystathionine beta synthase deficient mice fed a methionine enriched diet or a control diet, we first studied the link between cystathionine beta synthase and paraoxonase 1 activities and plasma homocysteine concentration. Among the animals used in this study, we observed a negative correlation between plasma homocysteine level and cystathionine beta synthase activity (rho=-0.52, P=0.0008) or paraoxonase 1 activity (rho=-0.49, P=0.002). Starting from these results, a homocysteine cut-off value of 15 microm has been found for both cystathionine beta synthase (P=0.0003) and paraoxonase 1 (P=0.0007) activities. Our results suggest that both cystathionine beta synthase and paraoxonase 1 activities are significantly decreased in mice with a plasma homocysteine value greater than 15 microm. In an attempt to set up preventive treatment for cardiovascular disease our results indicate that treatments should be started from 15 microm of plasma homocysteine.

  18. Identifying the catalytic components of cellulose synthase and the maize mixed-linkage beta-glucan synthase

    Energy Technology Data Exchange (ETDEWEB)

    Nicholas C Carpita

    2009-04-20

    Five specific objectives of this project are to develop strategies to identify the genes that encode the catalytic components of "mixed-linkage" (1→3),(1→4)-beta-D-glucans in grasses, to determine the protein components of the synthase complex, and determine the biochemical mechanism of synthesis. We have used proteomic approaches to define intrinsic and extrinsic polypeptides of Golgi membranes that are associated with polysaccharide synthesis and trafficking. We were successful in producing recombinant catalytic domains of cellulose synthase genes and discovered that they dimerize upon concentration, indicating that two CesA proteins form the catalytic unit. We characterized a brittle stalk2 mutant as a defect in a COBRA-like protein that results in compromised lignin-cellulose interactions that decrease tissue flexibility. We used virus-induced gene silencing of barley cell wall polysaccharide synthesis by BSMV in an attempt to silence specific members of the cellulose synthase-like gene family. However, we unexpectedly found that regardless of the specificity of the target gene, whole gene interaction networks were silenced. We discovered the cause to be an antisense transcript of the cellulose synthase gene initiated small interfering RNAs that spread silencing to related genes.

  19. Structure of the human beta-ketoacyl [ACP] synthase from the mitochondrial type II fatty acid synthase

    DEFF Research Database (Denmark)

    Christensen, Caspar Elo; Kragelund, Birthe B; von Wettstein-Knowles, Penny

    2007-01-01

    Two distinct ways of organizing fatty acid biosynthesis exist: the multifunctional type I fatty acid synthase (FAS) of mammals, fungi, and lower eukaryotes with activities residing on one or two polypeptides; and the dissociated type II FAS of prokaryotes, plastids, and mitochondria with individual...... activities encoded by discrete genes. The beta-ketoacyl [ACP] synthase (KAS) moiety of the mitochondrial FAS (mtKAS) is targeted by the antibiotic cerulenin and possibly by the other antibiotics inhibiting prokaryotic KASes: thiolactomycin, platensimycin, and the alpha-methylene butyrolactone, C75. The high...... degree of structural similarity between mitochondrial and prokaryotic KASes complicates development of novel antibiotics targeting prokaryotic KAS without affecting KAS domains of cytoplasmic FAS. KASes catalyze the C(2) fatty acid elongation reaction using either a Cys-His-His or Cys-His-Asn catalytic...

  20. Guidelines for the diagnosis and management of cystathionine beta-synthase deficiency

    NARCIS (Netherlands)

    Morris, A.A.; Kozich, V.; Santra, S.; Andria, G.; Ben-Omran, T.I.; Chakrapani, A.B.; Crushell, E.; Henderson, M.J.; Hochuli, M.; Huemer, M.; Janssen, M.C.H.; Maillot, F.; Mayne, P.D.; McNulty, J.; Morrison, T.M.; Ogier, H.; O'Sullivan, S.; Pavlikova, M.; Almeida, I.T. de; Terry, A.; Yap, S.; Blom, H.J.; Chapman, K.A.

    2017-01-01

    Cystathionine beta-synthase (CBS) deficiency is a rare inherited disorder in the methionine catabolic pathway, in which the impaired synthesis of cystathionine leads to accumulation of homocysteine. Patients can present to many different specialists and diagnosis is often delayed. Severely affected

  1. Calcium Co-regulates Oxidative Metabolism and ATP Synthase-dependent Respiration in Pancreatic Beta Cells

    Science.gov (United States)

    De Marchi, Umberto; Thevenet, Jonathan; Hermant, Aurelie; Dioum, Elhadji; Wiederkehr, Andreas

    2014-01-01

    Mitochondrial energy metabolism is essential for glucose-induced calcium signaling and, therefore, insulin granule exocytosis in pancreatic beta cells. Calcium signals are sensed by mitochondria acting in concert with mitochondrial substrates for the full activation of the organelle. Here we have studied glucose-induced calcium signaling and energy metabolism in INS-1E insulinoma cells and human islet beta cells. In insulin secreting cells a surprisingly large fraction of total respiration under resting conditions is ATP synthase-independent. We observe that ATP synthase-dependent respiration is markedly increased after glucose stimulation. Glucose also causes a very rapid elevation of oxidative metabolism as was followed by NAD(P)H autofluorescence. However, neither the rate of the glucose-induced increase nor the new steady-state NAD(P)H levels are significantly affected by calcium. Our findings challenge the current view, which has focused mainly on calcium-sensitive dehydrogenases as the target for the activation of mitochondrial energy metabolism. We propose a model of tight calcium-dependent regulation of oxidative metabolism and ATP synthase-dependent respiration in beta cell mitochondria. Coordinated activation of matrix dehydrogenases and respiratory chain activity by calcium allows the respiratory rate to change severalfold with only small or no alterations of the NAD(P)H/NAD(P)+ ratio. PMID:24554722

  2. Identification of a Glycogen Synthase Kinase-3[beta] Inhibitor that Attenuates Hyperactivity in CLOCK Mutant Mice

    Energy Technology Data Exchange (ETDEWEB)

    Kozikowski, Alan P.; Gunosewoyo, Hendra; Guo, Songpo; Gaisina, Irina N.; Walter, Richard L.; Ketcherside, Ariel; McClung, Colleen A.; Mesecar, Andrew D.; Caldarone, Barbara (Psychogenics); (Purdue); (UIC); (UTSMC)

    2012-05-02

    Bipolar disorder is characterized by a cycle of mania and depression, which affects approximately 5 million people in the United States. Current treatment regimes include the so-called 'mood-stabilizing drugs', such as lithium and valproate that are relatively dated drugs with various known side effects. Glycogen synthase kinase-3{beta} (GSK-3{beta}) plays a central role in regulating circadian rhythms, and lithium is known to be a direct inhibitor of GSK-3{beta}. We designed a series of second generation benzofuran-3-yl-(indol-3-yl)maleimides containing a piperidine ring that possess IC{sub 50} values in the range of 4 to 680 nM against human GSK-3{beta}. One of these compounds exhibits reasonable kinase selectivity and promising preliminary absorption, distribution, metabolism, and excretion (ADME) data. The administration of this compound at doses of 10 to 25 mg kg{sup -1} resulted in the attenuation of hyperactivity in amphetamine/chlordiazepoxide-induced manic-like mice together with enhancement of prepulse inhibition, similar to the effects found for valproate (400 mg kg{sup -1}) and the antipsychotic haloperidol (1 mg kg{sup -1}). We also tested this compound in mice carrying a mutation in the central transcriptional activator of molecular rhythms, the CLOCK gene, and found that the same compound attenuates locomotor hyperactivity in response to novelty. This study further demonstrates the use of inhibitors of GSK-3{beta} in the treatment of manic episodes of bipolar/mood disorders, thus further validating GSK-3{beta} as a relevant therapeutic target in the identification of new therapies for bipolar patients.

  3. Mice lacking cystathionine beta synthase have lung fibrosis and air space enlargement.

    Science.gov (United States)

    Hamelet, Julien; Maurin, Nicole; Fulchiron, Romain; Delabar, Jean-Maurice; Janel, Nathalie

    2007-10-01

    Cystathionine beta synthase (CBS) is a crucial regulator of plasma concentrations of homocysteine. Severe hyperhomocysteinemia due to CBS deficiency confers diverse clinical manifestations, notably pulmonary thrombotic disease. However, the association between hyperhomocysteinemia and chronic obstructive pulmonary disease is not well understood. To investigate the role of hyperhomocysteinemia in lung injury and pulmonary fibrosis, we analyzed the lung of CBS-deficient mice, a murine model of severe hyperhomocysteinemia. The degree of lung injury was assessed by histologic examination. Analysis of profibrogenic factors was performed by real-time quantitative reverse transcription-polymerase chain reaction. CBS-deficient mice develop fibrosis and air space enlargement in the lung, concomitant with an enhanced expression of heme oxygenase-1, pro(alpha)1 collagen type I, transforming growth factor-beta1 and alpha-smooth muscle actin. However, lung fibrosis was found in the absence of increased inflammatory cell infiltrates as determined by histology, without changes in gene expression of proinflammatory cytokines TNFalpha and interleukin 6. The increased expression of alpha-smooth muscle actin and transforming growth factor-beta1 emphasizes the role of myofibroblasts differentiation in case of lung fibrosis due to CBS deficiency in mice.

  4. Engineering of Ion Sensing by the Cystathionine beta-Synthase Module of the ABC Transporter OpuA

    NARCIS (Netherlands)

    Mahmood, Nik A. B. N.; Biemans-Oldehinkel, Esther; Poolman, Bert

    2009-01-01

    We have previously shown that the C-terminal cystathionine beta-synthase (CBS) domains of the nucleotide-binding domains of the ABC transporter OpuA, in conjunction with an anionic membrane surface function, act as sensor of internal ionic strength (I(in)). Here, we show that a surface-exposed

  5. Characterization and partial purification of beta-1,3-D-glucan (callose) synthase from barley (Hordeum vulgare) leaves

    DEFF Research Database (Denmark)

    Pedersen, L.H.; Jacobsen, S.; Hejgaard, J.

    1993-01-01

    The plasma membrane bound beta-1,3-D-glucan (callose) synthase. assumed to be involved in the resistance to the powdery mildew fungus (Erysiphe graminis f.sp. hordei), was partially purified from a microsomal fraction of green barley leaves (Hordeum vulgare L.). Plasma membranes were enriched...

  6. Crystallization and preliminary X-ray analysis of beta-alanine synthase from the yeast Saccharomyces kluyveri

    DEFF Research Database (Denmark)

    Dobritzsch, D.; Gojkovic, Zoran; Andersen, Birgit

    2003-01-01

    In eukaryotes and some bacteria, the third step of reductive pyrimidine catabolism is catalyzed by beta-alanine synthase (EC 3.5.1.6). Crystals of the recombinant enzyme from the yeast Saccharomyces kluyveri were obtained using sodium citrate as a precipitant. The crystals belong to space group P2...

  7. Nuclear glycogen synthase kinase-3 {beta} (GSK-3) in Rhipicephalus (Boophilus) microplus tick embryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Mentzingen, Leticia; Andrade, Josiana G. de; Logullo, Carlos [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, RJ (Brazil). Centro de Biociencias e Biotecnologia. Lab. de Quimica e Funcao de Proteinas e Peptideos (LQFPP); Andrade, Caroline P. de; Vaz Junior, Itabajara [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Centro de Biotecnologia

    2008-07-01

    Full text: Glycogen synthase kinase-3 (GSK3) is recognized as a key component of a large number of cellular processes and diseases. Several mechanisms play a part in controlling the actions of GSK3, including phosphorylation, protein complex formation, and subcellular distribution. Recent observations point to functions for phosphorylases several transcription factors in the nucleus. Also, GSK3b participate of the canonical W nt signalling pathway, which has been studied intensively in embryonic and cancer cells. Like in many other signaling pathways, most components in W nt signal transduction were highly conserved during the evolution. More than 40 proteins have been reported to be phosphorylated by GSK3, including over a dozen transcription factors. Although the mechanisms regulating GSK3 are not fully understood, precise control appears to be achieved by a combination of phosphorylation, localization, and interactions with GSK3-binding proteins. Although GSK3 is traditionally considered a cytosolic protein, it is also present in nuclei. Nuclear GSK3 is particularly interesting because of the many transcription factors that it regulates enabling GSK3 to influence many signaling pathways that converge on these transcription factors, thereby regulating the expression of many genes. Our group identified that GSK-3 {beta} could be detected in different stage eggs of R. micro plus. In this work we detected the GSK-3 in isolated nuclear fraction from the egg homogenates of R. micro plus by western-blot analysis, using anti-GSK- 3 {beta} antibodies. The enzyme activity was also detected radiochemically throughout embryogenesis in same fraction. The GSK-3 activity was inhibiting by using SB 216763 (selective molecule inhibitors of GSK-3). Taken together our results suggest that GSK-3 {beta} isoform probably is involved in gene transcription factors during R. micro plus embryo development.

  8. Isolation and characterization of beta-glucan synthase: A potential biochemical regulator of gravistimulated differential cell wall loosening

    Science.gov (United States)

    Kuzmanoff, K. M.

    1984-01-01

    In plants, gravity stimulates differential growth in the upper and lower halves of horizontally oriented organs. Auxin regulation of cell wall loosening and elongation is the basis for most models of this phenomenon. Auxin treatment of pea stem tissue rapidly increases the activity of Golgi-localized Beta-1,4-glucan synthase, an enzyme involved in biosynthesis of wall xyloglucan which apparently constitutes the substrate for the wall loosening process. The primary objective is to determine if auxin induces de novo formation of Golgi glucan synthase and increases the level of this glucan synthase mRNA. This shall be accomplished by (a) preparation of a monoclonal antibody to the synthase, (b) isolation, and characterization of the glucan synthase, and (c) examination for cross reactivity between the antibody and translation products of auxin induced mRNAs in pea tissue. The antibody will also be used to localize the glucan synthase in upper and lower halves of pea stem tissue before, during and after the response to gravity.

  9. A 31 bp VNTR in the cystathionine beta-synthase (CBS) gene is associated with reduced CBS activity and elevated post-load homocysteine levels.

    NARCIS (Netherlands)

    Lievers, K.J.; Kluijtmans, L.A.J.; Heil, S.G.; Boers, G.H.J.; Verhoef, P.; Oppenraaij-Emmerzaal, D. van; Heijer, M. den; Trijbels, J.M.F.; Blom, H.J.

    2001-01-01

    Molecular defects in genes encoding enzymes involved in homocysteine metabolism may account for mild hyperhomocysteinaemia, an independent and graded risk factor for cardiovascular disease (CVD). Although heterozygosity for cystathionine beta-synthase (CBS) deficiency has been excluded as a major

  10. Stimulation of Inducible Nitric Oxide Synthase Expression by Beta Interferon Increases Necrotic Death of Macrophages upon Listeria monocytogenes Infection▿

    OpenAIRE

    Zwaferink, Heather; Stockinger, Silvia; Reipert, Siegfried; Decker, Thomas

    2008-01-01

    Murine macrophage death upon infection with Listeria monocytogenes was previously shown to be increased by beta interferon, produced by the infected cells. We saw that interferon-upregulated caspase activation or other interferon-inducible, death-associated proteins, including TRAIL, protein kinase R, and p53, were not necessary for cell death. Macrophage death was reduced when inducible nitric oxide synthase (iNOS) was inhibited during infection, and iNOS-deficient macrophages were less susc...

  11. Involvement of beta 3-adrenoceptor in altered beta-adrenergic response in senescent heart: role of nitric oxide synthase 1-derived nitric oxide.

    Science.gov (United States)

    Birenbaum, Aurélie; Tesse, Angela; Loyer, Xavier; Michelet, Pierre; Andriantsitohaina, Ramaroson; Heymes, Christophe; Riou, Bruno; Amour, Julien

    2008-12-01

    In senescent heart, beta-adrenergic response is altered in parallel with beta1- and beta2-adrenoceptor down-regulation. A negative inotropic effect of beta3-adrenoceptor could be involved. In this study, the authors tested the hypothesis that beta3-adrenoceptor plays a role in beta-adrenergic dysfunction in senescent heart. beta-Adrenergic responses were investigated in vivo (echocardiography-dobutamine, electron paramagnetic resonance) and in vitro (isolated left ventricular papillary muscle, electron paramagnetic resonance) in young adult (3-month-old) and senescent (24-month-old) rats. Nitric oxide synthase (NOS) immunolabeling (confocal microscopy), nitric oxide production (electron paramagnetic resonance) and beta-adrenoceptor Western blots were performed in vitro. Data are mean percentages of baseline +/- SD. An impaired positive inotropic effect (isoproterenol) was confirmed in senescent hearts in vivo (117 +/- 23 vs. 162 +/- 16%; P < 0.05) and in vitro (127 +/- 10 vs. 179 +/- 15%; P < 0.05). In the young adult group, the positive inotropic effect was not significantly modified by the nonselective NOS inhibitor N-nitro-L-arginine methylester (L-NAME; 183 +/- 19%), the selective NOS1 inhibitor vinyl-L-N-5(1-imino-3-butenyl)-L-ornithine (L-VNIO; 172 +/- 13%), or the selective NOS2 inhibitor 1400W (183 +/- 19%). In the senescent group, in parallel with beta3-adrenoceptor up-regulation and increased nitric oxide production, the positive inotropic effect was partially restored by L-NAME (151 +/- 8%; P < 0.05) and L-VNIO (149 +/- 7%; P < 0.05) but not by 1400W (132 +/- 11%; not significant). The positive inotropic effect induced by dibutyryl-cyclic adenosine monophosphate was decreased in the senescent group with the specific beta3-adrenoceptor agonist BRL 37344 (167 +/- 10 vs. 142 +/- 10%; P < 0.05). NOS1 and NOS2 were significantly up-regulated in the senescent rat. In senescent cardiomyopathy, beta3-adrenoceptor overexpression plays an important role in the

  12. Lithium chloride ameliorates learning and memory ability and inhibits glycogen synthase kinase-3 beta activity in a mouse model of fragile X syndrome

    Institute of Scientific and Technical Information of China (English)

    Shengqiang Chen; Xuegang Luo; Quan Yang; Weiwen Sun; Kaiyi Cao; Xi Chen; Yueling Huang; Lijun Dai; Yonghong Yi

    2011-01-01

    In the present study, Fmr1 knockout mice (KO mice) were used as the model for fragile X syndrome. The results of step-through and step-down tests demonstrated that Fmr1 KO mice had shorter latencies and more error counts, indicating a learning and memory disorder. After treatment with 30, 60, 90, 120, or 200 mg/kg lithium chloride, the learning and memory abilities of the Fmr1 KO mice were significantly ameliorated, in particular, the 200 mg/kg lithium chloride treatment had the most significant effect. Western blot analysis showed that lithium chloride significantly enhanced the expression of phosphorylated glycogen synthase kinase 3 beta, an inactive form of glycogen synthase kinase 3 beta, in the cerebral cortex and hippocampus of the Fmr1 KO mice. These results indicated that lithium chloride improved learning and memory in the Fmr1 KO mice, possibly by inhibiting glycogen synthase kinase 3 beta activity.

  13. Platelet-derived growth factor-DD targeting arrests pathological angiogenesis by modulating glycogen synthase kinase-3beta phosphorylation.

    Science.gov (United States)

    Kumar, Anil; Hou, Xu; Lee, Chunsik; Li, Yang; Maminishkis, Arvydas; Tang, Zhongshu; Zhang, Fan; Langer, Harald F; Arjunan, Pachiappan; Dong, Lijin; Wu, Zhijian; Zhu, Linda Y; Wang, Lianchun; Min, Wang; Colosi, Peter; Chavakis, Triantafyllos; Li, Xuri

    2010-05-14

    Platelet-derived growth factor-DD (PDGF-DD) is a recently discovered member of the PDGF family. The role of PDGF-DD in pathological angiogenesis and the underlying cellular and molecular mechanisms remain largely unexplored. In this study, using different animal models, we showed that PDGF-DD expression was up-regulated during pathological angiogenesis, and inhibition of PDGF-DD suppressed both choroidal and retinal neovascularization. We also demonstrated a novel mechanism mediating the function of PDGF-DD. PDGF-DD induced glycogen synthase kinase-3beta (GSK3beta) Ser(9) phosphorylation and Tyr(216) dephosphorylation in vitro and in vivo, leading to increased cell survival. Consistently, GSK3beta activity was required for the antiangiogenic effect of PDGF-DD targeting. Moreover, PDGF-DD regulated the expression of GSK3beta and many other genes important for angiogenesis and apoptosis. Thus, we identified PDGF-DD as an important target gene for antiangiogenic therapy due to its pleiotropic effects on vascular and non-vascular cells. PDGF-DD inhibition may offer new therapeutic options to treat neovascular diseases.

  14. Lithium chloride increases the production of amyloid-beta peptide independently from its inhibition of glycogen synthase kinase 3.

    Science.gov (United States)

    Feyt, Christine; Kienlen-Campard, Pascal; Leroy, Karelle; N'Kuli, Francisca; Courtoy, Pierre J; Brion, Jean-Pierre; Octave, Jean-Noël

    2005-09-30

    Glycogen synthase kinase 3 (GSK3) is able to phosphorylate tau at many sites that are found to be phosphorylated in paired helical filaments in Alzheimer disease. Lithium chloride (LiCl) efficiently inhibits GSK3 and was recently reported to also decrease the production of amyloid-beta peptide (Abeta) from its precursor, the amyloid precursor protein. Therefore, lithium has been proposed as a combined therapeutic agent, inhibiting both the hyperphosphorylation of tau and the production of Abeta. Here, we demonstrate that the inhibition of GSK3 by LiCl induced the nuclear translocation of beta-catenin in Chinese hamster ovary cells and rat cultured neurons, in which a decrease in tau phosphorylation was observed. In both cellular models, a nontoxic concentration of LiCl increased the production of Abeta by increasing the beta-cleavage of amyloid precursor protein, generating more substrate for an unmodified gamma-secretase activity. SB415286, another GSK3 inhibitor, induced the nuclear translocation of beta-catenin and slightly decreased Abeta production. It is concluded that the LiCl-mediated increase in Abeta production is not related to GSK3 inhibition.

  15. Proteome analysis reveals phosphorylation of ATP synthase beta -subunit in human skeletal muscle and proteins with potential roles in type 2 diabetes

    DEFF Research Database (Denmark)

    Højlund, Kurt; Wrzesinski, Krzysztof; Larsen, Peter Mose

    2003-01-01

    quantitate a large number of proteins and their post-translational modifications simultaneously and is a powerful tool to study polygenic diseases like type 2 diabetes. Using this approach on human skeletal muscle biopsies, we have identified eight potential protein markers for type 2 diabetes in the fasting...... synthase beta-subunit phosphoisoform in diabetic muscle correlated inversely with fasting plasma glucose levels. These data suggest a role for phosphorylation of ATP synthase beta-subunit in the regulation of ATP synthesis and that alterations in the regulation of ATP synthesis and cellular stress proteins...

  16. Inhibitory effect of different product analogues on {beta}-alanine synthase: A thermodynamic and fluorescence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Andujar-Sanchez, Montserrat; Martinez-Gomez, Ana Isabel; Martinez-Rodriguez, Sergio; Clemente-Jimenez, Josefa Maria; Heras-Vazquez, Francisco Javier Las; Rodriguez-Vico, Felipe [Departamento de Quimica Fisica, Bioquimica y Quimica Inorganica, Facultad de Ciencias Experimentales, Universidad de Almeria, Carretera de Sacramento s/n, La Canada de San Urbano, Almeria 04120 (Spain); Jara-Perez, Vicente [Departamento de Quimica Fisica, Bioquimica y Quimica Inorganica, Facultad de Ciencias Experimentales, Universidad de Almeria, Carretera de Sacramento s/n, La Canada de San Urbano, Almeria 04120 (Spain)], E-mail: vjara@ual.es

    2009-02-15

    The enzyme N-carbamoyl-{beta}-alanine amidohydrolase catalyse the hydrolysis of N-carbamoyl-{beta}-alanine or N-carbamoyl-{beta}-aminoisobutyric acid to {beta}-alanine or 3-aminoisobutyric acid, under the release of carbon-dioxide and ammonia. This work studies the inhibition of N-carbamoyl-{beta}-alanine amidohydrolase from Agrobacterium tumefaciens C58 (At{beta}car) by different carboxylic acid compounds that differ in number of carbons, and position and size of ramification, while the binding thermodynamics of the inhibitors are studied by isothermal titration calorimetry (ITC) and fluorescence. From the binding constants and inhibition studies, we conclude that propionate is the most efficient inhibitor among those tested. Substitution of the linear alkyl acids in positions 2 and 3 resulted in a drastic decrease of the affinity. The thermodynamic parameters show that a conformational change is triggered upon ligand binding. Binding enthalpy {delta}H{sub b} is negative in all cases for all ligands, and thus, Van der Waals interactions and hydrogen bonding are most probably the major sources for this term. The process is entropically favoured at all temperatures and pH studied, most probably due to the liberation of water molecules accompanying the conformational change of the enzyme.

  17. Evolution of flavone synthase I from parsley flavanone 3beta-hydroxylase by site-directed mutagenesis.

    Science.gov (United States)

    Gebhardt, Yvonne Helen; Witte, Simone; Steuber, Holger; Matern, Ulrich; Martens, Stefan

    2007-07-01

    Flavanone 3beta-hydroxylase (FHT) and flavone synthase I (FNS I) are 2-oxoglutarate-dependent dioxygenases with 80% sequence identity, which catalyze distinct reactions in flavonoid biosynthesis. However, FNS I has been reported exclusively from a few Apiaceae species, whereas FHTs are more abundant. Domain-swapping experiments joining the N terminus of parsley (Petroselinum crispum) FHT with the C terminus of parsley FNS I and vice versa revealed that the C-terminal portion is not essential for FNS I activity. Sequence alignments identified 26 amino acid substitutions conserved in FHT versus FNS I genes. Homology modeling, based on the related anthocyanidin synthase structure, assigned seven of these amino acids (FHT/FNS I, M106T, I115T, V116I, I131F, D195E, V200I, L215V, and K216R) to the active site. Accordingly, FHT was modified by site-directed mutagenesis, creating mutants encoding from one to seven substitutions, which were expressed in yeast (Saccharomyces cerevisiae) for FNS I and FHT assays. The exchange I131F in combination with either M106T and D195E or L215V and K216R replacements was sufficient to confer some FNS I side activity. Introduction of all seven FNS I substitutions into the FHT sequence, however, caused a nearly complete change in enzyme activity from FHT to FNS I. Both FHT and FNS I were proposed to initially withdraw the beta-face-configured hydrogen from carbon-3 of the naringenin substrate. Our results suggest that the 7-fold substitution affects the orientation of the substrate in the active-site pocket such that this is followed by syn-elimination of hydrogen from carbon-2 (FNS I reaction) rather than the rebound hydroxylation of carbon-3 (FHT reaction).

  18. Characterization of a 1,4-. beta. -D-glucan synthase from Dictyostelium discoideum

    Energy Technology Data Exchange (ETDEWEB)

    Blanton, R.L.

    1992-01-15

    Various aspects of research concerning Dictyostelium discoideum are presented. The initial focus of this project was upon: the characterization of potential probes for the cellulose synthase (antibody and nucleic acid), the determination of the cultural induction conditions of cellulose synthesis, the solubilization of the enzyme activity, the development of a non-inhibitory disruption buffer, the generation and isolation of mutant strains deficient in cellulose synthesis, and the development of the capability to determine the degree of polymerization of the in vitro product. I have briefly summarized our most significant findings with only selected data sets being shown in this report in the interest of brevity.

  19. The structure of Rauvolfia serpentina strictosidine synthase is a novel six-bladed beta-propeller fold in plant proteins.

    Science.gov (United States)

    Ma, Xueyan; Panjikar, Santosh; Koepke, Juergen; Loris, Elke; Stöckigt, Joachim

    2006-04-01

    The enzyme strictosidine synthase (STR1) from the Indian medicinal plant Rauvolfia serpentina is of primary importance for the biosynthetic pathway of the indole alkaloid ajmaline. Moreover, STR1 initiates all biosynthetic pathways leading to the entire monoterpenoid indole alkaloid family representing an enormous structural variety of approximately 2000 compounds in higher plants. The crystal structures of STR1 in complex with its natural substrates tryptamine and secologanin provide structural understanding of the observed substrate preference and identify residues lining the active site surface that contact the substrates. STR1 catalyzes a Pictet-Spengler-type reaction and represents a novel six-bladed beta-propeller fold in plant proteins. Structure-based sequence alignment revealed a common repetitive sequence motif (three hydrophobic residues are followed by a small residue and a hydrophilic residue), indicating a possible evolutionary relationship between STR1 and several sequence-unrelated six-bladed beta-propeller structures. Structural analysis and site-directed mutagenesis experiments demonstrate the essential role of Glu-309 in catalysis. The data will aid in deciphering the details of the reaction mechanism of STR1 as well as other members of this enzyme family.

  20. Yeast beta-alanine synthase shares a structural scaffold and origin with dizinc-dependent exopeptidases

    DEFF Research Database (Denmark)

    Lundgren, S.; Gojkovic, Zoran; Piskur, Jure

    2003-01-01

    of the intersubunit contacts. Both domains exhibit a mixed alpha/beta-topology. Surprisingly, the observed high structural homology to a family of dizinc-dependent exopeptidases suggests that these two enzyme groups have a common origin. Alterations in the ligand composition of the metal-binding site can be explained...

  1. Stabilization of mismatch repair gene PMS2 by glycogen synthase kinase 3beta is implicated in the treatment of cervical carcinoma.

    Science.gov (United States)

    Zhang, Yuan; Shu, Yi Min; Wang, Shu Fang; Da, Bang Hong; Wang, Ze Hua; Li, Hua Bin

    2010-02-23

    PMS2 expression loss was reported in a variety of human. However, its importance has not been fully understood in cervical carcinoma. The aim of this study was to determine the expression of PMS2 in cervical carcinoma and evaluate the significance of mismatch repair gene PMS2 regulated by glycogen synthase kinase 3beta (GSK-3beta) in chemosensitivity. We examined PMS2 and phosphorylated GSK-3beta(s9) expression in cervical carcinoma tissues using immunohistochemical staining. Furthermore, we detected PMS2 expression in HeLa cells and evaluate the interaction with GSK-3beta after transfection with GSK-3beta by small interference RNA (siRNA), co-immunoprecipitation and immunoblotting. We also evaluated the effect of PMS2 transfection on HeLa cells' chemosensitivity to cisplatin treatment. We found significant downregulation of PMS2 in cervical carcinoma, which was negatively associated with phosphorylated GSK-3beta (s9). Furthermore, we demonstrated GSK-3beta transfection was able to interact with PMS2 and enhance PMS2 production in HeLa cells, and increased PMS2 production was responsible for enhanced chemosensitivity. Our results provide the evidence that stabilization of PMS2 production by GSK-3beta was important to improve chemosensitization, indicating the significance of GSK-3beta-related PMS2 downregulation in the development of cervical carcinoma and in developing a potential strategy for chemotherapy.

  2. Role of glycogen synthase kinase-3 beta in the inflammatory response caused by bacterial pathogens

    Directory of Open Access Journals (Sweden)

    Cortés-Vieyra Ricarda

    2012-06-01

    Full Text Available Abstract Glycogen synthase kinase 3β (GSK3β plays a fundamental role during the inflammatory response induced by bacteria. Depending on the pathogen and its virulence factors, the type of cell and probably the context in which the interaction between host cells and bacteria takes place, GSK3β may promote or inhibit inflammation. The goal of this review is to discuss recent findings on the role of the inhibition or activation of GSK3β and its modulation of the inflammatory signaling in monocytes/macrophages and epithelial cells at the transcriptional level, mainly through the regulation of nuclear factor-kappaB (NF-κB activity. Also included is a brief overview on the importance of GSK3 in non-inflammatory processes during bacterial infection.

  3. Role of glycogen synthase kinase-3 beta in the inflammatory response caused by bacterial pathogens.

    Science.gov (United States)

    Cortés-Vieyra, Ricarda; Bravo-Patiño, Alejandro; Valdez-Alarcón, Juan J; Juárez, Marcos Cajero; Finlay, B Brett; Baizabal-Aguirre, Víctor M

    2012-06-12

    Glycogen synthase kinase 3β (GSK3β) plays a fundamental role during the inflammatory response induced by bacteria. Depending on the pathogen and its virulence factors, the type of cell and probably the context in which the interaction between host cells and bacteria takes place, GSK3β may promote or inhibit inflammation. The goal of this review is to discuss recent findings on the role of the inhibition or activation of GSK3β and its modulation of the inflammatory signaling in monocytes/macrophages and epithelial cells at the transcriptional level, mainly through the regulation of nuclear factor-kappaB (NF-κB) activity. Also included is a brief overview on the importance of GSK3 in non-inflammatory processes during bacterial infection.

  4. Altered contractile response due to increased beta3-adrenoceptor stimulation in diabetic cardiomyopathy: the role of nitric oxide synthase 1-derived nitric oxide.

    Science.gov (United States)

    Amour, Julien; Loyer, Xavier; Le Guen, Morgan; Mabrouk, Nejma; David, Jean-Stéphane; Camors, Emmanuel; Carusio, Nunzia; Vivien, Benoît; Andriantsitohaina, Ramaroson; Heymes, Christophe; Riou, Bruno

    2007-09-01

    In the diabetic heart, the positive inotropic response to beta-adrenoceptor stimulation is altered and beta1 and beta2 adrenoceptors are down-regulated, whereas beta3 adrenoceptor is up-regulated. In heart failure, beta3-adrenoceptor stimulation induces a negative inotropic effect that results from endothelial nitric oxide synthase (NOS3)-derived nitric oxide production. The objective of our study was to investigate the role of beta3-adrenoceptor in diabetic cardiomyopathy. beta-Adrenergic responses were investigated in vivo (dobutamine echocardiography) and in vitro (left ventricular papillary muscle) in healthy and streptozotocin-induced diabetic rats. The effect of beta3-adrenoceptor inhibition on the inotropic response was studied in vitro. Immunoblots and NOS activities were performed in heart homogenates (electron paramagnetic resonance) and isolated cardiomyocytes. Data are mean percentage of baseline +/- SD. The impaired positive inotropic effect was confirmed in diabetes both in vivo (121 +/- 15% vs. 160 +/- 16%; P < 0.05) and in vitro (112 +/- 5% vs. 179 +/- 15%; P < 0.05). In healthy rat, the positive inotropic effect was not significantly modified in presence of beta3-adrenoceptor antagonist (174 +/- 20%), nonselective NOS inhibitor (N -nitro-l-arginine methylester [l-NAME]; 183 +/- 19%), or selective NOS1 inhibitor (vinyl-l-N-5-(1-imino-3-butenyl)-l-ornithine [l-VNIO]; 172 +/- 13%). In diabetes, in parallel with the increase in beta3-adrenoceptor protein expression, the positive inotropic effect was partially restored by beta3-adrenoceptor antagonist (137 +/- 8%; P < 0.05), l-NAME (133 +/- 11%; P < 0.05), or l-VNIO (130 +/- 13%; P < 0.05). Nitric oxide was exclusively produced by NOS1 within diabetic cardiomyocytes. NOS2 and NOS3 proteins were undetectable. beta3-Adrenoceptor is involved in altered positive inotropic response to beta-adrenoceptor stimulation in diabetic cardiomyopathy. This effect is mediated by NOS1-derived nitric oxide in diabetic

  5. Glycogen synthase kinase-3beta and the p25 activator of cyclin dependent kinase 5 increase pausing of mitochondria in neurons.

    Science.gov (United States)

    Morel, M; Authelet, M; Dedecker, R; Brion, J P

    2010-06-02

    The complex bi-directional axoplasmic transport of mitochondria is essential for proper metabolic functioning of neurons and is controlled by phosphorylation. We have investigated by time-lapse imaging the effects of increased expression of glycogen synthase kinase-3beta (GSK-3beta) and of the p25 activator of cyclin dependent kinase 5 on mitochondria movements in mammalian cortical neurons and in PC12 cells. Both GSK-3beta and p25 increased the stationary behaviour of mitochondria in PC12 and in neurons, decreased their anterograde transport but did not affect the intrinsic velocities of mitochondria. The microtubule-associated tau proteins were more phosphorylated in GSK-3beta and p25 transfected neurons, but ultrastructural observation showed that these cells still contained microtubules and nocodazole treatment further reduced residual mitochondria movements in GSK-3beta or p25 transfected neurons, indicating that microtubule disruption was not the primary cause of increased mitochondrial stationary behaviour in GSK-3beta or p25 transfected neurons. Our results suggest that increased expression of GSK-3beta and p25 acted rather by decreasing the frequency of mitochondrial movements driven by molecular motors and that GSK-3beta and p25 might regulate these transports by controlling the time that mitochondria spend pausing, rather than their velocities. Copyright 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

  6. Glycogen synthase kinase-3beta (GSK3beta) negatively regulates PTTG1/human securin protein stability, and GSK3beta inactivation correlates with securin accumulation in breast tumors.

    Science.gov (United States)

    Mora-Santos, Mar; Limón-Mortés, M Cristina; Giráldez, Servando; Herrero-Ruiz, Joaquín; Sáez, Carmen; Japón, Miguel Á; Tortolero, Maria; Romero, Francisco

    2011-08-26

    PTTG1, also known as securin, is an inactivating partner of separase, the major effector for chromosome segregation during mitosis. At the metaphase-to-anaphase transition, securin is targeted for proteasomal destruction by the anaphase-promoting complex or cyclosome, allowing activation of separase. In addition, securin is overexpressed in metastatic or genomically instable tumors, suggesting a relevant role for securin in tumor progression. Stability of securin is regulated by phosphorylation; some phosphorylated forms are degraded out of mitosis, by the action of the SKP1-CUL1-F-box protein (SCF) complex. The kinases targeting securin for proteolysis have not been identified, and mechanistic insight into the cause of securin accumulation in human cancers is lacking. Here, we demonstrate that glycogen synthase kinase-3β (GSK3β) phosphorylates securin to promote its proteolysis via SCF(βTrCP) E3 ubiquitin ligase. Importantly, a strong correlation between securin accumulation and GSK3β inactivation was observed in breast cancer tissues, indicating that GSK3β inactivation may account for securin accumulation in breast cancers.

  7. Neuroprotective effects of lentivirus-mediated cystathionine-beta-synthase overexpression against 6-OHDA-induced parkinson's disease rats.

    Science.gov (United States)

    Yin, Wei-Lan; Yin, Wei-Guo; Huang, Bai-Sheng; Wu, Li-Xiang

    2017-09-14

    Parkinson's disease (PD) is age-related neurodegenerative disorder by a progressive loss of dopaminergic(DA) neurons in the substantia nigra (SN) and striatum, which is at least partly associated with α-synuclein protein accumulation in these neurons. Hydrogen sulfide (H 2 S) plays an important role in the nervous system. Studies have shown that H 2 S has a protective effect on PD. However, as a kind of gas molecules, H 2 S is lively, volatile, and not conducive to scientific research and clinical application. Cystathionine-beta-synthase(CBS) is the main enzymes of synthesis of H 2 S in the brain. In order to examine the neuroprotective effects of CBS on PD, we detected the effects of CBS overexpression on 6-Hydroxydopamine (6-OHDA)-lesioned PD rats using lentivirus-mediated gene transfection techniques. In the injured SN of 6-OHDA-induced PD rats, the CBS expression and the endogenous H 2 S level markedly decreased, while administration of lentivirus-mediated CBS overexpression increased the CBS expression and the endogenous H 2 S production.CBS overexpression dramatically reversed apomorphine-induced rotation of the 6-OHDA model rats, decreased the number of TUNEL-positive neurons and the loss of the nigral DA neurons,specifically inhibited 6-OHDA-induced oxidase stress injury, and down-regulated the expression of α-synuclein(α-SYN) in the injured SN. NaHS (an H 2 S donor) had similar effects to CBS overexpression, while Amino-oxyacetate(AOAA, a CBS inhibitor) had opposite effects on PD rats. In summary, we demonstrated that CBS overexpression was able to provide neuroprotective on PD rats and improving the expression of CBS may be a potential therapeutic method for PD. Copyright © 2017. Published by Elsevier B.V.

  8. Augmented H2S production via cystathionine-beta-synthase upregulation plays a role in pregnancy-associated uterine vasodilation.

    Science.gov (United States)

    Sheibani, Lili; Lechuga, Thomas J; Zhang, Honghai; Hameed, Afshan; Wing, Deborah A; Kumar, Sathish; Rosenfeld, Charles R; Chen, Dong-Bao

    2017-03-01

    Endogenous hydrogen sulfide (H2S) synthesized via metabolizing L-cysteine by cystathionine-beta-synthase (CBS) and cystathionine-gamma-lyase (CSE) is a potent vasodilator and angiogenic factor. The objectives of this study were to determine if human uterine artery (UA) H2S production increases with augmented expression and/or activity of CBS and/or CSE during the menstrual cycle and pregnancy and whether exogenous H2S dilates UA. Uterine arteries from nonpregnant (NP) premenopausal proliferative (pPRM) and secretory (sPRM) phases of the menstrual cycle and pregnant (P) women were studied. H2S production was measured by the methylene blue assay. CBS and CSE mRNAs were assessed by quantitative real-time PCR, and proteins were assessed by immunoblotting and semiquantitative immunofluorescence microscopy. Effects of H2S on rat UA relaxation were determined by wire myography ex vivo. H2S production was greater in NP pPRM and P than NP sPRM UAs and inhibited by the specific CBS but not CSE inhibitor. CBS but not CSE mRNA and protein were greater in NP pPRM and P than NP sPRM UAs. CBS protein was localized to endothelium and smooth muscle and its levels were in a quantitative order of P >NP UAs of pPRM>sPRM. CSE protein was localized in UA endothelium and smooth muscle with no difference among groups. A H2S donor relaxed P > NP UAs but not mesentery artery. Thus, human UA H2S production is augmented with endothelium and smooth muscle CBS upregulation, contributing to UA vasodilation in the estrogen-dominant physiological states in the proliferative phase of the menstrual cycle and pregnancy. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. L-Tryptophan

    Science.gov (United States)

    ... tryptophan by mouth doesn't help reduce facial pain. Improving athletic ability. Some research shows that taking L-tryptophan for 3 days before exercising can improve power during exercise. This improvement in power helps increase ...

  10. Insulin like growth factor-1 prevents 1-mentyl-4-phenylphyridinium-induced apoptosis in PC12 cells through activation of glycogen synthase kinase-3beta

    International Nuclear Information System (INIS)

    Sun, Xin; Huang, Luqi; Zhang, Min; Sun, Shenggang; Wu, Yan

    2010-01-01

    Dopaminergic neurons are lost mainly through apoptosis in Parkinson's disease. Insulin like growth factor-1 (IGF-1) inhibits apoptosis in a wide variety of tissues. Here we have shown that IGF-1 protects PC12 cells from toxic effects of 1-methyl-4-phenylpyridiniumion (MPP + ). Treatment of PC12 cells with recombinant human IGF-1 significantly decreased apoptosis caused by MPP + as measured by acridine orange/ethidium bromide staining. IGF-1 treatment induced sustained phosphorylation of glycogen synthase kinase-3beta (GSK-3beta) as shown by western blot analysis. The anti-apoptotic effect of IGF-1 was abrogated by LY294002, which indirectly inhibits phosphorylation of GSK-3beta. Lithium chloride (LiCl), a known inhibitor of GSK-3beta, also blocked MPP + -induced apoptosis. Finally, although IGF-1 enhanced phosphorylation of extracellular signal-regulated kinases ERK1 and 2 (ERK1/2), PD98059, a specific inhibitor of ERK1/2, did not alter the survival effect of IGF-1. Thus, our findings indicate that IGF-1 protects PC12 cells exposed to MPP + from apoptosis via the GSK-3beta signaling pathway.

  11. Mechanical unloading of the failing human heart fails to activate the protein kinase B/Akt/glycogen synthase kinase-3beta survival pathway.

    Science.gov (United States)

    Razeghi, Peter; Bruckner, Brian A; Sharma, Saumya; Youker, Keith A; Frazier, O H; Taegtmeyer, Heinrich

    2003-01-01

    Left ventricular assist device (LVAD) support of the failing human heart improves myocyte function and increases cell survival. One potential mechanism underlying this phenomenon is activation of the protein kinase B (PKB)/Akt/glycogen synthase kinase-3beta (GSK-3beta) survival pathway. Left ventricular tissue was obtained both at the time of implantation and explantation of the LVAD (n = 11). Six patients were diagnosed with idiopathic dilated cardiomyopathy, 4 patients with ischemic cardiomyopathy and 1 patient with peripartum cardiomyopathy. The mean duration of LVAD support was 205 +/- 35 days. Myocyte diameter and phosphorylation of ERK were used as indices for reverse remodeling. Transcript levels of genes required for the activation of PKB/Akt (insulin-like growth factor-1, insulin receptor substrate-1) were measured by quantitative RT-PCR. In addition, we measured the relative activity of PKB/Akt and GSK-3beta, and assayed for molecular and histological indices of PKB/Akt activation (cyclooxygenase mRNA levels and glycogen levels). Myocyte diameter and phosphorylation of ERK decreased with LVAD support. In contrast, none of the components of the PKB/Akt/GSK-3beta pathway changed significantly with mechanical unloading. The PKB/Akt/GSK-3beta pathway is not activated during LVAD support. Other signaling pathways must be responsible for the improvement of cellular function and cell survival during LVAD support. Copyright 2003 S. Karger AG, Basel

  12. Epoetin beta pegol ameliorates flow-mediated dilation with improving endothelial nitric oxide synthase coupling state in nonobese diabetic rats.

    Science.gov (United States)

    Serizawa, Kenichi; Yogo, Kenji; Tashiro, Yoshihito; Kawasaki, Ryohei; Endo, Koichi; Shimonaka, Yasushi; Hirata, Michinori

    2017-04-01

    Patients with diabetic nephropathy have a high cardiovascular mortality. Epoetin beta pegol (continuous erythropoietin receptor activator, C.E.R.A.) is a drug for the treatment of renal anemia. In this study, we investigated the effect of C.E.R.A. on vascular endothelial function as evaluated by flow-mediated dilation (FMD) and the relationship between hematopoiesis and FMD in diabetic nephropathy rats. Male Spontaneously Diabetic Torii rats (SDT, 22 weeks old) were used. C.E.R.A. (0.6, 1.2 μg/kg) was administered subcutaneously once every 2 weeks for 8 weeks. At 1 week after last administration (31 weeks old), we assessed FMD in the femoral arteries of anesthetized rats using a high-resolution ultrasound system. FMD was also measured 1 week after single C.E.R.A. treatment (5.0 μg/kg) to examine the influence of hematopoiesis. Flow-mediated dilation was significantly decreased in SDT rats before the start of C.E.R.A. treatment (22 weeks old). Repeated administration of C.E.R.A. dose-dependently improved FMD in SDT rats (31 weeks old) without changing blood glucose, nitroglycerin-induced vasodilation, or kidney function. Long-term administration of C.E.R.A. improved the state of endothelial nitric oxide synthase uncoupling in the femoral arteries of SDT rats, which showed a positive correlation with FMD. On the other hand, there was no correlation between FMD and Hb or Hct in SDT rats. Furthermore, at 1 week after single administration of C.E.R.A., FMD was not significantly improved although hemoglobin levels were comparable with levels following long-term C.E.R.A. Long-term treatment with C.E.R.A. improved FMD in SDT rats even after onset of endothelial dysfunction. © 2017 The Authors. Cardiovascular Therapeutics Published by John Wiley & Sons Ltd.

  13. Glycogen synthase kinase 3 beta alters anxiety-, depression-, and addiction-related behaviors and neuronal activity in the nucleus accumbens shell

    Science.gov (United States)

    Crofton, Elizabeth J.; Nenov, Miroslav N.; Zhang, Yafang; Scala, Federico; Page, Sean A.; McCue, David L.; Li, Dingge; Hommel, Jonathan D.; Laezza, Fernanda; Green, Thomas A.

    2017-01-01

    Psychiatric disorders such as anxiety, depression and addiction are often comorbid brain pathologies thought to share common mechanistic biology. As part of the cortico-limbic circuit, the nucleus accumbens shell (NAcSh) plays a fundamental role in integrating information in the circuit, such that modulation of NAcSh circuitry alters anxiety, depression, and addiction-related behaviors. Intracellular kinase cascades in the NAcSh have proven important mediators of behavior. To investigate glycogen-synthase kinase 3 (GSK3) beta signaling in the NAcSh in vivo we knocked down GSK3beta expression with a novel adeno-associated viral vector (AAV2) and assessed changes in anxiety- and depression-like behavior and cocaine self-administration in GSK3beta knockdown rats. GSK3beta knockdown reduced anxiety-like behavior while increasing depression-like behavior and cocaine self-administration. Correlative electrophysiological recordings in acute brain slices were used to assess the effect of AAV-shGSK3beta on spontaneous firing and intrinsic excitability of tonically active interneurons (TANs), cells required for input and output signal integration in the NAcSh and for processing reward-related behaviors. Loose-patch recordings showed that TANs transduced by AAV-shGSK3beta exhibited reduction in tonic firing and increased spike half width. When assessed by whole-cell patch clamp recordings these changes were mirrored by reduction in action potential firing and accompanied by decreased hyperpolarization-induced depolarizing sag potentials, increased action potential current threshold, and decreased maximum rise time. These results suggest that silencing of GSK3beta in the NAcSh increases depression- and addiction-related behavior, possibly by decreasing intrinsic excitability of TANs. However, this study does not rule out contributions from other neuronal sub-types. PMID:28126496

  14. Effect of cysteine dosage on erythrocyte glutathione synthesis rate in a patient with cystathionine beta synthase deficiency

    NARCIS (Netherlands)

    van der Crabben, S. N.; Wijburg, F. A.; Ackermans, M. T.; Sauerwein, H. P.

    2008-01-01

    Cystathionine β-synthase (CBS)-deficient patients develop premature arteriosclerosis and thrombosis leading to a high risk of a vascular event before the age of 30 years. In CBS deficiency the transsulfuration pathway is impaired, leading to markedly elevated levels of homocysteine and methionine,

  15. Lithium ameliorates open-field and elevated plus maze behaviors, and brain phospho-glycogen synthase kinase 3-beta expression in fragile X syndrome model mice.

    Science.gov (United States)

    Chen, Xi; Sun, Weiwen; Pan, Ying; Yang, Quan; Cao, Kaiyi; Zhang, Jin; Zhang, Yizhi; Chen, Mincong; Chen, Feidi; Huang, Yueling; Dai, Lijun; Chen, Shengqiang

    2013-10-01

    To investigate whether lithium modifies open-field and elevated plus maze behavior, and brain phospho-glycogen synthase kinase 3 (P-GSK3beta) expression in Fmr1 knockout mice. One hundred and eighty FVB mice, including knockout and wild type, with an age of 30 days were used. An open-field and elevated plus maze was utilized to test behavior, while western blot was used to measure the P-GSK3beta expression. Six groups were formed: control (saline), lithium chloride 30, 60, 90, 120, and 200 mg/kg. The experiments were carried out in the Institute of Neuroscience, Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China between January and June 2012. Lithium significantly decreased total distance, crossing, central area time, and center entry in the open-field test (popen-arm tracking, open-arm entry, and open-arm time in the elevated plus maze (popen-field and elevated plus maze behaviors of Fmr1 knockout mice. This effect may be related to its enhancement of P-GSK3beta expression. Our findings suggest that lithium might have a therapeutic effect in fragile X syndrome.

  16. Characterization of a 1,4-{beta}-D-glucan synthase from Dictyostelium discoideum. Progress report, May 1990--January 1992

    Energy Technology Data Exchange (ETDEWEB)

    Blanton, R.L.

    1992-01-15

    Various aspects of research concerning Dictyostelium discoideum are presented. The initial focus of this project was upon: the characterization of potential probes for the cellulose synthase (antibody and nucleic acid), the determination of the cultural induction conditions of cellulose synthesis, the solubilization of the enzyme activity, the development of a non-inhibitory disruption buffer, the generation and isolation of mutant strains deficient in cellulose synthesis, and the development of the capability to determine the degree of polymerization of the in vitro product. I have briefly summarized our most significant findings with only selected data sets being shown in this report in the interest of brevity.

  17. Proteasome inhibition-induced p38 MAPK/ERK signaling regulates autophagy and apoptosis through the dual phosphorylation of glycogen synthase kinase 3{beta}

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Cheol-Hee [Research Center for Resistant Cells, Chosun University, Seosuk-dong, Dong-gu, Gwangju 501-759 (Korea, Republic of); Department of Pharmacology, College of Medicine, Chosun University, Seosuk-dong, Dong-gu, Gwangju 501-759 (Korea, Republic of); Lee, Byung-Hoon [College of Pharmacy and Multiscreening Center for Drug Development, Seoul National University, Seoul 151-742 (Korea, Republic of); Ahn, Sang-Gun [Department of Pathology, College of Dentistry, Chosun University, Gwangju 501-759 (Korea, Republic of); Oh, Seon-Hee, E-mail: oshccw@hanmail.net [Research Center for Resistant Cells, Chosun University, Seosuk-dong, Dong-gu, Gwangju 501-759 (Korea, Republic of)

    2012-02-24

    Highlights: Black-Right-Pointing-Pointer MG132 induces the phosphorylation of GSK3{beta}{sup Ser9} and, to a lesser extent, of GSK3{beta}{sup Thr390}. Black-Right-Pointing-Pointer MG132 induces dephosphorylation of p70S6K{sup Thr389} and phosphorylation of p70S6K{sup Thr421/Ser424}. Black-Right-Pointing-Pointer Inactivation of p38 dephosphorylates GSK3{beta}{sup Ser9} and phosphorylates GSK3{beta}{sup Thr390}. Black-Right-Pointing-Pointer Inactivation of p38 phosphorylates p70S6K{sup Thr389} and increases the phosphorylation of p70S6K{sup Thr421/Ser424}. Black-Right-Pointing-Pointer Inactivation of p38 decreases autophagy and increases apoptosis induced by MG132. -- Abstract: Proteasome inhibition is a promising approach for cancer treatment; however, the underlying mechanisms involved have not been fully elucidated. Here, we show that proteasome inhibition-induced p38 mitogen-activated protein kinase regulates autophagy and apoptosis by modulating the phosphorylation status of glycogen synthase kinase 3{beta} (GSK3{beta}) and 70 kDa ribosomal S6 kinase (p70S6K). The treatment of MDA-MB-231 cells with MG132 induced endoplasmic reticulum stress through the induction of ATF6a, PERK phosphorylation, and CHOP, and apoptosis through the cleavage of Bax and procaspase-3. MG132 caused the phosphorylation of GSK3{beta} at Ser{sup 9} and, to a lesser extent, Thr{sup 390}, the dephosphorylation of p70S6K at Thr{sup 389}, and the phosphorylation of p70S6K at Thr{sup 421} and Ser{sup 424}. The specific p38 inhibitor SB203080 reduced the p-GSK3{beta}{sup Ser9} and autophagy through the phosphorylation of p70S6K{sup Thr389}; however, it augmented the levels of p-ERK, p-GSK3{beta}{sup Thr390}, and p-70S6K{sup Thr421/Ser424} induced by MG132, and increased apoptotic cell death. The GSK inhibitor SB216763, but not lithium, inhibited the MG132-induced phosphorylation of p38, and the downstream signaling pathway was consistent with that in SB203580-treated cells. Taken together, our

  18. Interleukin 1 beta induces diabetes and fever in normal rats by nitric oxide via induction of different nitric oxide synthases

    DEFF Research Database (Denmark)

    Reimers, J I; Bjerre, U; Mandrup-Poulsen, T

    1994-01-01

    Substantial in vitro evidence suggests that nitric oxide may be a major mediator of interleukin 1 (IL-1) induced pancreatic beta-cell inhibition and destruction in the initial events leading to insulin-dependent diabetes mellitus. Using NG-nitro-L-arginine methyl ester, an inhibitor of both...

  19. Mutations in Arabidopsis thaliana genes involved in the tryptophan biosynthesis pathway affect root waving on tilted agar surfaces

    Science.gov (United States)

    Rutherford, R.; Gallois, P.; Masson, P. H.

    1998-01-01

    Arabidopsis thaliana roots grow in a wavy pattern upon a slanted surface. A novel mutation in the anthranilate synthase alpha 1 (ASA1) gene, named trp5-2wvc1, and mutations in the tryptophan synthase alpha and beta 1 genes (trp3-1 and trp2-1, respectively) confer a compressed root wave phenotype on tilted agar surfaces. When trp5-2wvc1 seedlings are grown on media supplemented with anthranilate metabolites, their roots wave like wild type. Genetic and pharmacological experiments argue that the compressed root wave phenotypes of trp5-2wvc1, trp2-1 and trp3-1 seedlings are not due to reduced IAA biosynthetic potential, but rather to a deficiency in L-tryptophan (L-Trp), or in a L-Trp derivative. Although the roots of 7-day-old seedlings possess higher concentrations of free L-Trp than the shoot as a whole, trp5-2wvc1 mutants show no detectable alteration in L-Trp levels in either tissue type, suggesting that a very localized shortage of L-Trp, or of a L-Trp-derived compound, is responsible for the observed phenotype.

  20. Inhibition of glycogen synthase kinase 3beta ameliorates triptolide-induced acute cardiac injury by desensitizing mitochondrial permeability transition

    International Nuclear Information System (INIS)

    Wang, Wenwen; Yang, Yanqin; Xiong, Zhewen; Kong, Jiamin; Fu, Xinlu; Shen, Feihai; Huang, Zhiying

    2016-01-01

    Triptolide (TP), a diterpene triepoxide, is a major active component of Tripterygium wilfordii extracts, which are prepared as tablets and has been used clinically for the treatment of inflammation and autoimmune disorders. However, TP's therapeutic potential is limited by severe adverse effects. In a previous study, we reported that TP induced mitochondria dependent apoptosis in cardiomyocytes. Glycogen synthase kinase-3β (GSK-3β) is a multifunctional serine/threonine kinase that plays important roles in the necrosis and apoptosis of cardiomyocytes. Our study aimed to investigate the role of GSK-3β in TP-induced cardiotoxicity. Inhibition of GSK-3β activity by SB 216763, a potent and selective GSK-3 inhibitor, prominently ameliorated the detrimental effects in C57BL/6J mice with TP administration, which was associated with a correction of GSK-3β overactivity. Consistently, in TP-treated H9c2 cells, SB 216763 treatment counteracted GSK-3β overactivity, improved cell viability, and prevented apoptosis by modulating the expression of Bcl-2 family proteins. Mechanistically, GSK-3β interacted with and phosphorylated cyclophilin F (Cyp-F), a key regulator of mitochondrial permeability transition pore (mPTP). GSK-3β inhibition prevented the phosphorylation and activation of Cyp-F, and desensitized mPTP. Our findings suggest that pharmacological targeting of GSK-3β could represent a promising therapeutic strategy for protecting against cardiotoxicity induced by TP. - Highlights: • GSK-3β inhibition ameliorates TP-induced cardiotoxicity in vitro and in vivo. • GSK-3β controls Cyp-F activation, and regulates mPTP and apoptosis in H9c2 cells. • The protective effect is attributed to GSK-3β activity rather than to protein level. • GSK-3β may be a promising target against TP-induced cardiotoxicity.

  1. Inhibition of glycogen synthase kinase 3beta ameliorates triptolide-induced acute cardiac injury by desensitizing mitochondrial permeability transition

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wenwen; Yang, Yanqin; Xiong, Zhewen; Kong, Jiamin [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China); Fu, Xinlu [Laboratory Animals Center, Sun Yat-sen University, Guangzhou 510006 (China); Shen, Feihai, E-mail: shenfh3@mail.sysu.edu.cn [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China); Huang, Zhiying, E-mail: hzhiying@mail.sysu.edu.cn [School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006 (China)

    2016-12-15

    Triptolide (TP), a diterpene triepoxide, is a major active component of Tripterygium wilfordii extracts, which are prepared as tablets and has been used clinically for the treatment of inflammation and autoimmune disorders. However, TP's therapeutic potential is limited by severe adverse effects. In a previous study, we reported that TP induced mitochondria dependent apoptosis in cardiomyocytes. Glycogen synthase kinase-3β (GSK-3β) is a multifunctional serine/threonine kinase that plays important roles in the necrosis and apoptosis of cardiomyocytes. Our study aimed to investigate the role of GSK-3β in TP-induced cardiotoxicity. Inhibition of GSK-3β activity by SB 216763, a potent and selective GSK-3 inhibitor, prominently ameliorated the detrimental effects in C57BL/6J mice with TP administration, which was associated with a correction of GSK-3β overactivity. Consistently, in TP-treated H9c2 cells, SB 216763 treatment counteracted GSK-3β overactivity, improved cell viability, and prevented apoptosis by modulating the expression of Bcl-2 family proteins. Mechanistically, GSK-3β interacted with and phosphorylated cyclophilin F (Cyp-F), a key regulator of mitochondrial permeability transition pore (mPTP). GSK-3β inhibition prevented the phosphorylation and activation of Cyp-F, and desensitized mPTP. Our findings suggest that pharmacological targeting of GSK-3β could represent a promising therapeutic strategy for protecting against cardiotoxicity induced by TP. - Highlights: • GSK-3β inhibition ameliorates TP-induced cardiotoxicity in vitro and in vivo. • GSK-3β controls Cyp-F activation, and regulates mPTP and apoptosis in H9c2 cells. • The protective effect is attributed to GSK-3β activity rather than to protein level. • GSK-3β may be a promising target against TP-induced cardiotoxicity.

  2. Overexpression Myocardial Inducible Nitric Oxide Synthase Exacerbates Cardiac Dysfunction and Beta-Adrenergic Desensitization in Experimental Hypothyroidism☆,☆☆

    Science.gov (United States)

    Shao, Qun; Cheng, Heng-Jie; Callahan, Michael F.; Kitzman, Dalane W; Li, Wei-Min; Cheng, Che Ping

    2015-01-01

    Background Altered nitric oxide synthase (NOS) has been implicated in the pathophysiology of heart failure (HF). Recent evidence links hypothyroidism to the pathology of HF. However, the precise mechanisms are incompletely understood. The alterations and functional effects of cardiac NOS in hypothyroidism are unknown. We tested the hypothesis that hypothyroidism increases cadiomyocyte inducible NOS (iNOS) expression, which plays an important role in hypothyroidism-induced depression of cardiomyocyte contractile properties, [Ca2+]i transient ([Ca2+]iT), and β-adrenergic hyporesponsiveness. Methods and Results We simultaneously evaluated LV functional performance and compared myocyte three NOS, β-adrenergic receptors (AR) and SERCA2a expressions and assessed cardiomyocyte contractile and [Ca2+]iT responses to β-AR stimulation with and without pretreatment of iNOS inhibitor (1400W, 10−5 mol/L) in 26 controls and 26 rats with hypothyroidism induced by methimazole (~30 mg/kg/day for 8 weeks in the drinking water). Compared with controls, in hypothyroidism, total serum T3 and T4 were significantly reduced followed by significantly decreased LV contractility (EES) with increased LV time constant of relaxation. These LV abnormalities were accompanied by concomitant significant decreases in myocyte contraction (dL/dtmax), relaxation (dR/dtmax), and [Ca2+]iT. In hypothyroidism, isoproterenol (10−8 M) produced significantly smaller increases in dL/dtmax, dR/dtmax and [Ca2+]iT. These changes were associated with decreased β1-AR and SERCA2a, but significantly increased iNOS. Moreover, only in hypothyroidism, pretreatment with iNOS inhibitor significantly improved basal and isoproterenol-stimulated myocyte contraction, relaxation and [Ca2+]iT. Conclusions Hypothyroidism produces intrinsic defects of LV myocyte force-generating capacity and relaxation with β-AR desensitization. Up-regulation of cadiomyocyte iNOS may promote progressive cardiac dysfunction in

  3. Quantitative Phosphoproteomic Study Reveals that Protein Kinase A Regulates Neural Stem Cell Differentiation Through Phosphorylation of Catenin Beta-1 and Glycogen Synthase Kinase 3β.

    Science.gov (United States)

    Wang, Shuxin; Li, Zheyi; Shen, Hongyan; Zhang, Zhong; Yin, Yuxin; Wang, Qingsong; Zhao, Xuyang; Ji, Jianguo

    2016-08-01

    Protein phosphorylation is central to the understanding of multiple cellular signaling pathways responsible for regulating the self-renewal and differentiation of neural stem cells (NSCs). Here we performed a large-scale phosphoproteomic analysis of rat fetal NSCs using strong cation exchange chromatography prefractionation and citric acid-assisted two-step enrichment with TiO2 strategy followed by nanoLC-MS/MS analysis. Totally we identified 32,546 phosphosites on 5,091 phosphoproteins, among which 23,945 were class I phosphosites, and quantified 16,000 sites during NSC differentiation. More than 65% of class I phosphosites were novel when compared with PhosphoSitePlus database. Quantification results showed that the early and late stage of NSC differentiation differ greatly. We mapped 69 changed phosphosites on 20 proteins involved in Wnt signaling pathway, including S552 on catenin beta-1 (Ctnnb1) and S9 on glycogen synthase kinase 3β (Gsk3β). Western blotting and real-time PCR results proved that Wnt signaling pathway plays critical roles in NSC fate determination. Furthermore, inhibition and activation of PKA dramatically affected the phosphorylation state of Ctnnb1 and Gsk3β, which regulates the differentiation of NSCs. Our data provides a valuable resource for studying the self-renewal and differentiation of NSCs. Stem Cells 2016;34:2090-2101. © 2016 AlphaMed Press.

  4. Attenuation of ischemia-reperfusion injury by sevoflurane postconditioning involves protein kinase B and glycogen synthase kinase 3 beta activation in isolated rat hearts.

    Science.gov (United States)

    Fang, Neng-Xin; Yao, Yun-Tai; Shi, Chun-Xia; Li, Li-Huan

    2010-12-01

    Volatile anesthetic ischemic postconditioning reduces infarct size following ischemia/reperfusion. Whether phosphorylation of protein kinase B (PKB/Akt) and glycogen synthase kinase 3 beta (GSK3β) is causal for cardioprotection by postconditioning is controversial. We therefore investigated the impact of PKB/Akt and GSK3β in isolated perfused rat hearts subjected to 40 min of ischemia followed by 1 h of reperfusion. 2.0% sevoflurane (1.0 minimum alveolar concentration) was administered at the onset of reperfusion in 15 min as postconditioning. Western blot analysis was used to determine phosphorylation of PKB/Akt and its downstream target GSK3β after 1 h of reperfusion. Mitochondrial and cytosolic content of cytochrome C checked by western blot served as a marker for mitochondrial permeability transition pore opening. Sevoflurane postconditioning significantly improved functional cardiac recovery and decreased infarct size in isolated rat hearts. Compared with unprotected hearts, sevoflurane postconditioning-induced phosphorylation of PKB/Akt and GSK3β were significantly increased. Increase of cytochrome C in mitochondria and decrease of it in cytosol is significant when compared with unprotected ones which have reversal effects on cytochrome C. The current study presents evidence that sevoflurane-induced cardioprotection at the onset of reperfusion are partly through activation of PKB/Akt and GSK3β.

  5. A jojoba beta-Ketoacyl-CoA synthase cDNA complements the canola fatty acid elongation mutation in transgenic plants.

    Science.gov (United States)

    Lassner, M W; Lardizabal, K; Metz, J G

    1996-02-01

    beta-Ketoacyl-coenzyme A (CoA) synthase (KCS) catalyzes the condensation of malonyl-CoA with long-chain acyl-CoA. This reaction is the initial step of the microsomal fatty acyl-CoA elongation pathway responsible for formation of very long chain fatty acids (VLCFAs, or fatty acids with chain lengths > 18 carbons). Manipulation of this pathway is significant for agriculture, because it is the basis of conversion of high erucic acid rapeseed into canola. High erucic acid rapeseed oil, used as an industrial feedstock, is rich in VLCFAs, whereas the edible oil extracted from canola is essentially devoid of VLCFAs. Here, we report the cloning of a cDNA from developing jojoba embryos involved in microsomal fatty acid elongation. The jojoba cDNA is homologous to the recently cloned Arabidopsis FATTY ACID ELONGATION1 (FAE1) gene that has been suggested to encode KCS. We characterize the jojoba enzyme and present biochemical data indicating that the jojoba cDNA does indeed encode KCS. Transformation of low erucic acid rapeseed with the jojoba cDNA restored KCS activity to developing embryos and altered the transgenic seed oil composition to contain high levels of VLCFAs. The data reveal the key role KCS plays in determining the chain lengths of fatty acids found in seed oils.

  6. Tyrosinase inhibition due to interaction of homocyst(e)ine with copper: the mechanism for reversible hypopigmentation in homocystinuria due to cystathionine beta-synthase deficiency.

    Science.gov (United States)

    Reish, O; Townsend, D; Berry, S A; Tsai, M Y; King, R A

    1995-01-01

    Deficiency of cystathionine beta-synthase (CBS) is a genetic disorder of transsulfuration resulting in elevated plasma homocyst(e)ine and methionine and decreased cysteine. Affected patients have multisystem involvement, which may include light skin and hair. Reversible hypopigmentation in treated homocystinuric patients has been infrequently reported, and the mechanism is undefined. Two CBS-deficient homocystinuric patients manifested darkening of their hypopigmented hair following treatment that decreased plasma homocyst(e)ine. We hypothesized that homocyst(e)ine inhibits tyrosinase, the major pigment enzyme. The activity of tyrosinase extracted from pigmented human melanoma cells (MNT-1) that were grown in the presence of homocysteine was reduced in comparison to that extracted from cells grown without homocysteine. Copper sulfate restored homocyst(e)ine-inhibited tyrosinase activity when added to the culture cell media at a proportion of 1.25 mol of copper sulfate per 1 mol of DL-homocysteine. Holo-tyrosinase activity was inhibited by adding DL-homocysteine to the assay reaction mixture, and the addition of copper sulfate to the reaction mixture prevented this inhibition. Other tested compounds, L-cystine and betaine did not affect tyrosinase activity. Our data suggest that reversible hypopigmentation in homocystinuria is the result of tyrosinase inhibition by homocyst(e)ine and that the probable mechanism of this inhibition is the interaction of homocyst(e)ine with copper at the active site of tyrosinase. Images Figure 1 PMID:7611281

  7. Rotational spectrum of tryptophan

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, M. Eugenia, E-mail: maria.sanz@kcl.ac.uk; Cabezas, Carlos, E-mail: ccabezas@qf.uva.es; Mata, Santiago, E-mail: santiago.mata@uva.es; Alonso, Josè L., E-mail: jlalonso@qf.uva.es [Grupo de Espectroscopia Molecular (GEM), Edificio Quifima, Laboratorios de Espectroscopia y Bioespectroscopia, Unidad Asociada CSIC, Parque Científico Uva, Universidad de Valladolid, 47011 Valladolid (Spain)

    2014-05-28

    The rotational spectrum of the natural amino acid tryptophan has been observed for the first time using a combination of laser ablation, molecular beams, and Fourier transform microwave spectroscopy. Independent analysis of the rotational spectra of individual conformers has conducted to a definitive identification of two different conformers of tryptophan, with one of the observed conformers never reported before. The analysis of the {sup 14}N nuclear quadrupole coupling constants is of particular significance since it allows discrimination between structures, thus providing structural information on the orientation of the amino group. Both observed conformers are stabilized by an O–H···N hydrogen bond in the side chain and a N–H···π interaction forming a chain that reinforce the strength of hydrogen bonds through cooperative effects.

  8. Identification of 2-aminothiazole-4-carboxylate derivatives active against Mycobacterium tuberculosis H37Rv and the beta-ketoacyl-ACP synthase mtFabH.

    Directory of Open Access Journals (Sweden)

    Qosay Al-Balas

    Full Text Available BACKGROUND: Tuberculosis (TB is a disease which kills two million people every year and infects approximately over one-third of the world's population. The difficulty in managing tuberculosis is the prolonged treatment duration, the emergence of drug resistance and co-infection with HIV/AIDS. Tuberculosis control requires new drugs that act at novel drug targets to help combat resistant forms of Mycobacterium tuberculosis and reduce treatment duration. METHODOLOGY/PRINCIPAL FINDINGS: Our approach was to modify the naturally occurring and synthetically challenging antibiotic thiolactomycin (TLM to the more tractable 2-aminothiazole-4-carboxylate scaffold to generate compounds that mimic TLM's novel mode of action. We report here the identification of a series of compounds possessing excellent activity against M. tuberculosis H(37R(v and, dissociatively, against the beta-ketoacyl synthase enzyme mtFabH which is targeted by TLM. Specifically, methyl 2-amino-5-benzylthiazole-4-carboxylate was found to inhibit M. tuberculosis H(37R(v with an MIC of 0.06 microg/ml (240 nM, but showed no activity against mtFabH, whereas methyl 2-(2-bromoacetamido-5-(3-chlorophenylthiazole-4-carboxylate inhibited mtFabH with an IC(50 of 0.95+/-0.05 microg/ml (2.43+/-0.13 microM but was not active against the whole cell organism. CONCLUSIONS/SIGNIFICANCE: These findings clearly identify the 2-aminothiazole-4-carboxylate scaffold as a promising new template towards the discovery of a new class of anti-tubercular agents.

  9. Glycogen synthase kinase 3 beta inhibits microRNA-183-96-182 cluster via the β-Catenin/TCF/LEF-1 pathway in gastric cancer cells.

    Science.gov (United States)

    Tang, Xiaoli; Zheng, Dong; Hu, Ping; Zeng, Zongyue; Li, Ming; Tucker, Lynne; Monahan, Renee; Resnick, Murray B; Liu, Manran; Ramratnam, Bharat

    2014-03-01

    Glycogen synthase kinase 3 beta (GSK3β) is a critical protein kinase that phosphorylates numerous proteins in cells and thereby impacts multiple pathways including the β-Catenin/TCF/LEF-1 pathway. MicroRNAs (miRs) are a class of noncoding small RNAs of ∼22 nucleotides in length. Both GSK3β and miR play myriad roles in cell functions including stem cell development, apoptosis, embryogenesis and tumorigenesis. Here we show that GSK3β inhibits the expression of miR-96, miR-182 and miR-183 through the β-Catenin/TCF/LEF-1 pathway. Knockout of GSK3β in mouse embryonic fibroblast cells increases expression of miR-96, miR-182 and miR-183, coinciding with increases in the protein level and nuclear translocation of β-Catenin. In addition, overexpression of β-Catenin enhances the expression of miR-96, miR-182 and miR-183 in human gastric cancer AGS cells. GSK3β protein levels are decreased in human gastric cancer tissue compared with surrounding normal gastric tissue, coinciding with increases of β-Catenin protein, miR-96, miR-182, miR-183 and primary miR-183-96-182 cluster (pri-miR-183). Furthermore, suppression of miR-183-96-182 cluster with miRCURY LNA miR inhibitors decreases the proliferation and migration of AGS cells. Knockdown of GSK3β with siRNA increases the proliferation of AGS cells. Mechanistically, we show that β-Catenin/TCF/LEF-1 binds to the promoter of miR-183-96-182 cluster gene and thereby activates the transcription of the cluster. In summary, our findings identify a novel role for GSK3β in the regulation of miR-183-96-182 biogenesis through β-Catenin/TCF/LEF-1 pathway in gastric cancer cells.

  10. A 31 bp VNTR in the cystathionine beta-synthase (CBS) gene is associated with reduced CBS activity and elevated post-load homocysteine levels

    NARCIS (Netherlands)

    Lievers, K.J.; Kluijtmans, L.A.; Heil, S.G.; Boers, G.H.J.; Verhoef, P.; Oppenraay-Emmerzaal, van D.; Heijer, den M.; Trijbels, F.J.M.; Blom, H.J.

    2001-01-01

    Molecular defects in genes encoding enzymes involved in homocysteine metabolism may account for mild hyperhomocysteinaemia, an independent and graded risk factor for cardiovascular disease (CVD). Although heterozygosity for cystathionine -synthase (CBS) deficiency has been excluded as a major

  11. TRYPTOPHAN PROMOTES CHARITABLE DONATING

    Directory of Open Access Journals (Sweden)

    Laura eSteenbergen

    2014-12-01

    Full Text Available The link between serotonin (5-HT and one of the most important elements of prosocial behavior, charity, has remained largely uninvestigated. In the present study, we tested whether charitable donating can be promoted by administering the food supplement L-Tryptophan (TRP, the biochemical precursor of 5-HT. Participants were compared with respect to the amount of money they donated when given the opportunity to make a charitable donation. As expected, compared to a neutral placebo, TRP appears to increase the participants’ willingness to donate money to a charity. This result supports the idea that the food we eat may act as a cognitive enhancer modulating the way we think and perceive the world and others.

  12. Intravenous beta-endorphin administration fails to alter hypothalamic blood flow in rats expressing normal or reduced nitric oxide synthase activity

    NARCIS (Netherlands)

    Benyo, Z.; Szabo, C; Velkel, M.H; Bohus, B.G J; Wahl, M.A; Sandor, P

    1996-01-01

    beta-Endorphin (beta-END) significantly contributes to the maintenance of hypothalamic blood flow (HBF) autoregulation during hemorrhagic hypotension in rats. Recently, several natural and synthetic opioid peptides were reported to induce nitric oxide (NO)-mediated dilation in the cerebrovascular

  13. Cordycepin (3'-deoxyadenosine) inhibits the growth of B16-BL6 mouse melanoma cells through the stimulation of adenosine A3 receptor followed by glycogen synthase kinase-3beta activation and cyclin D1 suppression.

    Science.gov (United States)

    Yoshikawa, Noriko; Yamada, Shizuo; Takeuchi, Chihiro; Kagota, Satomi; Shinozuka, Kazumasa; Kunitomo, Masaru; Nakamura, Kazuki

    2008-06-01

    Cordyceps sinensis, a parasitic fungus on the larvae of Lepidoptera, has been used as a traditional Chinese medicine. We previously reported that the growth of B16-BL6 mouse melanoma (B16-BL6) cells was inhibited by cordycepin (3'-deoxyadenosine), an active ingredient of C. sinensis, and its effect was antagonized by MRS1191, a selective adenosine A3 receptor antagonist. In this study, the radioligand binding assay using [125I]-AB-MECA (a selective adenosine A3 receptor agonist) has shown that B16-BL6 cells express adenosine A3 receptors and that cordycepin binds to these receptors. We also confirmed the involvement of adenosine A3 receptors in the action of cordycepin using MRS1523 and MRS1220, specific adenosine A3 receptor antagonists. Next, indirubin, a glycogen synthase kinase-3beta (GSK-3beta) inhibitor, antagonized the growth suppression induced by cordycepin. Furthermore, the level of cyclin D1 protein in B16-BL6 cells was decreased by cordycepin using Western blot analysis. In conclusion, this study demonstrated that cordycepin inhibits the proliferation of B16-BL6 cells by stimulating adenosine A3 receptors followed by the Wnt signaling pathway, including GSK-3beta activation and cyclin D1 inhibition.

  14. Chromosomal mapping and mutational analysis of the coding region of the glycogen synthase kinase-3alpha and beta isoforms in patients with NIDDM

    DEFF Research Database (Denmark)

    Hansen, L; Arden, K C; Rasmussen, S B

    1997-01-01

    isoforms of GSK-3alpha and GSK-3beta in 72 NIDDM patients and 12 control subjects. No structural changes were detected apart from a few silent mutations. Mapping of the GSK-3alpha to chromosome 19q13.1-13.2 and the GSK-3beta to chromosome 3q13.3-q21 outside known genetic loci linked to NIDDM further makes...

  15. Leptin promotes osteoblast differentiation and mineralization of primary cultures of vascular smooth muscle cells by inhibiting glycogen synthase kinase (GSK)-3{beta}

    Energy Technology Data Exchange (ETDEWEB)

    Zeadin, Melec G.; Butcher, Martin K.; Shaughnessy, Stephen G. [Department of Medicine, McMaster University, Hamilton, ON (Canada); Thrombosis and Atherosclerosis Research Institute, Hamilton, ON (Canada); Werstuck, Geoff H., E-mail: Geoff.Werstuck@taari.ca [Department of Medicine, McMaster University, Hamilton, ON (Canada); Thrombosis and Atherosclerosis Research Institute, Hamilton, ON (Canada)

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer Leptin promotes osteoblast differentiation of primary smooth muscle cells. Black-Right-Pointing-Pointer Leptin regulates the expression of genes involved in osteoblast differentiation. Black-Right-Pointing-Pointer Constitutively active GSK-3{beta} attenuates leptin-induced osteoblast differentiation. Black-Right-Pointing-Pointer This suggests that leptin signals through GSK-3{beta} to promote osteoblast differentiation. -- Abstract: In this study, we begin to investigate the underlying mechanism of leptin-induced vascular calcification. We found that treatment of cultured bovine aortic smooth muscle cells (BASMCs) with leptin (0.5-4 {mu}g/ml) induced osteoblast differentiation in a dose-dependent manner. Furthermore, we found that leptin significantly increased the mRNA expression of osteopontin and bone sialoprotein, while down-regulating matrix gla protein (MGP) expression in BASMCs. Key factors implicated in osteoblast differentiation, including members of the Wnt signaling pathway, were examined. Exposure to leptin enhanced phosphorylation of GSK-3{beta} on serine-9 thereby inhibiting activity and promoting the nuclear accumulation of {beta}-catenin. Transfection of BASMCs with an adenovirus that expressed constitutively active GSK-3{beta} (Ad-GSK-3{beta} S9A) resulted in a >2-fold increase in GSK-3{beta} activity and a significant decrease in leptin-induced alkaline phosphatase (ALP) activity. In addition, qRT-PCR analysis showed that GSK-3{beta} activation resulted in a significant decrease in the expression of osteopontin and bone sialoprotein, but a marked increase in MGP mRNA expression. When taken together, our results suggest a mechanism by which leptin promotes osteoblast differentiation and vascular calcification in vivo.

  16. Tryptophan Research in Panic Disorder

    Directory of Open Access Journals (Sweden)

    Eduard Maron

    2008-01-01

    Full Text Available A considerable body of evidence suggests the involvement of serotonin neurotransmission in the pathogenesis of panic disorder. Research on pathways and functions of tryptophan, an essential amino acid converted into serotonin, may advance our understanding of serotonergic actions in panic disorder and related phenomena. The investigative approaches in this field include manipulations of tryptophan availability as well as genetic association and functional brain imaging studies. In this review we examine the principle findings of these studies and propose further research directions.

  17. An Arabidopsis callose synthase

    DEFF Research Database (Denmark)

    Ostergaard, Lars; Petersen, Morten; Mattsson, Ole

    2002-01-01

    in the Arabidopsis mpk4 mutant which exhibits systemic acquired resistance (SAR), elevated beta-1,3-glucan synthase activity, and increased callose levels. In addition, AtGsl5 is a likely target of salicylic acid (SA)-dependent SAR, since AtGsl5 mRNA accumulation is induced by SA in wild-type plants, while...... expression of the nahG salicylate hydroxylase reduces AtGsl5 mRNA levels in the mpk4 mutant. These results indicate that AtGsl5 is likely involved in callose synthesis in flowering tissues and in the mpk4 mutant....

  18. Positron emission tomographic studies on aromatic L-amino acid decarboxylase activity in vivo for L-dopa and 5-hydroxy-L-tryptophan in the monkey brain

    Energy Technology Data Exchange (ETDEWEB)

    Hartvig, P; Tedroff, J; Lindner, K J; Bjurling, P; Chang, C W; Laangstroem, B [Uppsala Univ. (Sweden); Tsukada, H [Central Research Lab., Hamamatsu Photonics Shizuoka, Osaka (Japan); Watanabe, Y [Dept. of Neuroscience, Osaka Bioscience Inst., Osaka (Japan)

    1993-01-01

    The regional brain kinetics following 5-hydroxy-L-([beta]-11 C)tryptophan and L-([beta]-11 C)DOPA intravenous injection was measured in twelve Rhesus monkeys using positron emission tomography (PET). The radiolabelled compounds were also injected together with various doses of unlabelled 5-hydroxy-L-tryptophan or L-DOPA. The radioactivity accumulated in the striatal region and the rate of increased utilization with time was calculated using a graphical method with back of the brain as a reference region. The rate constants for decarboxylation were 0.0070 [+-] 0.0007 (S. D) and 0.0121 [+-] 0.0010 min[sup -1] for 5-hydroxy-L-([beta]-11 C)tryptophan and L-([beta]-11 C)DOPA, respectively. After concomitant injection with unlabelled 5-hydroxy-L-tryptophan, the rate constant of 5-hydroxy-L-([beta]-11 C)tryptophan decreased dose-dependently and a 50 percent reduction was seen with a dose of about 4 mg/kg of unlabelled compound. A decreased utilization rate of L-([beta]-11 C)DOPA was seen only after simultaneous injection of 30 mg/kg of either L-DOPA or 5-hydroxy-L-tryptophan. This capacity limitation was most likely interpreted as different affinity of the striatal aromatic amino acid decarboxylase for L-DOPA and 5-hydroxy-L-tryptophan, respectively.

  19. Beta-amyloid-induced cholinergic denervation correlates with enhanced nitric oxide synthase activity in rat cerebral cortex: Reversal by NMDA receptor blockade : Reversal by NMDA receptor blockade

    NARCIS (Netherlands)

    O’Mahony, S.; Harkany, T.; Ábrahám, I.; Jong, G.I. de; Varga, J.L.; Zarándi, M.; Penke, B.; Nyakas, C.; Luiten, P.G.M.; Leonard, B.E.

    1998-01-01

    Ample experimental evidence indicates that acute beta-amyloid infusion into the nucleus basalis of rats elicits abrupt degeneration of the magnocellular cholinergic neurons projecting to the cerebral cortex, In fact, involvement of a permanent Ca2+ overload, partially via N-methyl-D-aspartate (NMDA)

  20. Glycogen synthase kinase 3-{beta} phosphorylates novel S/T-P-S/T domains in Notch1 intracellular domain and induces its nuclear localization

    Energy Technology Data Exchange (ETDEWEB)

    Han, Xiangzi [Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Department of Preventive Medicine, Yanbian University College of Medicine, Yanji (China); Ju, Ji-hyun [Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Shin, Incheol, E-mail: incheol@hanyang.ac.kr [Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2012-06-29

    Highlights: Black-Right-Pointing-Pointer Novel S/T-P-S/T domains were identified in NICD. Black-Right-Pointing-Pointer Phosphorylation of NICD on the S/T-P-S/T domains induced nuclear localization. Black-Right-Pointing-Pointer GSK-3{beta} phosphorylated S and T residues in NICD S/T-P-S/T domains. -- Abstract: We identified two S/T-P-S/T domains (2122-2124, 2126-2128) inducing Notch intracellular domain (NICD) nuclear localization. The GFP-NICD (1963-2145) fusion protein deletion mutant without classical NLS was localized in the nucleus like the full length GFP-NICD. However, quadruple substitution mutant (T2122A T2124A S2126A T2128A) showed increased cytoplasmic localization. GSK-3{beta} enhanced nuclear localization and transcriptional activity of WT NICD but not of quadruple substitution mutant. In vitro kinase assays revealed that GSK-3{beta} phosphorylated S and T residues in NICD S/T-P-S/T domains. These results suggest that the novel S/T-P-S/T domain, phosphorylated by GSK-3{beta} is also involved in the nuclear localization of NICD as well as classical NLS.

  1. Structure and mechanism of the diterpene cyclase ent-copalyl diphosphate synthase

    Energy Technology Data Exchange (ETDEWEB)

    Köksal, Mustafa; Hu, Huayou; Coates, Robert M.; Peters, Reuben J.; Christianson, David W. (UIUC); (Iowa State); (Penn)

    2011-09-20

    The structure of ent-copalyl diphosphate synthase reveals three {alpha}-helical domains ({alpha}, {beta} and {gamma}), as also observed in the related diterpene cyclase taxadiene synthase. However, active sites are located at the interface of the {beta}{gamma} domains in ent-copalyl diphosphate synthase but exclusively in the {alpha} domain of taxadiene synthase. Modular domain architecture in plant diterpene cyclases enables the evolution of alternative active sites and chemical strategies for catalyzing isoprenoid cyclization reactions.

  2. Benzalacetone Synthase

    Directory of Open Access Journals (Sweden)

    Ikuro eAbe

    2012-03-01

    Full Text Available Benzalacetone synthase, from the medicinal plant Rheum palmatum (Polygonaceae (RpBAS, is a plant-specific chalcone synthase (CHS superfamily of type III polyketide synthase (PKS. RpBAS catalyzes the one-step, decarboxylative condensation of 4-coumaroyl-CoA with malonyl-CoA to produce the C6-C4 benzalacetone scaffold. The X-ray crystal structures of RpBAS confirmed that the diketide-forming activity is attributable to the characteristic substitution of the conserved active-site "gatekeeper" Phe with Leu. Furthermore, the crystal structures suggested that RpBAS employs novel catalytic machinery for the thioester bond cleavage of the enzyme-bound diketide intermediate and the final decarboxylation reaction to produce benzalacetone. Finally, by exploiting the remarkable substrate tolerance and catalytic versatility of RpBAS, precursor-directed biosynthesis efficiently generated chemically and structurally divergent, unnatural novel polyketide scaffolds. These findings provided a structural basis for the functional diversity of the type III PKS enzymes.

  3. Determination of cystathionine beta-synthase activity in human plasma by LC-MS/MS: potential use in diagnosis of CBS deficiency.

    LENUS (Irish Health Repository)

    Krijt, Jakub

    2011-02-01

    Cystathionine β-synthase (CBS) deficiency is usually confirmed by assaying the enzyme activity in cultured skin fibroblasts. We investigated whether CBS is present in human plasma and whether determination of its activity in plasma could be used for diagnostic purposes. We developed an assay to measure CBS activity in 20 μL of plasma using a stable isotope substrate - 2,3,3-(2)H serine. The activity was determined by measurement of the product of enzyme reaction, 3,3-(2)H-cystathionine, using LC-MS\\/MS. The median enzyme activity in control plasma samples was 404 nmol\\/h\\/L (range 66-1,066; n = 57). In pyridoxine nonresponsive CBS deficient patients, the median plasma activity was 0 nmol\\/ho\\/L (range 0-9; n = 26), while in pyridoxine responsive patients the median activity was 16 nmol\\/hour\\/L (range 0-358; n = 28); this overlapped with the enzyme activity from control subject. The presence of CBS in human plasma was confirmed by an in silico search of the proteome database, and was further evidenced by the activation of CBS by S-adenosyl-L-methionine and pyridoxal 5\\'-phosphate, and by configuration of the detected reaction product, 3,3-(2)H-cystathionine, which was in agreement with the previously observed CBS reaction mechanism. We hypothesize that the CBS enzyme in plasma originates from liver cells, as the plasma CBS activities in patients with elevated liver aminotransferase activities were more than 30-fold increased. In this study, we have demonstrated that CBS is present in human plasma and that its catalytic activity is detectable by LC-MS\\/MS. CBS assay in human plasma brings new possibilities in the diagnosis of pyridoxine nonresponsive CBS deficiency.

  4. Chemical modification as an approach for the identification of UDPG-binding polypeptides of UDPG-glucose: (1,3)-Beta-glucan synthase

    International Nuclear Information System (INIS)

    Mason, T.L.

    1989-01-01

    The lysine-reactive chemical modification reagents uridine diphosphate pyridoxal (UDP-pyridoxal) and formaldehyde (HCHO) were used to identify UDPG-binding polypeptides of UDP-glucose: (1,3)-β-D-glucan synthase (GS) from red beet storage tissue. Complete enzyme inactivation occurred after exposure to micromolar levels of UDP-pyridoxal and millimolar levels of HCHO. Divalent cations (Mg 2+ and Ca 2+ , particularly Ca 2+ ) were required by both for inactivation. Substrate (UDPG) and chelators (EDTA and EGTA) protected plasma membrane GS (PMGS) against UDP-pyridoxal and HCHO inhibition. UDPG protected CHAPS solubilized GS (CSGS) against UDP-pyridoxal inactivation, but not against HCHO. It was concluded that beet GS contains a lysine residue at the UDPG-binding site. When PMGS was directly labeled with UDP[ 3 H]-pyridoxal or [ 14 C]HCHO, random labeling occurred. Therefore, a multi-step labeling procedure was developed. Nonessential lysine residues were first blocked with HCHO while 5 mM UDPG protected the active site lysine. Background labeling was reduced 4-fold. Membranes were recovered by centrifugation and the active site lysine exposed to [ 14 C] HCHO. Major labeled polypeptides were at 200, 76, and 54 kD. Minor polypeptides were seen at 94, 82, 68, 60, and 20-25 kD. CSGS was labeled by a modified multi-step procedure. CSGS was blocked by reaction with UDP-pyridoxal in the presence of UDPG. CSGS was then recovered by product entrapment and labeled with [ 14 C]HCHO. Background labeling was reduced by 8-fold and potential UDPG-binding polypeptides narrowed to 68, 54, 25 and 22 kD

  5. Oxidative Modification of Tryptophan-Containing Peptides

    DEFF Research Database (Denmark)

    Petersen, Jonas; Christensen, Pia Katrine; Nielsen, Mathias T

    2018-01-01

    We herein present a broadly useful method for the chemoselective modification of a wide range of tryptophan-containing peptides. Exposing a tryptophan-containing peptide to 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) resulted in a selective cyclodehydration between the peptide backbone...

  6. Inhibition of tryptophan - pyrrolase activity and elevation of brain tryptophan concentration by fluoxetine in rats

    International Nuclear Information System (INIS)

    Bano, S.; Sherkheli, M.A

    2003-01-01

    Objective: To investigate in-vitro as well as in-vivo effects of various doses of fluoxetine (SSRI) on tryptophan metabolism in rates. Results: In in-vitro (10 - 1000 mM) as well in-vivo (0.5 - 30 mg/kg body wt.) studies, fluoxetine showed a statistically significant inhibition of rat liver tryptophan pyrrolase (tryptophan-2,3-dioxygenase; EC 1.13.11.11) activity. Significant increases were noted at 10 and 30 mg/kg doses in brain, serum (total and free) and liver L-tryptophan concentrations. Similarly, serum non-esterified free fatty acids showed a significant increase at both doses. There was no effect on serum glucose and albumin concentrations. Conclusion: It is suggested that major mechanism of action of fluoxetine is that of elevating brain tryptophan concentration and hence 5-HT synthesis by increasing the availability of circulating tryptophan to the brain secondarily to inhibition of major tryptophan degrading enzyme, hepatic tryptophan pyrrolase. It is assumed that fluoxetine inhibits the binding of apoenzyme form of tryptophan pyrrolase with its cofactor haem. The results are discussed in relation to possible involvement of disturbed hepatic tryptophan metabolism in depressive illness. (author)

  7. Cyclopiazonic acid biosynthesis in Aspergillus sp.: characterization of a reductase-like R* domain in cyclopiazonate synthetase that forms and releases cyclo-acetoacetyl-L-tryptophan.

    Science.gov (United States)

    Liu, Xinyu; Walsh, Christopher T

    2009-09-15

    The fungal neurotoxin alpha-cyclopiazonic acid (CPA), a nanomolar inhibitor of Ca2+-ATPase, has a pentacyclic indole tetramic acid scaffold that arises from one molecule of tryptophan, acetyl-CoA, malonyl-CoA, and dimethylallyl pyrophosphate by consecutive action of three enzymes, CpaS, CpaD, and CpaO. CpaS is a hybrid, two module polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) that makes and releases cyclo-acetoacetyl-L-tryptophan (cAATrp), the tetramic acid that serves as substrate for subsequent prenylation and oxidative cyclization to the five ring CPA scaffold. The NRPS module in CpaS has a predicted four-domain organization of condensation, adenylation, thiolation, and reductase* (C-A-T-R*), where R* lacks the critical Ser-Tyr-Lys catalytic triad of the short chain dehydrogenase/reductase (SDR) superfamily. By heterologous overproduction in Escherichia coli of the 56 kDa Aspergillus flavus CpaS TR* didomain and the single T and R* domains, we demonstrate that CpaS catalyzes a Dieckmann-type cyclization on the N-acetoacetyl-Trp intermediate bound in thioester linkage to the phosphopantetheinyl arm of the T domain to form and release cAATrp. This occurs without any participation of NAD(P)H, so R* does not function as a canonical SDR family member. Use of the T and R* domains in in trans assays enabled multiple turnovers and evaluation of specific mutants. Mutation of the D3803 residue in the R* domain, conserved in other fungal tetramate synthetases, abolished activity both in in trans and in cis (TR*) activity assays. It is likely that cyclization of beta-ketoacylaminoacyl-S-pantetheinyl intermediates to released tetramates represents a default cyclization/release route for redox-incompetent R* domains embedded in NRPS assembly lines.

  8. Dendritic biomimicry: microenvironmental hydrogen-bonding effects on tryptophan fluorescence.

    Science.gov (United States)

    Koenig, S; Müller, L; Smith, D K

    2001-03-02

    Two series of dendritically modified tryptophan derivatives have been synthesised and their emission spectra measured in a range of different solvents. This paper presents the syntheses of these novel dendritic structures and discusses their emission spectra in terms of both solvent and dendritic effects. In the first series of dendrimers, the NH group of the indole ring is available for hydrogen bonding, whilst in the second series, the indole NH group has been converted to NMe. Direct comparison of the emission wavelengths of analogous NH and NMe derivatives indicates the importance of the Kamlet-Taft solvent beta3 parameter, which reflects the ability of the solvent to accept a hydrogen bond from the NH group, an effect not possible for the NMe series of dendrimers. For the NH dendrimers, the attachment of a dendritic shell to the tryptophan subunit leads to a red shift in emission wavelength. This dendritic effect only operates in non-hydrogen-bonding solvents. For the NMe dendrimers, however, the attachment of a dendritic shell has no effect on the emission spectra of the indole ring. This proves the importance of hydrogen bonding between the branched shell and the indole NH group in causing the dendritic effect. This is the first time a dendritic effect has been unambiguously assigned to individual hydrogen-bonding interactions and indicates that such intramolecular interactions are important in dendrimers, just as they are in proteins. Furthermore, this paper sheds light on the use of tryptophan residues as a probe of the microenvironment within proteins--in particular, it stresses the importance of hydrogen bonds formed by the indole NH group.

  9. [Acute tryptophan depletion in eating disorders].

    Science.gov (United States)

    Díaz-Marsa, M; Lozano, C; Herranz, A S; Asensio-Vegas, M J; Martín, O; Revert, L; Saiz-Ruiz, J; Carrasco, J L

    2006-01-01

    This work describes the rational bases justifying the use of acute tryptophan depletion technique in eating disorders (ED) and the methods and design used in our studies. Tryptophan depletion technique has been described and used in previous studies safely and makes it possible to evaluate the brain serotonin activity. Therefore it is used in the investigation of hypotheses on serotonergic deficiency in eating disorders. Furthermore, and given the relationship of the dysfunctions of serotonin activity with impulsive symptoms, the technique may be useful in biological differentiation of different subtypes, that is restrictive and bulimic, of ED. 57 female patients with DSM-IV eating disorders and 20 female controls were investigated with the tryptophan depletion test. A tryptophan-free amino acid solution was administered orally after a two-day low tryptophan diet to patients and controls. Free plasma tryptophan was measured at two and five hours following administration of the drink. Eating and emotional responses were measured with specific scales for five hours following the depletion. A study of the basic characteristics of the personality and impulsivity traits was also done. Relationship of the response to the test with the different clinical subtypes and with the temperamental and impulsive characteristics of the patients was studied. The test was effective in considerably reducing plasma tryptophan in five hours from baseline levels (76%) in the global sample. The test was well tolerated and no severe adverse effects were reported. Two patients withdrew from the test due to gastric intolerance. The tryptophan depletion test could be of value to study involvement of serotonin deficits in the symptomatology and pathophysiology of eating disorders.

  10. Further analysis of multicentre cystathionine beta synthase deficiency thrombosis data and metabolic pathways suggests potentially better treatment via improved cysteine supplementation, diet, antioxidant supplementation, follow-up and testing for thrombophilic mutations

    Directory of Open Access Journals (Sweden)

    David Vance

    2017-01-01

    Full Text Available Background Homozygous or compound heterozygous Cystathionine-beta-synthase deficiency (CBS-- may result in thrombosis. Treatment has included various combinations of: low-methionine diets, cystine (cystine dimer-enriched amino acid supplementation, vitamin B6, folic acid, vitamin B12 and betaine. Treatment compliance and outcomes even in the most-developed countries are mostly sub-optimal and variable, and the differing theoretical metabolic ramifications due to differing treatments have not been well addressed. The aim of this work was to further analyse the thrombosis events data of Yap et al (2001/2003, and to compare these with the rate of thrombosis in the general population, and to examine the theoretical significance of the metabolic pathways affected by CBS-- and its treatments, and so find any potential improvements in treatments, considering also less-developed areas. Methods Yap et al’s (2001/2003 data of the thrombosis outcomes of five major (CBS---treating centers: in Dublin, Sydney, Nijmegen, Manchester and London; were statistically compared with outcomes predicted by Mudd et al’s (1985 untreated natural history outcomes, and then Dublin versus the others; these rates were then compared with those of general populations; and treatments were examined regarding their theoretical metabolic ramifications. Results There were less thrombosis outcomes (P<.05 in the treated and followed CBS-- patient groups of each of the five centers, even when considered singly, than that expected in the absence of treatment by reference to the natural history data of Mudd et al (1985, but the reduction was less than half that claimed by Yap et al, and the remaining level of thrombosis is roughly 10 times that of the general population. The thromboses outcome (nil of the Dublin group is better than that of the other four groups, but only at P ~ 0.16 with the other four groups combined, or P = 0.14 to 0.23 singly. Treatment regimens differ, including

  11. Crystal structure of riboflavin synthase

    Energy Technology Data Exchange (ETDEWEB)

    Liao, D.-I.; Wawrzak, Z.; Calabrese, J.C.; Viitanen, P.V.; Jordan, D.B. (DuPont); (NWU)

    2010-03-05

    Riboflavin synthase catalyzes the dismutation of two molecules of 6,7-dimethyl-8-(1'-D-ribityl)-lumazine to yield riboflavin and 4-ribitylamino-5-amino-2,6-dihydroxypyrimidine. The homotrimer of 23 kDa subunits has no cofactor requirements for catalysis. The enzyme is nonexistent in humans and is an attractive target for antimicrobial agents of organisms whose pathogenicity depends on their ability to biosynthesize riboflavin. The first three-dimensional structure of the enzyme was determined at 2.0 {angstrom} resolution using the multiwavelength anomalous diffraction (MAD) method on the Escherichia coli protein containing selenomethionine residues. The homotrimer consists of an asymmetric assembly of monomers, each of which comprises two similar {beta} barrels and a C-terminal {alpha} helix. The similar {beta} barrels within the monomer confirm a prediction of pseudo two-fold symmetry that is inferred from the sequence similarity between the two halves of the protein. The {beta} barrels closely resemble folds found in phthalate dioxygenase reductase and other flavoproteins. The three active sites of the trimer are proposed to lie between pairs of monomers in which residues conserved among species reside, including two Asp-His-Ser triads and dyads of Cys-Ser and His-Thr. The proposed active sites are located where FMN (an analog of riboflavin) is modeled from an overlay of the {beta} barrels of phthalate dioxygenase reductase and riboflavin synthase. In the trimer, one active site is formed, and the other two active sites are wide open and exposed to solvent. The nature of the trimer configuration suggests that only one active site can be formed and be catalytically competent at a time.

  12. Alzheimer's disease evaluation using label-free, stainless, fluorescence to measure tryptophan metabolism along the kynurenine pathway

    Science.gov (United States)

    Sordillo, Laura A.; Zhang, Lin; Shi, Lingyan; Sriramoju, Vidyasagar; Sordillo, Peter P.; Alfano, Robert R.

    2018-02-01

    Under stress conditions, pro-inflammatory cytokines, such as tumor necrosis factor-alpha, interleukin-1 beta, interleukin 6 and interferon gamma are released. It is known that these cytokines stimulate indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO), which increase tryptophan metabolism through the kynurenine pathway, and that this can cause increased production of neurotoxic compounds. Brain tissues from Alzheimer's disease patients and agematched controls were investigated using label-free fluorescence spectroscopy. Tryptophan (exc. 280/ em. 340 nm) and its metabolites (N-formyl-L-kynurenine (exc. 325/em. 434 nm), kynurenine (exc. 365/em. 480 nm) and kynurenic acid (exc. 330/em. 390 nm)) have distinct spectral profiles. Preliminary results show a difference in the optical signatures in three important areas of the brain (hippocampus, BA 9, BA 17) between patients with Alzheimer's disease and agedmatched controls (normal), and a marked relative increase in tryptophan in the Alzheimer's patients. Thus determinations of tryptophan to tryptophan metabolite ratios could potentially be used to measure IDO and TDO activity and the degree of inflammation in the brain. This label-free optical technique may be useful in the study of Alzheimer's and other neurodegenerative diseases.

  13. Tryptophan-induced pathogenesis of breast cancer

    African Journals Online (AJOL)

    Aims: To investigate the pathogenesis of breast cancer through targeted metabolomics of amino acids ... Furthermore, the biological function of tryptophan was determined through determining the influence ... profiling all the small molecules in the biosamples (e.g., .... is a promising therapeutic agent for pancreatic cancer7.

  14. Influence of the tryptophan-indole-IFNγ axis on human genital Chlamydia trachomatis infection: role of vaginal co-infections.

    Science.gov (United States)

    Aiyar, Ashok; Quayle, Alison J; Buckner, Lyndsey R; Sherchand, Shardulendra P; Chang, Theresa L; Zea, Arnold H; Martin, David H; Belland, Robert J

    2014-01-01

    The natural history of genital Chlamydia trachomatis infections can vary widely; infections can spontaneously resolve but can also last from months to years, potentially progressing to cause significant pathology. The host and bacterial factors underlying this wide variation are not completely understood, but emphasize the bacterium's capacity to evade/adapt to the genital immune response, and/or exploit local environmental conditions to survive this immune response. IFNγ is considered to be a primary host protective cytokine against endocervical C. trachomatis infections. IFNγ acts by inducing the host enzyme indoleamine 2,3-dioxgenase, which catabolizes tryptophan, thereby depriving the bacterium of this essential amino acid. In vitro studies have revealed that tryptophan deprivation causes Chlamydia to enter a viable but non-infectious growth pattern that is termed a persistent growth form, characterized by a unique morphology and gene expression pattern. Provision of tryptophan can reactivate the bacterium to the normal developmental cycle. There is a significant difference in the capacity of ocular and genital C. trachomatis serovars to counter tryptophan deprivation. The latter uniquely encode a functional tryptophan synthase to synthesize tryptophan via indole salvage, should indole be available in the infection microenvironment. In vitro studies have confirmed the capacity of indole to mitigate the effects of IFNγ; it has been suggested that a perturbed vaginal microbiome may provide a source of indole in vivo. Consistent with this hypothesis, the microbiome associated with bacterial vaginosis includes species that encode a tryptophanase to produce indole. In this review, we discuss the natural history of genital chlamydial infections, morphological and molecular changes imposed by IFNγ on Chlamydia, and finally, the microenvironmental conditions associated with vaginal co-infections that can ameliorate the effects of IFNγ on C. trachomatis.

  15. Influence of the tryptophan-indole-IFNγ axis on human genital Chlamydia trachomatis infection: role of vaginal co-infections

    Directory of Open Access Journals (Sweden)

    Ashok eAiyar

    2014-06-01

    Full Text Available The natural history of genital Chlamydia trachomatis infections can vary widely; infections can spontaneously resolve but can also last from months to years, potentially progressing to cause significant pathology. The host and bacterial factors underlying this wide variation are not completely understood, but emphasize the bacterium’s capacity to evade/adapt to the genital immune response, and/or exploit local environmental conditions to survive this immune response. IFNγ is considered to be a primary host protective cytokine against endocervical C. trachomatis infections. IFNγ acts by inducing the host enzyme indoleamine 2,3-dioxygenase, which catabolizes tryptophan, thereby depriving the bacterium of this essential amino acid. In vitro studies have revealed that tryptophan deprivation causes Chlamydia to enter a viable but non-infectious growth pattern that is termed a persistent growth form, characterized by a unique morphology and gene expression pattern. Provision of tryptophan can reactivate the bacterium to the normal developmental cycle. There is a significant difference in the capacity of ocular and genital C. trachomatis serovars to counter tryptophan deprivation. The latter uniquely encode a functional tryptophan synthase to synthesize tryptophan via indole salvage, should indole be available in the infection microenvironment. In vitro studies have confirmed the capacity of indole to mitigate the effects of IFNγ; it has been suggested that a perturbed vaginal microbiome may provide a source of indole in vivo. Consistent with this hypothesis, the microbiome associated with bacterial vaginosis includes species that encode a tryptophanase to produce indole. In this review, we discuss the natural history of genital chlamydial infections, morphological and molecular changes imposed by IFNγ on Chlamydia, and finally, the microenvironmental conditions associated with vaginal co-infections that can ameliorate the effects of IFNγ on C

  16. Tryptophan, thiamine and indole-3-acetic acid exchange between Chlorella sorokiniana and the plant growth-promoting bacterium Azospirillum brasilense.

    Science.gov (United States)

    Palacios, Oskar A; Gomez-Anduro, Gracia; Bashan, Yoav; de-Bashan, Luz E

    2016-06-01

    During synthetic mutualistic interactions between the microalga Chlorella sorokiniana and the plant growth-promoting bacterium (PGPB) Azospirillum brasilense, mutual exchange of resources involved in producing and releasing the phytohormone indole-3-acetic acid (IAA) by the bacterium, using tryptophan and thiamine released by the microalga, were measured. Although increased activities of tryptophan synthase in C. sorokiniana and indole pyruvate decarboxylase (IPDC) in A. brasilense were observed, we could not detect tryptophan or IAA in the culture medium when both organisms were co-immobilized. This indicates that no extra tryptophan or IAA is produced, apart from the quantities required to sustain the interaction. Over-expression of the ipdC gene occurs at different incubation times: after 48 h, when A. brasilense was immobilized alone and grown in exudates of C. sorokiniana and at 96 h, when A. brasilense was co-immobilized with the microalga. When A. brasilense was cultured in exudates of C. sorokiniana, increased expression of the ipdC gene, corresponding increase in activity of IPDC encoded by the ipdC gene, and increase in IAA production were measured during the first 48 h of incubation. IAA production and release by A. brasilense was found only when tryptophan and thiamine were present in a synthetic growth medium (SGM). The absence of thiamine in SGM yielded no detectable IAA. In summary, this study demonstrates that C. sorokiniana can exude sufficient tryptophan and thiamine to allow IAA production by a PGPB during their interaction. Thiamine is essential for IAA production by A. brasilense and these three metabolites are part of a communication between the two microorganisms. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Tryptophan Transport in Human Fibroblast Cells—A Functional Characterization

    Directory of Open Access Journals (Sweden)

    Ravi Vumma

    2011-01-01

    Full Text Available There are indications that serotonergic neurotransmission is disturbed in several psychiatric disorders. One explanation may be disturbed transport of tryptophan (precursor for serotonin synthesis across cell membranes. Human fibroblast cells offer an advantageous model to study the transport of amino acids across cell membranes, since they are easy to propagate and the environmental factors can be controlled. The aim of this study was to functionally characterize tryptophan transport and to identify the main transporters of tryptophan in fibroblast cell lines from healthy controls. Tryptophan kinetic parameters ( V max and K m at low and high concentrations were measured in fibroblasts using the cluster tray method. Uptake of 3 H (5-L-tryptophan at different concentrations in the presence and absence of excess concentrations of inhibitors or combinations of inhibitors of amino acid transporters were also measured. Tryptophan transport at high concentration (0.5 mM had low affinity and high V max and the LAT1 isoform of system-L was responsible for approximately 40% of the total uptake of tryptophan. In comparison, tryptophan transport at low concentration (50 nM had higher affinity, lower V max and approximately 80% of tryptophan uptake was transported by system-L with LAT1 as the major isoform. The uptake of tryptophan at the low concentration was mainly sodium (Na + dependent, while uptake at high substrate concentration was mainly Na + independent. A series of different transporter inhibitors had varying inhibitory effects on tryptophan uptake. This study indicates that tryptophan is transported by multiple transporters that are active at different substrate concentrations in human fibroblast cells. The tryptophan transport trough system-L was mainly facilitated by the LAT1 isoform, at both low and high substrate concentrations of tryptophan.

  18. Psychosocial stress and inflammation driving tryptophan breakdown in children and adolescents: A cross-sectional analysis of two cohorts.

    Science.gov (United States)

    Michels, Nathalie; Clarke, Gerard; Olavarria-Ramirez, Loreto; Gómez-Martínez, Sonia; Díaz, Ligia Esperanza; Marcos, Ascensión; Widhalm, Kurt; Carvalho, Livia A

    2018-05-15

    Tryptophan breakdown is an important mechanism in several diseases e.g. inflammation and stress-induced inflammation have been associated with the development of depression via enhanced tryptophan breakdown. Depression is a major public health problem which commonly starts during adolescence, thus identifying underlying mechanisms during early life is crucial in prevention. The aim of this work was to verify whether independent and interacting associations of psychosocial stress and inflammation on tryptophan breakdown already exist in children and adolescents as a vulnerable age group. Two cross-sectional population-based samples of children/adolescents (8-18 y) were available: 315 from the European HELENA study and 164 from the Belgian ChiBS study. In fasting serum samples, tryptophan, kynurenine, kynurenic acid, C-reactive protein (CRP), interleukin (IL)-6, tumor necrosis factor (TNF)-α, interferon (IFN)-ɣ, soluble vascular adhesion molecule 1 (sVCAM1) and soluble intercellular adhesion molecule 1 (sICAM1) were measured. Psychological stress was measured by stress reports (subjective) and cortisol (objective - awakening salivary cortisol or hair cortisol). Linear regressions with stress or inflammation as predictor were adjusted for age, sex, body mass index, puberty, socio-economic status and country. In both cohorts, inflammation as measured by higher levels of CRP, sVCAM1 and sICAM1 was associated with kynurenine/tryptophan ratio and thus enhanced tryptophan breakdown (beta: 0.145-0.429). Psychological stress was only associated with tryptophan breakdown in the presence of higher inflammatory levels (TNF-α in both populations). Inflammatory levels were replicable key in enhancing tryptophan breakdown along the kynurenine pathway, even at young age and in a non-clinical sample. The stress-inflammation interaction indicated that only the stress exposures inducing higher inflammatory levels (or in an already existing inflammatory status) were associated

  19. Dietary tryptophan intake and suicide rate in industrialized nations.

    Science.gov (United States)

    Voracek, Martin; Tran, Ulrich S

    2007-03-01

    The objective of this study was to assess the ecological association of dietary tryptophan intake and suicide rates across industrialized nations. Tryptophan, an essential amino acid, is the rate-limiting precursor of serotonin biosynthesis. The serotonergic system has been strongly implicated in the neurobiology of suicide. Contemporary male and female suicide rates for the general population (42 countries) and the elderly (38 countries) were correlated with national estimates of dietary tryptophan intake. Measures of tryptophan intake were significantly negatively associated to national suicide rates. Controlling for national affluence, total alcohol consumption and happiness levels slightly attenuated these associations, but left all of them negative. The effect is an ecological (group-level) finding. Estimated per capita tryptophan supply is only a proxy for actual consumption. Developed nations ranking high in dietary tryptophan intake rank low in suicide rates, independent of national wealth, alcohol intake and happiness.

  20. Tryptophan and kynurenine determination in human hair by liquid chromatography.

    Science.gov (United States)

    Dario, Michelli F; Freire, Thamires Batello; Pinto, Claudinéia Aparecida Sales de Oliveira; Prado, María Segunda Aurora; Baby, André R; Velasco, Maria Valéria R

    2017-10-15

    Tryptophan, an amino acid found in hair proteinaceous structure is used as a marker of hair photodegradation. Also, protein loss caused by several chemical/physical treatments can be inferred by tryptophan quantification. Kynurenine is a photo-oxidation product of tryptophan, expected to be detected when hair is exposed mainly to UVB (290-320nm) radiation range. Tryptophan from hair is usually quantified directly as a solid or after alkaline hydrolysis, spectrofluorimetrically. However, these types of measure are not sufficiently specific and present several interfering substances. Thus, this work aimed to propose a quantification method for both tryptophan and kynurenine in hair samples, after alkali hydrolysis process, by using high-performance liquid chromatography (HPLC) with fluorimetric and UV detection. The tryptophan and kynurenine quantification method was developed and validated. Black, white, bleached and dyed (blond and auburn) hair tresses were used in this study. Tryptophan and kynurenine were separated within ∼9min by HPLC. Both black and white virgin hair samples presented similar concentrations of tryptophan, while bleaching caused a reduction in the tryptophan content as well as dyeing process. Unexpectedly, UV/vis radiation did not promote significantly the conversion of tryptophan into its photo-oxidation product and consequently, kynurenine was not detected. Thus, this works presented an acceptable method for quantification of tryptophan and its photooxidation metabolite kynurenine in hair samples. Also, the results indicated that bleaching and dyeing processes promoted protein/amino acids loss but tryptophan is not extensively degraded in human hair by solar radiation. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Tryptophan decarboxylase plays an important role in ajmalicine biosynthesis in Rauvolfia verticillata.

    Science.gov (United States)

    Liu, Wanhong; Chen, Rong; Chen, Min; Zhang, Haoxing; Peng, Meifang; Yang, Chunxian; Ming, Xingjia; Lan, Xiaozhong; Liao, Zhihua

    2012-07-01

    Tryptophan decarboxylase (TDC) converts tryptophan into tryptamine that is the indole moiety of ajmalicine. The full-length cDNA of Rauvolfia verticillata (RvTDC) was 1,772 bps that contained a 1,500-bp ORF encoding a 499-amino-acid polypeptide. Recombinant 55.5 kDa RvTDC converted tryptophan into tryptamine. The K (m) of RvTDC for tryptophan was 2.89 mM, higher than those reported in other TIAs-producing plants. It demonstrated that RvTDC had lower affinity to tryptophan than other plant TDCs. The K (m) of RvTDC was also much higher than that of strictosidine synthase and strictosidine glucosidase in Rauvolfia. This suggested that TDC might be the committed-step enzyme involved in ajmalicine biosynthesis in R. verticillata. The expression of RvTDC was slightly upregulated by MeJA; the five MEP pathway genes and SGD showed no positive response to MeJA; and STR was sharply downregulated by MeJA. MeJA-treated hairy roots produced higher level of ajmalicine (0.270 mg g(-1) DW) than the EtOH control (0.183 mg g(-1) DW). Highest RvTDC expression level was detected in hairy root, about respectively 11, 19, 65, and 109-fold higher than in bark, young leaf, old leaf, and root. Highest ajmalicine content was also found in hairy root (0.249 mg g(-1) DW) followed by in bark (0.161 mg g(-1) DW) and young leaf (0.130 mg g(-1) DW), and least in root (0.014 mg g(-1) DW). Generally, the expression level of RvTDC was positively consistent with the accumulation of ajmalicine. Therefore, it could be deduced that TDC might be the key enzyme involved in ajmalicine biosynthesis in Rauvolfia.

  2. Characterization of 5-(2- 18F-fluoroethoxy)-L-tryptophan for PET imaging of the pancreas

    OpenAIRE

    Abbas, Ahmed; Beamish, Christine; McGirr, Rebecca; Demarco, John; Cockburn, Neil; Krokowski, Dawid; Lee, Ting-Yim; Kovacs, Michael; Hatzoglou, Maria; Dhanvantari, Savita

    2016-01-01

    Purpose: In diabetes, pancreatic beta cell mass declines significantly prior to onset of fasting hyperglycemia. This decline may be due to endoplasmic reticulum (ER) stress, and the system L amino acid transporter LAT1 may be a biomarker of this process. In this study, we used 5-(2- 18F-fluoroethoxy)-L-tryptophan ( 18F-L-FEHTP) to target LAT1 as a potential biomarker of beta cell function in diabetes. Procedures: Uptake of 18F-L-FEHTP was determined in wild-type C57BL/6 mice by ex vivo biodis...

  3. BETA digital beta radiometer

    International Nuclear Information System (INIS)

    Borovikov, N.V.; Kosinov, G.A.; Fedorov, Yu.N.

    1989-01-01

    Portable transportable digital beta radiometer providing for measuring beta-decay radionuclide specific activity in the range from 5x10 -9 up to 10 -6 Cu/kg (Cu/l) with error of ±25% is designed and introduced into commercial production for determination of volume and specific water and food radioactivity. The device specifications are given. Experience in the BETA radiometer application under conditions of the Chernobyl' NPP 30-km zone has shown that it is convenient for measuring specific activity of the order of 10 -8 Cu/kg, and application of a set of different beta detectors gives an opportunity to use it for surface contamination measurement in wide range of the measured value

  4. Tryptophan depletion affects compulsive behaviour in rats

    DEFF Research Database (Denmark)

    Merchán, A; Navarro, S V; Klein, A B

    2017-01-01

    investigated whether 5-HT manipulation, through a tryptophan (TRP) depletion by diet in Wistar and Lister Hooded rats, modulates compulsive drinking in schedule-induced polydipsia (SIP) and locomotor activity in the open-field test. The levels of dopamine, noradrenaline, serotonin and its metabolite were......-depleted HD Wistar rats, while the LD Wistar and the Lister Hooded rats did not exhibit differences in SIP. In contrast, the TRP-depleted Lister Hooded rats increased locomotor activity compared to the non-depleted rats, while no differences were found in the Wistar rats. Serotonin 2A receptor binding...

  5. Tryptophan exposure and accessibility in the chitooligosaccharide-specific phloem exudate lectin from pumpkin (Cucurbita maxima). A fluorescence study.

    Science.gov (United States)

    Narahari, Akkaladevi; Swamy, Musti J

    2009-10-06

    The exposure and accessibility of the tryptophan residues in the chitooligosaccharide-specific pumpkin (Cucurbita maxima) phloem exudate lectin (PPL) have been investigated by fluorescence spectroscopy. The emission lambda(max) of native PPL, seen at 338nm was red-shifted to 348nm upon denaturation by 6M Gdn.HCl in the presence of 10mM beta-mercaptoethanol, indicating near complete exposure of the tryptophan residues to the aqueous medium, whereas a blue-shift to 335nm was observed in the presence of saturating concentrations of chitotriose, suggesting that ligand binding leads to a decrease in the solvent exposure of the tryptophan residues. The extent of quenching was maximum with the neutral molecule, acrylamide whereas the ionic species, iodide and Cs(+) led to significantly lower quenching, which could be attributed to the presence of charged amino acid residues in close proximity to some of the tryptophan residues. The Stern-Volmer plot for acrylamide was linear for native PPL and upon ligand binding, but became upward curving upon denaturation, indicating that the quenching occurs via a combination of static and dynamic mechanisms. In time-resolved fluorescence experiments, the decay curves could be best fit to biexponential patterns, for native protein, in the presence of ligand and upon denaturation. In each case both lifetimes systematically decreased with increasing acrylamide concentrations, indicating that quenching occurs predominantly via a dynamic process.

  6. Confirmation of antibodies against L-tryptophan-like epitope in ...

    African Journals Online (AJOL)

    Confirmation of antibodies against L-tryptophan-like epitope in human African trypanosomosis serological diagnostic. ... number of patients in Congo. A diagnostic test based on this synthetic epitope, especially in combination with other tests, might improve the HAT diagnostic test in field conditions. Key words: Tryptophan ...

  7. L-Tryptophan depletion bioreactor, a possible cancer therapy

    Directory of Open Access Journals (Sweden)

    Rolf Bambauer

    2015-04-01

    Full Text Available The cancer therapeutic strategies knownto date are not adequate for all cancer patients. Most of them are followed by a high rate of side effects and complications. The L-tryptophan depletion bioreactor is described as a possible new method of cancer therapy. L-tryptophan is an essential amino acid which has been recognized as an important cancer nutrient and its removal can lead to destruction of the tumour. Normal human cells or tumor cells cannot synthesize L-tryptophan and therefore tumor resistance is unlikely to develop. L-tryptophan is also a constituent for different bio-molecules such as Serotonin, Melatonin, and is needed for other synthesis processes in the cell growth. L-tryptophan degrading enzymes with 3 iso-enzymes called tryptophan side chain oxydase (TSO I, II, III were isolated. The 3 iso-enzymes can be differentiated by tryptic digestion. They have different molecular weights with different effectivenesses. All the TSO enzymes have heme that can catalyze essentially similar reactions involving L-tryptophan as a substrate. The most effective TSO is the type TSO III. A column which contained TSO as a bioreactor was integrated in a plasmapheresis unit and tested it in different animals. In sheep and rabbits L-tryptophan depletion in plasma was shown at 95% and 100% rates respectively by a single pass through the bioreactor. The results in immune supprimized rats with tumors were impressive, too. In 20 different tumor cell lines there were different efficacies. Brest cancer and medulloblastoma showed the greatest efficacy of L-tryptophan degrading. The gene technology of TSO production from Pseudomonas is associated with formation of endotoxins. This disadvantage can be prevented by different washing procedures or by using fungal sources for the TSO production. TSO III is developed to treat cancer diseases successfully, and has low side effects. A combination of L-tryptophan depletion with all available cancer therapies is

  8. Tryptophan levels, excessive exercise, and nutritional status in anorexia nervosa.

    Science.gov (United States)

    Favaro, A; Caregaro, L; Burlina, A B; Santonastaso, P

    2000-01-01

    It has been hypothesized that reduced dietary availability of tryptophan may be the cause of impaired serotonin activity in underweight anorexics. The study reported here evaluated the relationship between tryptophan availability in the blood and nutritional status in anorexia nervosa. The total amount of tryptophan and the ratio between tryptophan and other large neutral amino acids (TRP/LNAA) were assessed in a sample of 16 starving anorexic patients. Body weight and composition and energy intake were evaluated in all patients. All subjects also completed self-reported questionnaires such as the Hopkins Symptom Checklist and Eating Disorders Inventory (EDI). The TRP/LNAA ratio seems to be higher in patients with a more severe catabolic status. It is, in fact, significantly inversely correlated with body mass index, body fat, muscle mass, daily energy intake, and daily tryptophan intake. The TRP/LNAA ratio also correlates with growth hormone and the EDI drive for thinness. Patients who exercise excessively had significantly higher TRP/LNAA ratios. In starving anorexic patients, the TRP/LNAA ratio does not seem to be determined by the content of tryptophan in the diet, but it correlates with measures of catabolism. The relationship of the TRP/LNAA ratio to excessive exercise and starvation indicates the importance of further investigations exploring the role of tryptophan availability in maintaining anorexia nervosa.

  9. Exploring the mechanism of tryptophan 2,3-dioxygenase

    Science.gov (United States)

    Thackray, Sarah J.; Mowat, Christopher G.; Chapman, Stephen K.

    2008-01-01

    The haem proteins TDO (tryptophan 2,3-dioxygenase) and IDO (indoleamine 2,3-dioxygenase) are specific and powerful oxidation catalysts that insert one molecule of dioxygen into L-tryptophan in the first and rate-limiting step in the kynurenine pathway. Recent crystallographic and biochemical analyses of TDO and IDO have greatly aided our understanding of the mechanisms employed by these enzymes in the binding and activation of dioxygen and tryptophan. In the present paper, we briefly discuss the function, structure and possible catalytic mechanism of these enzymes. PMID:19021508

  10. Malarial pigment haemozoin, IFN-gamma, TNF-alpha, IL-1beta and LPS do not stimulate expression of inducible nitric oxide synthase and production of nitric oxide in immuno-purified human monocytes

    Directory of Open Access Journals (Sweden)

    Ceretto Monica

    2007-06-01

    Full Text Available Abstract Background Enhanced production of nitric oxide (NO following upmodulation of the inducible isoform of NO synthase (iNOS by haemozoin (HZ, inflammatory cytokines and LPS may provide protection against Plasmodium falciparum malaria by killing hepatic and blood forms of parasites and inhibiting the cytoadherence of parasitized erythrocytes (RBC to endothelial cells. Monocytes and macrophages are considered to contribute importantly to protective upregulation of iNOS and production of NO. Data obtained with murine phagocytes fed with human HZ and synthetic HZ (sHZ indicate that supplemental treatment of those cells with IFN-gamma elicited significant increases in protein and mRNA expression of iNOS and NO production, providing a potential mechanism linking HZ phagocytosis and increased production of NO. Purpose of this study was to analyse the effect of P. falciparum HZ and sHZ supplemental to treatment with IFN-gamma and/or a stimulatory cytokine-LPS mix on iNOS protein and mRNA expression in immuno-purified human monocytes. Methods Adherent immunopurified human monocytes (purity >85%, and murine phagocytic cell lines RAW 264.7, N11 and ANA1 were fed or not with P. falciparum HZ or sHZ and treated or not with IFN-gamma or a stimulatory cytokine-LPS mix. Production of NO was quantified in supernatants, iNOS protein and mRNA expression were measured after immunoprecipitation and Western blotting and quantitative RT-PCT, respectively. Results Phagocytosis of HZ/sHZ by human monocytes did not increase iNOS protein and mRNA expression and NO production either after stimulation by IFN-gamma or the cytokine-LPS mix. By contrast, in HZ/sHZ-laden murine macrophages, identical treatment with IFN-gamma and the cytokine-LPS mix elicited significant increases in protein and mRNA expression of iNOS and NOS metabolites production, in agreement with literature data. Conclusion Results indicate that human monocytes fed or not with HZ/sHZ were constantly

  11. Hybrid polyketide synthases

    Energy Technology Data Exchange (ETDEWEB)

    Fortman, Jeffrey L.; Hagen, Andrew; Katz, Leonard; Keasling, Jay D.; Poust, Sean; Zhang, Jingwei; Zotchev, Sergey

    2016-05-10

    The present invention provides for a polyketide synthase (PKS) capable of synthesizing an even-chain or odd-chain diacid or lactam or diamine. The present invention also provides for a host cell comprising the PKS and when cultured produces the even-chain diacid, odd-chain diacid, or KAPA. The present invention also provides for a host cell comprising the PKS capable of synthesizing a pimelic acid or KAPA, and when cultured produces biotin.

  12. Tryptophan and ATTO 590: mutual fluorescence quenching and exciplex formation.

    Science.gov (United States)

    Bhattacharjee, Ujjal; Beck, Christie; Winter, Arthur; Wells, Carson; Petrich, Jacob W

    2014-07-24

    Investigation of fluorescence quenching of probes, such as ATTO dyes, is becoming an increasingly important topic owing to the use of these dyes in super-resolution microscopies and in single-molecule studies. Photoinduced electron transfer is their most important nonradiative pathway. Because of the increasing frequency of the use of ATTO and related dyes to investigate biological systems, studies are presented for inter- and intramolecular quenching of ATTO 590 with tryptophan. In order to examine intramolecular quenching, an ATTO 590-tryptophan conjugate was synthesized. It was determined that tryptophan is efficiently quenching ATTO 590 fluorescence by excited-state charge transfer and two charge transfer complexes are forming. In addition, it was discovered that an exciplex (whose lifetime is 5.6 ns) can be formed between tryptophan and ATTO 590, and it is suggested that the possibility of such exciplex formation should be taken into account when protein fluorescence is monitored in a system tagged with ATTO dyes.

  13. Development of Bacillus subtilis mutants to produce tryptophan in pigs

    DEFF Research Database (Denmark)

    Bjerre, Karin; Cantor, Mette D.; Nørgaard, Jan Værum

    2017-01-01

    Objectives To generate tryptophan-overproducing Bacillus subtilis strains for in situ use in pigs, to reduce the feed cost for farmers and nitrogen pollution. Results A novel concept has been investigated—to generate B. subtilis strains able to produce tryptophan (Trp) in situ in pigs. Mutagenesis......-excreting B. subtilis strains were obtained with UV-mutagenesis and analogue selection and can be used in animal feed applications....

  14. Speculative Betas

    OpenAIRE

    Harrison Hong; David Sraer

    2012-01-01

    We provide a model for why high beta assets are more prone to speculative overpricing than low beta ones. When investors disagree about the common factor of cash-flows, high beta assets are more sensitive to this macro-disagreement and experience a greater divergence-of-opinion about their payoffs. Short-sales constraints for some investors such as retail mutual funds result in high beta assets being over-priced. When aggregate disagreement is low, expected return increases with beta due to r...

  15. Monoterpene synthases from common sage (Salvia officinalis)

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, Rodney Bruce (Pullman, WA); Wise, Mitchell Lynn (Pullman, WA); Katahira, Eva Joy (Pullman, WA); Savage, Thomas Jonathan (Christchurch 5, NZ)

    1999-01-01

    cDNAs encoding (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase from common sage (Salvia officinalis) have been isolated and sequenced, and the corresponding amino acid sequences has been determined. Accordingly, isolated DNA sequences (SEQ ID No:1; SEQ ID No:3 and SEQ ID No:5) are provided which code for the expression of (+)-bornyl diphosphate synthase (SEQ ID No:2), 1,8-cineole synthase (SEQ ID No:4) and (+)-sabinene synthase SEQ ID No:6), respectively, from sage (Salvia officinalis). In other aspects, replicable recombinant cloning vehicles are provided which code for (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase, or for a base sequence sufficiently complementary to at least a portion of (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding (+)-bornyl diphosphate synthase, 1,8-cineole synthase or (+)-sabinene synthase. Thus, systems and methods are provided for the recombinant expression of the aforementioned recombinant monoterpene synthases that may be used to facilitate their production, isolation and purification in significant amounts. Recombinant (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase may be used to obtain expression or enhanced expression of (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase in plants in order to enhance the production of monoterpenoids, or may be otherwise employed for the regulation or expression of (+)-bornyl diphosphate synthase, 1,8-cineole synthase and (+)-sabinene synthase, or the production of their products.

  16. Estradiol or fluoxetine alters depressive behavior and tryptophan hydroxylase in rat raphe.

    Science.gov (United States)

    Yang, Fu-Zhong; Wu, Yan; Zhang, Wei-Guo; Cai, Yi-Yun; Shi, Shen-Xun

    2010-03-10

    The effects of 17beta-estradiol and fluoxetine on behavior of ovariectomized rats subjected to the forced swimming test and the expression of tryptophan hydroxylase (TPH) in dorsal and median raphe were investigated, respectively through time sampling technique of behavior scoring and immunohistochemistry. Both estradiol and fluoxetine increased swimming and decreased immobility in the forced swimming test. The forced swimming stress decreased integrated optical density of TPH-positive regions in dorsal and median raphe. Both estradiol and fluoxetine administration prevented integrated optical density of TPH-positive regions from being decreased by forced swimming stress. These observations suggest that both estradiol and fluoxetine have protective bearing on ovariectomized rats enduring forced swimming stress.

  17. Kynurenine pathway in psychosis: evidence of increased tryptophan degradation.

    LENUS (Irish Health Repository)

    Barry, Sandra

    2009-05-01

    The kynurenine pathway of tryptophan degradation may serve to integrate disparate abnormalities heretofore identified in research aiming to elucidate the complex aetiopathogenesis of psychotic disorders. Post-mortem brain tissue studies have reported elevated kynurenine and kynurenic acid in the frontal cortex and upregulation of the first step of the pathway in the anterior cingulate cortex of individuals with schizophrenia. In this study, we examined kynurenine pathway activity by measuring tryptophan breakdown, a number of pathway metabolites and interferon gamma (IFN-gamma), which is the preferential activator of the first-step enzyme, indoleamine dioxygenase (IDO), in the plasma of patients with major psychotic disorder. Plasma tryptophan, kynurenine pathway metabolites were measured using high-performance liquid chromatography (HPLC) in 34 patients with a diagnosis on the psychotic spectrum (schizophrenia or schizoaffective disorder) and in 36 healthy control subjects. IFN-gamma was measured using enzyme-linked immunosorbent assay (ELISA). The mean tryptophan breakdown index (kynurenine\\/tryptophan) was significantly higher in the patient group compared with controls (P < 0.05). IFN-gamma measures did not differ between groups (P = 0.23). No relationship was found between measures of psychopathology, symptom severity and activity in the first step in the pathway. A modest correlation was established between the tryptophan breakdown index and illness duration. These results provide evidence for kynurenine pathway upregulation, specifically involving the first enzymatic step, in patients with major psychotic disorder. Increased tryptophan degradation in psychoses may have potential consequences for the treatment of these disorders by informing the development of novel therapeutic compounds.

  18. Tryptophan metabolism in breast cancers: molecular imaging and immunohistochemistry studies

    International Nuclear Information System (INIS)

    Juhász, Csaba; Nahleh, Zeina; Zitron, Ian; Chugani, Diane C.; Janabi, Majid Z.; Bandyopadhyay, Sudeshna; Ali-Fehmi, Rouba; Mangner, Thomas J.; Chakraborty, Pulak K.; Mittal, Sandeep; Muzik, Otto

    2012-01-01

    Introduction: Tryptophan oxidation via the kynurenine pathway is an important mechanism of tumoral immunoresistance. Increased tryptophan metabolism via the serotonin pathway has been linked to malignant progression in breast cancer. In this study, we combined quantitative positron emission tomography (PET) with tumor immunohistochemistry to analyze tryptophan transport and metabolism in breast cancer. Methods: Dynamic α-[ 11 C]methyl-L-tryptophan (AMT) PET was performed in nine women with stage II–IV breast cancer. PET tracer kinetic modeling was performed in all tumors. Expression of L-type amino acid transporter 1 (LAT1), indoleamine 2,3-dioxygenase (IDO; the initial and rate-limiting enzyme of the kynurenine pathway) and tryptophan hydroxylase 1 (TPH1; the initial enzyme of the serotonin pathway) was assessed by immunostaining of resected tumor specimens. Results: Tumor AMT uptake peaked at 5–20 min postinjection in seven tumors; the other two cases showed protracted tracer accumulation. Tumor standardized uptake values (SUVs) varied widely (2.6–9.8) and showed a strong positive correlation with volume of distribution values derived from kinetic analysis (P < .01). Invasive ductal carcinomas (n = 6) showed particularly high AMT SUVs (range, 4.7–9.8). Moderate to strong immunostaining for LAT1, IDO and TPH1 was detected in most tumor cells. Conclusions: Breast cancers show differential tryptophan kinetics on dynamic PET. SUVs measured 5–20 min postinjection reflect reasonably the tracer's volume of distribution. Further studies are warranted to determine if in vivo AMT accumulation in these tumors is related to tryptophan metabolism via the kynurenine and serotonin pathways.

  19. Tryptophan metabolism, disposition and utilization in pregnancy.

    Science.gov (United States)

    Badawy, Abdulla A-B

    2015-09-17

    Tryptophan (Trp) requirements in pregnancy are several-fold: (1) the need for increased protein synthesis by mother and for fetal growth and development; (2) serotonin (5-HT) for signalling pathways; (3) kynurenic acid (KA) for neuronal protection; (4) quinolinic acid (QA) for NAD(+) synthesis (5) other kynurenines (Ks) for suppressing fetal rejection. These goals could not be achieved if maternal plasma [Trp] is depleted. Although plasma total (free + albumin-bound) Trp is decreased in pregnancy, free Trp is elevated. The above requirements are best expressed in terms of a Trp utilization concept. Briefly, Trp is utilized as follows: (1) In early and mid-pregnancy, emphasis is on increased maternal Trp availability to meet the demand for protein synthesis and fetal development, most probably mediated by maternal liver Trp 2,3-dioxygenase (TDO) inhibition by progesterone and oestrogens. (2) In mid- and late pregnancy, Trp availability is maintained and enhanced by the release of albumin-bound Trp by albumin depletion and non-esterified fatty acid (NEFA) elevation, leading to increased flux of Trp down the K pathway to elevate immunosuppressive Ks. An excessive release of free Trp could undermine pregnancy by abolishing T-cell suppression by Ks. Detailed assessment of parameters of Trp metabolism and disposition and related measures (free and total Trp, albumin, NEFA, K and its metabolites and pro- and anti-inflammatory cytokines in maternal blood and, where appropriate, placental and fetal material) in normal and abnormal pregnancies may establish missing gaps in our knowledge of the Trp status in pregnancy and help identify appropriate intervention strategies. © 2015 Authors.

  20. Tryptophan circuit in fatigue: From blood to brain and cognition.

    Science.gov (United States)

    Yamashita, Masatoshi; Yamamoto, Takanobu

    2017-11-15

    Brain tryptophan and its neuroactive metabolites play key roles in central fatigue. However, previous brain function analysis targets may have included both glia and neurons together. Here, we clarified the fatigue-cognitive circuit of the central-peripheral linkage, including the role of glial-neuronal interaction in cognition. Using a rat model of central fatigue induced by chronic sleep disorder (CFSD), we isolated presynaptic terminals and oligodendrocytes. Results showed that compared to control group, presynaptic levels of tryptophan, kynurenine, and kynurenic acid, but not serotonin, in the CFSD group were higher in the hypothalamus and hippocampus. Moreover, CFSD group had higher oligodendrocytic levels of tryptophan, and impaired spatial cognitive memory accuracy and increased hyperactivity and impulsivity. These findings suggest that dynamic change in glial-neuronal interactions within the hypothalamus-hippocampal circuit causes central fatigue, and increased tryptophan-kynurenic acid pathway activity in this circuit causes reduced cognitive function. Additionally, CFSD group had 1.5 times higher plasma levels of tryptophan and kynurenine. Furthermore, in rats undergoing intraperitoneal administration of kynurenine (100mg/kg) versus vehicle, kynurenine-treated rats showed enhanced production of kynurenic acid in the hippocampus, with suppressed recall of retained spatial cognitive memory. The study revealed that uptake of periphery-derived kynurenine and tryptophan into the brain enhances kynurenic acid production in the brain, and the three factors produce amplification effect involved in the role of central-peripheral linkage in central fatigue, triggering cognitive dysfunction. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Maternal dietary tryptophan deficiency alters cardiorespiratory control in rat pups.

    Science.gov (United States)

    Penatti, Eliana M; Barina, Alexis E; Raju, Sharat; Li, Aihua; Kinney, Hannah C; Commons, Kathryn G; Nattie, Eugene E

    2011-02-01

    Malnutrition during pregnancy adversely affects postnatal forebrain development; its effect upon brain stem development is less certain. To evaluate the role of tryptophan [critical for serotonin (5-HT) synthesis] on brain stem 5-HT and the development of cardiorespiratory function, we fed dams a diet ∼45% deficient in tryptophan during gestation and early postnatal life and studied cardiorespiratory variables in the developing pups. Deficient pups were of normal weight at postnatal day (P)5 but weighed less than control pups at P15 and P25 (P interactions between nutrition, brain stem physiology, and age that are potentially relevant to understanding 5-HT deficiency in the sudden infant death syndrome.

  2. Tryptophan Requirement of the Enterally Fed Term Infant in the First Month of Life

    NARCIS (Netherlands)

    Huang, L.S.; Hogewind-Schoonenboom, J.E.; Zhu, L.; Kraaijenga, J.V.S.; van Haren, N.P.C.; Voortman, G.J.; Schierbeek, H.; Twisk, J.W.R.; Huang, Y.; Chen, C.; van Goudoever, J.B.

    2014-01-01

    OBJECTIVES: Tryptophan not only is an amino acid essential to protein synthesis but also serves as a precursor in 2 important metabolic pathways: the serotonin and the kynurenine pathways. Tryptophan is related to sleeping patterns. The objective of the present study was to determine the tryptophan

  3. Application of gene targeting to designed mutation breeding of high-tryptophan rice.

    Science.gov (United States)

    Saika, Hiroaki; Oikawa, Akira; Matsuda, Fumio; Onodera, Haruko; Saito, Kazuki; Toki, Seiichi

    2011-07-01

    Site-directed mutagenesis via gene targeting (GT) based on homologous recombination is the ultimate mutation breeding technology because it enables useful information acquired from structural- and computational-based protein engineering to be applied directly to molecular breeding, including metabolic engineering, of crops. Here, we employed this rationale to introduce precise mutations in OASA2--an α-subunit of anthranilate synthase that is a key enzyme of tryptophan (Trp) biosynthesis in rice (Oryza sativa)--via GT, with subsequent selection of GT cells using a Trp analog. The expression level of OASA2 in plants homozygous and heterozygous for modified OASA2 was similar to that of nontransformants, suggesting that OASA2 transcription in GT plants was controlled in the same manner as endogenous OASA2, and that GT could lead to a lower risk of gene silencing than in conventional overexpression approaches. Moreover, we showed that enzymatic properties deduced from protein engineering or in vitro analysis could be reproduced in GT plants as evidenced by Trp accumulation levels. Interestingly, mature seeds of homozygous GT plants accumulated Trp levels 230-fold higher than in nontransformants without any apparent morphological or developmental changes. Thus, we have succeeded in producing a novel rice plant of great potential nutritional benefit for both man and livestock that could not have been selected using conventional mutagenesis approaches. Our results demonstrate the effectiveness of directed crop improvement by combining precision mutagenesis via GT with a knowledge of protein engineering.

  4. Dimeric Complexes of Tryptophan with M2+ Metal Ions

    NARCIS (Netherlands)

    Dunbar, R. C.; Steill, J. D.; Polfer, N. C.; Oomens, J.

    2009-01-01

    IRMPD spectroscopy using the FELIX free electron laser and a Fourier transform ICR mass spectrometer was used to characterize the structures of electrosprayed dimer complexes M(2+)Trp(2) of tryptophan with a series of eight doubly charged metal ions, including alkaline earths Ca, Sr, and Ba, and

  5. Tryptophan Levels during Grape Ripening: Effects of Cultural Practices

    Directory of Open Access Journals (Sweden)

    Ana Ruiz-Rodríguez

    2017-06-01

    Full Text Available Some cultural practices that are carried out during the grape ripening period are associated with vine stress, including leaf removal, grape bunch removal, and vegetable cover crops. Additionally, several nitrogen and sulfur supplements have also been used directly on leaves during the last stage of the ripening period. In the work described here, five different cultural practices and the reference were applied in three replicates in the same vineyard. The evolution of tryptophan levels was evaluated from just after grape veraison until the harvest date. In some cases, certain specific treatments were also evaluated after the regular harvest date. The cultural techniques that involved the application of nitrogen led to higher levels of tryptophan at the harvest day when compared to other cultural techniques. It was also found that the application of nitrogen without sulfur had a faster effect on the level of tryptophan. It was established that a period of around 20 days is needed for the grapes to show clear differences in tryptophan levels after the application of nitrogen.

  6. Binding of tryptophan and iron by reptilion plasnna proteins

    African Journals Online (AJOL)

    transport functions. Albumin of the alligator (Alligator mississippiensis) and other reptiles binds, amongst other ions, tryptophan (McMenamy & Watson 1968) and transferrin binds iron (Barber & Sheeler 1963). Multiple transferrins are present in the plasma of many reptiles. (Dessauer et af 1962) and the albumin region of the.

  7. Beta spectrometry

    International Nuclear Information System (INIS)

    Dryak, P.; Zderadicka, J.; Plch, J.; Kokta, L.; Novotna, P.

    1977-01-01

    For the purpose of beta spectrometry, a semiconductor spectrometer with one Si(Li) detector cooled with liquid nitrogen was designed. Geometrical detection efficiency is about 10% 4 sr. The achieved resolution for 624 keV conversion electrons of sup(137m)Ba is 2.6 keV (FWHM). A program was written in the FORTRAN language for the correction of the deformation of the measured spectra by backscattering in the analysis of continuous beta spectra. The method permits the determination of the maximum energy of the beta spectrum with an accuracy of +-5 keV. (author)

  8. The role of tryptophan 2,3-dioxygenase in the hormonal control of tryptophan metabolism in isolated rat liver cells. Effects of glucocorticoids and experimental diabetes.

    OpenAIRE

    Salter, M; Pogson, C I

    1985-01-01

    The metabolism of L-tryptophan by isolated liver cells prepared from control, adrenalectomized, glucocorticoid-treated, acute-diabetic, chronic-diabetic and insulin-treated chronic-diabetic rats was studied. Liver cells from adrenalectomized rats metabolized tryptophan at rates comparable with the minimum diurnal rates of controls, but different from rates determined for cells from control rats 4h later. Administration of dexamethasone phosphate increased the activity of tryptophan 2,3-dioxyg...

  9. Laser Desorption of Tryptophan from Tryptophan-HCl Salt on a Graphite Substrate

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hae Jun; Kim, Jeong Jin; Kang, Hyuk [Ajou University, Suwon (Korea, Republic of)

    2016-03-15

    Laser spectroscopy of biological molecules in the gas phase has been pioneered by Levy and coworkers when they first produced a supersonic molecular beam of tryptophan (Trp) and obtained its electronic spectrum. They were able to obtain enough vapor pressure needed for spectroscopy by heating a powder sample of Trp, although a special thermal spray was used to minimize fragmentation during heating. Many amine compounds, including biomolecules like amino acids and peptides, are usually available only as HCl salt form in order to prevent oxidation in air. Chemical processing is required to recover a neutral amine compound from its salt, thus limiting the applicability of laser-desorption spectroscopy of biomolecules. The experimental setup is a standard molecular beam machine composed of a pulsed valve with a laser-desorption module in a vacuum chamber, a second buffer chamber, a skimmer that separates the first and the second chambers, and a third vacuum chamber that is a time-of-flight mass spectrometer (TOF MS)

  10. Beta Blockers

    Science.gov (United States)

    ... may not work as effectively for people of African heritage and older people, especially when taken without ... conditions/high-blood-pressure/in-depth/beta-blockers/ART-20044522 . Mayo Clinic Footer Legal Conditions and Terms ...

  11. Structure-activity relationships of N-beta-phenylpropionyl-L-tyrosine and its derivatives on the inhibition of an identifiable giant neurone of an African giant snail (Achatina fulica Férussac).

    Science.gov (United States)

    Ariyoshi, Y.; Takeuchi, H.

    1982-01-01

    1 Inhibitory effects of N-beta-phenylpropionyl-L-tyrosine, N-beta-phenylpropionyl-L-tryptophan and their derivatives on an identifiable giant neurone, TAN (tonically autoactive neurone) of an African giant snail (Achatina fulica Férussac) were examined in an attempt to elucidate which structural features are necessary to produce the effect. 2 Of the compounds examined, N-beta-cyclohexylpropionyl-L-tyrosine showed the strongest effect. Its critical concentration (c.c.) was 3 X 10(-8)-10(-7)M, about ten times lower than that of N-beta-phenylpropionyl-L-tyrosine (c.c., 3 X 10(-7)-10(-6)M). N-beta-cyclohexylpropionyl-L-tryptophan (c.c., 10(-6)M) had an effect almost similar to that of N-beta-phenylpropionyl-L-tryptophan (c.c., 10(-6)M). 3 N-beta-Phenylpropionyl-N-methyl-L-tyrosine had no effect at a high concentration. 4 Effects of N-beta-phenylpropionyl-L-tyrosine amide (c.c., 3 X 10(-7)-10(-6)M) and N-beta-phenylpropionyl-L-tryptophan amide (c.c., 10(-6)M) were very similar to those of N-beta-phenylpropionyl-L-tyrosine and N-beta-phenylpropionyl-L-tryptophan respectively. 5 N-beta-Phenylpropionyl-p-amino-L-phenylalanine (c.c., 3 X 10(-5)-10(-4)M) and N-beta-phenylpropionyl-p-chloro-L-phenylalanine (c.c., 10(-4)M) had only a weak effect. 6 It is proposed that the structural features producing the effect are as follows: the active compound has a phenyl or a cyclohexyl group (hydrophobic binding group), after a suitable distance a peptide bond (proton donor and proton acceptor), adjacently a carbonyl group (proton acceptor), and a phenolic hydroxyl or an indolyl imino group (proton donor) in the molecule. PMID:7150871

  12. Influence of gibberellin and daminozide on the expression of terpene synthases and on monoterpenes in common sage (Salvia officinalis).

    Science.gov (United States)

    Schmiderer, Corinna; Grausgruber-Gröger, Sabine; Grassi, Paolo; Steinborn, Ralf; Novak, Johannes

    2010-07-01

    Common sage (Salvia officinalis L., Lamiaceae) is one of the most important medicinal and aromatic plants, with antioxidant, antimicrobial, spasmolytic, astringent, antihidrotic and specific sensorial properties. The essential oil of the plant, composed mainly of the monoterpenes 1,8-cineole, alpha-thujone, beta-thujone and camphor, is responsible for some of these effects. Gibberellins regulate diverse physiological processes in plants, such as seed germination, shoot elongation and cell division. In this study, we analyzed the effect of exogenously applied plant growth regulators, namely gibberellic acid (GA(3)) and daminozide, on leaf morphology and essential oil formation of two leaf stages during the period of leaf expansion. Essential oil content increased with increasing levels of gibberellins and decreased when gibberellin biosynthesis was blocked with daminozide. With increasing levels of gibberellins, 1,8-cineole and camphor contents increased. Daminozide blocked the accumulation of alpha- and beta-thujone. GA(3) at the highest level applied also led to a significant decrease of alpha- and beta-thujone. Monoterpene synthases are a class of enzymes responsible for the first step in monoterpene biosynthesis, competing for the same substrate geranylpyrophosphate. The levels of gene expression of the three most important monoterpene synthases in sage were investigated, 1,8-cineole synthase leading directly to 1,8-cineole, (+)-sabinene synthase responsible for the first step in the formation of alpha- and beta-thujone, and (+)-bornyl diphosphate synthase, the first step in camphor biosynthesis. The foliar application of GA(3) increased, while daminozide significantly decreased gene expression of the monoterpene synthases. The amounts of two of the end products, 1,8-cineole and camphor, were directly correlated with the levels of gene expression of the respective monoterpene synthases, indicating transcriptional control, while the formation of alpha- and beta

  13. Increased serum free tryptophan in patients with diarrhea-predominant irritable bowel syndrome.

    Science.gov (United States)

    Christmas, David M; Badawy, Abdulla A-B; Hince, Dana; Davies, Simon J C; Probert, Christopher; Creed, Tom; Smithson, John; Afzal, Muhammad; Nutt, David J; Potokar, John P

    2010-10-01

    Irregularities of serotonin function in irritable bowel syndrome (IBS) may be due to changes in the metabolism of the serotonin precursor l-tryptophan. Dietary alteration of tryptophan intake may impact upon the mood and bowel symptoms of IBS. We hypothesized that diarrhea-predominant irritable bowel syndrome (d-IBS) patients would exhibit an increase in plasma tryptophan due to alterations in tryptophan metabolism. We also hypothesized that a diet low in tryptophan would reverse this change and reduce symptoms. Thirteen patients with d-IBS had fasting serum free and total tryptophan, large neutral amino acids, and 6 kynurenine metabolites measured before and after 2 weeks of a strict dairy-free diet. Baseline tryptophan parameters were compared with an age- and sex-matched control group. Changes in the specific tryptophan parameters before and after dairy-free diet were correlated with symptoms of IBS and mood. Compared with the control group, d-IBS patients at baseline exhibited significantly higher free serum tryptophan (10.5 ± 4.35 vs 4.75 ± 2.43 μmol/L [means ± standard deviation], P = .006) and significantly lower tryptophan dioxygenase and total tryptophan oxidation as measured by the kynurenine to free tryptophan and total kynurenines to free tryptophan ratios (23.37 ± 10.12 vs 55.33 ± 16.02, P < .001 and 49.34 ± 17.84 vs 258.46 ± 98.67, P < .001, respectively). Dairy-free diet did not modulate metabolites of the kynurenine pathway or symptoms. Tryptophan metabolism along the kynurenine pathway is inhibited in d-IBS, and a dairy-free diet does not alter this. Our findings are consistent with possible enhanced serotonin activity in d-IBS. Copyright © 2010 Elsevier Inc. All rights reserved.

  14. New oxidation and photo-oxidation products of tryptophan

    International Nuclear Information System (INIS)

    Savige, W.E.

    1975-01-01

    Dye-sensitized photo-oxidation of tryptophan in water gives N'-formylkynurenine and (+-)-3a-hydroxy-1,2,3a,8,8a-hexahydropyrrolo[2,3-b] indole-2-carboxylic acid. The latter rearranges to oxindolyl-3-alanine on irradiation with UV light and reacts with thiols, including cysteine, in warm 20% acetic acid to give the corresponding 2-tryptophyl sulphides. (orig.) [de

  15. Tryptophan Predicts the Risk for Future Type 2 Diabetes

    OpenAIRE

    Chen, Tianlu; Zheng, Xiaojiao; Ma, Xiaojing; Bao, Yuqian; Ni, Yan; Hu, Cheng; Rajani, Cynthia; Huang, Fengjie; Zhao, Aihua; Jia, Weiping; Jia, Wei

    2016-01-01

    Recently, 5 amino acids were identified and verified as important metabolites highly associated with type 2 diabetes (T2D) development. This report aims to assess the association of tryptophan with the development of T2D and to evaluate its performance with existing amino acid markers. A total of 213 participants selected from a ten-year longitudinal Shanghai Diabetes Study (SHDS) were examined in two ways: 1) 51 subjects who developed diabetes and 162 individuals who remained metabolically h...

  16. A Jerte Valley Cherry-Based Product as a Supply of Tryptophan

    Directory of Open Access Journals (Sweden)

    María Garrido

    2012-01-01

    Full Text Available L -Tryptophan (tryptophan is an essential amino acid in humans. It has important roles as a precursor of different bioactive compounds. Based on previous studies in which tryptophan has been shown to be present in fresh cherries, the aim of the present work was to analyze the tryptophan content of a Jerte Valley cherry-based product. A previously optimized method of analysis of tryptophan was used, ie, high-performance liquid chromatography with fluorescence detection (HPLC/FL. As expected, HPLC/FL technique permitted to detect and quantify the tryptophan content in a different matrix rather than fresh cherries. In fact, the Jerte Valley cherry-based product contained 69.54 ± 10.64 ppm of tryptophan, thereby showing that this product is a good source of tryptophan. In summary, it has been proven that the Jerte Valley cherry-based product is rich in tryptophan and may be indicated as a supply of this essential amino acid as well as having potential health benefits for conditions where tryptophan is necessary.

  17. Heme-containing enzymes and inhibitors for tryptophan metabolism.

    Science.gov (United States)

    Yan, Daojing; Lin, Ying-Wu; Tan, Xiangshi

    2017-09-20

    Iron-containing enzymes such as heme enzymes play crucial roles in biological systems. Three distinct heme-containing dioxygenase enzymes, tryptophan 2,3-dioxygenase (TDO), indoleamine 2,3-dioxygenase 1 (IDO1) and indoleamine 2,3-dioxygenase 2 (IDO2) catalyze the initial and rate-limiting step of l-tryptophan catabolism through the kynurenine pathway in mammals. Overexpression of these enzymes causes depletion of tryptophan and the accumulation of metabolic products, which contributes to tumor immune tolerance and immune dysregulation in a variety of disease pathologies. In the past few decades, IDO1 has garnered the most attention as a therapeutic target with great potential in cancer immunotherapy. Many potential inhibitors of IDO1 have been designed, synthesized and evaluated, among which indoximod (d-1-MT), INCB024360, GDC-0919 (formerly NLG-919), and an IDO1 peptide-based vaccine have advanced to the clinical trial stage. However, recently, the roles of TDO and IDO2 have been elucidated in immune suppression. In this review, the current drug discovery landscape for targeting TDO, IDO1 and IDO2 is highlighted, with particular attention to the recent use of drugs in clinical trials. Moreover, the crystal structures of these enzymes, in complex with inhibitors, and the mechanisms of Trp catabolism in the first step, are summarized to provide information for facilitating the discovery of new enzyme inhibitors.

  18. Kinetics and mechanism of the condensation of pyridoxal hydrochloride with L-tryptophan and D-tryptophan, and the chemical transformation of their products

    Science.gov (United States)

    Pishchugin, F. V.; Tuleberdiev, I. T.

    2017-10-01

    The kinetics and mechanism of interaction between pyridoxal and L-tryptophan, D-tryptophan, and their derivatives are studied. It is found that condensation reactions proceed via three kinetically distinguishable stages: (1) the rapid intraplanar addition of the NH2 groups of the amino acids to pyridoxal with the formation of amino alcohols; (2) the rotational isomerism of amino alcohol fragments with their subsequent dehydration and the formation of a Schiff base with a specific configuration; (3) the abstraction of α-hydrogen in the product of condensation of pyridoxal with L-tryptophan, or the abstraction of CO2 in the product of condensation of pyridoxal with D-tryptophan with the formation of quinoid structures, hydrolysis of which results in the preparation of pyridoxamine and keto acid or pyridoxal and tryptamine, respectively. Schiff bases resistant to further chemical transformations are formed in the reaction with tryptophan methyl ester.

  19. Digestible tryptophan levels for male broilers in pre-starter and starter diets

    Directory of Open Access Journals (Sweden)

    Bruno Samuel Borges

    2016-09-01

    Full Text Available The objective was to determine the digestible tryptophan requirements for male broilers in pre-starter and starter phases. Two experiments using 400 Cobb broilers were performed 200 males in the first experiment for the pre-starter phase (one to seven days old, and 200 males in the second experiment for the starter phase (eight to 21 days old. Chicks were housed in batter boxes made of galvanized steel as an experimental shed. The experiments were performed in a completely randomized design, with four treatments and five replicates, with ten birds each. In both experiments, the tryptophan requirement was determined using diets with different levels of digestible tryptophan. A tryptophan-deficient diet was formulated, as a basal diet, which was supplemented with increased levels of L-tryptophan in order to achieve the desirable digestible tryptophan levels. Treatments consisted of 0.209% (basal diet; 0.223%; 0.235% and 0.248% digestible tryptophan for the pre-starter phase (experiment 1 and 0.187% (basal diet; 0.200%, 0.211% and 0.223% digestible tryptophan for the starter phase (experiment 2. We evaluated feed intake, weight gain and feed conversion, as well as the metabolizability of feed nutrients. The performance and metabolic data were subjected to analysis of variance, and estimates of digestible tryptophan levels were made through polynomial regression models at 5% probability. There was no significant difference between the digestible tryptophan levels in the diet over performance and digestibility in both treatments. It is possible to conclude that the basal diet with 0.209% digestible tryptophan for the pre-starter phase and 0.187% for the starter phase, at a tryptophan: lysine ratio of 16%, as sufficient to meet the broilers requirements.

  20. Suppression of aggression in rainbow trout (Oncorhynchus mykiss) by dietary L-tryptophan.

    Science.gov (United States)

    Winberg, S; Øverli, Ø; Lepage, O

    2001-11-01

    Juvenile rainbow trout Oncorhynchus mykiss were isolated in individual compartments in observation aquaria and allowed to acclimate for 1 week, during which they were fed commercial trout feed. Thereafter, the fish were tested for aggressive behaviour using a resident/intruder test. Following this first resident/intruder test, the feed was exchanged for an experimental wet feed supplemented with 0.15 % or 1.5 % L-tryptophan (by wet mass). Controls received the same feed but without L-tryptophan supplementation. The fish were fed to satiety daily, and their individual feed intake was recorded. Aggressive behaviour was quantified again after 3 and 7 days of L-tryptophan feeding using the resident/intruder test. Feeding the fish L-tryptophan-supplemented feed for 3 days had no effect on aggressive behaviour, whereas feeding the fish L-tryptophan-supplemented feed for 7 days significantly suppressed aggressive behaviour in the fish, an effect seen at both levels of L-tryptophan supplementation. Fish fed L-tryptophan-supplemented feed showed elevated plasma and brain levels of L-tryptophan. The amino acid L-tryptophan is the precursor of serotonin, and supplementary dietary L-tryptophan was found to elevate levels of 5-hydroxyindoleacetic acid (5-HIAA) and the 5-HIAA/serotonin concentration ratio in the brain. Neither feed intake nor plasma cortisol level was significantly affected by dietary L-tryptophan. Central serotonin is believed to have an inhibitory effect on aggressive behaviour, and it is suggested that the suppressive effect of dietary L-tryptophan on aggressive behaviour is mediated by an elevation of brain serotonergic activity.

  1. UV radiation-induced photochemical damage of tryptophan in peptides, proteins and ocular lenses

    International Nuclear Information System (INIS)

    Hibbard, L.B.

    1985-01-01

    These studies were undertaken to investigate the possible involvement of the amino acid tryptophan in the near-ultraviolet radiation-induced photochemical alteration of peptides and proteins and the role tryptophan photolysis plays in ocular lens damage. Sample irradiations were performed to determine if tryptophan photolysis occurs with radiation in the UV-A region in comparison to photolysis induced by wavelengths in the normal absorption band of the amino acid (UV-B). Photolysis studies were carried out on free tryptophan and two dipeptides, tryptophyglycine and glycyltryptophan, in aqueous solutions at different pH values in the range 4.5-10.0 under aerated or anaerobic conditions. Rates of photolysis of these 290 nm-irradiated compounds, detected by observing tryptophan fluorescence intensity loss during irradiation, were compared and significant differences were observed for each compound which varied with pH and oxygen environment. Another series of experiments examined the photolysis of tryptophan residues in lens proteins in whole rat lenses induced by 290 nm and 298 nm dye laser radiation. Tryptophan residue photolysis was, once again, monitored by loss in tryptophan fluorescence intensity. A relationship was derived between tryptophan loss and photoproduct buildup during irradiation

  2. Protein- and tryptophan-restricted diets induce changes in rat gonadal hormone levels.

    Science.gov (United States)

    Del Angel-Meza, A R.; Feria-Velasco, A; Ontiveros-Martínez, L; Gallardo, L; Gonzalez-Burgos, I; Beas-Zárate, C

    2001-04-01

    The release of gonadotrophic hormones starts at puberty and, along with the subsequent estral cyclicity, is subject to hormonal feedback systems and to the action of diverse neuroactive substances such as gamma amino butyric acid and catecholamines. This study shows the effect of the administration during 40 days of protein-restricted and corn-based (tryptophan- and lysine-deficient) diets on the serotonin concentration in medial hypothalamic fragments as well as in follicle-stimulating luteinizing hormones, 17-beta-estradiol and progesterone serum levels, and estral cyclicity in 60- and 100-day-old rats (young, mature, and in gestation). In young rats, a delay in vaginal aperture development, and a lengthening of the estral cycle to a continuous anestral state was observed, mainly in the group fed corn. This group showed a 25% decrease in the serotonin concentration compared with the protein-restricted group, which exhibited an increase of 9% over the control group. Luteinizing hormone levels decreased in 16% and 13%, whereas follicle-stimulating hormone increased in 13% and 5% in the young animals of restricted groups, respectively, compared with the control group. Serum progesterone levels decreased only in young restricted versus control animals, and no differences were seen among adult and gestational rats. Serum levels of 17-beta-estradiol in restricted animals showed different concentration patterns, mainly in the corn group, which was higher at the 20th gestational day, falling drastically postpartum. The results obtained in this study show serotonin to be a very important factor in the release of gonadotrophic hormones and the start of puberty.

  3. Gallium uptake in tryptophan-related pulmonary disease

    International Nuclear Information System (INIS)

    Kim, S.M.; Park, C.H.; Intenzo, C.M.; Patel, R.

    1991-01-01

    We describe a patient who developed fever, fatigue, muscle weakness, dyspnea, skin rash, and eosinophilia after taking high doses of tryptophan for insomnia for two years. A gallium-67 scan revealed diffuse increased uptake in the lung and no abnormal uptake in the muscular distribution. Bronchoscopy and biopsy confirmed inflammatory reactions with infiltration by eosinophils, mast cells, and lymphocytes. CT scan showed an interstitial alveolar pattern without fibrosis. EMG demonstrated diffuse myopathy. Muscle biopsy from the right thigh showed an inflammatory myositis with eosinophilic and lymphocytic infiltrations

  4. Purification, characterization and gene cloning of thermostable O-acetyl-L-serine sulfhydrylase forming {beta}-cyano-L-alanine

    Energy Technology Data Exchange (ETDEWEB)

    Omura, Hironori; Yoshida, Toyokazu; Nagasawa, Toru [Gifu Univ. (Japan). Dept. of Biomolecular Science; Kuroda, Masako [Ikeda Food Research Co., Ltd., Fukuyama, Hiroshima (Japan); Kobayashi, Michihiko; Shimizu, Sakayu [Kyoto Univ. (Japan). Agricultural Sciences

    2003-10-01

    A thermophilic and cyanide ion-tolerant bacterium, Bacillus stearothermophilus CN3 isolated from a hot spring in Japan, was found to produce thermostable {beta}-cyano-L-alanine synthase. The enzyme catalyzes the synthesis of {beta}-cyano-L-alanine from O-acetyl-L-serine and cyanide ions. The purified enzyme has a molecular mass of approximately 70 kDa and consists of two identical sub-units. It was stable in the pH range of 6.0 to 10.0 and up to 70degC. The enzyme also catalyzes the synthesis of various {beta}-substituted-L-alanine derivatives from O-acetyl-L-serine and nucleophilic reagents. The gene encoding the {beta}-cyano-L-alanine synthase was isolated from B. stearothermophilus CN3. Sequence homology analysis revealed that the {beta}-cyano-L-alanine synthase of the bacterium is O-acetyl-L-serine sulfhydrylase. A recombinant plasmid, constructed by ligation of the cloned gene and an expression vector, pKK223-3, was introduced into E. coli JM109. The transformed E. coli cells overexpressed {beta}-cyano-L-alanine synthase. Heat stable {beta}-cyano-L-alanine synthase can be applied to the synthesis of [4-{sup 11}C]L-2,4-diaminobutyric acid as a tracer for positron emission tomography. (author)

  5. Antihypertensive and cardioprotective effects of the dipeptide isoleucine-tryptophan and whey protein hydrolysate.

    Science.gov (United States)

    Martin, M; Kopaliani, I; Jannasch, A; Mund, C; Todorov, V; Henle, T; Deussen, A

    2015-12-01

    Angiotensin-converting enzyme inhibitors are treatment of choice in hypertensive patients. Clinically used inhibitors exhibit a structural similarity to naturally occurring peptides. This study evaluated antihypertensive and cardioprotective effects of ACE-inhibiting peptides derived from food proteins in spontaneously hypertensive rats. Isoleucine-tryptophan (in vitro IC50 for ACE = 0.7 μm), a whey protein hydrolysate containing an augmented fraction of isoleucine-tryptophan, or captopril was given to spontaneously hypertensive rats (n = 60) over 14 weeks. Two further groups, receiving either no supplement (Placebo) or intact whey protein, served as controls. Systolic blood pressure age-dependently increased in the Placebo group, whereas the blood pressure rise was effectively blunted by isoleucine-tryptophan, whey protein hydrolysate and captopril (-42 ± 3, -38 ± 5, -55 ± 4 mm Hg vs. Placebo). At study end, myocardial mass was lower in isoleucine-tryptophan and captopril groups but only partially in the hydrolysate group. Coronary flow reserve (1 μm adenosine) was improved in isoleucine-tryptophan and captopril groups. Plasma ACE activity was significantly decreased in isoleucine-tryptophan, hydrolysate and captopril groups, but in aortic tissue only after isoleucine-tryptophan or captopril treatment. This was associated with lowered expression and activity of matrix metalloproteinase-2. Following isoleucine-tryptophan and captopril treatments, gene expression of renin was significantly increased indicating an active feedback within renin-angiotensin system. Whey protein hydrolysate and isoleucine-tryptophan powerfully inhibit plasma ACE resulting in antihypertensive effects. Moreover, isoleucine-tryptophan blunts tissue ACE activity, reduces matrix metalloproteinase-2 activity and improves coronary flow reserve. Thus, whey protein hydrolysate and particularly isoleucine-tryptophan may serve as innovative food additives with the goal of attenuating

  6. Aberrant tryptophan transport in cultured fibroblast from patients with Male Idiopathic Osteoporosis: An in vitro study

    Directory of Open Access Journals (Sweden)

    Ylva Pernow

    2018-06-01

    Full Text Available It has been demonstrated, that long-term chronic tryptophan deficiency, results in decreased serotonin synthesis, which may lead to low bone mass and low bone formation. Findings from studies in male patients with idiopathic osteoporosis suggested a decreased transport of tryptophan in erythrocytes of osteoporotic patients, indicating that serotonin system defects may be involved in the etiology of low bone mass. Tryptophan is the precursor of serotonin, and a disturbed transport of tryptophan is implicated in altered serotonin synthesis. However, no study has investigated the tryptophan transport kinetics in MIO patients. The aim of this study is to investigate the kinetic parameters of tryptophan transport in fibroblasts derived from MIO patients compared to age and sex matched controls.Fibroblast cells were cultured from skin biopsies obtained from 14 patients diagnosed with Male Idiopathic Osteoporosis and from 13 healthy age-sex matched controls, without a diagnosis of osteoporosis. Transport of the amino acid tryptophan across the cell membrane was measured by the cluster tray method. The kinetic parameters, maximal transport capacity (Vmax and affinity constant (Km were determined by using the Lineweaver-Burke plot equation.The results of this study have shown a significantly lower mean value for Vmax (p=0.0138 and lower Km mean value (p=0.0009 of tryptophan transport in fibroblasts of MIO patients compared to the control group. A lower Vmax implied a decreased tryptophan transport availability in MIO patients.In conclusion, reduced cellular tryptophan availability in MIO patients might result in reduced brain serotonin synthesis and its endogenous levels in peripheral tissues, and this may contribute to low bone mass/formation. The findings of the present study could contribute to the etiology of idiopathic osteoporosis and for the development of novel approaches for diagnosis, treatment and management strategies of MIO. Keywords: Male

  7. The preference of tryptophan for membrane interfaces: insights from N-methylation of tryptophans in gramicidin channels.

    Science.gov (United States)

    Sun, Haiyan; Greathouse, Denise V; Andersen, Olaf S; Koeppe, Roger E

    2008-08-08

    To better understand the structural and functional roles of tryptophan at the membrane/water interface in membrane proteins, we examined the structural and functional consequences of Trp --> 1-methyl-tryptophan substitutions in membrane-spanning gramicidin A channels. Gramicidin A channels are miniproteins that are anchored to the interface by four Trps near the C terminus of each subunit in a membrane-spanning dimer. We masked the hydrogen bonding ability of individual or multiple Trps by 1-methylation of the indole ring and examined the structural and functional changes using circular dichroism spectroscopy, size exclusion chromatography, solid state (2)H NMR spectroscopy, and single channel analysis. N-Methylation causes distinct changes in the subunit conformational preference, channel-forming propensity, single channel conductance and lifetime, and average indole ring orientations within the membrane-spanning channels. The extent of the local ring dynamic wobble does not increase, and may decrease slightly, when the indole NH is replaced by the non-hydrogen-bonding and more bulky and hydrophobic N-CH(3) group. The changes in conformational preference, which are associated with a shift in the distribution of the aromatic residues across the bilayer, are similar to those observed previously with Trp --> Phe substitutions. We conclude that indole N-H hydrogen bonding is of major importance for the folding of gramicidin channels. The changes in ion permeability, however, are quite different for Trp --> Phe and Trp --> 1-methyl-tryptophan substitutions, indicating that the indole dipole moment and perhaps also ring size and are important for ion permeation through these channels.

  8. Structural Basis of Catalysis in the Bacterial Monoterpene Synthases Linalool Synthase and 1,8-Cineole Synthase

    OpenAIRE

    Karuppiah, Vijaykumar; Ranaghan, Kara E.; Leferink, Nicole G. H.; Johannissen, Linus O.; Shanmugam, Muralidharan; Ní Cheallaigh, Aisling; Bennett, Nathan J.; Kearsey, Lewis J.; Takano, Eriko; Gardiner, John M.; van der Kamp, Marc W.; Hay, Sam; Mulholland, Adrian J.; Leys, David; Scrutton, Nigel S.

    2017-01-01

    Terpenoids form the largest and stereochemically most diverse class of natural products, and there is considerable interest in producing these by biocatalysis with whole cells or purified enzymes, and by metabolic engineering. The monoterpenes are an important class of terpenes and are industrially important as flavors and fragrances. We report here structures for the recently discovered Streptomyces clavuligerus monoterpene synthases linalool synthase (bLinS) and 1,8-cineole synthase (bCinS)...

  9. Improved Synthesis of 4-Cyanotryptophan and Other Tryptophan Analogues in Aqueous Solvent Using Variants of TrpB from Thermotoga maritima.

    Science.gov (United States)

    Boville, Christina E; Romney, David K; Almhjell, Patrick J; Sieben, Michaela; Arnold, Frances H

    2018-04-27

    The use of enzymes has become increasingly widespread in synthesis as chemists strive to reduce their reliance on organic solvents in favor of more environmentally benign aqueous media. With this in mind, we previously endeavored to engineer the tryptophan synthase β-subunit (TrpB) for production of noncanonical amino acids that had previously been synthesized through multistep routes involving water-sensitive reagents. This enzymatic platform proved effective for the synthesis of analogues of the amino acid tryptophan (Trp), which are frequently used in pharmaceutical synthesis as well as chemical biology. However, certain valuable compounds, such as the blue fluorescent amino acid 4-cyanotryptophan (4-CN-Trp), could only be made in low yield, even at elevated temperature (75 °C). Here, we describe the engineering of TrpB from Thermotoga maritima that improved synthesis of 4-CN-Trp from 24% to 78% yield. Remarkably, although the final enzyme maintains high thermostability ( T 50 = 93 °C), its temperature profile is shifted such that high reactivity is observed at ∼37 °C (76% yield), creating the possibility for in vivo 4-CN-Trp production. The improvements are not specific to 4-CN-Trp; a boost in activity at lower temperature is also demonstrated for other Trp analogues.

  10. (+)-(10R)-Germacrene A synthase from goldenrod, Solidago canadensis; cDNA isolation, bacterial expression and functional analysis.

    Science.gov (United States)

    Prosser, Ian; Phillips, Andy L; Gittings, Simon; Lewis, Mervyn J; Hooper, Antony M; Pickett, John A; Beale, Michael H

    2002-08-01

    Profiling of sesquiterpene hydrocarbons in extracts of goldenrod, Solidago canadensis, by GC-MS revealed the presence of both enantiomers of germacrene D and lesser amounts of germacrene A, alpha-humulene, and beta-caryophyllene. A similarity-based cloning strategy using degenerate oligonucleotide primers, based on conserved amino acid sequences in known plant sesquiterpene synthases and RT-PCR, resulted in the isolation of a full length sesquiterpene synthase cDNA. Functional expression of the cDNA in E. coli, as an N-terminal thioredoxin fusion protein using the pET32b vector yielded an enzyme that was readily purified by nickel-chelate affinity chromatography. Chiral GC-MS analysis of products from of (3)H- and (2)H-labelled farnesyl diphosphate identified the enzyme as (+)-(10R)-germacrene A synthase. Sequence analysis and molecular modelling was used to compare this enzyme with the mechanistically related epi-aristolochene synthase from tobacco.

  11. Tryptophan Biochemistry: Structural, Nutritional, Metabolic, and Medical Aspects in Humans.

    Science.gov (United States)

    Palego, Lionella; Betti, Laura; Rossi, Alessandra; Giannaccini, Gino

    2016-01-01

    L-Tryptophan is the unique protein amino acid (AA) bearing an indole ring: its biotransformation in living organisms contributes either to keeping this chemical group in cells and tissues or to breaking it, by generating in both cases a variety of bioactive molecules. Investigations on the biology of Trp highlight the pleiotropic effects of its small derivatives on homeostasis processes. In addition to protein turn-over, in humans the pathways of Trp indole derivatives cover the synthesis of the neurotransmitter/hormone serotonin (5-HT), the pineal gland melatonin (MLT), and the trace amine tryptamine. The breakdown of the Trp indole ring defines instead the "kynurenine shunt" which produces cell-response adapters as L-kynurenine, kynurenic and quinolinic acids, or the coenzyme nicotinamide adenine dinucleotide (NAD(+)). This review aims therefore at tracing a "map" of the main molecular effectors in human tryptophan (Trp) research, starting from the chemistry of this AA, dealing then with its biosphere distribution and nutritional value for humans, also focusing on some proteins responsible for its tissue-dependent uptake and biotransformation. We will thus underscore the role of Trp biochemistry in the pathogenesis of human complex diseases/syndromes primarily involving the gut, neuroimmunoendocrine/stress responses, and the CNS, supporting the use of -Omics approaches in this field.

  12. Tryptophan autofluorescence imaging of neoplasms of the human colon

    Science.gov (United States)

    Banerjee, Bhaskar; Renkoski, Timothy; Graves, Logan R.; Rial, Nathaniel S.; Tsikitis, Vassiliki Liana; Nfonsom, Valentine; Pugh, Judith; Tiwari, Piyush; Gavini, Hemanth; Utzinger, Urs

    2012-01-01

    Detection of flat neoplasia is a major challenge in colorectal cancer screening, as missed lesions can lead to the development of an unexpected `incident' cancer prior to the subsequent endoscopy. The use of a tryptophan-related autofluorescence has been reported to be increased in murine intestinal dysplasia. The emission spectra of cells isolated from human adenocarcinoma and normal mucosa of the colon were studied and showed markedly greater emission intensity from cancerous cells compared to cells obtained from the surrounding normal mucosa. A proto-type multispectral imaging system optimized for ultraviolet macroscopic imaging of tissue was used to obtain autofluorescence images of surgical specimens of colonic neoplasms and normal mucosa after resection. Fluorescence images did not display the expected greater emission from the tumor as compared to the normal mucosa, most probably due to increased optical absorption and scattering in the tumors. Increased fluorescence intensity in neoplasms was observed however, once fluorescence images were corrected using reflectance images. Tryptophan fluorescence alone may be useful in differentiating normal and cancerous cells, while in tissues its autofluorescence image divided by green reflectance may be useful in displaying neoplasms.

  13. Results of correlation of values of individual behaviour of rats with liver tryptophan pyrrolase activity.

    Science.gov (United States)

    Tikal, K; Kunz, K

    1976-01-01

    A significant negative correlation was found between the individual animal's horizontal activity in an open field and liver tryptophan pyrrolase (LTP) activity. On the other hand, the duration of immobility in an open field correlated postively and significantly with liver tryptophan pyrrolase activity.

  14. Inhibition of hormonal and behavioral effects of stress by tryptophan in rats.

    Science.gov (United States)

    Gul, Sumera; Saleem, Darakhshan; Haleem, Muhammad A; Haleem, Darakhshan Jabeen

    2017-11-03

    Stress in known to alter hormonal systems. Pharmacological doses of tryptophan, the essential amino acid precursor of serotonin, increase circulating leptin and decrease ghrelin in normal healthy adults. Because systemically injected leptin inhibits stress-induced behavioral deficits and systemically injected serotonin modulates leptin release from the adipocytes, we used tryptophan as a pharmacological tool to modulate hormonal and behavioral responses in unstressed and stressed rats. Leptin, ghrelin, serotonin, tryptophan, and behavior were studied in unstressed and stressed rats following oral administration of 0, 100, 200, and 300 mg/kg of tryptophan. Following oral administration of tryptophan at a dose of 300 mg/kg, circulating levels of serotonin and leptin increased and those of ghrelin decreased in unstressed animals. No effect occurred on 24-hours cumulative food intake and elevated plus maze performance. Exposure to 2 hours immobilization stress decreased 24 hours cumulative food intake and impaired performance in elevated plus maze monitored next day. Serum serotonin decreased, leptin increased, and no effect occurred on ghrelin. Stress effects on serotonin, leptin, food intake, and elevated plus maze performance did not occur in tryptophan-pretreated animals. Tryptophan-induced decreases of ghrelin also did not occur in stressed animals. The findings show an important role of serum serotonin, leptin, and ghrelin in responses to stress and suggest that the essential amino acid tryptophan can improve therapeutics in stress-induced hormonal and behavioral disorders.

  15. Delaying aging and the aging-associated decline in protein homeostasis by inhibition of tryptophan degradation

    NARCIS (Netherlands)

    van der Goot, Annemieke T.; Zhu, Wentao; Vazquez-Manrique, Rafael P.; Seinstra, Renee I.; Dettmer, Katja; Michels, Helen; Farina, Francesca; Krijnen, Jasper; Melki, Ronald; Buijsman, Rogier C.; Silva, Mariana Ruiz; Thijssen, Karen L.; Kema, Ido P.; Neri, Christian; Oefner, Peter J.; Nollen, Ellen A. A.

    2012-01-01

    Toxicity of aggregation-prone proteins is thought to play an important role in aging and age-related neurological diseases like Parkinson and Alzheimer's diseases. Here, we identify tryptophan 2,3-dioxygenase (tdo-2), the first enzyme in the kynurenine pathway of tryptophan degradation, as a

  16. The association of sleep quality and insomnia with dietary intake of tryptophan and niacin

    NARCIS (Netherlands)

    Verster, J.; Fernstrand, A.; Bury, D.; Roth, T.; Garssen, J.

    2015-01-01

    Introduction: Dietary intake of tryptophan and niacin have been related to sleep. However, the sleep-promoting effects of these nutrients are still under investigation. The aim of the current study was to examine the relationship between daily dietary intake of tryptophan and niacin and sleep.

  17. Does acute tryptophan depletion affect peripheral serotonin metabolism in the intestine?

    NARCIS (Netherlands)

    Keszthelyi, D.; Troost, F.J.; Jonkers, D.M.; Donkelaar, van E.L.; Dekker, J.; Buurman, W.A.; Masclee, A.A.

    2012-01-01

    Background: Serotonin (5-hydroxytryptamine; 5-HT), a tryptophan metabolite, plays an important regulatory role in the human central nervous system and in the gastrointestinal tract. Acute tryptophan depletion (ATD) is currently the most widely established method to investigate 5-HT metabolism.

  18. Photophysics of tryptophan in H2O, D2O, and in nonaqueous solvents

    International Nuclear Information System (INIS)

    Gudgin, E.; Lopez-Delgado, R.; Ware, W.R.

    1983-01-01

    The fluorescence properties of tryptophan in water and deuterated water have been examined. Tryptophan molecules exhibit three distinct fluorescence lifetimes in water which become longer in deuterated water; the two shorter lifetimes are present below the pK of the amino group and the long lifetime appears as the pH is raised through this pK. The steady-state quenching of tryptophan fluorescence by hydrogen ion in the region of pH less than 3 shows a definite wavelength effect, consistent with less-pronounced quenching of the subnanosecond component whose emission maximum is at 330 nm. The Stern-Volmer plots show a marked curvature in the direction of decreasing Stern-Volmer constant as [H 3 O + ] increases. Deuterium ion also quenches tryptophan fluorescence at low pD. A kinetic scheme is proposed which reproduces both the steady-state and lifetime quenching results. Tryptophan in methanol or ethanol exhibits three fluorescence lifetimes; the relative percentage of the long component vs. the intermediate component can be varied by the addition of triethylamine or acid. In dimethyl sulfoxide, tryptophan and tryptophan deuterated at the amino and ring nirogen positions show identical behavior, both having the same decay parameters. These results are discussed in light of the theories which have recently been proposed to account for the several components in tryptophan fluorescence decay. Solvent interaction is suggested to play a critical role

  19. Enhancement of stability of L-tryptophan dehydrogenase from Nostoc punctiforme ATCC29133 and its application to L-tryptophan assay.

    Science.gov (United States)

    Matsui, Daisuke; Okazaki, Seiji; Matsuda, Motoki; Asano, Yasuhisa

    2015-02-20

    Microbial NAD(+)-dependent L-tryptophan dehydrogenase (TrpDH, EC1.4.1.19), which catalyzes the reversible oxidative deamination and the reductive amination between L-tryptophan and indole-3-pyruvic acid, was found in the scytonemin biosynthetic pathway of Nostoc punctiforme ATCC29133. The TrpDH exhibited high specificity toward L-tryptophan, but its instability was a drawback for L-tryptophan determination. The mutant enzyme TrpDH L59F/D168G/A234D/I296N with thermal stability was obtained by screening of Escherichia coli transformants harboring various mutant genes, which were generated by error-prone PCR using complementation in an L-tryptophan auxotroph of E. coli. The specific activity and stability of this mutant enzyme were higher than those of the wild type enzyme. We also revealed here that in these four mutation points, the two amino acid residues Asp168 and Ile296 contributed to increase the enzyme stability, and the Leu59, Ala234 residues to increase its specific activity. Growth of the strain harboring the gene of above 4 point mutated enzyme was accelerated by the enhanced performance. In the present study, we demonstrated that TrpDH L59F/D168G/A234D/I296N was available for determination of L-tryptophan in human plasma. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. The crystal structure of tryptophan hydroxylase with bound amino acid substrate

    DEFF Research Database (Denmark)

    Windahl, Michael Skovbo; Petersen, Charlotte Rode; Christensen, Hans Erik Mølager

    2008-01-01

    Tryptophan hydroxylase (TPH) is a mononuclear non-heme iron enzyme, which catalyzes the reaction between tryptophan, O2, and tetrahydrobiopterin (BH4) to produce 5-hydroxytryptophan and 4a-hydroxytetrahydrobiopterin. This is the first and rate-limiting step in the biosynthesis of the neurotransmi......Tryptophan hydroxylase (TPH) is a mononuclear non-heme iron enzyme, which catalyzes the reaction between tryptophan, O2, and tetrahydrobiopterin (BH4) to produce 5-hydroxytryptophan and 4a-hydroxytetrahydrobiopterin. This is the first and rate-limiting step in the biosynthesis...... acid hydroxylase with bound natural amino acid substrate. The iron coordination can be described as distorted trigonal bipyramidal coordination with His273, His278, and Glu318 (partially bidentate) and one imidazole as ligands. The tryptophan stacks against Pro269 with a distance of 3.9 Å between...

  1. Characterization of two trpE genes encoding anthranilate synthase α-subunit in Azospirillum brasilense

    International Nuclear Information System (INIS)

    Ge Shimei; Xie Baoen; Chen Sanfeng

    2006-01-01

    The previous report from our laboratory has recently identified a new trpE gene (termed trpE 2 ) which exists independently in Azospirillum brasilense Yu62. In this study, amplification of trpE(G) (termed trpE 1 (G) here) confirmed that there are two copies of trpE gene, one trpE being fused into trpG while the other trpE existed independently. This is First report to suggest that two copies of the trpE gene exist in this bacterium. Comparison of the nucleotide sequence demonstrated that putative leader peptide, terminator, and anti-terminator were found upstream of trpE 1 (G) while these sequence features did not exist in front of trpE 2 . The β-galactosidase activity of an A. brasilense strain carrying a trpE 2 -lacZ fusion remained constant at different tryptophan concentrations, but the β-galactosidase activity of the same strain carrying a trpE 1 (G)-lacZ fusion decreased as the tryptophan concentration increased. These data suggest that the expression of trpE 1 (G) is regulated at the transcriptional level by attenuation while trpE 2 is constantly expressed. The anthranilate synthase assays with trpE 1 (G) - and trpE 2 - mutants demonstrated that TrpE 1 (G) fusion protein is feedback inhibited by tryptophan while TrpE 2 protein is not. We also found that both trpE 1 (G) and trpE 2 gene products were involved in IAA synthesis

  2. F1F0-ATP synthase from bovine heart mitochondria: development of the purification of a monodisperse oligomycin-sensitive ATPase.

    OpenAIRE

    Lutter, R; Saraste, M; van Walraven, H S; Runswick, M J; Finel, M; Deatherage, J F; Walker, J E

    1993-01-01

    A new procedure for the isolation of ATP synthase from bovine mitochondria has been developed, with the primary objective of producing enzyme suitable for crystallization trials. Proteins were extracted from mitochondrial membranes with dodecyl-beta-D-maltoside, and the ATP synthase was purified from the extract in the presence of the same detergent by a combination of ion-exchange and gel-filtration chromatography and ammonium sulphate precipitation. This simple and rapid procedure yields 20...

  3. Implications of secondary structure prediction and amino acid sequence comparison of class I and class II phosphoribosyl diphosphate synthases on catalysis, regulation, and quaternary structure

    DEFF Research Database (Denmark)

    Krath, B N; Hove-Jensen, B

    2001-01-01

    Spinach 5-phospho-D-ribosyl alpha-1-diphosphate (PRPP) synthase isozyme 4 was synthesized in Escherichia coli and purified to near homogeneity. The activity of the enzyme is independent of P(i); it is inhibited by ADP in a competitive manner, indicating a lack of an allosteric site; and it accepts...... is consistent with a homotrimer. Secondary structure prediction shows that spinach PRPP synthase isozyme 4 has a general folding similar to that of Bacillus subtilis class I PRPP synthase, for which the three-dimensional structure has been solved, as the position and extent of helices and beta-sheets of the two...... in the spinach enzyme. In contrast, residues of the active site of B. subtilis PRPP synthase show extensive conservation in spinach PRPP synthase isozyme 4....

  4. Sphingomyelin synthases regulate protein trafficking and secretion.

    Directory of Open Access Journals (Sweden)

    Marimuthu Subathra

    Full Text Available Sphingomyelin synthases (SMS1 and 2 represent a class of enzymes that transfer a phosphocholine moiety from phosphatidylcholine onto ceramide thus producing sphingomyelin and diacylglycerol (DAG. SMS1 localizes at the Golgi while SMS2 localizes both at the Golgi and the plasma membrane. Previous studies from our laboratory showed that modulation of SMS1 and, to a lesser extent, of SMS2 affected the formation of DAG at the Golgi apparatus. As a consequence, down-regulation of SMS1 and SMS2 reduced the localization of the DAG-binding protein, protein kinase D (PKD, to the Golgi. Since PKD recruitment to the Golgi has been implicated in cellular secretion through the trans golgi network (TGN, the effect of down-regulation of SMSs on TGN-to-plasma membrane trafficking was studied. Down regulation of either SMS1 or SMS2 significantly retarded trafficking of the reporter protein vesicular stomatitis virus G protein tagged with GFP (VSVG-GFP from the TGN to the cell surface. Inhibition of SMSs also induced tubular protrusions from the trans Golgi network reminiscent of inhibited TGN membrane fission. Since a recent study demonstrated the requirement of PKD activity for insulin secretion in beta cells, we tested the function of SMS in this model. Inhibition of SMS significantly reduced insulin secretion in rat INS-1 cells. Taken together these results provide the first direct evidence that both enzymes (SMS1 and 2 are capable of regulating TGN-mediated protein trafficking and secretion, functions that are compatible with PKD being a down-stream target for SMSs in the Golgi.

  5. Pivotal role of glycogen synthase kinase-3: A therapeutic target for Alzheimer's disease.

    Science.gov (United States)

    Maqbool, Mudasir; Mobashir, Mohammad; Hoda, Nasimul

    2016-01-01

    Neurodegenerative diseases are among the most challenging diseases with poorly known mechanism of cause and paucity of complete cure. Out of all the neurodegenerative diseases, Alzheimer's disease is the most devastating and loosening of thinking and judging ability disease that occurs in the old age people. Many hypotheses came forth in order to explain its causes. In this review, we have enlightened Glycogen Synthase Kinase-3 which has been considered as a concrete cause for Alzheimer's disease. Plaques and Tangles (abnormal structures) are the basic suspects in damaging and killing of nerve cells wherein Glycogen Synthase Kinase-3 has a key role in the formation of these fatal accumulations. Various Glycogen Synthase Kinase-3 inhibitors have been reported to reduce the amount of amyloid-beta as well as the tau hyperphosphorylation in both neuronal and nonneuronal cells. Additionally, Glycogen Synthase Kinase-3 inhibitors have been reported to enhance the adult hippocampal neurogenesis in vivo as well as in vitro. Keeping the chemotype of the reported Glycogen Synthase Kinase-3 inhibitors in consideration, they may be grouped into natural inhibitors, inorganic metal ions, organo-synthetic, and peptide like inhibitors. On the basis of their mode of binding to the constituent enzyme, they may also be grouped as ATP, nonATP, and allosteric binding sites competitive inhibitors. ATP competitive inhibitors were known earlier inhibitors but they lack efficient selectivity. This led to find the new ways for the enzyme inhibition. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  6. Cloning and functional characterization of three terpene synthases from lavender (Lavandula angustifolia).

    Science.gov (United States)

    Landmann, Christian; Fink, Barbara; Festner, Maria; Dregus, Márta; Engel, Karl-Heinz; Schwab, Wilfried

    2007-09-15

    The essential oil of lavender (Lavandula angustifolia) is mainly composed of mono- and sesquiterpenes. Using a homology-based PCR strategy, two monoterpene synthases (LaLIMS and LaLINS) and one sesquiterpene synthase (LaBERS) were cloned from lavender leaves and flowers. LaLIMS catalyzed the formation of (R)-(+)-limonene, terpinolene, (1R,5S)-(+)-camphene, (1R,5R)-(+)-alpha-pinene, beta-myrcene and traces of alpha-phellandrene. The proportions of these products changed significantly when Mn(2+) was supplied as the cofactor instead of Mg(2+). The second enzyme LaLINS produced exclusively (R)-(-)-linalool, the main component of lavender essential oil. LaBERS transformed farnesyl diphosphate and represents the first reported trans-alpha-bergamotene synthase. It accepted geranyl diphosphate with higher affinity than farnesyl diphosphate and also produced monoterpenes, albeit at low rates. LaBERS is probably derived from a parental monoterpene synthase by the loss of the plastidial signal peptide and by broadening its substrate acceptance spectrum. The identification and description of the first terpene synthases from L. angustifolia forms the basis for the biotechnological modification of essential oil composition in lavender.

  7. Producing biofuels using polyketide synthases

    Science.gov (United States)

    Katz, Leonard; Fortman, Jeffrey L; Keasling, Jay D

    2013-04-16

    The present invention provides for a non-naturally occurring polyketide synthase (PKS) capable of synthesizing a carboxylic acid or a lactone, and a composition such that a carboxylic acid or lactone is included. The carboxylic acid or lactone, or derivative thereof, is useful as a biofuel. The present invention also provides for a recombinant nucleic acid or vector that encodes such a PKS, and host cells which also have such a recombinant nucleic acid or vector. The present invention also provides for a method of producing such carboxylic acids or lactones using such a PKS.

  8. Comparative dual-tracer studies of carbon-14 tryptophan and iodine-131 HIPDM in animal models of pancreatic diseases

    International Nuclear Information System (INIS)

    Kubota, K.; Som, P.; Brill, A.B.; Sacker, D.F.; Meinken, G.E.; Srivastava, S.C.; Atkins, H.L.

    1989-01-01

    Our previous studies have shown that a significant amount of the diamine derivative 131 I-N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3- propanediamine (HIPDM) is taken up and retained by the normal pancreas. Therefore, we studied the uptake of [ 13 1I]HIPDM in various pathophysiological models in mice (chronic alcoholism, diabetes with beta-cell atrophy and obesity with beta-cell hypertrophy) and compared to 14 C-L-Tryptophan (TRY) distribution in order to determine the factors influencing their pancreatic uptake. In normal animals, the pancreas uptake of TRY was generally higher than HIPDM. In diabetes, the relative concentration of both compounds was higher over the controls; however, in obesity, TRY showed lower accumulation than in controls while HIPDM showed no significant difference. Chronic ethanol (20%) ingestion increased TRY uptake in the pancreas compared to controls (36.88 ± 3.21 vs. 30.03 ± 4.17% ID/g; p less than 0.01) after 5 wk study period, but it decreased by 10 wk (22.36 ± 0.95% ID/g; p less than 0.005). There were no significant changes in [ 131 I]HIPDM distribution in alcoholics as compared to the controls. Radioiodinated HIPDM has potential advantages over [ 11 C]TRY for pancreatic imaging since conventional imaging techniques can be employed. Our data, however, suggest that 11 C-L-TRY is a more sensitive indicator of various pancreatic disorders

  9. Doxycycline induced photodamage to human neutrophils and tryptophan

    International Nuclear Information System (INIS)

    Sandberg, S.; Glette, J.; Hopen, G.; Solberg, C.O.

    1984-01-01

    Neutrophil function were studied following irradiation (340-380 nm) of the cells in the presence of 22 μM doxycycline. At increasing light fluence the locomotion, chemiluminescence and glucose oxidation (by the hexose monophosphate shunt) of the neutrophils steadily decreased. The photodamage increased with increasing preincubation temperature and time and was enhanced in D 2 O, reduced in azide and abolished in anaerobiosis. Superoxide dismutase, catalase or mannitol did not influence the photodamage. Photooxidation of tryptophan in the presence of doxycycline was increased 9-10-fold in D 2 O and nearly abolished in the presence of 0.25 mM NaN 3 , indicating that singlet oxygen is the most important reactive oxygen species in the doxycycline-induced photodamage. The results may explain some of the features of tetracycline-induced photosensitivity and why other authors have obtained diverging results when studying the influence of tetracyclines on neutrophil functions. (author)

  10. Sequence and features of the tryptophan operon of Vibrio parahemolyticus.

    Science.gov (United States)

    Crawford, I P; Han, C Y; Silverman, M

    1991-01-01

    The nucleotide sequence of the trp operon of the marine enteric bacterium Vibrio parahemolyticus is presented. The gene order E, G, D, C(F), B, A is identical to that of other enterics. The structural genes of the operon are preceded by a long leader region encoding a 41-residue peptide containing five tryptophan residues. The organization of the leader region suggests that transcription of the operon is subject to attenuation control. The promoter-operator region of the V. parahemolyticus trp operon is almost identical to the corresponding promoter-operator of E. coli. The similarities suggest that promoter strength and operator function are identical in the two species, and that transcription initiation is regulated by repression. The operon appears to lack the internal promoter within trpD that is common in terrestrial enteric species.

  11. Mapping Hfq-RNA interaction surfaces using tryptophan fluorescence quenching

    Science.gov (United States)

    Robinson, Kirsten E.; Orans, Jillian; Kovach, Alexander R.; Link, Todd M.; Brennan, Richard G.

    2014-01-01

    Hfq is a posttranscriptional riboregulator and RNA chaperone that binds small RNAs and target mRNAs to effect their annealing and message-specific regulation in response to environmental stressors. Structures of Hfq-RNA complexes indicate that U-rich sequences prefer the proximal face and A-rich sequences the distal face; however, the Hfq-binding sites of most RNAs are unknown. Here, we present an Hfq-RNA mapping approach that uses single tryptophan-substituted Hfq proteins, all of which retain the wild-type Hfq structure, and tryptophan fluorescence quenching (TFQ) by proximal RNA binding. TFQ properly identified the respective distal and proximal binding of A15 and U6 RNA to Gram-negative Escherichia coli (Ec) Hfq and the distal face binding of (AA)3A, (AU)3A and (AC)3A to Gram-positive Staphylococcus aureus (Sa) Hfq. The inability of (GU)3G to bind the distal face of Sa Hfq reveals the (R-L)n binding motif is a more restrictive (A-L)n binding motif. Remarkably Hfq from Gram-positive Listeria monocytogenes (Lm) binds (GU)3G on its proximal face. TFQ experiments also revealed the Ec Hfq (A-R-N)n distal face-binding motif should be redefined as an (A-A-N)n binding motif. TFQ data also demonstrated that the 5′-untranslated region of hfq mRNA binds both the proximal and distal faces of Ec Hfq and the unstructured C-terminus. PMID:24288369

  12. Role for tryptophan in regulation of protein synthesis in porcine muscle

    International Nuclear Information System (INIS)

    Lin, F.D.; Smith, T.K.; Bayley, H.S.

    1988-01-01

    Experiments were conducted to determine the effect of varying concentrations of dietary tryptophan on growth rate and protein synthesis in edible muscle tissues of growing swine. A total of 45 immature swine (initial weight approximately 24 kg) were fed corn-gelatin diets containing 0.5 (n = 8), 0.8 (n = 10), 1.3 (n = 10), 1.5 (n = 7) or 2.0 (n = 10) g tryptophan/kg diet for 35 d. Animals fed 0.5 and 0.8 g tryptophan/kg grew more slowly, consumed less feed and had a lower efficiency of feed utilization than animals fed higher concentrations of tryptophan. Thirty similar animals were used in a second experiment. Diets containing 0.5, 0.8, 1.0, 1.5 or 2.0 g tryptophan/kg diet (n = 6) were fed for 14 d, after which all animals were killed and samples were taken of longissimus dorsi, triceps brachii and biceps femoris. Protein synthetic activity was determined by monitoring the incorporation of [ 14 C]phenylalanine into protein in vitro. There was no significant difference in synthetic activity between different muscle types. There was no effect of diet on the activity of the muscle soluble protein fraction. The activity of the muscle ribosomal fraction, however, was positively correlated with increasing concentrations of dietary tryptophan. It was concluded that tryptophan has the potential to regulate muscle protein synthesis in a manner beyond serving simply as a component of protein

  13. Steady-state fluorescence and phosphorescence spectroscopic studies of bacterial luciferase tryptophan mutants.

    Science.gov (United States)

    Li, Z; Meighen, E A

    1994-09-01

    Bacterial luciferase, which catalyzes the bioluminescence reaction in luminous bacteria, consists of two nonidentical polypeptides, α and β. Eight mutants of luciferase with each of the tryptophans replaced by tyrosine were generated by site-directed mutagenesis and purified to homogeneity. The steady-state tryptophan fluorescence and low-temperature phosphorescence spectroscopic properties of these mutants were characterized. In some instances, mutation of only a single tryptophan residue resulted in large spectral changes. The tryptophan residues conserved in both the α and the β subunits exhibited distinct fluorescence emission properties, suggesting that these tryptophans have different local enviroments. The low-temperature phosphorescence data suggest that the tryptophans conserved in bot the α and the β subunits are not located at the subunit interface and/or involved in subunit interactions. The differences in the spectral properties of the mutants have provided useful information on the local environment of the individual tryptophan residues as well as on the quaternary structure of the protein.

  14. Heterooligomeric phosphoribosyl diphosphate synthase of Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne

    2004-01-01

    The yeast Saccharomyces cerevisiae contains five phosphoribosyl diphosphate (PRPP) synthase-homologous genes (PRS1-5), which specify PRPP synthase subunits 1-5. Expression of the five S. cerevisiae PRS genes individually in an Escherichia coli PRPP-less strain (Deltaprs) showed that a single PRS...

  15. Threonine phosphorylation of rat liver glycogen synthase

    International Nuclear Information System (INIS)

    Arino, J.; Arro, M.; Guinovart, J.J.

    1985-01-01

    32 P-labeled glycogen synthase specifically immunoprecipitated from 32 P-phosphate incubated rat hepatocytes contains, in addition to [ 32 P] phosphoserine, significant levels of [ 32 P] phosphothreonine. When the 32 P-immunoprecipitate was cleaved with CNBr, the [ 32 P] phosphothreonine was recovered in the large CNBr fragment (CB-2, Mapp 28 Kd). Homogeneous rat liver glycogen synthase was phosphorylated by all the protein kinases able to phosphorylate CB-2 in vitro. After analysis of the immunoprecipitated enzyme for phosphoaminoacids, it was observed that only casein kinase II was able to phosphorylate on threonine and 32 P-phosphate was only found in CB-2. These results demonstrate that rat liver glycogen synthase is phosphorylated at threonine site(s) contained in CB-2 and strongly indicate that casein kinase II may play a role in the ''in vivo'' phosphorylation of liver glycogen synthase. This is the first protein kinase reported to phosphorylate threonine residues in liver glycogen synthase

  16. The influence of tryptophan on gluconeogenesis in the perfused liver of irradiated rats

    International Nuclear Information System (INIS)

    Borovikova, G.V.; Mashkova, N.Yu.; Dokshina, G.A.

    1985-01-01

    The liver isolated at different times after exposure to 7 Gy radiation responded in a different way to the effect of tryptophan (0.75 g/l) used as a gluconeogenesis inhibitor. While 24 h after irradiation of the addition of tryptophan inhibited gluconeogenesis from circulating exogenous amino acids, in 3 days, on the contrary, gluconeogenesis in the liver of donors was enhanced. It is suggested that these effects of tryptophan are associated with different functional status of the liver during the postirradiation observation period

  17. Modulation of hyaluronan synthase activity in cellular membrane fractions.

    Science.gov (United States)

    Vigetti, Davide; Genasetti, Anna; Karousou, Evgenia; Viola, Manuela; Clerici, Moira; Bartolini, Barbara; Moretto, Paola; De Luca, Giancarlo; Hascall, Vincent C; Passi, Alberto

    2009-10-30

    Hyaluronan (HA), the only non-sulfated glycosaminoglycan, is involved in morphogenesis, wound healing, inflammation, angiogenesis, and cancer. In mammals, HA is synthesized by three homologous HA synthases, HAS1, HAS2, and HAS3, that polymerize the HA chain using UDP-glucuronic acid and UDP-N-acetylglucosamine as precursors. Since the amount of HA is critical in several pathophysiological conditions, we developed a non-radioactive assay for measuring the activity of HA synthases (HASs) in eukaryotic cells and addressed the question of HAS activity during intracellular protein trafficking. We prepared three cellular fractions: plasma membrane, cytosol (containing membrane proteins mainly from the endoplasmic reticulum and Golgi), and nuclei. After incubation with UDP-sugar precursors, newly synthesized HA was quantified by polyacrylamide gel electrophoresis of fluorophore-labeled saccharides and high performance liquid chromatography. This new method measured HAS activity not only in the plasma membrane fraction but also in the cytosolic membranes. This new technique was used to evaluate the effects of 4-methylumbeliferone, phorbol 12-myristate 13-acetate, interleukin 1beta, platelet-derived growth factor BB, and tunicamycin on HAS activities. We found that HAS activity can be modulated by post-translational modification, such as phosphorylation and N-glycosylation. Interestingly, we detected a significant increase in HAS activity in the cytosolic membrane fraction after tunicamycin treatment. Since this compound is known to induce HA cable structures, this result links HAS activity alteration with the capability of the cell to promote HA cable formation.

  18. Glycogen synthase kinase 3: more than a namesake.

    Science.gov (United States)

    Rayasam, Geetha Vani; Tulasi, Vamshi Krishna; Sodhi, Reena; Davis, Joseph Alex; Ray, Abhijit

    2009-03-01

    Glycogen synthase kinase 3 (GSK3), a constitutively acting multi-functional serine threonine kinase is involved in diverse physiological pathways ranging from metabolism, cell cycle, gene expression, development and oncogenesis to neuroprotection. These diverse multiple functions attributed to GSK3 can be explained by variety of substrates like glycogen synthase, tau protein and beta catenin that are phosphorylated leading to their inactivation. GSK3 has been implicated in various diseases such as diabetes, inflammation, cancer, Alzheimer's and bipolar disorder. GSK3 negatively regulates insulin-mediated glycogen synthesis and glucose homeostasis, and increased expression and activity of GSK3 has been reported in type II diabetics and obese animal models. Consequently, inhibitors of GSK3 have been demonstrated to have anti-diabetic effects in vitro and in animal models. However, inhibition of GSK3 poses a challenge as achieving selectivity of an over achieving kinase involved in various pathways with multiple substrates may lead to side effects and toxicity. The primary concern is developing inhibitors of GSK3 that are anti-diabetic but do not lead to up-regulation of oncogenes. The focus of this review is the recent advances and the challenges surrounding GSK3 as an anti-diabetic therapeutic target.

  19. Beta Emission and Bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-13

    Bremsstrahlung is continuous radiation produced by beta particles decelerating in matter; different beta emitters have different endpoint energies; high-energy betas interacting with high-Z materials will more likely produce bremsstrahlung; depending on the data, sometimes all you can say is that a beta emitter is present.

  20. Glycogen Synthase Kinase-3β

    DEFF Research Database (Denmark)

    Munkholm, Klaus; Lenskjold, Toke; Jacoby, Anne Sophie

    2016-01-01

    cells were quantitated using enzyme immunometric assays. The activity of GSK-3β (serine-9-phosphorylated GSK-3β/total GSK-3β) was lower at baseline compared with follow-up. No significant mean change over time was observed in levels of total GSK-3β and serine-9-phosphorylated GSK-3β. Exploratory......Evidence indicates a role for glycogen synthase kinase-3β (GSK-3β) in the pathophysiology of mood disorders and in cognitive disturbances; however, the natural variation in GSK-3β activity over time is unknown. We aimed to investigate GSK-3β activity over time and its possible correlation...... with emotional lability, subjective mood fluctuations and cognitive function in healthy individuals. Thirty-seven healthy subjects were evaluated with neuropsychological tests and blood samples at baseline and 12-week follow-up. Total GSK-3β and serine-9-phosphorylated GSK-3β in peripheral blood mononuclear...

  1. FLIM-FRET image analysis of tryptophan in prostate cancer cells

    Science.gov (United States)

    Periasamy, Ammasi; Alam, Shagufta R.; Svindrych, Zdenek; Wallrabe, Horst

    2017-07-01

    A region of interest (ROI) based quantitative FLIM-FRET image analysis is developed to quantitate the autofluorescence signals of the essential amino acid tryptophan as a biomarker to investigate the metabolism in prostate cancer cells.

  2. Acute tryptophan depletion dose dependently impairs object memory in serotonin transporter knockout rats

    NARCIS (Netherlands)

    Olivier, J D A; Jans, L A W; Korte-Bouws, G A H; Korte, S M; Deen, P M T; Cools, A R; Ellenbroek, B A; Blokland, A

    2008-01-01

    RATIONALE: Acute tryptophan depletion (ATD) transiently lowers central serotonin levels and can induce depressive mood states and cognitive defects. Previous studies have shown that ATD impairs object recognition in rats. OBJECTIVES: As individual differences exist in central serotonin

  3. Immunosuppressive Tryptophan Catabolism and Gut Mucosal Dysfunction Following Early HIV Infection

    NARCIS (Netherlands)

    Jenabian, Mohammad-Ali; El-Far, Mohamed; Vyboh, Kishanda; Kema, Ido; Costiniuk, Cecilia T.; Thomas, Rejean; Baril, Jean-Guy; LeBlanc, Roger; Kanagaratham, Cynthia; Radzioch, Danuta; Allam, Ossama; Ahmad, Ali; Lebouche, Bertrand; Tremblay, Cecile; Ancuta, Petronela; Routy, Jean-Pierre

    2015-01-01

    Background. Tryptophan (Trp) catabolism into kynurenine (Kyn) contributes to immune dysfunction in chronic human immunodeficiency virus (HIV) infection. To better define the relationship between Trp catabolism, inflammation, gut mucosal dysfunction, and the role of early antiretroviral therapy

  4. Tryptophan Oxidative Metabolism Catalyzed by : A Thermophile Isolated from Kuwait Soil Contaminated with Petroleum Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Jassim M. Al-Hassan

    2011-01-01

    Full Text Available Tryptophan metabolism has been extensively studied in humans as well as in soil. Its metabolism takes place mainly through kynurenine pathway yielding hydroxylated, deaminated and many other products of physiological significance. However, tryptophan metabolism has not been studied in an isolated thermophilic bacterium. Geobacillus stearothermophilus is a local thermophile isolated from Kuwait desert soil contaminated with petroleum hydrocarbons. The bacterium grows well at 65 °C in 0.05 M phosphate buffer (pH 7, when supplied with organic compounds as a carbon source and has a good potential for transformation of steroids and related molecules. In the present study, we used tryptophan ethyl ester as a carbon source for the bacterium to study the catabolism of the amino acid at pH 5 and pH 7. In this endeavor, we have resolved twenty one transformation products of tryptophan by GC/LC and have identified them through their mass spectral fragmentation.

  5. Picosecond Fluorescence Dynamics of Tryptophan and 5-Fluorotryptophan in Monellin : Slow Water-Protein Relaxation Unmasked

    NARCIS (Netherlands)

    Xu, Jianhua; Chen, Binbin; Callis, Patrik Robert; Muiño, Pedro L; Rozeboom, Henriette J; Broos, Jaap; Toptygin, Dmitri; Brand, Ludwig; Knutson, Jay R

    2015-01-01

    Time Dependent Fluorescence Stokes (emission wavelength) Shifts (TDFSS) from tryptophan (Trp) following sub-picosecond excitation are increasingly used to investigate protein dynamics, most recently enabling active research interest into water dynamics near the surface of proteins. Unlike many

  6. Linoleic acid, thymine, and tryptophan radiosensitization by protoporphyrin in presence of oxygene

    International Nuclear Information System (INIS)

    Champel, P.; Mignot, M.A.; Pillement, B.; Fontenil, L.; Rocquet, G.

    Sensitizing effect induced by protoporphyrin, an active molecule in photooxidation is studied. Studied substances are tryptophan, thymine, linoleic acid, each component representing one of the great groups of biological components, nucleic acid, proteins, lipids [fr

  7. Chemical rescue of cleft palate and midline defects in conditional GSK-3beta mice.

    Science.gov (United States)

    Liu, Karen J; Arron, Joseph R; Stankunas, Kryn; Crabtree, Gerald R; Longaker, Michael T

    2007-03-01

    Glycogen synthase kinase-3beta (GSK-3beta) has integral roles in a variety of biological processes, including development, diabetes, and the progression of Alzheimer's disease. As such, a thorough understanding of GSK-3beta function will have a broad impact on human biology and therapeutics. Because GSK-3beta interacts with many different pathways, its specific developmental roles remain unclear. We have discovered a genetic requirement for GSK-3beta in midline development. Homozygous null mice display cleft palate, incomplete fusion of the ribs at the midline and bifid sternum as well as delayed sternal ossification. Using a chemically regulated allele of GSK-3beta (ref. 6), we have defined requirements for GSK-3beta activity during discrete temporal windows in palatogenesis and skeletogenesis. The rapamycin-dependent allele of GSK-3beta produces GSK-3beta fused to a tag, FRB* (FKBP/rapamycin binding), resulting in a rapidly destabilized chimaeric protein. In the absence of drug, GSK-3beta(FRB)*(/FRB)* mutants appear phenotypically identical to GSK-3beta-/- mutants. In the presence of drug, GSK-3betaFRB* is rapidly stabilized, restoring protein levels and activity. Using this system, mutant phenotypes were rescued by restoring endogenous GSK-3beta activity during two distinct periods in gestation. This technology provides a powerful tool for defining windows of protein function during development.

  8. Characterization of 5-(2-18F-fluoroethoxy-L-tryptophan for PET imaging of the pancreas [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Ahmed Abbas

    2016-11-01

    Full Text Available Purpose: In diabetes, pancreatic beta cell mass declines significantly prior to onset of fasting hyperglycemia. This decline may be due to endoplasmic reticulum (ER stress, and the system L amino acid transporter LAT1 may be a biomarker of this process. In this study, we used 5-(2-18F-fluoroethoxy-L-tryptophan (18F-L-FEHTP to target LAT1 as a potential biomarker of beta cell function in diabetes. Procedures: Uptake of 18F-L-FEHTP was determined in wild-type C57BL/6 mice by ex vivo biodistribution. Both dynamic and static positron emission tomography (PET images were acquired in wild-type and Akita mice, a model of ER stress-induced diabetes, as well as in mice treated with streptozotocin (STZ. LAT1 expression in both groups of mice was evaluated by immunofluorescence microscopy. Results: Uptake of 18F-L-FEHTP was highest in the pancreas, and static PET images showed highly specific pancreatic signal. Time-activity curves showed significantly reduced 18F-L-FEHTP uptake in Akita mice, and LAT1 expression was also reduced. However, mice treated with STZ, in which beta cell mass was reduced by 62%, showed no differences in 18F-L-FEHTP uptake in the pancreas, and there was no significant correlation of 18F-L-FEHTP uptake with beta cell mass. Conclusions: 18F-L-FEHTP is highly specific for the pancreas with little background uptake in kidney or liver. We were able to detect changes in LAT1 in a mouse model of diabetes, but these changes did not correlate with beta cell function or mass. Therefore, 18F-L-FEHTP PET is not a suitable method for the noninvasive imaging of changes in beta cell function during the progression of diabetes.

  9. Effects of Tryptophan Content and Backbone Spacing on the Uptake Efficiency of Cell-Penetrating Peptides

    KAUST Repository

    Rydberg, Hanna A.; Matson, Maria; Å mand, Helene L.; Esbjö rner, Elin K.; Nordé n, Bengt

    2012-01-01

    Cell-penetrating peptides (CPPs) are able to traverse cellular membranes and deliver macromolecular cargo. Uptake occurs through both endocytotic and nonendocytotic pathways, but the molecular requirements for efficient internalization are not fully understood. Here we investigate how the presence of tryptophans and their position within an oligoarginine influence uptake mechanism and efficiency. Flow cytometry and confocal fluorescence imaging are used to estimate uptake efficiency, intracellular distribution and toxicity in Chinese hamster ovarian cells. Further, membrane leakage and lipid membrane affinity are investigated. The peptides contain eight arginine residues and one to four tryptophans, the tryptophans positioned either at the N-terminus, in the middle, or evenly distributed along the amino acid sequence. Our data show that the intracellular distribution varies among peptides with different tryptophan content and backbone spacing. Uptake efficiency is higher for the peptides with four tryptophans in the middle, or evenly distributed along the peptide sequence, than for the peptide with four tryptophans at the N-terminus. All peptides display low cytotoxicity except for the one with four tryptophans at the N-terminus, which was moderately toxic. This finding is consistent with their inability to induce efficient leakage of dye from lipid vesicles. All peptides have comparable affinities for lipid vesicles, showing that lipid binding is not a decisive parameter for uptake. Our results indicate that tryptophan content and backbone spacing can affect both the CPP uptake efficiency and the CPP uptake mechanism. The low cytotoxicity of these peptides and the possibilities of tuning their uptake mechanism are interesting from a therapeutic point of view. © 2012 American Chemical Society.

  10. Effects of Tryptophan Content and Backbone Spacing on the Uptake Efficiency of Cell-Penetrating Peptides

    KAUST Repository

    Rydberg, Hanna A.

    2012-07-10

    Cell-penetrating peptides (CPPs) are able to traverse cellular membranes and deliver macromolecular cargo. Uptake occurs through both endocytotic and nonendocytotic pathways, but the molecular requirements for efficient internalization are not fully understood. Here we investigate how the presence of tryptophans and their position within an oligoarginine influence uptake mechanism and efficiency. Flow cytometry and confocal fluorescence imaging are used to estimate uptake efficiency, intracellular distribution and toxicity in Chinese hamster ovarian cells. Further, membrane leakage and lipid membrane affinity are investigated. The peptides contain eight arginine residues and one to four tryptophans, the tryptophans positioned either at the N-terminus, in the middle, or evenly distributed along the amino acid sequence. Our data show that the intracellular distribution varies among peptides with different tryptophan content and backbone spacing. Uptake efficiency is higher for the peptides with four tryptophans in the middle, or evenly distributed along the peptide sequence, than for the peptide with four tryptophans at the N-terminus. All peptides display low cytotoxicity except for the one with four tryptophans at the N-terminus, which was moderately toxic. This finding is consistent with their inability to induce efficient leakage of dye from lipid vesicles. All peptides have comparable affinities for lipid vesicles, showing that lipid binding is not a decisive parameter for uptake. Our results indicate that tryptophan content and backbone spacing can affect both the CPP uptake efficiency and the CPP uptake mechanism. The low cytotoxicity of these peptides and the possibilities of tuning their uptake mechanism are interesting from a therapeutic point of view. © 2012 American Chemical Society.

  11. Kinetic tritium isotopic effects in the position 2 for 5'-hydroxy-L-tryptophane

    International Nuclear Information System (INIS)

    Boroda, E.; Kanska, M.

    2006-01-01

    Tryptophanase converts 5'-hydroxy-L-tryptophane to pyrogronic acid and ammonia, however there are known conditions for the reversed reaction. Mechanism of the processes are not known till now. Kinetic isotopic effect (KIE) permits finding the rate determining stage in the multistage process. In presented communication, 5'-hydroxy-[2- 3 H]-L-tryptophane was synthesized and the KIE in the room temperature determined for different reaction stages

  12. Syntheses and Self-assembling Behaviors of Pentagonal Conjugates of Tryptophane Zipper-Forming Peptide

    Directory of Open Access Journals (Sweden)

    Nobuo Kimizuka

    2011-08-01

    Full Text Available Pentagonal conjugates of tryptophane zipper-forming peptide (CKTWTWTE with a pentaazacyclopentadecane core (Pentagonal-Gly-Trpzip and Pentagonal-Ala-Trpzip were synthesized and their self-assembling behaviors were investigated in water. Pentagonal-Gly-Trpzip self-assembled into nanofibers with the width of about 5 nm in neutral water (pH 7 via formation of tryptophane zipper, which irreversibly converted to nanoribbons by heating. In contrast, Pentagonal-Ala-Trpzip formed irregular aggregates in water.

  13. Changes of intermediary taurine and tryptophan metabolism after combined radiation-thermal injury

    International Nuclear Information System (INIS)

    Konnova, L.A.; Novoselova, G.S.

    1986-01-01

    The dynamics of changes of the taurine and tryptophane concentration in blood serum of rats has been studied during 30 days after 3b degree burn of 15% of body surface after total even exposure to radiation in doses of 3 and 6 Gy, and after combined radiation thermal injury. Combined radiation-thermal injury was found to be characterized by reduced concentration of taurine but an increase of the tryptophane level from the second-third day after the injury

  14. GPR142 Controls Tryptophan-Induced Insulin and Incretin Hormone Secretion to Improve Glucose Metabolism

    OpenAIRE

    Lin, Hua V.; Efanov, Alexander M.; Fang, Xiankang; Beavers, Lisa S.; Wang, Xuesong; Wang, Jingru; Gonzalez Valcarcel, Isabel C.; Ma, Tianwei

    2016-01-01

    GPR142, a putative amino acid receptor, is expressed in pancreatic islets and the gastrointestinal tract, but the ligand affinity and physiological role of this receptor remain obscure. In this study, we show that in addition to L-Tryptophan, GPR142 signaling is also activated by L-Phenylalanine but not by other naturally occurring amino acids. Furthermore, we show that Tryptophan and a synthetic GPR142 agonist increase insulin and incretin hormones and improve glucose disposal in mice in a G...

  15. Removing the by-products acetic acid and NH4+ from the l-tryptophan broth by vacuum thin film evaporation during l-tryptophan production

    Directory of Open Access Journals (Sweden)

    Qingyang Xu

    2018-05-01

    Full Text Available Background: During l-tryptophan production by Escherichia coli, the by-products, acetic acid and NH4+, accumulate in the fermentation broth, resulting in inhibited cell growth and activity and decreased l-tryptophan production. To improve the l-tryptophan yield and glucose conversion rate, acetic acid and NH4+ were removed under low-temperature vacuum conditions by vacuum scraper concentrator evaporation; the fermentation broth after evaporation was pressed into another fermenter to continue fermentation. To increase the volatilisation rate of acetic acid and NH4+ and reduce damage to bacteria during evaporation, different vacuum evaporation conditions were studied. Results: The optimum operating conditions were as follows: vacuum degree, 720 mm Hg; concentration ratio, 10%; temperature, 60°C; and feeding rate, 300 mL/min. The biomass yield of the control fermentation (CF and fermentation by vacuum evaporation (VEF broths was 55.1 g/L and 58.3 g/L at 38 h, respectively, (an increase of 5.8%; the living biomass yield increased from 8.9 (CF to 10.2 pF (VEF; an increase of 14.6%. l-tryptophan production increased from 50.2 g/L (CF to 60.2 g/L (VEF (an increase of 19.9%, and glucose conversion increased from 18.2% (CF to 19.5% (VEF; an increase of 7.1%. The acetic acid concentrations were 2.74 g/L and 6.70 g/L, and the NH4+ concentrations were 85.3 mmol/L and 130.9 mmol/L in VEF and CF broths, respectively. Conclusions: The acetic acid and NH4+ in the fermentation broth were quickly removed using the vacuum scraper concentrator, which reduced bacterial inhibition, enhanced bacterial activity, and improved the production of l-tryptophan and glucose conversion rate.How to cite: Xu Q, Bai F, Chen N, et al. Removing the by-products acetic acid and NH4+ from the l-tryptophan broth by vacuum thin film evaporation during l-tryptophan production. Electron J Biotechnol 2018; 33. https://doi.org/10.1016/j.ejbt.2018.04.003. Keywords: Acetic acid

  16. Flexible Enantioselectivity of Tryptophanase Attributable to Benzene Ring in Heterocyclic Moiety of D-Tryptophan

    Directory of Open Access Journals (Sweden)

    Akihiko Shimada

    2012-05-01

    Full Text Available The invariance principle of enzyme enantioselectivity must be absolute because it is absolutely essential to the homochiral biological world. Most enzymes are strictly enantioselective, and tryptophanase is one of the enzymes with extreme absolute enantioselectivity for L-tryptophan. Contrary to conventional knowledge about the principle, tryptophanase becomes flexible to catalyze D-tryptophan in the presence of diammonium hydrogenphosphate. Since D-amino acids are ordinarily inert or function as inhibitors even though they are bound to the active site, the inhibition behavior of D-tryptophan and several inhibitors involved in this process was examined in terms of kinetics to explain the reason for this flexible enantioselectivity in the presence of diammonium hydrogenphosphate. Diammonium hydrogenphosphate gave tryptophanase a small conformational change so that D-tryptophan could work as a substrate. As opposed to other D-amino acids, D-tryptophan is a very bulky amino acid with a benzene ring in its heterocyclic moiety, and so we suggest that this structural feature makes the catalysis of D-tryptophan degradation possible, consequently leading to the flexible enantioselectivity. The present results not only help to understand the mechanism of enzyme enantioselectivity, but also shed light on the origin of homochirality.

  17. Room temperature phosphorescence study on the structural flexibility of single tryptophan containing proteins

    Science.gov (United States)

    Kowalska-Baron, Agnieszka; Gałęcki, Krystian; Wysocki, Stanisław

    2015-01-01

    In this study, we have undertaken efforts to find correlation between phosphorescence lifetimes of single tryptophan containing proteins and some structural indicators of protein flexibility/rigidity, such as the degree of tryptophan burial or its exposure to solvent, protein secondary and tertiary structure of the region of localization of tryptophan as well as B factors for tryptophan residue and its immediate surroundings. Bearing in mind that, apart from effective local viscosity of the protein/solvent matrix, the other factor that concur in determining room temperature tryptophan phosphorescence (RTTP) lifetime in proteins is the extent of intramolecular quenching by His, Cys, Tyr and Trp side chains, the crystallographic structures derived from the Brookhaven Protein Data Bank were also analyzed concentrating on the presence of potentially quenching amino acid side chains in the close proximity of the indole chromophore. The obtained results indicated that, in most cases, the phosphorescence lifetimes of tryptophan containing proteins studied tend to correlate with the above mentioned structural indicators of protein rigidity/flexibility. This correlation is expected to provide guidelines for the future development of phosphorescence lifetime-based method for the prediction of structural flexibility of proteins, which is directly linked to their biological function.

  18. Influence of tryptophan and related compounds on ergot alkaloid formation in Claviceps purpurea (FR.) Tul.

    Science.gov (United States)

    Erge, D; Schumann, B; Gröger, D

    1984-01-01

    L-Tryptophan did not exert any influence on peptide alkaloid formation in an ergotamine and in an ergosine-accumulating C. purpurea strain. A different picture was observed in a series of related C. purpurea strains. Tryptophan showed a slight stimulatory effect on the ergotoxine producer Pepty 695/S. A blocked mutant of it, designated as Pepty 695/ch which was able to accumulate secoclavines gave similar results. In a high-yielding elymoclavine strain Pepty 695/e, the progeny of the former one, tryptophan up to a concentration of 25 mM stimulated remarkably clavine biosynthesis. Furthermore, tryptophan could overcome the block of synthesis by inorganic phosphate. Increased specific activities of chanoclavine cyclase but not DMAT synthetase were observed in cultures of strain Pepty 695/e supplemented with tryptophan. 5-Methyltryptophan and bioisosteres of tryptophan were ineffective in alkaloid stimulation. These results are compared with those obtained with the grass ergot strain SD 58 and discussed with the relation to other induction phenomena.

  19. Delaying aging and the aging-associated decline in protein homeostasis by inhibition of tryptophan degradation

    Science.gov (United States)

    van der Goot, Annemieke T.; Zhu, Wentao; Vázquez-Manrique, Rafael P.; Seinstra, Renée I.; Dettmer, Katja; Michels, Helen; Farina, Francesca; Krijnen, Jasper; Melki, Ronald; Buijsman, Rogier C.; Ruiz Silva, Mariana; Thijssen, Karen L.; Kema, Ido P.; Neri, Christian; Oefner, Peter J.; Nollen, Ellen A. A.

    2012-01-01

    Toxicity of aggregation-prone proteins is thought to play an important role in aging and age-related neurological diseases like Parkinson and Alzheimer’s diseases. Here, we identify tryptophan 2,3-dioxygenase (tdo-2), the first enzyme in the kynurenine pathway of tryptophan degradation, as a metabolic regulator of age-related α-synuclein toxicity in a Caenorhabditis elegans model. Depletion of tdo-2 also suppresses toxicity of other heterologous aggregation-prone proteins, including amyloid-β and polyglutamine proteins, and endogenous metastable proteins that are sensors of normal protein homeostasis. This finding suggests that tdo-2 functions as a general regulator of protein homeostasis. Analysis of metabolite levels in C. elegans strains with mutations in enzymes that act downstream of tdo-2 indicates that this suppression of toxicity is independent of downstream metabolites in the kynurenine pathway. Depletion of tdo-2 increases tryptophan levels, and feeding worms with extra l-tryptophan also suppresses toxicity, suggesting that tdo-2 regulates proteotoxicity through tryptophan. Depletion of tdo-2 extends lifespan in these worms. Together, these results implicate tdo-2 as a metabolic switch of age-related protein homeostasis and lifespan. With TDO and Indoleamine 2,3-dioxygenase as evolutionarily conserved human orthologs of TDO-2, intervening with tryptophan metabolism may offer avenues to reducing proteotoxicity in aging and age-related diseases. PMID:22927396

  20. Role of decreased Plasma Tryptophan in memory deficits observed in Type-I diabetes

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, S.; Tabassum, S.; Haider, S. [University of Karachi (Pakistan). Dept. of Biochemistry

    2013-01-15

    Objective: To investigate the relationship between plasma tryptophan and the occurrence of memory dysfunctions in male and female type 1 diabetics. Methods: The case-control study was conducted at two urban healthcare facilities in Karachi from January to June 2009, and comprised 100 diabetic subjects of among whom were 50 men and 50 women. The controls were also similar in number and gender. A questionnaire was used to evaluate the memory impairment in the subjects. Plasma tryptophan was determined by high performance liquid chromatography with ultra-violet method. Students t-test was used to analyse tryptophan data. Results: There was considerable memory impairment in the cases (n=40) compared to the controls (n=5). Results also showed a significant (p<0.01) decrease in plasma tryptophan levels in both male and female diabetic patients. Conclusions: Diabetic subjects exhibited occurrence of memory impairment with concomitant decline in plasma tryptophan levels. The findings indicate that decreased brain uptake of tryptophan and lowered brain 5-hydroxytryptamine levels may be responsible for the memory deficits seen in diabetics. (author)

  1. Role of decreased Plasma Tryptophan in memory deficits observed in Type-I diabetes

    International Nuclear Information System (INIS)

    Ahmad, S.; Tabassum, S.; Haider, S.

    2013-01-01

    Objective: To investigate the relationship between plasma tryptophan and the occurrence of memory dysfunctions in male and female type 1 diabetics. Methods: The case-control study was conducted at two urban healthcare facilities in Karachi from January to June 2009, and comprised 100 diabetic subjects of among whom were 50 men and 50 women. The controls were also similar in number and gender. A questionnaire was used to evaluate the memory impairment in the subjects. Plasma tryptophan was determined by high performance liquid chromatography with ultra-violet method. Students t-test was used to analyse tryptophan data. Results: There was considerable memory impairment in the cases (n=40) compared to the controls (n=5). Results also showed a significant (p<0.01) decrease in plasma tryptophan levels in both male and female diabetic patients. Conclusions: Diabetic subjects exhibited occurrence of memory impairment with concomitant decline in plasma tryptophan levels. The findings indicate that decreased brain uptake of tryptophan and lowered brain 5-hydroxytryptamine levels may be responsible for the memory deficits seen in diabetics. (author)

  2. Ab initio study on electron excitation and electron transfer in tryptophan-tyrosine system

    International Nuclear Information System (INIS)

    Tong Jing; Li Xiangyuan

    2002-01-01

    In this article, ab initio calculation has been performed to evaluate the transition energy of electronic excitation in tryptophan and tyrosine by using semiempirical molecular orbital method AM1 and complete active space self-consistent field method. The solvent effect has been considered by means of the conductor-like screening model. After geometric optimizations of isolated tryptophan and tyrosine, and their corresponding radicals and cations, reaction heat of these electron transfer reactions have been obtained by the means of complete active space self-consistent field method. The transition energies from the ground state, respectively, to the lowest excited state and to the lowest triplet state of these two amino acids are also calculated and compared with the experimentally observed values. The ionization potential and electron affinity are also calculated for tryptophan and tyrosine employing Koopmans' theorem and ab initio calculation. Compared with the experimental measurements, the theoretical results are found satisfactory. Theoretical results give good explanations on the experimental phenomena that N 3 · can preferably oxide the side chain of tryptophan residue and then the electron transfer from tyrosine residue to tryptophan residue follows in peptides involving tryptophan and tyrosine

  3. The cellulose synthase companion proteins act non-redundantly with CELLULOSE SYNTHASE INTERACTING1/POM2 and CELLULOSE SYNTHASE 6

    OpenAIRE

    Endler, Anne; Schneider, Rene; Kesten, Christopher; Lampugnani, Edwin R.; Persson, Staffan

    2016-01-01

    Cellulose is a cell wall constituent that is essential for plant growth and development, and an important raw material for a range of industrial applications. Cellulose is synthesized at the plasma membrane by massive cellulose synthase (CesA) complexes that track along cortical microtubules in elongating cells of Arabidopsis through the activity of the protein CELLULOSE SYNTHASE INTERACTING1 (CSI1). In a recent study we identified another family of proteins that also are associated with the ...

  4. Increasing protein stability by improving beta-turns.

    Science.gov (United States)

    Fu, Hailong; Grimsley, Gerald R; Razvi, Abbas; Scholtz, J Martin; Pace, C Nick

    2009-11-15

    Our goal was to gain a better understanding of how protein stability can be increased by improving beta-turns. We studied 22 beta-turns in nine proteins with 66-370 residues by replacing other residues with proline and glycine and measuring the stability. These two residues are statistically preferred in some beta-turn positions. We studied: Cold shock protein B (CspB), Histidine-containing phosphocarrier protein, Ubiquitin, Ribonucleases Sa2, Sa3, T1, and HI, Tryptophan synthetase alpha-subunit, and Maltose binding protein. Of the 15 single proline mutations, 11 increased stability (Average = 0.8 +/- 0.3; Range = 0.3-1.5 kcal/mol), and the stabilizing effect of double proline mutants was additive. On the basis of this and our previous work, we conclude that proteins can generally be stabilized by replacing nonproline residues with proline residues at the i + 1 position of Type I and II beta-turns and at the i position in Type II beta-turns. Other turn positions can sometimes be used if the phi angle is near -60 degrees for the residue replaced. It is important that the side chain of the residue replaced is less than 50% buried. Identical substitutions in beta-turns in related proteins give similar results. Proline substitutions increase stability mainly by decreasing the entropy of the denatured state. In contrast, the large, diverse group of proteins considered here had almost no residues in beta-turns that could be replaced by Gly to increase protein stability. Improving beta-turns by substituting Pro residues is a generally useful way of increasing protein stability. 2009 Wiley-Liss, Inc.

  5. Antitumour agents as inhibitors of tryptophan 2,3-dioxygenase

    Energy Technology Data Exchange (ETDEWEB)

    Pantouris, Georgios; Mowat, Christopher G., E-mail: C.G.Mowat@ed.ac.uk

    2014-01-03

    Highlights: •∼2800 National Cancer Institute USA compounds have been screened as potential inhibitors of TDO and/or IDO. •Seven compounds with anti-tumour properties have been identified as potent inhibitors. •NSC 36398 (taxifolin, dihydroquercetin) is selective for TDO with a K{sub i} of 16 M. •This may help further our understanding of the role of TDO in cancer. -- Abstract: The involvement of tryptophan 2,3-dioxygenase (TDO) in cancer biology has recently been described, with the enzyme playing an immunomodulatory role, suppressing antitumour immune responses and promoting tumour cell survival and proliferation. This finding reinforces the need for specific inhibitors of TDO that may potentially be developed for therapeutic use. In this work we have screened ∼2800 compounds from the library of the National Cancer Institute USA and identified seven potent inhibitors of TDO with inhibition constants in the nanomolar or low micromolar range. All seven have antitumour properties, killing various cancer cell lines. For comparison, the inhibition potencies of these compounds were tested against IDO and their inhibition constants are reported. Interestingly, this work reveals that NSC 36398 (dihydroquercetin, taxifolin), with an in vitro inhibition constant of ∼16 μM, is the first TDO-selective inhibitor reported.

  6. Mechanisms of tryptophan adsorption onto single-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Zhou Jieping; Tan Jun; Xu Pengshou; Sheng Liusi; Pan Guoqiang

    2011-01-01

    Near edge X-ray absorption fine structure spectroscopy (NEXAFS) and synchrotron radiation photoelectron spectroscopy (SRPES) were employed to investigate the adsorption mechanism of tryptophan (Trp) onto single-walled carbon nanotubes (SWCNTs). The difference of the carbon K-edge NEXAFS spectra between Trp molecules and Trp-adsorbed SWCNTs shows that a significant interaction occurs among the SWCNTs and Trp molecules adsorbed. However, negligible changes in the peak profiles and energy positions of nitrogen K-edge imply that neither of the two nitrogen atoms in Trp molecule is involved in the interface interaction. A change of the shape of the main absorption peak at the oxygen K-edge reveals that O atoms of the C=O or C-O or both are likely involved in the interface interaction. The fact that the peak at about 529 eV at the O K-edge become sharper and stronger demonstrates that the O atom in the C=O participates in the interface interaction, which was confirmed by O1s SRPES spectrum. (authors)

  7. Endothelial nitric oxide synthase gene polymorphisms associated ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-05-24

    May 24, 2010 ... chronic periodontitis (CP), 31 with gingivitis (G) and 50 healthy controls. Probing depth ..... Periodontal disease in pregnancy I. Prevalence and severity. ... endothelial nitric oxide synthase gene in premenopausal women with.

  8. Terpene synthases from Cannabis sativa.

    Directory of Open Access Journals (Sweden)

    Judith K Booth

    Full Text Available Cannabis (Cannabis sativa plants produce and accumulate a terpene-rich resin in glandular trichomes, which are abundant on the surface of the female inflorescence. Bouquets of different monoterpenes and sesquiterpenes are important components of cannabis resin as they define some of the unique organoleptic properties and may also influence medicinal qualities of different cannabis strains and varieties. Transcriptome analysis of trichomes of the cannabis hemp variety 'Finola' revealed sequences of all stages of terpene biosynthesis. Nine cannabis terpene synthases (CsTPS were identified in subfamilies TPS-a and TPS-b. Functional characterization identified mono- and sesqui-TPS, whose products collectively comprise most of the terpenes of 'Finola' resin, including major compounds such as β-myrcene, (E-β-ocimene, (--limonene, (+-α-pinene, β-caryophyllene, and α-humulene. Transcripts associated with terpene biosynthesis are highly expressed in trichomes compared to non-resin producing tissues. Knowledge of the CsTPS gene family may offer opportunities for selection and improvement of terpene profiles of interest in different cannabis strains and varieties.

  9. Terpene synthases from Cannabis sativa.

    Science.gov (United States)

    Booth, Judith K; Page, Jonathan E; Bohlmann, Jörg

    2017-01-01

    Cannabis (Cannabis sativa) plants produce and accumulate a terpene-rich resin in glandular trichomes, which are abundant on the surface of the female inflorescence. Bouquets of different monoterpenes and sesquiterpenes are important components of cannabis resin as they define some of the unique organoleptic properties and may also influence medicinal qualities of different cannabis strains and varieties. Transcriptome analysis of trichomes of the cannabis hemp variety 'Finola' revealed sequences of all stages of terpene biosynthesis. Nine cannabis terpene synthases (CsTPS) were identified in subfamilies TPS-a and TPS-b. Functional characterization identified mono- and sesqui-TPS, whose products collectively comprise most of the terpenes of 'Finola' resin, including major compounds such as β-myrcene, (E)-β-ocimene, (-)-limonene, (+)-α-pinene, β-caryophyllene, and α-humulene. Transcripts associated with terpene biosynthesis are highly expressed in trichomes compared to non-resin producing tissues. Knowledge of the CsTPS gene family may offer opportunities for selection and improvement of terpene profiles of interest in different cannabis strains and varieties.

  10. Unchanged gene expression of glycogen synthase in muscle from patients with NIDDM following sulphonylurea-induced improvement of glycaemic control

    DEFF Research Database (Denmark)

    Vestergaard, H; Lund, S; Bjørbaek, C

    1995-01-01

    We have previously shown that the mRNA expression of muscle glycogen synthase is decreased in non-insulin-dependent diabetic (NIDDM) patients; the objective of the present protocol was to examine whether the gene expression of muscle glycogen synthase in NIDDM is affected by chronic sulphonylurea...... as enhanced beta-cell responses to an oral glucose load. During euglycaemic, hyperinsulinaemic clamp (2 mU x kg-1 x min-1) in combination with indirect calorimetry, a 35% (p=0.005) increase in whole-body insulin-stimulated glucose disposal rate, predominantly due to an increased non-oxidative glucose....... In conclusion, improved blood glucose control in gliclazide-treated obese NIDDM patients has no impact on the gene expression of muscle glycogen synthase....

  11. The alpha2-5'AMP-activated protein kinase is a site 2 glycogen synthase kinase in skeletal muscle and is responsive to glucose loading

    DEFF Research Database (Denmark)

    Jørgensen, Sebastian B; Nielsen, Jakob N.; Birk, Jesper Bratz

    2004-01-01

    The 5'AMP-activated protein kinase (AMPK) is a potential antidiabetic drug target. Here we show that the pharmacological activation of AMPK by 5-aminoimidazole-1-beta-4-carboxamide ribofuranoside (AICAR) leads to inactivation of glycogen synthase (GS) and phosphorylation of GS at Ser 7 (site 2). ...

  12. Photoinduced Intramolecular Tryptophan Oxidation and Excited-State Behavior of [Re(L-AA)(CO)3(r-diimine)] þ (L = Pyridine or Imidazole, AA = Tryptophan, Tyrosine, Phenylalanine)

    Czech Academy of Sciences Publication Activity Database

    Blanco-Rodríguez, A. M.; Towrie, M.; Sýkora, Jan; Záliš, Stanislav; Vlček, Antonín

    2011-01-01

    Roč. 50, č. 13 (2011), s. 6122-6134 ISSN 0020-1669 R&D Projects: GA MŠk(CZ) LD11082 Institutional research plan: CEZ:AV0Z40400503 Keywords : tryptophan * tyrosine * phenylalanine Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.601, year: 2011

  13. Photolysis of carotenoids in chloroform: enhanced yields of carotenoid radical cations in the presence of a tryptophan ester

    International Nuclear Information System (INIS)

    El-Agamey, Ali; Burke, Marc; Edge, Ruth; Land, Edward J.; McGarvey, David J.; Truscott, T. George

    2005-01-01

    The presence of an acetyl tryptophan ester gives rise to enhanced yields of carotenoid radical cations in chloroform following 355 nm laser excitation of the carotenoid, even though the tryptophan does not absorb at this wavelength. The increase is attributed to positive charge transfer from semi-oxidized tryptophan itself generated by light absorbed by the carotenoid. The mechanism of these radical processes has been elucidated by pulse radiolysis studies

  14. Tryptophan pathway alterations in the postpartum period and in acute postpartum psychosis and depression.

    Science.gov (United States)

    Veen, Cato; Myint, Aye Mu; Burgerhout, Karin M; Schwarz, Markus J; Schütze, Gregor; Kushner, Steven A; Hoogendijk, Witte J; Drexhage, Hemmo A; Bergink, Veerle

    2016-01-01

    Women are at very high risk for the first onset of acute and severe mood disorders the first weeks after delivery. Tryptophan breakdown is increased as a physiological phenomenon of the postpartum period and might lead to vulnerability for affective psychosis (PP) and severe depression (PD). The aim of the current study was to investigate alterations in tryptophan breakdown in the physiological postpartum period compared to patients with severe postpartum mood disorders. We included 52 patients (29 with PP, 23 with PD), 52 matched healthy postpartum women and 29 healthy non-postpartum women. Analyzes of serum tryptophan metabolites were performed using LC-MS/MS system for tryptophan, kynurenine, 3-hydroxykynurenine, kynurenic acid and 5-hydroxyindoleacetic acid. The first two months of the physiological postpartum period were characterized by low tryptophan levels, increased breakdown towards kynurenine and a downstream shift toward the 3-OH-kynurenine arm, away from the kynurenic acid arm. Kynurenine was significantly lower in patients with PP and PD as compared to healthy postpartum women (p=0.011 and p=0.001); the remaining tryptophan metabolites demonstrated few differences between patients and healthy postpartum women. Low prevalence of the investigated disorders and strict exclusion criteria to obtain homogenous groups, resulted in relatively small sample sizes. The high kynurenine levels and increased tryptophan breakdown as a phenomenon of the physiological postpartum period was not present in patients with severe postpartum mood disorders. No differences were observed in the levels of the 'neurotoxic' 3-OH-kynurenine and the 'neuroprotective' kynurenic acid arms between patients and healthy postpartum women. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. From tryptophan to hydroxytryptophan: reflections on a busy life.

    Science.gov (United States)

    Fisher, Hans

    2009-01-01

    Given the very difficult odyssey of my early years, who could have imagined the incredible and successful journey that constituted my life path after age 13? I was born into a Jewish family in Breslau, Germany, right before the rise of Nazism and Hitler's election. After Kristallnacht, when my father was taken to Buchenwald Concentration Camp, we had to leave Germany as soon as possible. The first opportunity came in May of 1939, when we boarded the SS St. Louis bound for Havana, Cuba. Almost all passengers were denied entrance into Cuba, and the ship had to go back to Europe, where I ended up in France. In December of 1939, during World War II, I was fortunate to be able to leave France. This time I made it to Cuba, where my father was already in residence. A year later, my entire family was allowed into the United States. I took advantage of all the educational resources in this land of opportunity. I graduated valedictorian of my high school class and earned a four-year scholarship to Rutgers University, where I obtained a Bachelor of Science degree. I went on to earn a Master's degree from the University of Connecticut and finally a PhD from the University of Illinois. Within two months after graduating from Illinois, I was hired as an assistant professor of nutritional biochemistry at Rutgers, where I enjoyed a most productive research and teaching career. My PhD research involved tryptophan and niacin metabolism in the chick, and upon arrival at Rutgers I continued amino acid studies with the goal of assessing the essential amino acid requirements for egg production. This research was crowned with success and was followed with amino acid requirement studies for maintenance and for growth in rabbits, and ultimately with a reevaluation of requirements in adult humans. An outgrowth of the maintenance requirements led to a series of investigations into the metabolism of histidine, histamine, and carnosine (a histidine-containing dipeptide). Histamine, we found

  16. Restoration of tryptophan hydroxylase functions and serotonin content in the Atlantic croaker hypothalamus by antioxidant treatment during hypoxic stress

    Directory of Open Access Journals (Sweden)

    Md. Saydur Rahman

    2014-05-01

    Full Text Available Antioxidants are prototypical scavengers of oxygen-free radicals and have been shown to prevent neuroendocrine dysfunction in vertebrates during oxidative stress. In the present study, we investigated whether antioxidant treatment can reverse hypoxia-induced down-regulation of hypothalamic tryptophan hydroxylase (TPH and serotonergic functions in Atlantic croaker. Hypothalamic neuronal contents of TPH-1 and TPH-2 proteins, serotonin (5-hydroxytryptamine, 5-HT and its precursor, 5-hydroxytryptophan (5-HTP as well as hypothalamic TPH-1 and TPH-2 mRNA expression and TPH activity were measured in croaker after exposure to hypoxia and treatment with pharmacological agents. Multiple injections of N-ethylmaleimide, a sulfhydryl alkylating agent, caused comparable decreases in hypothalamic TPHs functions and 5-HT contents to that induced by hypoxia exposure (dissolved oxygen: 1.7 mg/L for 4 weeks which were partially restored by repeated injections with a nitric oxide synthase (NOS-inhibitor and/or vitamin E. Double-labeled immunohistochemical results showed that TPHs and 5-HT neurons were co-expressed with neuronal NOS (nNOS, a neuroenzyme that catalyzes the production of nitric oxide, a free radical, in hypothalamic neurons. These results suggest that hypoxia-induced impairment of TPH and serotonergic functions are mediated by nNOS and involve the generation of free radicals and a decrease in the antioxidant status. This study provides, to our knowledge, the first evidence of a protective role for an antioxidant in maintaining neural TPHs functions and 5-HT regulation in an aquatic vertebrate during hypoxic stress.

  17. Plasma Tryptophan and the Kynurenine–Tryptophan Ratio Are Associated with the Acquisition of Statural Growth Deficits and Oral Vaccine Underperformance in Populations with Environmental Enteropathy

    Science.gov (United States)

    Kosek, Margaret N.; Mduma, Estomih; Kosek, Peter S.; Lee, Gwenyth O.; Svensen, Erling; Pan, William K. Y.; Olortegui, Maribel Paredes; Bream, Jay H.; Patil, Crystal; Asayag, Cesar Ramal; Sanchez, Graciela Meza; Caulfield, Laura E.; Gratz, Jean; Yori, Pablo Peñataro

    2016-01-01

    Early childhood enteric infections have adverse impacts on child growth and can inhibit normal mucosal responses to oral vaccines, two critical components of environmental enteropathy. To evaluate the role of indoleamine 2,3-dioxygenase 1 (IDO1) activity and its relationship with these outcomes, we measured tryptophan and the kynurenine–tryptophan ratio (KTR) in two longitudinal birth cohorts with a high prevalence of stunting. Children in rural Peru and Tanzania (N = 494) contributed 1,251 plasma samples at 3, 7, 15, and 24 months of age and monthly anthropometrics from 0 to 36 months of age. Tryptophan concentrations were directly associated with linear growth from 1 to 8 months after biomarker assessment. A 1-SD increase in tryptophan concentration was associated with a gain in length-for-age Z-score (LAZ) of 0.17 over the next 6 months in Peru (95% confidence interval [CI] = 0.11–0.23, P < 0.001) and a gain in LAZ of 0.13 Z-scores in Tanzania (95% CI = 0.03–0.22, P = 0.009). Vaccine responsiveness data were available for Peru only. An increase in kynurenine by 1 μM was associated with a 1.63 (95% CI = 1.13–2.34) increase in the odds of failure to poliovirus type 1, but there was no association with tetanus vaccine response. A KTR of 52 was 76% sensitive and 50% specific in predicting failure of response to serotype 1 of the oral polio vaccine. KTR was associated with systemic markers of inflammation, but also interleukin-10, supporting the association between IDO1 activity and immunotolerance. These results strongly suggest that the activity of IDO1 is implicated in the pathophysiology of environmental enteropathy, and demonstrates the utility of tryptophan and kynurenine as biomarkers for this syndrome, particularly in identifying those at risk for hyporesponsivity to oral vaccines. PMID:27503512

  18. Levered and unlevered Beta

    OpenAIRE

    Fernandez, Pablo

    2003-01-01

    We prove that in a world without leverage cost the relationship between the levered beta ( L) and the unlevered beta ( u) is the No-costs-of-leverage formula: L = u + ( u - d) D (1 - T) / E. We also analyze 6 alternative valuation theories proposed in the literature to estimate the relationship between the levered beta and the unlevered beta (Harris and Pringle (1985), Modigliani and Miller (1963), Damodaran (1994), Myers (1974), Miles and Ezzell (1980), and practitioners) and prove that all ...

  19. Beta Thalassemia (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Beta Thalassemia KidsHealth / For Parents / Beta Thalassemia What's in this ... Symptoms Diagnosis Treatment Print en español Beta talasemia Thalassemias Thalassemias are a group of blood disorders that ...

  20. Plasma L-tryptophan concentration in major depressive disorder: new data and meta-analysis.

    Science.gov (United States)

    Ogawa, Shintaro; Fujii, Takashi; Koga, Norie; Hori, Hiroaki; Teraishi, Toshiya; Hattori, Kotaro; Noda, Takamasa; Higuchi, Teruhiko; Motohashi, Nobutaka; Kunugi, Hiroshi

    2014-09-01

    Tryptophan, an essential amino acid, is the precursor to serotonin and is metabolized mainly by the kynurenine pathway. Both serotonin and kynurenine have been implicated in the pathophysiology of major depressive disorder (MDD). However, plasma tryptophan concentration in patients with MDD has not unequivocally been reported to be decreased, which prompted us to perform a meta-analysis on previous studies and our own data. We searched the PubMed database for case-control studies published until August 31, 2013, using the search terms plasma AND tryptophan AND synonyms for MDD. An additional search was performed for the term amino acid instead of tryptophan. We obtained our own data in 66 patients with MDD (DSM-IV) and 82 controls who were recruited from March 2011 to July 2012. The majority of the patients were medicated (N = 53). Total plasma tryptophan concentrations were measured by the liquid chromatography/mass spectrometry method. We scrutinized 160 studies for eligibility. Original articles that were written in English and documented plasma tryptophan values in patients and controls were selected. We included 24 studies from the literature and our own data in the meta-analysis, which involved a total of 744 patients and 793 controls. Data on unmedicated patients (N = 156) and their comparison subjects (N = 203) were also extracted. To see the possible correlation between tryptophan concentrations and depression severity, meta-regression analysis was performed for 10 studies with the Hamilton Depression Rating Scale 17-item version score. In our case-control study, mean (SD) plasma tryptophan level was significantly decreased in the MDD patients versus the controls (53.9 [10.9] vs 57.2 [11.3] μmol/L; P = .03). The meta-analysis after adjusting for publication bias showed a significant decrease in patients with MDD with a modest effect size (Hedges g, -0.45). However, analysis on unmedicated subjects yielded a large effect (Hedges g, -0.84; P = .00015). We

  1. Lignans from Carthamus tinctorius suppress tryptophan breakdown via indoleamine 2,3-dioxygenase

    Science.gov (United States)

    Kuehnl, Susanne; Schroecksnadel, Sebastian; Temml, Veronika; Gostner, Johanna M.; Schennach, Harald; Schuster, Daniela; Schwaiger, Stefan; Rollinger, Judith M.; Fuchs, Dietmar; Stuppner, Hermann

    2013-01-01

    Seed extracts of Carthamus tinctorius L. (Asteraceae), safflower, have been traditionally used to treat coronary disease, thrombotic disorders, and menstrual problems but also against cancer and depression. A possible effect of C. tinctorius compounds on tryptophan-degrading activity of enzyme indoleamine 2,3-dioxygenase (IDO) could explain many of its activities. To test for an effect of C. tinctorius extracts and isolated compounds on cytokine-induced IDO activity in immunocompetent cells in vitro methanol and ethylacetate seed extracts were prepared from cold pressed seed cakes of C. tinctorius and three lignan derivatives, trachelogenin, arctigenin and matairesinol were isolated. The influence on tryptophan breakdown was investigated in peripheral blood mononuclear cells (PBMCs). Effects were compared to neopterin production in the same cellular assay. Both seed extracts suppressed tryptophan breakdown in stimulated PBMC. The three structurally closely related isolates exerted differing suppressive activity on PBMC: arctigenin (IC50 26.5 μM) and trachelogenin (IC50 of 57.4 μM) showed higher activity than matairesinol (IC50 >200 μM) to inhibit tryptophan breakdown. Effects on neopterin production were similar albeit generally less strong. Data show an immunosuppressive property of compounds which slows down IDO activity. The in vitro results support the view that some of the anti-inflammatory, anti-cancer and antidepressant properties of C. tinctorius lignans might relate to their suppressive influence on tryptophan breakdown. PMID:23867649

  2. Severe Tryptophan Starvation Blocks Onset of Conventional Persistence and Reduces Reactivation of Chlamydia trachomatis▿

    Science.gov (United States)

    Leonhardt, Ralf M.; Lee, Seung-Joon; Kavathas, Paula B.; Cresswell, Peter

    2007-01-01

    The intracellular survival of the bacterial pathogen Chlamydia trachomatis depends on protein synthesis by the microbe soon after internalization. Pharmacologic inhibition of bacterial translation inhibits early trafficking of the parasitophorous vacuole (inclusion) to the microtubule-organizing center (MTOC) and promotes its fusion with lysosomes, which is normally blocked by Chlamydia. Depletion of cellular tryptophan pools by gamma interferon-inducible indoleamine-2,3-dioxygenase (IDO) is believed to be the major innate immune mechanism controlling C. trachomatis infection in human cells, an action to which the bacteria can respond by converting into a nonreplicating but highly reactivatable persistent state. However, whether severe IDO-mediated tryptophan starvation can be sufficient to fully arrest the chlamydial life cycle and thereby counteract the onset of persistence is unknown. Here we demonstrate that at low exogenous tryptophan concentrations a substantial fraction of C. trachomatis bacteria fail to traffic to the MTOC or to switch into the conventional persistent state in gamma interferon-induced human cells. The organisms stay scattered in the cell periphery, do not retain infectivity, and display only low transcriptional activity. Importantly, the rate at which these aberrant Chlamydia bacteria become reactivated upon replenishment of cellular tryptophan pools is substantially lower. Thus, severe tryptophan depletion in cells with high IDO activity affects chlamydial development more rigorously than previously described. PMID:17724071

  3. Tuning electronic transport via hepta-alanine peptides junction by tryptophan doping.

    Science.gov (United States)

    Guo, Cunlan; Yu, Xi; Refaely-Abramson, Sivan; Sepunaru, Lior; Bendikov, Tatyana; Pecht, Israel; Kronik, Leeor; Vilan, Ayelet; Sheves, Mordechai; Cahen, David

    2016-09-27

    Charge migration for electron transfer via the polypeptide matrix of proteins is a key process in biological energy conversion and signaling systems. It is sensitive to the sequence of amino acids composing the protein and, therefore, offers a tool for chemical control of charge transport across biomaterial-based devices. We designed a series of linear oligoalanine peptides with a single tryptophan substitution that acts as a "dopant," introducing an energy level closer to the electrodes' Fermi level than that of the alanine homopeptide. We investigated the solid-state electron transport (ETp) across a self-assembled monolayer of these peptides between gold contacts. The single tryptophan "doping" markedly increased the conductance of the peptide chain, especially when its location in the sequence is close to the electrodes. Combining inelastic tunneling spectroscopy, UV photoelectron spectroscopy, electronic structure calculations by advanced density-functional theory, and dc current-voltage analysis, the role of tryptophan in ETp is rationalized by charge tunneling across a heterogeneous energy barrier, via electronic states of alanine and tryptophan, and by relatively efficient direct coupling of tryptophan to a Au electrode. These results reveal a controlled way of modulating the electrical properties of molecular junctions by tailor-made "building block" peptides.

  4. The effect of acute tryptophan depletion on mood and impulsivity in polydrug ecstasy users.

    Science.gov (United States)

    Young, Simon N; Regoli, Martine; Leyton, Marco; Pihl, Robert O; Benkelfat, Chawki

    2014-02-01

    Several studies suggest users of 3,4-methylenedioxymethamphetamine (ecstasy) have low levels of serotonin. Low serotonin may make them susceptible to lowered mood. This work aims to study the acute effects on mood and impulsivity of lowering serotonin levels with acute tryptophan depletion in polydrug ecstasy users and to determine whether effects were different in men and women. In a double-blind cross-over study, participants who had used ecstasy at least 25 times (n = 13) and nonuser controls (n = 17) received a tryptophan-deficient amino acid mixture and a control amino acid mixture containing tryptophan, at least 1 week apart. Mood was measured using the profile of mood states, and impulsivity was measured with the Go/No-Go task. The main result shows that a lowering of mood after acute tryptophan depletion occurred only in female polydrug ecstasy users (n = 7), relative to controls (n = 9). Results from the Go/No-Go task suggested that impulsivity was not increased by acute tryptophan depletion in polydrug ecstasy users. The group sizes were small, when males and females were considered separately. Women polydrug ecstasy users appear to be more susceptible than men to the effects of lowered serotonin levels. If use of ecstasy alone or in conjunction with other drugs causes progressive damage of serotonin neurons, women polydrug ecstasy users may become susceptible to clinical depression.

  5. Characterization of f-actin tryptophan phosphorescence in the presence and absence of tryptophan-free myosin motor domain.

    Science.gov (United States)

    Bódis, Emöke; Strambini, Giovanni B; Gonnelli, Margherita; Málnási-Csizmadia, András; Somogyi, Béla

    2004-08-01

    The effect of binding the Trp-free motor domain mutant of Dictyostelium discoideum, rabbit skeletal muscle myosin S1, and tropomyosin on the dynamics and conformation of actin filaments was characterized by an analysis of steady-state tryptophan phosphorescence spectra and phosphorescence decay kinetics over a temperature range of 140-293 K. The binding of the Trp-free motor domain mutant of D. discoideum to actin caused red shifts in the phosphorescence spectrum of two internal Trp residues of actin and affected the intrinsic lifetime of each emitter, decreasing by roughly twofold the short phosphorescence lifetime components (tau(1) and tau(2)) and increasing by approximately 20% the longest component (tau(3)). The alteration of actin phosphorescence by the motor protein suggests that i), structural changes occur deep down in the core of actin and that ii), subtle changes in conformation appear also on the surface but in regions distant from the motor domain binding site. When actin formed complexes with skeletal S1, an extra phosphorescence lifetime component appeared (tau(4), twice as long as tau(3)) in the phosphorescence decay that is absent in the isolated proteins. The lack of this extra component in the analogous actin-Trp-free motor domain mutant of D. discoideum complex suggests that it should be assigned to Trps in S1 that in the complex attain a more compact local structure. Our data indicated that the binding of tropomyosin to actin filaments had no effect on the structure or flexibility of actin observable by this technique.

  6. Forward-Looking Betas

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

    Few issues are more important for finance practice than the computation of market betas. Existing approaches compute market betas using historical data. While these approaches differ in terms of statistical sophistication and the modeling of the time-variation in the betas, they are all backward......-looking. This paper introduces a radically different approach to estimating market betas. Using the tools in Bakshi and Madan (2000) and Bakshi, Kapadia and Madan (2003) we employ the information embedded in the prices of individual stock options and index options to compute our forward-looking market beta...

  7. Mutational, Phylogeny and Evolution Analyses of Salvia Copalyl Diphosphate Synthase

    International Nuclear Information System (INIS)

    Hao, D. C.; Thimmappa, R. B.; Xiao, P. G.

    2016-01-01

    The cyclization of geranylgeranyl diphosphate (GGPP) is catalyzed by copalyl diphosphate synthase (CPS), a class II diterpene synthase (diTPS), to form copalyl diphosphate (CPP), which is an essential substrate of a variety of diterpenes in secondary metabolism of angiosperm including Salvia medicinal plants. The protein environment of the N-terminal class II active site stabilizes the carbocation intermediates and maintains the catalytic activity of angiosperm class II diTPS. The virtual modeling and mutagenesis of the class II diTPS of Salvia miltiorrhiza (SmCPS) were accomplished to illuminate the catalytic activity of SmCPS. Terminal truncations and point mutations established the role of the Beta-Gamma domain and Alpha domain, i.e., they facilitate the flexible conformational change of the class II active site after substrate binding. E203 and K238 in the N-ter Gamma domain of SmCPS1 are functional in the substrate binding and conformational transition and might be essential in catalysis. Similar to other CPSs, the ensuing protonation of the GGPP substrate and coordination of the diphosphate group are governed by highly conserved residues in the DxDD motif of SmCPS, e.g., D372 of CPS1. Moreover, F256 and Y505 stabilize the carbocation and control the enzymatic activity during CPP formation. The amino acids of the predicted active sites, despite under purifying selection, vary greatly, corresponding to the functional flexibility of angiosperm CPSs. Molecular phylogeny and evolution analyses suggest early and ongoing evolution of labdane-related diterpenoid metabolism in angiosperm. (author)

  8. SIRT3 deacetylates ATP synthase F1 complex proteins in response to nutrient- and exercise-induced stress.

    Science.gov (United States)

    Vassilopoulos, Athanassios; Pennington, J Daniel; Andresson, Thorkell; Rees, David M; Bosley, Allen D; Fearnley, Ian M; Ham, Amy; Flynn, Charles Robb; Hill, Salisha; Rose, Kristie Lindsey; Kim, Hyun-Seok; Deng, Chu-Xia; Walker, John E; Gius, David

    2014-08-01

    Adenosine triphosphate (ATP) synthase uses chemiosmotic energy across the inner mitochondrial membrane to convert adenosine diphosphate and orthophosphate into ATP, whereas genetic deletion of Sirt3 decreases mitochondrial ATP levels. Here, we investigate the mechanistic connection between SIRT3 and energy homeostasis. By using both in vitro and in vivo experiments, we demonstrate that ATP synthase F1 proteins alpha, beta, gamma, and Oligomycin sensitivity-conferring protein (OSCP) contain SIRT3-specific reversible acetyl-lysines that are evolutionarily conserved and bind to SIRT3. OSCP was further investigated and lysine 139 is a nutrient-sensitive SIRT3-dependent deacetylation target. Site directed mutants demonstrate that OSCP(K139) directs, at least in part, mitochondrial ATP production and mice lacking Sirt3 exhibit decreased ATP muscle levels, increased ATP synthase protein acetylation, and an exercise-induced stress-deficient phenotype. This work connects the aging and nutrient response, via SIRT3 direction of the mitochondrial acetylome, to the regulation of mitochondrial energy homeostasis under nutrient-stress conditions by deacetylating ATP synthase proteins. Our data suggest that acetylome signaling contributes to mitochondrial energy homeostasis by SIRT3-mediated deacetylation of ATP synthase proteins.

  9. Interaction between bradykinin potentiating nonapeptide (BPP9a) and {beta}-cyclodextrin: A structural and thermodynamic study

    Energy Technology Data Exchange (ETDEWEB)

    Lula, Ivana; De Sousa, Frederico B. [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901, Belo Horizonte, MG (Brazil); Denadai, Angelo M.L. [Centro Federal de Educacao Tecnologica de Minas Gerais, CEFET-MG, Campus VII, 35.183-006, Timoteo, MG (Brazil); Ferreira de Lima, Guilherme; Duarte, Helio Anderson [Departamento de Quimica, Instituto de Ciencias Exatas, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, 31270-901, Belo Horizonte, MG (Brazil); Mares Guia, Thiago R. dos [Departamento de Bioquimica e Imunologia, ICB, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG (Brazil); Faljoni-Alario, Adelaide [Departamento de Bioquimica, Instituto de Quimica, Universidade de Sao Paulo, 05508-900, Sao Paulo, SP (Brazil); Santoro, Marcelo M. [Departamento de Bioquimica e Imunologia, ICB, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG (Brazil); Camargo, Antonio C.M. de [Center for Applied Toxinology CAT-CEPID, Laboratorio Especial de Toxicologia Aplicada, Instituto Butantan, 05503-900, Sao Paulo, SP (Brazil); Santos, Robson A.S. dos [Departamento de Fisiologia e Biofisica, ICB, Universidade Federal de Minas Gerais, 31270-901, Belo Horizonte, MG (Brazil); and others

    2012-02-01

    Herein, we demonstrate the physical and chemical characterizations of the supramolecular complex formed between {beta}-cyclodextrin ({beta}CD) and bradykinin potentiating nonapeptide (BPP9a), an endogenous toxin found in Bothrops jararaca. Circular dichroism results indicate a conformational change in the BPP9a secondary structure upon its complexation with {beta}CD. Nuclear magnetic resonance results, mainly from NOESY experiments, and theoretical calculations showed a favorable interaction between the tryptophan residue of BPP9a and the {beta}CD cavity. Thermodynamic inclusion parameters were investigated by isothermal titration calorimetry, demonstrating that {beta}CD/BPP9a complex formation is an exothermic process that results in a reduction in entropy. Additionally, in vitro degradation study of BPP9a against trypsin (37 Degree-Sign C, pH 7.2) showed higher stability of peptide in presence of {beta}CD. This {beta}CD/BPP9a complex, which presents new chemical properties arising from the peptide inclusion process, may be useful as an antihypertensive drug in oral pharmaceutical formulations. Highlights: Black-Right-Pointing-Pointer Cd and NMR showed evidences for the existence of more than one structure in solution. Black-Right-Pointing-Pointer Complexation with {beta}CD reduces the conformational rigidity of the peptide. Black-Right-Pointing-Pointer {beta}CD cavity recognize Trp and/or Pro segments of BPP9a. Black-Right-Pointing-Pointer Interactions involving disaggregation of BPP9a assemblies and binding with {beta}CD.

  10. Regulation of galactan synthase expression to modify galactan content in plants

    Science.gov (United States)

    None

    2017-08-22

    The disclosure provides methods of engineering plants to modulate galactan content. Specifically, the disclosure provides methods for engineering a plant to increase the galactan content in a plant tissue by inducing expression of beta-1,4-galactan synthase (GALS), modulated by a heterologous promoter. Further disclosed are the methods of modulating expression level of GALS under the regulation of a transcription factor, as well as overexpression of UDP-galactose epimerse in the same plant tissue. Tissue specific promoters and transcription factors can be used in the methods are also provided.

  11. Effects of environmental lighting and tryptophan devoid diet on the rat vaginal cycle.

    Science.gov (United States)

    Giammanco, S; Ernandes, M; La Guardia, M

    1997-09-01

    Cerebral serotonin level influences luteinizing hormone release and, consequently, ovulation. The present study evaluated the effects of precooked maize meal (polenta), a diet almost devoid of tryptophan the serotonin precursor on the alterations of the estrus cycle as measured by vaginal smears analysis in Wistar rats. Several conditions of environmental lighting were used in order to modify ovarian cycle: 1) natural alternating light/dark cycle; 2) continuous darkness; 3) continuous light by sodium steams: 4) continuous light by fluorescent neon tubes. Rats bred in continuous lighting showed estrus-proestrus rate significantly greater than rats bred in normal lighting or in continuous darkness. The feeding with precooked maize meal suppressed persistent estrus in rats bred in continuous lighting, and significantly cut down the estrus-proestrus frequency in any condition of environmental lighting. Our results lead to hypothesize that polenta diet, for its low tryptophan content, cutting down both tryptophan plasma content and serotonin neuronal synthesis, promotes luteinizing hormone peak.

  12. Dosimetry of D- and L-enantiomers of 11C-labeled tryptophan and valine

    International Nuclear Information System (INIS)

    Washburn, L.C.; Byrd, B.L.; Sun, T.T.; Crook, J.E.; Hubner, K.F.; Coffey, J.L.; Watson, E.E.

    1985-01-01

    We have previously reported the radiation dosimetry of 11 C-labeled DL-tryptophan and DL-valine, as well as clinical pancreatic imaging studies with these agents. Because of significant uptake in both normal pancreas and in pancreatic tumors (thought to be due to the presence of the D-enantiomer), differential diagnosis of pancreatic carcinoma was not feasible. High-performance liquid chromatographic (HPLC) methods were developed for rapid resolution of 11 C-labeled DL-tryptophan and DL-valine. Radiation dose estimates to the various organs in man were calculated for the D- and L-enantiomers of 11 C-labeled tryptophan and valine, based on tissue distribution data in rats. The dose estimates were sufficiently low that 20-mCi doses of each of the enantiomeric amino acids were approved by the FDA for intravenous administration to humans. 21 refs., 3 tabs

  13. Dosimetry of D- and L-enantiomers of 11C-labeled tryptophan and valine

    International Nuclear Information System (INIS)

    Washburn, L.C.; Byrd, B.L.; Sun, T.T.; Crook, J.E.; Hubner, K.F.; Coffey, J.L.; Watson, E.E.

    1986-01-01

    The authors have previously reported the radiation dosimetry of 11 C-labeled DL-tryptophan and DL-valine, as well as clinical pancreatic imaging studies with these agents. Because of significant uptake in both normal pancreas and in pancreatic tumors (thought to be due to the presence of the D-enantiomer), differential diagnosis of pancreatic carcinoma was not feasible. High-performance liquid chromatographic (HPLC) methods were developed for rapid resolution of 11 C-labeled DL-tryptophan and DL-valine. Radiation dose estimates to the various organs in man were calculated for the D- and L-enantiomers of 11 C-labeled tryptophan and valine, based on tissue distribution data in rats. The dose estimates were sufficiently low that 20-mCi doses of each of the enantiomeric amino acids were approved by the FDA for intravenous administration to humans. 21 references, 3 tables

  14. Synthesis of no-carrier-added alpha-[11C]methyl-L-tryptophan

    International Nuclear Information System (INIS)

    Chaly, T.; Diksic, M.

    1988-01-01

    Described here is a synthesis of no-carrier-added alpha-[ 11 C]methyl-L-tryptophan based on alkylation with 11 CH 3 I of an anion generated by reacting the Schiff base of L-tryptophan methyl ester with di-isopropylamine. The synthesis requires approximately 30 min after the end of 11 CO 2 collection and gives alpha-[ 11 C]methyl-L-tryptophan in a 20-25% radiochemical yield calculated at the end of the synthesis and without correction for radioactive decay. The specific activity of the final radiopharmaceutical, measured at the end of the synthesis, was around 2000 Ci/mmol. Data confirming the stereospecificity of the synthesis are also presented

  15. GPR142 Controls Tryptophan-Induced Insulin and Incretin Hormone Secretion to Improve Glucose Metabolism.

    Directory of Open Access Journals (Sweden)

    Hua V Lin

    Full Text Available GPR142, a putative amino acid receptor, is expressed in pancreatic islets and the gastrointestinal tract, but the ligand affinity and physiological role of this receptor remain obscure. In this study, we show that in addition to L-Tryptophan, GPR142 signaling is also activated by L-Phenylalanine but not by other naturally occurring amino acids. Furthermore, we show that Tryptophan and a synthetic GPR142 agonist increase insulin and incretin hormones and improve glucose disposal in mice in a GPR142-dependent manner. In contrast, Phenylalanine improves in vivo glucose disposal independently of GPR142. Noteworthy, refeeding-induced elevations in insulin and glucose-dependent insulinotropic polypeptide are blunted in Gpr142 null mice. In conclusion, these findings demonstrate GPR142 is a Tryptophan receptor critically required for insulin and incretin hormone regulation and suggest GPR142 agonists may be effective therapies that leverage amino acid sensing pathways for the treatment of type 2 diabetes.

  16. Tryptophan metabolism in tsetse flies and the consequences of its derangement

    Directory of Open Access Journals (Sweden)

    R. H. Gooding

    1987-01-01

    Full Text Available Literature comparing salmon and wild type Glossina morsitans morsitans and that comparing tan and wild type Glossina palpalis palpalis is reviewed. New information is presented on behaviour and biochemistry of salmon and wild type G. m. morsitans. The eye color mutants result from two lesions in the tryptophan to xanthommatin pathway: lack of tryptophan oxygenase in G. m morsitans and failure to produce or retain xanthommatin in eyes (but not in testes of G. p. palpalis. The salmon allele in G. m. morsitans is pleiotropic and profoundly affects many aspects of fly biology including longevity, reproductive capacity, vision, vectorial capacity and duration of flight, but not circadian rhythms. The tan allele in G. p. palpalis has little effect upon the biology of flies under laboratory conditions, except that tan flies appear less active than normal. Adult tsetse flies metabolize tryptophan to kynurenine which is excreted; fluctuations in activities of the enzymes producing kynurenine suggest this pathway is under metabolic control.

  17. IL4I1 Is a Novel Regulator of M2 Macrophage Polarization That Can Inhibit T Cell Activation via L-Tryptophan and Arginine Depletion and IL-10 Production.

    Directory of Open Access Journals (Sweden)

    Yinpu Yue

    Full Text Available Interleukin 4-induced gene-1 (IL4I1 was initially described as an early IL-4-inducible gene in B cells. IL4I1 protein can inhibit T cell proliferation by releasing its enzymatic catabolite, H2O2, and this effect is associated with transient down-regulation of T cell CD3 receptor-zeta (TCRζ expression. Herein, we show that IL4I1 contributes to the regulation of macrophage programming. We found that expression of IL4I1 increased during bone marrow-derived macrophage (BMDM differentiation, expression of IL4I1 is much higher in primary macrophages than monocytes, and IL4I1 expression in BMDMs could be induced by Th1 and Th2 cytokines in two different patterns. Gene expression analysis revealed that overexpression of IL4I1 drove the expression of M2 markers (Fizz1, Arg1, YM-1, MR and inhibited the expression of M1-associated cytokines. Conversely, knockdown of IL4I1 by siRNA resulted in opposite effects, and also attenuated STAT-3 and STAT-6 phosphorylation. Furthermore, IL4I1 produced by macrophages catalyzed L-tryptophan degradation, while levo-1-methyl-tryptophan (L-1-MT, but not dextro-1-methyl-tryptophan, partially rescued IL4I1-dependent inhibition of T cell activation. Other inhibitors, such as diphenylene iodonium (DPI, an anti-IL-10Rα blocking antibody, and a nitric oxide synthase inhibitor, NG-monomethyl-L-arginine, also had this effect. Overall, our findings indicate that IL4I1 promotes an enhanced M2 functional phenotype, which is most likely associated with the phosphorylation of STAT-6 and STAT-3. Moreover, DPI, L-1-MT, NG-monomethyl-L-arginine, and anti-IL-10Rα blocking antibody were all found to be effective IL4I1 inhibitors in vitro.

  18. Bacillus caldolyticus prs gene encoding phosphoribosyldiphosphate synthase

    DEFF Research Database (Denmark)

    Krath, Britta N.; Hove-Jensen, Bjarne

    1996-01-01

    The prs gene, encoding phosphoribosyl-diphosphate (PRPP) synthase, as well as the flanking DNA sequences were cloned and sequenced from the Gram-positive thermophile, Bacillus caldolyticus. Comparison with the homologous sequences from the mesophile, Bacillus subtilis, revealed a gene (gca......D) encoding N-acetylglucosamine-l-phosphate uridyltransferase upstream of prs, and a gene homologous to ctc downstream of prs. cDNA synthesis with a B. caldolyticus gcaD-prs-ctc-specified mRNA as template, followed by amplification utilising the polymerase chain reaction indicated that the three genes are co......-transcribed. Comparison of amino acid sequences revealed a high similarity among PRPP synthases across a wide phylogenetic range. An E. coli strain harbouring the B. caldolyticus prs gene in a multicopy plasmid produced PRPP synthase activity 33-fold over the activity of a haploid B. caldolyticus strain. B. caldolyticus...

  19. Pigment Production on L-Tryptophan Medium by Cryptococcus gattii and Cryptococcus neoformans

    Science.gov (United States)

    Chaskes, Stuart; Cammer, Michael; Nieves, Edward; Casadevall, Arturo

    2014-01-01

    In recent years strains previously grouped within Cryptococcus neoformans have been divided into two species C. neoformans and C. gattii, with Cryptococcus neoformans comprising serotypes A, D, and AD and C. gattii comprising serotypes B and C. Cryptococcus neoformans have also been subdivided into two varieties C. neoformans var. grubii, serotype A, and C. neoformans var. neoformans, serotype D. We analyzed the growth and pigment production characteristics of 139 strains of Cryptococcus spp. in L-tryptophan containing media. Nearly all strains of Cryptococcus, including each variety and serotype tested produced a pink water-soluble pigment (molecular weight of 535.2 Da) from L-tryptophan. Consequently, the partial separation of the species was based on whether the pink pigment was secreted into the medium (extracellular) or retained as an intracellular pigment. On L-tryptophan medium C. neoformans var. grubii and serotype AD produced a pink extracellular pigment. In contrast, for C. gattii, the pink pigment was localized intracellularly and masked by heavy production of brown pigments. Pigment production by C. neoformans var. neoformans was variable with some strains producing the pink extracellular pigment and others retained the pink pigment intracellularly. The pink intracellular pigment produced by strains of C. neoformans var. neoformans was masked by production of brown pigments. Cryptococcus laccase mutants failed to produce pigments from L-tryptophan. This is the first report that the enzyme laccase is involved in tryptophan metabolism. Prior to this report Cryptococcus laccase produced melanin or melanin like-pigments from heterocyclic compounds that contained ortho or para diphenols, diaminobenzenes and aminophenol compounds. The pigments produced from L-tryptophan were not melanin. PMID:24736553

  20. Pigment production on L-tryptophan medium by Cryptococcus gattii and Cryptococcus neoformans.

    Science.gov (United States)

    Chaskes, Stuart; Cammer, Michael; Nieves, Edward; Casadevall, Arturo

    2014-01-01

    In recent years strains previously grouped within Cryptococcus neoformans have been divided into two species C. neoformans and C. gattii, with Cryptococcus neoformans comprising serotypes A, D, and AD and C. gattii comprising serotypes B and C. Cryptococcus neoformans have also been subdivided into two varieties C. neoformans var. grubii, serotype A, and C. neoformans var. neoformans, serotype D. We analyzed the growth and pigment production characteristics of 139 strains of Cryptococcus spp. in L-tryptophan containing media. Nearly all strains of Cryptococcus, including each variety and serotype tested produced a pink water-soluble pigment (molecular weight of 535.2 Da) from L-tryptophan. Consequently, the partial separation of the species was based on whether the pink pigment was secreted into the medium (extracellular) or retained as an intracellular pigment. On L-tryptophan medium C. neoformans var. grubii and serotype AD produced a pink extracellular pigment. In contrast, for C. gattii, the pink pigment was localized intracellularly and masked by heavy production of brown pigments. Pigment production by C. neoformans var. neoformans was variable with some strains producing the pink extracellular pigment and others retained the pink pigment intracellularly. The pink intracellular pigment produced by strains of C. neoformans var. neoformans was masked by production of brown pigments. Cryptococcus laccase mutants failed to produce pigments from L-tryptophan. This is the first report that the enzyme laccase is involved in tryptophan metabolism. Prior to this report Cryptococcus laccase produced melanin or melanin like-pigments from heterocyclic compounds that contained ortho or para diphenols, diaminobenzenes and aminophenol compounds. The pigments produced from L-tryptophan were not melanin.

  1. Pigment production on L-tryptophan medium by Cryptococcus gattii and Cryptococcus neoformans.

    Directory of Open Access Journals (Sweden)

    Stuart Chaskes

    Full Text Available In recent years strains previously grouped within Cryptococcus neoformans have been divided into two species C. neoformans and C. gattii, with Cryptococcus neoformans comprising serotypes A, D, and AD and C. gattii comprising serotypes B and C. Cryptococcus neoformans have also been subdivided into two varieties C. neoformans var. grubii, serotype A, and C. neoformans var. neoformans, serotype D. We analyzed the growth and pigment production characteristics of 139 strains of Cryptococcus spp. in L-tryptophan containing media. Nearly all strains of Cryptococcus, including each variety and serotype tested produced a pink water-soluble pigment (molecular weight of 535.2 Da from L-tryptophan. Consequently, the partial separation of the species was based on whether the pink pigment was secreted into the medium (extracellular or retained as an intracellular pigment. On L-tryptophan medium C. neoformans var. grubii and serotype AD produced a pink extracellular pigment. In contrast, for C. gattii, the pink pigment was localized intracellularly and masked by heavy production of brown pigments. Pigment production by C. neoformans var. neoformans was variable with some strains producing the pink extracellular pigment and others retained the pink pigment intracellularly. The pink intracellular pigment produced by strains of C. neoformans var. neoformans was masked by production of brown pigments. Cryptococcus laccase mutants failed to produce pigments from L-tryptophan. This is the first report that the enzyme laccase is involved in tryptophan metabolism. Prior to this report Cryptococcus laccase produced melanin or melanin like-pigments from heterocyclic compounds that contained ortho or para diphenols, diaminobenzenes and aminophenol compounds. The pigments produced from L-tryptophan were not melanin.

  2. The pharmacokinetics of L-tryptophan following its intravenous and oral administration.

    OpenAIRE

    Green, A R; Aronson, J K; Cowen, P J

    1985-01-01

    The pharmacokinetics of L-tryptophan (5 g and 7.5 g) have been studied after its intravenous administration to healthy subjects and the results compared with those obtained after oral administration (0.7 g-3.5 g). In order to do this, we have re-analysed previously published data relating to oral administration. The data obtained following the oral administration of L-tryptophan suggest that the total body clearance and apparent volume of distribution are saturable. The pharmacokinetics of tr...

  3. Don't panic. A guide to tryptophan depletion with disorder-specific anxiety provocation.

    Science.gov (United States)

    Hood, S D; Bell, C J; Argyropoulos, S V; Nutt, D J

    2016-11-01

    The 2002 paper "Does 5-HT restrain panic? A tryptophan depletion study in panic disorder patients recovered on paroxetine" by Bell and colleagues - reprinted in this issue of the Journal - reports on a study undertaken in the halcyon days of David Nutt's Psychopharmacology Unit at the University of Bristol, England. In this invited commentary authors of the original work discuss the impact of this paper on the field of acute tryptophan depletion research (especially in the field of clinical anxiety disorders) and the development of disorder-specific anxiogenic provocations over the past decade. © The Author(s) 2016.

  4. Twenty-four-hour plasma tryptophan concentrations and ratios are below normal in obese subjects and are not normalized by substantial weight reduction

    DEFF Research Database (Denmark)

    Breum, Leif; Rasmussen, Michael H; Hilsted, Jannik

    2003-01-01

    BACKGROUND: Plasma tryptophan concentrations and the ratio of tryptophan to other large neutral amino acids (plasma tryptophan ratio) are reportedly low in obese subjects. The plasma tryptophan ratio predicts brain tryptophan uptake and serotonin production. If this ratio is low in obese subjects......, serotonin function may also be low. Plasma tryptophan concentrations and ratios have been measured only at single time points in obese subjects; it is not known whether low values for these 2 variables persist throughout a 24-h period. OBJECTIVE: Our objective was to determine whether plasma tryptophan...... concentrations and ratios in obese subjects are lower than those in normal-weight subjects throughout a 24-h period and whether they increase when body weight is reduced. DESIGN: Plasma tryptophan concentrations and ratios were examined in obese subjects before and after weight loss and in nonobese control...

  5. L-tryptophan synthesis from 14C-anthranilic acid in plants with high and low tryptophan content

    International Nuclear Information System (INIS)

    Kutacek, M.; Eder, J.; Vackova, K.; Prochazka, S.

    1978-01-01

    The biosynthesis of L-tryptophan (L-trp) from anthranilic acid- 14 C (AA- 14 C) in undamaged organs of the seedlings of kohlrabi and peas, with high L-trp content and maize plants, with low L-trp content was compared. As for maize the experiments were carried out with normal and opaque-2 phenotypes, both with the seedlings and with the ripening kernels. AA- 14 C is metabolized in the plants to L-trp pool and to glycosyl esters of AA. In maize seedlings L-trp- 14 C is synthesized relatively less than in kohlrabi and in pea. The de novo formation of L-trp- 14 C is stopped earlier in maize than in kohlrabi. The level of free L-trp- 14 C is relatively low in maize in comparison with kohlrabi and peas. In spite of this the formation of L-trp- 14 C from AA- 14 C is sufficient in maize to incorporate L-trp both into the proteins and into a secondary metabolite that is not yet defined. At the period of seedlings the incorporation in maize of L-trp into the proteins is comparable with that in kohlrabi, and it is maximum in pea. Maize, at the stage of germination, thus forms proteins rich in L-trp. The formation of free L-trp is approximately ten times lower in ripening kernels and in the leaves adjacent to the ear and it further decreases in the course of the ripening of the kernels. Although the activity of the biosynthesis of the AA- 14 C→L-trp- 14 C pathway is relatively lower in maize than in kohlrabi and peas, this pathway is most responsible for the differences in the content of L-trp in these plants. Neither amitrol nor histidine affected the biosynthesis of L-trp in kohlrabi; the interaction of the biosynthetic pathways of L-trp and histidine known in microorganisms is thus not important in a higher plant. (author)

  6. Activation of Beta-Catenin Signaling in Androgen Receptor–Negative Prostate Cancer Cells

    Science.gov (United States)

    Wan, Xinhai; Liu, Jie; Lu, Jing-Fang; Tzelepi, Vassiliki; Yang, Jun; Starbuck, Michael W.; Diao, Lixia; Wang, Jing; Efstathiou, Eleni; Vazquez, Elba S.; Troncoso, Patricia; Maity, Sankar N.; Navone, Nora M.

    2012-01-01

    Purpose To study Wnt/beta-catenin in castrate-resistant prostate cancer (CRPC) and understand its function independently of the beta-catenin–androgen receptor (AR) interaction. Experimental Design We performed beta-catenin immunocytochemical analysis, evaluated TOP-flash reporter activity (a reporter of beta-catenin–mediated transcription), and sequenced the beta-catenin gene in MDA PCa 118a, MDA PCa 118b, MDA PCa 2b, and PC-3 prostate cancer (PCa) cells. We knocked down beta-catenin in AR-negative MDA PCa 118b cells and performed comparative gene-array analysis. We also immunohistochemically analyzed beta-catenin and AR in 27 bone metastases of human CRPCs. Results Beta-catenin nuclear accumulation and TOP-flash reporter activity were high in MDA PCa 118b but not in MDA PCa 2b or PC-3 cells. MDA PCa 118a and 118b cells carry a mutated beta-catenin at codon 32 (D32G). Ten genes were expressed differently (false discovery rate, 0.05) in MDA PCa 118b cells with downregulated beta-catenin. One such gene, hyaluronan synthase 2 (HAS2), synthesizes hyaluronan, a core component of the extracellular matrix. We confirmed HAS2 upregulation in PC-3 cells transfected with D32G-mutant beta-catenin. Finally, we found nuclear localization of beta-catenin in 10 of 27 human tissue specimens; this localization was inversely associated with AR expression (P = 0.056, Fisher’s exact test), suggesting that reduced AR expression enables Wnt/beta-catenin signaling. Conclusion We identified a previously unknown downstream target of beta-catenin, HAS2, in PCa, and found that high beta-catenin nuclear localization and low or no AR expression may define a subpopulation of men with bone-metastatic PCa. These findings may guide physicians in managing these patients. PMID:22298898

  7. Preservation of the positive lusitropic effect of beta-adrenoceptors stimulation in diabetic cardiomyopathy.

    Science.gov (United States)

    Amour, Julien; Loyer, Xavier; Michelet, Pierre; Birenbaum, Aurélie; Riou, Bruno; Heymes, Christophe

    2008-10-01

    In diabetic cardiomyopathy, diastolic dysfunction results in part from sarcoplasmic reticulum abnormalities affecting both phospholamban and sarcoplasmic reticulum Ca2+ uptake (SERCA2a). Consequently, the positive lusitropic effect of beta-adrenoceptors stimulation could be altered, and beta3-adrenoceptor over-expression may play a role, as previously demonstrated with an altered positive inotropic effect. In this study, we tested the hypothesis that the beta-adrenergic positive lusitropic effect is altered in diabetic cardiomyopathy, and that beta3-adrenoceptor over-expression is involved. beta-adrenergic responses were investigated in vivo (dobutamine-echocardiography) and in vitro (papillary muscle preparation) in healthy and diabetic rats killed 4 (4W) and 12 (12W) wk after IV streptozotocin injection. The effect of beta3-adrenoceptor pathway inhibition by S-cyanopindolol (selective beta3-adrenoceptor antagonist) or by NG-nitro-L-arginine-methyl-ester (nonselective nitric oxide synthase inhibitor) on the lusitropic response to isoproterenol (nonselective beta-adrenoceptors agonist) was studied in vitro. Western blots were performed to quantify the protein expressions of beta1- and beta3-adrenoceptors, phospholamban, and SERCA2a. Data are presented as mean percentages of baseline+/-sd. Despite the increased phospholamban/SERCA2a protein ratio and documented diastolic dysfunction, the positive lusitropic effect of beta-adrenoceptors stimulation was preserved in vivo (dobutamine) and in vitro (isoproterenol) in 4W and 12W diabetic, compared with healthy, rats. The beta3-adrenoceptor was up-regulated whereas beta1-adrenoceptor was down-regulated in 4W and 12W diabetic, compared with healthy, rats. Nevertheless, S-cyanopindolol or NG-nitro-L-arginine-methyl-ester had no lusitropic effect. The positive lusitropic effect of beta-adrenoceptor stimulation was preserved in diabetic cardiomyopathy. beta3-adrenoceptor over-expression does not seem to affect this process.

  8. Ingestion of branched-chain amino acids and tryptophan during sustained exercise in man: failure to affect performance

    DEFF Research Database (Denmark)

    Van Hall, Gerrit; Raaymakers, J S; Saris, W H

    1995-01-01

    1. An increased uptake of tryptophan in the brain may increase serotoninergic activity and recently has been suggested to be a cause of fatigue during prolonged exercise. The present study, therefore, investigates whether ingestion of tryptophan or the competing branched-chain amino acids (BCAAs......) affect performance. Ten endurance-trained male athletes were studied during cycle exercise at 70-75% maximal power output, while ingesting, ad random and double-blind, drinks that contained 6% sucrose (control) or 6% sucrose supplemented with (1) tryptophan (3 g l-1), (2) a low dose of BCAA (6 g l-1...... tryptophan ingestion caused a 7- to 20-fold increase. Exercise time to exhaustion was not different between treatments (122 +/- 3 min). 3. The data suggest that manipulation of tryptophan supply to the brain either has no additional effect upon serotoninergic activity during prolonged exhaustive exercise...

  9. Betting Against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model’s five central predictions: (1) Since constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for U...... of the BAB factor is low; (4) Increased funding liquidity risk compresses betas toward one; (5) More constrained investors hold riskier assets........S. equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures; (2) A betting-against-beta (BAB) factor, which is long leveraged low beta assets and short high-beta assets, produces significant positive risk-adjusted returns; (3) When funding constraints tighten, the return...

  10. Roughing up Beta

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Li, Sophia Zhengzi; Todorov, Viktor

    -section. An investment strategy that goes long stocks with high jump betas and short stocks with low jump betas produces significant average excess returns. These higher risk premiums for the discontinuous and overnight market betas remain significant after controlling for a long list of other firm characteristics......Motivated by the implications from a stylized equilibrium pricing framework, we investigate empirically how individual equity prices respond to continuous, or \\smooth," and jumpy, or \\rough," market price moves, and how these different market price risks, or betas, are priced in the cross......-section of expected returns. Based on a novel highfrequency dataset of almost one-thousand individual stocks over two decades, we find that the two rough betas associated with intraday discontinuous and overnight returns entail significant risk premiums, while the intraday continuous beta is not priced in the cross...

  11. Murrayafoline A attenuates the Wnt/{beta}-catenin pathway by promoting the degradation of intracellular {beta}-catenin proteins

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyuk; Gwak, Jungsug; Cho, Munju; Ryu, Min-Jung [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Lee, Jee-Hyun; Kim, Sang Kyum; Kim, Young Ho [College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Lee, Gye Won [Department of Pharmaceutical Engineering, Konyang University, Nonsan 320-711 (Korea, Republic of); Yun, Mi-Young [Department of Beauty Health Care, Daejeon University, Daejeon 305-764 (Korea, Republic of); Cuong, Nguyen Manh [Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology, Hanoi (Viet Nam); Shin, Jae-Gook [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Song, Gyu-Yong, E-mail: gysong@cnu.ac.kr [College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Oh, Sangtaek, E-mail: ohsa@inje.ac.kr [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of)

    2010-01-01

    Molecular lesions in Wnt/{beta}-catenin signaling and subsequent up-regulation of {beta}-catenin response transcription (CRT) occur frequently during the development of colon cancer. To identify small molecules that suppress CRT, we screened natural compounds in a cell-based assay for detection of TOPFalsh reporter activity. Murrayafoline A, a carbazole alkaloid isolated from Glycosmis stenocarpa, antagonized CRT that was stimulated by Wnt3a-conditioned medium (Wnt3a-CM) or LiCl, an inhibitor of glycogen synthase kinase-3{beta} (GSK-3{beta}), and promoted the degradation of intracellular {beta}-catenin without altering its N-terminal phosphorylation at the Ser33/37 residues, marking it for proteasomal degradation, or the expression of Siah-1, an E3 ubiquitin ligase. Murrayafoline A repressed the expression of cyclin D1 and c-myc, which is known {beta}-catenin/T cell factor (TCF)-dependent genes and thus inhibited the proliferation of various colon cancer cells. These findings indicate that murrayafoline A may be a potential chemotherapeutic agent for use in the treatment of colon cancer.

  12. Beta limits for ETF

    International Nuclear Information System (INIS)

    Helton, F.J.; Miller, R.L.

    1982-01-01

    ETF (Engineering Test Facility) one-dimensional transport simulations indicate that a volume-average beta of 4% is required for ignition. It is therefore important that theoretical beta limits, determined by requiring equilibria to be stable to all ideal modes, exceed 4%. This paper documents an ideal MHD analysis wherein it is shown that, with appropriate plasma cross-sectional shape and current profile optimization, operation near 5% is possible. The critical beta value, however, depends on the functional form used for ff', which suggests that higher critical betas could be achieved by directly optimizing the safety factor profile. (author)

  13. Beta-energy averaging and beta spectra

    International Nuclear Information System (INIS)

    Stamatelatos, M.G.; England, T.R.

    1976-07-01

    A simple yet highly accurate method for approximately calculating spectrum-averaged beta energies and beta spectra for radioactive nuclei is presented. This method should prove useful for users who wish to obtain accurate answers without complicated calculations of Fermi functions, complex gamma functions, and time-consuming numerical integrations as required by the more exact theoretical expressions. Therefore, this method should be a good time-saving alternative for investigators who need to make calculations involving large numbers of nuclei (e.g., fission products) as well as for occasional users interested in restricted number of nuclides. The average beta-energy values calculated by this method differ from those calculated by ''exact'' methods by no more than 1 percent for nuclides with atomic numbers in the 20 to 100 range and which emit betas of energies up to approximately 8 MeV. These include all fission products and the actinides. The beta-energy spectra calculated by the present method are also of the same quality

  14. Cloning and expression of pineapple sucrosephosphate synthase ...

    African Journals Online (AJOL)

    A 1132-base pairs (bp) polymerase-chain-reaction product of sucrose-phosphate synthase (SPS) (EC 2.3.1.14) from pineapple (Ananas comosus cv. Comte de paris) fruit was cloned and nominated as Ac- SPS1. The sequence encodes a putative 377 amino acids protein containing two serine conserved features that had ...

  15. Endothelial nitric oxide synthase gene polymorphisms associated ...

    African Journals Online (AJOL)

    Endothelial nitric oxide synthase (NOS3) is involved in key steps of immune response. Genetic factors predispose individuals to periodontal disease. This study's aim was to explore the association between NOS3 gene polymorphisms and clinical parameters in patients with periodontal disease. Genomic DNA was obtained ...

  16. HAEM SYNTHASE AND COBALT PORPHYRIN SYNTHASE IN VARIOUS MICRO-ORGANISMS.

    Science.gov (United States)

    PORRA, R J; ROSS, B D

    1965-03-01

    1. The preparation of a crude extract of Clostridium tetanomorphum containing cobalt porphyrin synthase but little haem-synthase activity is described. 2. The properties of cobalt porphyrin synthase in the clostridial extracts is compared with the properties of a haem synthase present in crude extracts of the yeast Torulopsis utilis. 3. Cobalt porphyrin synthase in extracts of C. tetanomorphum inserts Co(2+) ions into the following dicarboxylic porphyrins in descending order of rate of insertion: meso-, deutero- and proto-porphyrins. Esterification renders meso- and deutero-porphyrins inactive as substrates. Neither the tetracarboxylic (coproporphyrin III) nor the octacarboxylic (uroporphyrin III) compounds are converted into cobalt porphyrins by the extract, but the non-enzymic incorporation of Co(2+) ions into these two porphyrins is rapid. These extracts are unable to insert Mn(2+), Zn(2+), Mg(2+) or Cu(2+) ions into mesoporphyrin. 4. Crude extracts of T. utilis readily insert both Co(2+) and Fe(2+) ions into deutero-, meso, and proto-porphyrins. Unlike the extracts of C. tetanomorphum, these preparations catalyse the insertion of Co(2+) ions into deuteroporphyrin more rapidly than into mesoporphyrin. This parallels the formation of haems by the T. utilis extract. 5. Cobalt porphyrin synthase is present in the particulate fraction of the extracts of C. tetanomorphum but requires a heat-stable factor present in the soluble fraction. This soluble factor can be replaced by GSH. 6. Cobalt porphyrin synthase in the clostridial extract is inhibited by iodoacetamide and to a smaller extent by p-chloromercuribenzoate and N-ethylmaleimide. The haem synthases of T. utilis and Micrococcus denitrificans are also inhibited by various thiol reagents.

  17. Comprehensive analysis of the tryptophan metabolome in urine of patients with acute intermittent porphyria.

    Science.gov (United States)

    Gomez-Gomez, Alex; Marcos, Josep; Aguilera, Paula; To-Figueras, Jordi; Pozo, Oscar J

    2017-08-15

    Acute intermittent porphyria (AIP) is a rare metabolic disorder due to a deficiency of porphobilinogen deaminase, the third enzyme of the heme biosynthetic pathway. This low enzymatic activity may predispose to the appearance of acute neurological attacks. Seminal studies suggested that AIP was associated with changes in tryptophan homeostasis with inconclusive results. Therefore, the aim of this study was to analyze the urinary metabolome of AIP patients focusing on tryptophan metabolism using state-of-the-art technology. This was a case-control study including a group of 25 AIP patients with active biochemical disease and increased excretion of heme-precursors and 25 healthy controls. Tryptophan and related compounds and metabolites including: large neutral amino acids (LNAAs), serotonin, kynurenine, kynurenic acid and anthranilic acid were quantified in urine by liquid chromatography tandem-mass spectrometry (LC-MS/MS). Twenty-nine biological markers (including metabolic ratios and absolute concentrations) were compared between patients and controls. Significant differences were found in the tryptophan-kynurenine metabolic pathway. Compared to controls, AIP patients showed: (a) increased urinary excretion of kynurenine and anthranilic acid (Pmetabolome of hepatic porphyrias. Copyright © 2017. Published by Elsevier B.V.

  18. Serum Stabilities of Short Tryptophan-and Arginine-Rich Antimicrobial Peptide Analogs

    NARCIS (Netherlands)

    Nguyen, L.T.; Chau, J.K.; Perry, N.A.; de Boer, L.; Zaat, S.A.J.; Vogel, H.J.

    2010-01-01

    Background: Several short antimicrobial peptides that are rich in tryptophan and arginine residues were designed with a series of simple modifications such as end capping and cyclization. The two sets of hexapeptides are based on the Trp- and Arg-rich primary sequences from the "antimicrobial

  19. pH tuning of Nafion for selective detection of tryptophan

    International Nuclear Information System (INIS)

    Frith, K.-A.; Limson, J.L.

    2009-01-01

    Selective and sensitive detection of the amino acid tryptophan is of importance in food processing, pharmaceutical formulations and in biological fluids. Electrochemical methods of detection of tryptophan are hampered by sluggish electron transfer kinetics and in complex matrices through overlapping peaks from interferents. This study examines the potential of the cation exchange membrane Nafion to enhance selectivity and sensitivity of this analyte through a seldom explored feature of this membrane: pH manipulation. A detailed examination of the effect of pH on the selectivity afforded by Nafion as a function of the analyte charge is presented. Selective detection of tryptophan and significant increases in sensitivity of its detection was observed in the presence of melatonin, dopamine and other interferents present in a pharmaceutical formulation through manipulation of the pH of the solution. At pH 3.0 at a Nafion-modified electrode, changes in the protonation of melatonin and tryptophan lowered the anodic potential of the analytes in a non-uniform manner increasing the peak resolution and permitting analyses with detection limits of 1.6 ± 0.1 nM and 1.6 ± 0.2 nM, respectively.

  20. Physiological roles of tryptophan in teleosts: current knowledge and perspectives for future studies

    DEFF Research Database (Denmark)

    Hoseini, Seyyed Morteza; Pérez-Jiménez, Amelia; Costas, Benjamin

    2017-01-01

    from the neuroendocrine to the immune system in vertebrates. In aquaculture, extensive research has been performed to optimize the levels of tryptophan in the commercial diets for many fish species. Providing adequate levels of this amino acid is critically important for fish growth but also for fish...

  1. Tryptophan biosynthesis in stramenopiles: eukaryotic winners in the diatom complex chloroplast

    Czech Academy of Sciences Publication Activity Database

    Jiroutová, Kateřina; Horák, Aleš; Bowler, C.; Oborník, Miroslav

    2007-01-01

    Roč. 65, č. 5 (2007), s. 496-511 ISSN 0022-2844 R&D Projects: GA AV ČR IAA500220502 Institutional research plan: CEZ:AV0Z60220518 Keywords : tryptophan synthesis * mosaic origin * diatom * Oomycetes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.234, year: 2007

  2. PYROLYTIC PRODUCTS FROM TRYPTOPHAN AND GLUTAMIC-ACID ARE POSITIVE IN THE MAMMALIAN SPOT-TEST

    DEFF Research Database (Denmark)

    Jensen, Niels Juul

    1983-01-01

    Pyrolysates of tryptophan (Trp-P-2) and glutamic acid (Glu-P-1) are known mutagens in in vitro short term mutagenicity tests, and have also shown carcinogenic effects in long term animal studies. The present study demonstrates that they also produce mutations in somatic cells. This result...

  3. Lactococcus lactis as expression host for the biosynthetic incorporation of tryptophan analogues into recombinant proteins

    NARCIS (Netherlands)

    El Khattabi, Mohamed; van Roosmalen, Maarten L.; Jager, Dennis; Metselaar, Heidi; Permentier, Hjalmar; Leenhouts, Kees; Broos, Jaap

    2008-01-01

    Incorporation of Trp (tryptophan) analogues into a protein may facilitate its structural analysis by spectroscopic techniques. Development of a biological system for the biosynthetic incorporation of such analogues into proteins is of considerable importance. The Gram-negative Escherichia coli is

  4. Recognizing emotions in faces : effects of acute tryptophan depletion and bright light

    NARCIS (Netherlands)

    aan het Rot, Marije; Coupland, Nicholas; Boivin, Diane B.; Benkelfat, Chawki; Young, Simon N.

    2010-01-01

    In healthy never-depressed individuals, acute tryptophan depletion (ATD) may selectively decrease the accurate recognition of fearful facial expressions. Here we investigated the perception of facial emotions after ATD in more detail. We also investigated whether bright light, which can reverse

  5. Dietary l-tryptophan leaves a lasting impression on the brain and the stress response

    DEFF Research Database (Denmark)

    Höglund, Erik; Øverli, Øyvind; Åberg Andersson, Madelene

    2017-01-01

    Comparative models suggest that effects of dietary tryptophan (Trp) on brain serotonin (5-hydroxytryptamine; 5-HT) neurochemistry and stress responsiveness are present throughout the vertebrate lineage. Moreover, hypothalamic 5-HT seems to play a central role in control of the neuroendocrine stre...

  6. No Tryptophan, Tyrosine and Phenylalanine Abnormalities in Children with Attention-Deficit/Hyperactivity Disorder

    NARCIS (Netherlands)

    Bergwerff, C.E.; Luman, M.; Blom, H.J.; Oosterlaan, J.

    2016-01-01

    Background The aim of the current study was to explore the role of aromatic amino acids (AAAs) in blood in relation to attention-deficit/hyperactivity disorder (ADHD). Given their impact on the synthesis of serotonin and dopamine, decreased concentrations of the AAAs tryptophan, tyrosine and

  7. Central fatigue and nycthemeral change of serum tryptophan and serotonin in the athletic horse

    Directory of Open Access Journals (Sweden)

    Percipalle Maurizio

    2005-04-01

    Full Text Available Abstract Background The serotonergic system is associated with numerous brain functions, including the resetting of the mammalian circadian clock. The synthesis and metabolism of 5-HT in the brain increases in response to exercise and is correlated with high levels of blood-borne tryptophan (TRP. The present investigation was aimed at testing the existence of a daily rhythm of TRP and 5-HT in the blood of athletic horses. Methods Blood samples from 5 Thoroughbred mares were collected at 4-hour intervals for 48 hours (starting at 08:00 hours on day 1 and finishing at 4:00 on day 2 via an intravenous cannula inserted into the jugular vein. Tryptophan and serotonin concentrations were assessed by HPLC. Data analysis was conducted by one-way repeated measures analysis of variance (ANOVA and by the single cosinor method. Results ANOVA showed a highly significant influence of time both on tryptophan and on serotonin, in all horses, on either day, with p values Conclusion The results showed that serotonin and tryptophan blood levels undergo nycthemeral variation with typical evening acrophases. These results enhance the understanding of the athlete horse's chronoperformance and facilitate the establishment of training programs that take into account the nycthemeral pattern of aminoacids deeply involved in the onset of central fatigue.

  8. Reprint of 'pH tuning of Nafion for selective detection of tryptophan'

    Energy Technology Data Exchange (ETDEWEB)

    Frith, K.-A. [Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown, 6140 (South Africa); Limson, J.L., E-mail: j.limson@ru.ac.z [Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown, 6140 (South Africa)

    2010-05-30

    Selective and sensitive detection of the amino acid tryptophan is of importance in food processing, pharmaceutical formulations and in biological fluids. Electrochemical methods of detection of tryptophan are hampered by sluggish electron transfer kinetics and in complex matrices through overlapping peaks from interferents. This study examines the potential of the cation exchange membrane Nafion to enhance selectivity and sensitivity of this analyte through a seldom explored feature of this membrane: pH manipulation. A detailed examination of the effect of pH on the selectivity afforded by Nafion as a function of the analyte charge is presented. Selective detection of tryptophan and significant increases in sensitivity of its detection was observed in the presence of melatonin, dopamine and other interferents present in a pharmaceutical formulation through manipulation of the pH of the solution. At pH 3.0 at a Nafion-modified electrode, changes in the protonation of melatonin and tryptophan lowered the anodic potential of the analytes in a non-uniform manner increasing the peak resolution and permitting analyses with detection limits of 1.6 +- 0.1 nM and 1.6 +- 0.2 nM, respectively.

  9. pH tuning of Nafion for selective detection of tryptophan

    Energy Technology Data Exchange (ETDEWEB)

    Frith, K.-A. [Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown, 6140 (South Africa); Limson, J.L. [Department of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown, 6140 (South Africa)], E-mail: j.limson@ru.ac.za

    2009-05-01

    Selective and sensitive detection of the amino acid tryptophan is of importance in food processing, pharmaceutical formulations and in biological fluids. Electrochemical methods of detection of tryptophan are hampered by sluggish electron transfer kinetics and in complex matrices through overlapping peaks from interferents. This study examines the potential of the cation exchange membrane Nafion to enhance selectivity and sensitivity of this analyte through a seldom explored feature of this membrane: pH manipulation. A detailed examination of the effect of pH on the selectivity afforded by Nafion as a function of the analyte charge is presented. Selective detection of tryptophan and significant increases in sensitivity of its detection was observed in the presence of melatonin, dopamine and other interferents present in a pharmaceutical formulation through manipulation of the pH of the solution. At pH 3.0 at a Nafion-modified electrode, changes in the protonation of melatonin and tryptophan lowered the anodic potential of the analytes in a non-uniform manner increasing the peak resolution and permitting analyses with detection limits of 1.6 {+-} 0.1 nM and 1.6 {+-} 0.2 nM, respectively.

  10. Direct fluorination of melatonin and 5-hydroxy-L-tryptophan with [18F]F2

    International Nuclear Information System (INIS)

    Chirakal, R.; Firnau, G.; Garnett, E.S.

    1986-01-01

    In order that melatonin receptors may be studied in man with positron emission tomography, melatonin labelled with a positron emitting isotope is needed. The preparation of 6-fluoro-melatonin labelled with F-18 is described. Using the same fluorination method, 5-hydroxy-6-(F-18)fluorotryptophan and 4-(F-18)fluoro-5-hydroxy-tryptophan were also prepared. (UK)

  11. REPLACEMENT OF TRYPTOPHAN RESIDUES IN HALOALKANE DEHALOGENASE REDUCES HALIDE BINDING AND CATALYTIC ACTIVITY

    NARCIS (Netherlands)

    KENNES, C; PRIES, F; KROOSHOF, GH; BOKMA, E; Kingma, Jacob; JANSSEN, DB

    1995-01-01

    Haloalkane dehalogenase catalyzes the hydrolytic cleavage of carbon-halogen bonds in short-chain haloalkanes. Two tryptophan residues of the enzyme (Trp125 and Trp175) form a halide-binding site in the active-site cavity, and were proposed to play a role in catalysis. The function of these residues

  12. Synthesis of 2-substituted tryptophans via a C3- to C2-alkyl migration

    Directory of Open Access Journals (Sweden)

    Michele Mari

    2014-08-01

    Full Text Available The reaction of 3-substituted indoles with dehydroalanine (Dha derivatives under Lewis acid-mediated conditions has been investigated. The formation of 2-substituted tryptophans is proposed to occur through a selective alkylative dearomatization–cyclization followed by C3- to C2-alkyl migration and rearomatization.

  13. Tryptophan catabolism restricts IFN-γ-expressing neutrophils and Clostridium difficile immunopathology

    NARCIS (Netherlands)

    El-Zaatari, Mohamad; Chang, Yu-Ming; Zhang, Min; Franz, Matthew; Shreiner, Andrew; McDermott, Andrew J.; van der Sluijs, Koenraad F.; Lutter, René; Grasberger, Helmut; Kamada, Nobuhiko; Young, Vincent B.; Huffnagle, Gary B.; Kao, John Y.

    2014-01-01

    The interplay between Clostridium difficile and the host's metabolome is believed to influence the severity of infection. However, the mechanism for this phenomenon remains unclear. In this study, we model one of these metabolic pathways by focusing on tryptophan metabolism in the host. We found

  14. Internal Energies of Ion-Sputtered Neutral Tryptophan and Thymine Molecules Determined by Vacuum Ultraviolet Photoionization

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jia; Takahashi, Lynelle; Wilson, Kevin R.; Leone, Stephen R.; Ahmed, Musahid

    2010-03-11

    Vacuum ultraviolet photoionization coupled to secondary neutral mass spectrometry (VUV-SNMS) of deposited tryptophan and thymine films are performed at the Chemical Dynamics Beamline. The resulting mass spectra show that while the intensity of the VUV-SNMS signal is lower than the corresponding secondary ion mass spectroscopy (SIMS) signal, the mass spectra are significantly simplified in VUV-SNMS. A detailed examination of tryptophan and thymine neutral molecules sputtered by 25 keV Bi3 + indicates that the ion-sputtered parent molecules have ~;;2.5 eV of internal energy. While this internal energy shifts the appearance energy of the photofragment ions for both tryptophan and thymine, it does not change the characteristic photoionizaton efficiency (PIE) curves of thymine versus photon energy. Further analysis of the mass spectral signals indicate that approximately 80 neutral thymine molecules and 400 tryptophan molecules are sputtered per incident Bi3 + ion. The simplified mass spectra and significant characteristic ion contributions to the VUV-SNMS spectra indicate the potential power of the technique for organic molecule surface analysis.

  15. Reprint of 'pH tuning of Nafion for selective detection of tryptophan'

    International Nuclear Information System (INIS)

    Frith, K.-A.; Limson, J.L.

    2010-01-01

    Selective and sensitive detection of the amino acid tryptophan is of importance in food processing, pharmaceutical formulations and in biological fluids. Electrochemical methods of detection of tryptophan are hampered by sluggish electron transfer kinetics and in complex matrices through overlapping peaks from interferents. This study examines the potential of the cation exchange membrane Nafion to enhance selectivity and sensitivity of this analyte through a seldom explored feature of this membrane: pH manipulation. A detailed examination of the effect of pH on the selectivity afforded by Nafion as a function of the analyte charge is presented. Selective detection of tryptophan and significant increases in sensitivity of its detection was observed in the presence of melatonin, dopamine and other interferents present in a pharmaceutical formulation through manipulation of the pH of the solution. At pH 3.0 at a Nafion-modified electrode, changes in the protonation of melatonin and tryptophan lowered the anodic potential of the analytes in a non-uniform manner increasing the peak resolution and permitting analyses with detection limits of 1.6 ± 0.1 nM and 1.6 ± 0.2 nM, respectively.

  16. Study of interaction between tryptophan, tyrosine, and phenylalanine separately with silver nanoparticles by fluorescence quenching method

    International Nuclear Information System (INIS)

    Roy, S.; Das, T.K.

    2015-01-01

    Using the spectroscopic method, the individual interaction of the three biochemically important amino acids, which are constituents of protein, namely, tryptophan, tyrosine, and phenylalanine with biologically synthesized silver nanoparticles has been investigated. The obtained UV-Vis spectra show the formation of ground-state complexes between tryptophan, tyrosine, and phenylalanine with silver nanoparticles. Silver nanoparticles possess the ability to quench the intrinsic fluorescence of the aforesaid amino acids by a dynamic quenching process. The binding constant, number of binding sites, and corresponding thermodynamic parameters (ΔH, ΔS, and ΔG) based on the interaction system were calculated for 293, 303, and 313 K. In the case of tryptophan and phenylalanine, with increase in temperature, the binding constant K was found to decrease; conversely, it was found to increase with increase in temperature in the case of tyrosine. The thermodynamic results revealed that the binding process was spontaneous; hydrogen bonding and van der Waals interaction were the predominant forces responsible for the complex stabilization in the case of tryptophan and phenylalanine, respectively, whereas in the case of tyrosine, hydrophobic interaction was the sole force conferring stability. Moreover, the Förster non-radiation energy transfer theory has been applied to calculate the average binding distance among the above amino acids and silver nanoparticles. The results show a binding distance of <7 nm, which ensures that energy transfer does occur between the said amino acids and silver nanoparticles. (authors)

  17. Early Posttransplant Tryptophan Metabolism Predicts Long-term Outcome of Human Kidney Transplantation

    NARCIS (Netherlands)

    Vavrincova-Yaghi, Diana; Seelen, Marc A.; Kema, Ido P.; Deelman, Leo E.; Heuvel, van den Marius; Breukelman, Henk; Van den Eynde, Benoit J.; Henning, Rob H.; van Goor, Harry; Sandovici, Maria

    Background. Chronic transplant dysfunction (CTD) is the leading cause of long-term loss of the renal allograft. So far, no single test is available to reliably predict the risk for CTD. Monitoring of tryptophan (trp) metabolism through indoleamine 2.3-dioxygenase (IDO) has been previously proposed

  18. Cross-linking of lens crystallin proteins induced by tryptophan metabolites and metal ions

    DEFF Research Database (Denmark)

    Tweeddale, Helen J; Hawkins, Clare Louise; Janmie, Joane F

    2016-01-01

    Long-wavelength solar UV radiation is implicated in photodamage to the human eye. The human lens contains multiple tryptophan-derived compounds that have significant absorbance bands in the UVA region (λ 315-400 nm) that act as efficient physical filters for these wavelengths. The concentrations...

  19. Metabolic engineering of Saccharomyces cerevisiae for production of germacrene A, a precursor of beta-elemene

    DEFF Research Database (Denmark)

    Hu, Yating; Zhou, Yongjin J.; Bao, Jichen

    2017-01-01

    inefficient and suffers from limited natural resources. Here, we engineered a yeast cell factory for the sustainable production of germacrene A, which can be transformed to beta-elemene by a one-step chemical reaction in vitro. Two heterologous germacrene A synthases (GASs) converting farnesyl pyrophosphate...... (FPP) to germacrene A were evaluated in yeast for their ability to produce germacrene A. Thereafter, several metabolic engineering strategies were used to improve the production level. Overexpression of truncated 3-hydroxyl-3-methylglutaryl-CoA reductase and fusion of FPP synthase with GAS, led...

  20. CTP limitation increases expression of CTP synthase in Lactococcus lactis

    DEFF Research Database (Denmark)

    Jørgensen, C.M.; Hammer, Karin; Martinussen, Jan

    2003-01-01

    CTP synthase is encoded by the pyrG gene and catalyzes the conversion of UTP to CTP. A Lactococcus lactis pyrG mutant with a cytidine requirement was constructed, in which beta-galactosidase activity in a pyrG-lacLM transcriptional fusion was used to monitor gene expression of pyrG. A 10-fold...... decrease in the CTP pool induced by cytidine limitation was found to immediately increase expression of the L. lactis pyrG gene. The final level of expression of pyrG is 37-fold higher than the uninduced level. CTP limitation has pronounced effects on central cellular metabolism, and both RNA and protein...... for regulation of the pyrG gene. It is possible to fold the pyrG leader in an alternative structure that would prevent the formation of the terminator. We suggest a model for pyrG regulation in L. lactis, and probably in other gram-positive bacteria as well, in which pyrG expression is directly dependent...

  1. High beta tokamaks

    International Nuclear Information System (INIS)

    Dory, R.A.; Berger, D.P.; Charlton, L.A.; Hogan, J.T.; Munro, J.K.; Nelson, D.B.; Peng, Y.K.M.; Sigmar, D.J.; Strickler, D.J.

    1978-01-01

    MHD equilibrium, stability, and transport calculations are made to study the accessibility and behavior of ''high beta'' tokamak plasmas in the range β approximately 5 to 15 percent. For next generation devices, beta values of at least 8 percent appear to be accessible and stable if there is a conducting surface nearby

  2. Sorting out Downside Beta

    NARCIS (Netherlands)

    G.T. Post (Thierry); P. van Vliet (Pim); S.D. Lansdorp (Simon)

    2009-01-01

    textabstractDownside risk, when properly defined and estimated, helps to explain the cross-section of US stock returns. Sorting stocks by a proper estimate of downside market beta leads to a substantially larger cross-sectional spread in average returns than sorting on regular market beta. This

  3. Betting against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    2014-01-01

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model's five central predictions: (1) Because constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically...

  4. Fluorescence imaging of tryptophan and collagen cross-links to evaluate wound closure ex vivo

    Science.gov (United States)

    Wang, Ying; Ortega-Martinez, Antonio; Farinelli, Bill; Anderson, R. R.; Franco, Walfre

    2016-02-01

    Wound size is a key parameter in monitoring healing. Current methods to measure wound size are often subjective, time-consuming and marginally invasive. Recently, we developed a non-invasive, non-contact, fast and simple but robust fluorescence imaging (u-FEI) method to monitor the healing of skin wounds. This method exploits the fluorescence of native molecules to tissue as functional and structural markers. The objective of the present study is to demonstrate the feasibility of using variations in the fluorescence intensity of tryptophan and cross-links of collagen to evaluate proliferation of keratinocyte cells and quantitate size of wound during healing, respectively. Circular dermal wounds were created in ex vivo human skin and cultured in different media. Two serial fluorescence images of tryptophan and collagen cross-links were acquired every two days. Histology and immunohistology were used to validate correlation between fluorescence and epithelialization. Images of collagen cross-links show fluorescence of the exposed dermis and, hence, are a measure of wound area. Images of tryptophan show higher fluorescence intensity of proliferating keratinocytes forming new epithelium, as compared to surrounding keratinocytes not involved in epithelialization. These images are complementary since collagen cross-links report on structure while tryptophan reports on function. HE and immunohistology show that tryptophan fluorescence correlates with newly formed epidermis. We have established a fluorescence imaging method for studying epithelialization processes during wound healing in a skin organ culture model, our approach has the potential to provide a non-invasive, non-contact, quick, objective and direct method for quantitative measurements in wound healing in vivo.

  5. Tryptophan Depletion Promotes Habitual over Goal-Directed Control of Appetitive Responding in Humans.

    Science.gov (United States)

    Worbe, Yulia; Savulich, George; de Wit, Sanne; Fernandez-Egea, Emilio; Robbins, Trevor W

    2015-02-05

    Optimal behavioral performance results from a balance between goal-directed and habitual systems of behavioral control, which are modulated by ascending monoaminergic projections. While the role of the dopaminergic system in behavioral control has been recently addressed, the extent to which changes in global serotonin neurotransmission could influence these 2 systems is still poorly understood. We employed the dietary acute tryptophan depletion procedure to reduce serotonin neurotransmission in 18 healthy volunteers and 18 matched controls. We used a 3-stage instrumental learning paradigm that includes an initial instrumental learning stage, a subsequent outcome-devaluation test, and a slip-of-action stage, which directly tests the balance between hypothetical goal-directed and habitual systems. We also employed a separate response inhibition control test to assess the behavioral specificity of the results. Acute tryptophan depletion produced a shift of behavioral performance towards habitual responding as indexed by performance on the slip-of-action test. Moreover, greater habitual responding in the acute tryptophan depletion group was predicted by a steeper decline in plasma tryptophan levels. In contrast, acute tryptophan depletion left intact the ability to use discriminative stimuli to guide instrumental choice as indexed by the instrumental learning stage and did not impair inhibitory response control. The major implication of this study is that serotonin modulates the balance between goal-directed and stimulus-response habitual systems of behavioral control. Our findings thus imply that diminished serotonin neurotransmission shifts behavioral control towards habitual responding. © The Author 2015. Published by Oxford University Press on behalf of CINP.

  6. Genetics Home Reference: beta thalassemia

    Science.gov (United States)

    ... Facebook Twitter Home Health Conditions Beta thalassemia Beta thalassemia Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Beta thalassemia is a blood disorder that reduces the production ...

  7. Effects of tryptophan derivatives and β-carboline alkaloids on radiation- and peroxide-induced transformations of ethanol

    International Nuclear Information System (INIS)

    Sverdlov, R.L.; Brinkevich, S.D.; Shadyro, O.I.

    2014-01-01

    The subject of this study was investigation of interactions of tryptophan and its derivatives, including structurally related β-carboline alkaloids with oxygen- and carbon-centered radicals being formed during radiation- and peroxide-induced transformations of ethanol. It was shown that the above named compounds suppressed recombination and disproportionation reactions of α-hydroxyethyl radicals. The inhibitory effects of tryptophan, 5-hydroxytryptophan and serotonin were mainly realized by means of reduction and addition reactions, while those of β-carboline alkaloids – harmine, harmane and harmaline – were due to oxidation reactions. Melatonin displayed low reactivity towards α-hydroxyethyl radicals. Tryptophan derivatives and β-carboline alkaloids were found to inhibit radiation-induced oxidation of ethanol while being virtually not used up. The low transformation yields of tryptophan, 5-hydroxytryptophan and serotonin, as well as β-carboline alkaloids, indicate their capability of regeneration, which could occur on interaction of tryptophan with O ·− 2 and HO · 2 , or on oxidation of α-hydroxyethyl radicals by β-carboline alkaloids. - Highlights: • Tryptophan, 5-hydroxytryptophane and serotonin can reduce or add α-HER. • β-Carboline alkaloids – harmane, harmine, harmaline – can oxidize α-HER. • Tryptophan and its derivatives can reduce oxygen-centered radicals

  8. Uptake and incorporation of labeled tryptophan isomers into IAA in the jsR1 mutant of Lemna gibba

    International Nuclear Information System (INIS)

    Baldi, B.G.; Maher, B.R.; Cohen, J.D.

    1989-01-01

    Analyses of the IAA-overproducing mutant of Lemna have been initiated in order to study in vivo biosynthesis of IAA. Using radiolabelled tryptophan isomers prepared from commercial sources of 14 C-D,L tryptophan by chiral separation kinetics of uptake of L and D tryptophan were determined for sterile cultures of individual jsR 1 four-frond colonies. Over a 24 h period, about 50% of the radioactivity from 14 C-L-TRP in media, or about 25% from 14 C-D-TRP, was found in the plant tissue. Maximal rates of uptake were seen in the first six hors for both isomers. Endogenous levels of tryptophan determined in jsR 1 as measures of pool sizes in vivo show 5 to 10 ug/g FW total tryptophan with less than 1% in the D isomer form. Information on uptake and endogenous pool sizes of tryptophan isomers is being used for feeding of stable isotope labeled tryptophan ( 13 C, 14 N) to jsR 1 at physiological levels. Analyses of incorporation of label into IAA using GC-MS and high resolution mass spectrometry are currently underway

  9. N-acetyl-L-tryptophan, a substance-P receptor antagonist attenuates aluminum-induced spatial memory deficit in rats.

    Science.gov (United States)

    Fernandes, Joylee; Mudgal, Jayesh; Rao, Chamallamudi Mallikarjuna; Arora, Devinder; Basu Mallik, Sanchari; Pai, K S R; Nampoothiri, Madhavan

    2018-06-01

    Neuroinflammation plays an important role in the pathophysiology of Alzheimer's disease. Neurokinin substance P is a key mediator which modulates neuroinflammation through neurokinin receptor. Involvement of substance P in Alzheimer's disease is still plausible and various controversies exist in this hypothesis. Preventing the deleterious effects of substance P using N-acetyl-L-tryptophan, a substance P antagonist could be a promising therapeutic strategy. This study was aimed to evaluate the effect of N-acetyl-L-tryptophan on aluminum induced spatial memory alterations in rats. Memory impairment was induced using aluminum chloride (AlCl 3 ) at a dose of 10 mg/kg for 42 d. After induction of dementia, rats were exposed to 30 and 50 mg/kg of N-acetyl-L-tryptophan for 28 d. Spatial memory alterations were measured using Morris water maze. Acetylcholinesterase activity and antioxidant enzyme glutathione level were assessed in hippocampus, frontal cortex and striatum. The higher dose of N-acetyl-L-tryptophan (50 mg/kg) significantly improved the aluminum induced memory alterations. N-acetyl-L-tryptophan exposure resulted in significant increase in acetylcholinesterase activity and glutathione level in hippocampus. The neuroprotective effect of N-acetyl-L-tryptophan could be due to its ability to block substance P mediated neuroinflammation, reduction in oxidative stress and anti-apoptotic properties. To conclude, N-acetyl-L-tryptophan may be considered as a novel neuroprotective therapy in Alzheimer's disease.

  10. Chemical-modification studies of a unique sialic acid-binding lectin from the snail Achatina fulica. Involvement of tryptophan and histidine residues in biological activity.

    Science.gov (United States)

    Basu, S; Mandal, C; Allen, A K

    1988-01-01

    A unique sialic acid-binding lectin, achatininH (ATNH) was purified in single step from the haemolymph of the snail Achatina fulica by affinity chromatography on sheep submaxillary-gland mucin coupled to Sepharose 4B. The homogeneity was checked by alkaline gel electrophoresis, immunodiffusion and immunoelectrophoresis. Amino acid analysis showed that the lectin has a fairly high content of acidic amino acid residues (22% of the total). About 1.3% of the residues are half-cystine. The glycoprotein contains 21% carbohydrate. The unusually high content of xylose (6%) and fucose (2.7%) in this snail lectin is quite interesting. The protein was subjected to various chemical modifications in order to detect the amino acid residues and carbohydrate residues present in its binding sites. Modification of tyrosine and arginine residues did not affect the binding activity of ATNH; however, modification of tryptophan and histidine residues led to a complete loss of its biological activity. A marked decrease in the fluorescence emission was found as the tryptophan residues of ATNH were modified. The c.d. data showed the presence of an identical type of conformation in the native and modified agglutinin. The modification of lysine and carboxy residues partially diminished the biological activity. The activity was completely lost after a beta-elimination reaction, indicating that the sugars are O-glycosidically linked to the glycoprotein's protein moiety. This result confirms that the carbohydrate moiety also plays an important role in the agglutination property of this lectin. Images Fig. 3. PMID:3140796

  11. Rapid synthesis of beta zeolites

    Science.gov (United States)

    Fan, Wei; Chang, Chun -Chih; Dornath, Paul; Wang, Zhuopeng

    2015-08-18

    The invention provides methods for rapidly synthesizing heteroatom containing zeolites including Sn-Beta, Si-Beta, Ti-Beta, Zr-Beta and Fe-Beta. The methods for synthesizing heteroatom zeolites include using well-crystalline zeolite crystals as seeds and using a fluoride-free, caustic medium in a seeded dry-gel conversion method. The Beta zeolite catalysts made by the methods of the invention catalyze both isomerization and dehydration reactions.

  12. Relation of plasma tryptophan concentrations during pregnancy to maternal sleep and mental well-being: The GUSTO cohort.

    Science.gov (United States)

    van Lee, Linde; Cai, Shirong; Loy, See Ling; Tham, Elaine K H; Yap, Fabian K P; Godfrey, Keith M; Gluckman, Peter D; Shek, Lynette P C; Teoh, Oon Hoe; Goh, Daniel Y T; Tan, Kok Hian; Chong, Yap Seng; Meaney, Michael J; Chen, Helen; Broekman, Birit F P; Chong, Mary F F

    2018-01-01

    Evidence suggests a relation between plasma tryptophan concentrations and sleep and mental well-being. As no studies have been performed in pregnant women, we studied the relation of plasma tryptophan concentrations during pregnancy with sleep quality, and mood during and after pregnancy. Pregnant women (n = 572) from the Growing Up in Singapore Towards healthy Outcomes study completed the Pittsburgh Sleep Quality Index (PSQI), the Edinburgh Postnatal Depression Scale (EPDS) and the State-Trait Anxiety Inventory (STAI) at 26-28 weeks gestation and three months post-delivery. Plasma tryptophan concentrations were measured at 26-28 weeks gestation. Poisson regressions estimated prevalence ratios (PR) for the association between tryptophan and poor sleep quality (PSQI global score > 5), probable antenatal depression (EPDS ≥ 15) and probable anxiety (STAI-state ≥ 41) were calculated adjusting for covariates. Mean plasma tryptophan concentrations was 48.0µmol/L (SD: 8.09). Higher plasma tryptophan concentrations were associated with a lower prevalence of antenatal poor sleep quality adjusting for covariates [PR: 0.88 (95% CI 0.80, 0.97) per 10µmol/L], especially in those participants who also suffered from anxiety symptoms [PR: 0.80 (95% CI 0.67, 0.95)]. No associations were observed between tryptophan concentrations during pregnancy and postnatal sleep quality or mental well-being. Subjective measures were used to assess sleep and mental well-being. We observed that higher plasma tryptophan concentrations were associated with a 12% lower prevalence of poor sleep quality during pregnancy, in particular among those with anxiety symptoms. These findings suggest the importance of having adequate tryptophan concentrations during pregnancy. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Contribution of tryptophan residues to the combining site of a monoclonal anti dinitrophenyl spin-label antibody

    International Nuclear Information System (INIS)

    Anglister, J.; Bond, M.W.; Frey, T.; Leahy, D.; Levitt, M.; McConnell, H.M.; Rule, G.S.; Tomasello, J.; Whittaker, M.

    1987-01-01

    Two Fab fragments of the monoclonal anti dinitrophenyl (DNP) spin-label antibody AN02 were prepared by recombination of specifically deuterated heavy and light chains. In the recombinant H(I)L(II) all the tyrosines and phenylalanines were perdeuterated as were the tryptophan residues of the heavy chain. In the recombinant H(II)L(I) all the tyrosines and phenylalanines were perdeuterated as were the tryptophan residues of the light chain. Saturation of three resonances of H(I)L(II), assigned to tryptophan protons of the light chain, resulted in magnetization transfer to the aromatic proton at position 6 of the DNP ring and to the CH2 protons of the glycines linked to the DNP in a diamagnetic hapten (DNP-DG). Saturation of three resonances of H(II)L(I) assigned to tryptophan protons of the heavy chain resulted in magnetization transfer to the CH2 protons of the glycines in DNP-DG. From the dependence of the magnetization transfer on the irradiation time, the cross relaxation rates between the involved protons were estimated. The inferred distances between these protons of the hapten and certain tryptophan protons are 3-4 A. It is concluded that in the combining site of AN02 there is one tryptophan from the light chain and one tryptophan from the heavy chain that are very near the hapten. When all tyrosines and phenylalanines were perdeuterated and all tryptophan aromatic protons were deuterated except for the protons at positions 2 and 5, titration of the Fab fragments with variable amounts of paramagnetic hapten showed that one proton from the light chain tryptophan is near (less than 7 A) the unpaired electron and that three other protons are significantly closer than 15 A

  14. Contribution of tryptophan residues to the combining site of a monoclonal anti dinitrophenyl spin-label antibody

    Energy Technology Data Exchange (ETDEWEB)

    Anglister, J.; Bond, M.W.; Frey, T.; Leahy, D.; Levitt, M.; McConnell, H.M.; Rule, G.S.; Tomasello, J.; Whittaker, M.

    1987-09-22

    Two Fab fragments of the monoclonal anti dinitrophenyl (DNP) spin-label antibody AN02 were prepared by recombination of specifically deuterated heavy and light chains. In the recombinant H(I)L(II) all the tyrosines and phenylalanines were perdeuterated as were the tryptophan residues of the heavy chain. In the recombinant H(II)L(I) all the tyrosines and phenylalanines were perdeuterated as were the tryptophan residues of the light chain. Saturation of three resonances of H(I)L(II), assigned to tryptophan protons of the light chain, resulted in magnetization transfer to the aromatic proton at position 6 of the DNP ring and to the CH2 protons of the glycines linked to the DNP in a diamagnetic hapten (DNP-DG). Saturation of three resonances of H(II)L(I) assigned to tryptophan protons of the heavy chain resulted in magnetization transfer to the CH2 protons of the glycines in DNP-DG. From the dependence of the magnetization transfer on the irradiation time, the cross relaxation rates between the involved protons were estimated. The inferred distances between these protons of the hapten and certain tryptophan protons are 3-4 A. It is concluded that in the combining site of AN02 there is one tryptophan from the light chain and one tryptophan from the heavy chain that are very near the hapten. When all tyrosines and phenylalanines were perdeuterated and all tryptophan aromatic protons were deuterated except for the protons at positions 2 and 5, titration of the Fab fragments with variable amounts of paramagnetic hapten showed that one proton from the light chain tryptophan is near (less than 7 A) the unpaired electron and that three other protons are significantly closer than 15 A.

  15. Thirteen week toxicity study of dietary l-tryptophan in rats with a recovery period of 5 weeks.

    Science.gov (United States)

    Shibui, Yusuke; Matsumoto, Hideki; Masuzawa, Yoko; Ohishi, Takumi; Fukuwatari, Tsutomu; Shibata, Katsumi; Sakai, Ryosei

    2018-04-01

    Although l-tryptophan is nutritionally important and widely used in medical applications, toxicity data for its oral administration are limited. The purpose of this study was to evaluate the potential toxicity of an experimental diet containing added l-tryptophan at doses of 0 (basal diet), 1.25%, 2.5% and 5.0% when administered to Sprague-Dawley rats for 13 weeks. There were no toxicological changes in clinical signs, ophthalmology, urinalysis, hematology, necropsy, organ weight and histopathology between control rats and those fed additional l-tryptophan. Body weight gain and food consumption significantly decreased throughout the administration period in males in the 2.5% group and in both sexes in the 5.0% group. At the end of the dosing period, decreases in water intake in males in the 5.0% group and in serum glucose in females in the 5.0% group were observed. The changes described above were considered toxicologically significant; however, they were not observed after a 5 week recovery period, suggesting reversibility. Consequently, the no-observed-adverse-effect level of l-tryptophan in the present study was 1.25% for males and 2.5% for females (mean intake of l-tryptophan: 779 mg kg -1 body weight day -1 [males] and 1765 mg kg -1 body weight day -1 [females]). As the basal diet used in this study contained 0.27% of proteinaceous l-tryptophan, the no-observed-adverse-effect level of overall l-tryptophan was 1.52% for males and 2.77% for females (mean intake of overall l-tryptophan: 948 mg kg -1 body weight day -1 (males) and 1956 mg kg -1 body weight day -1 (females)). We conclude that l-tryptophan has a low toxicity profile in terms of human use. Copyright © 2017 John Wiley & Sons, Ltd.

  16. The Effects of Tryptophan on Everyday Interpersonal Encounters and Social Cognitions in Individuals with a Family History of Depression.

    Science.gov (United States)

    Hogenelst, Koen; Schoevers, Robert A; Aan Het Rot, Marije

    2015-03-02

    Individuals with a family history of depression show subtle abnormalities in the processing of social stimuli. This could negatively affect their interpersonal functioning and contribute to their depression risk. Repeated administration of the serotonin precursor tryptophan has previously been shown to increase agreeable behavior and reduce quarrelsome behavior in irritable people, who are also considered at risk for depression. To examine the effects of tryptophan on social functioning in individuals with a family history of depression, 40 men and women with at least one first-degree relative with depression received tryptophan (1g three times a day) and placebo for 14 days each in a double-blind crossover design and recorded their social behavior and mood during everyday interpersonal encounters. Participants also provided daily ratings of their positive and negative cognitions concerning their social functioning. Tryptophan improved mood. Unexpectedly, tryptophan increased quarrelsome behavior and reduced agreeable behavior, specifically during interactions at home. The behavioral effects of tryptophan were not moderated by mood or by the interaction partner. Negative social cognitions were lower when tryptophan was given second and lower during placebo when placebo was given second. Overall, tryptophan may not alter social behavior in individuals with a family history of depression as it does in irritable people. However, the behavioral effects of tryptophan at home might be seen as a way for individuals with a family history of depression to achieve more control. Over time, this may positively influence the way they feel and think about themselves in a social context. © The Author 2015. Published by Oxford University Press on behalf of CINP.

  17. A Brief Historic Overview of Clinical Disorders Associated with Tryptophan: The Relevance to Chronic Fatigue Syndrome (CFS and Fibromyalgia (FM.

    Directory of Open Access Journals (Sweden)

    Adele Blankfield

    2012-01-01

    Full Text Available Last century there was a short burst of interest in the tryptophan related disorders of pellagra and related abnormalities that are usually presented in infancy. 1 , 2 Nutritional physiologists recognized that a severe human dietary deficiency of either tryptophan or the B group vitamins could result in central nervous system (CNS sequelae such as ataxia, cognitive dysfunction and dysphoria, accompanied by skin hyperpigmentation. 3 , 4 The current paper will focus on the emerging role of tryptophan in chronic fatigue syndrome (CFS and fibromyalgia (FM.

  18. Crystallization of the c[subscript 14]-rotor of the chloroplast ATP synthase reveals that it contains pigments

    Energy Technology Data Exchange (ETDEWEB)

    Varco-Merth, Benjamin; Fromme, Raimund; Wang, Meitian; Fromme, Petra (AZU)

    2008-08-27

    The ATP synthase is one of the most important enzymes on earth as it couples the transmembrane electrochemical potential of protons to the synthesis of ATP from ADP and inorganic phosphage, providing the main ATP source of almost all higher life on earth. During ATP synthesis, stepwise protonation of a conserved carboxylate on each protein subunit of an oligomeric ring of 10--15 c-subunits is commonly thought to drive rotation of the rotor moiety (c{sub 10-14}{gamma}{sup {epsilon}}) relative to stator moiety ({alpha}{sub 3}{beta}{sub 3}{delta}ab{sub 2}). Here we report the isolation and crystallization of the c{sub 14}-ring of subunit c from the spinach chloroplast enzyme diffracting as far as 2.8 {angstrom}. Though ATP synthase was not previously know to contain any pigments, the crystals of the c-subunit possessed a strong yellow color. The pigment analysis revaled that they contain 1 chlorophyll and 2 carotenoids, thereby showing for the first time that the chloroplast ATP synthase contains cofactors, leading to the question of the possible roles of the functions of the pigments in the chloroplast ATP synthase.

  19. Beta particle measurement fundamentals

    International Nuclear Information System (INIS)

    Alvarez, J.L.

    1986-01-01

    The necessary concepts for understanding beta particle behavior are stopping power, range, and scattering. Dose as a consequence of beta particle interaction with tissue can be derived and explained by these concepts. Any calculations of dose, however, assume or require detailed knowledge of the beta spectrum at the tissue depth of calculation. A rudimentary knowledge of the incident spectrum can be of use in estimating dose, interpretating dose measuring devices and designing protection. The stopping power and range based on the csda will give a conservative estimate in cases of protection design, as scattering will reduce the range. Estimates of dose may be low because scattering effects were neglected

  20. Etiological classification of depression based on the enzymes of tryptophan metabolism.

    Science.gov (United States)

    Fukuda, Katsuhiko

    2014-12-24

    Viewed in terms of input and output, the mechanisms of depression are still akin to a black box. However, there must be main pivots for diverse types of depression. From recent therapeutic observations, both the serotonin (5-HT) and kynurenine pathways of tryptophan metabolism may be of particular importance to improved understanding of depression. Here, I propose an etiological classification of depression, based on key peripheral and central enzymes of tryptophan metabolism. Endogenous depression is caused by a larger genetic component than reactive depression. Besides enterochromaffin and mast cells, tryptophan hydroxylase 1 (TPH1), primarily expressed in the gastrointestinal tract, is also found in 5-hydroxytryptophan-producing cells (5-HTP cells) in normal intestinal enterocytes, which are thought to essentially shunt 5-HT production in 5-HT-producing cells. Genetic studies have reported an association between TPH1 and depression, or the responsiveness of depression to antidepressive medication. Therefore, it is possible that hypofunctional 5-HTP cells (reflecting TPH1 dysfunction) in the periphery lead to deficient brain 5-HT levels. Additionally,it has been reported that higher TPH2 expression in depressed suicides may reflect a homeostatic response to deficient 5-HT levels. Subsequently, endogenous depression may be caused by TPH1 dysfunction combined with compensatory TPH2 activation. Reactive depression results from life stresses and involves the hypothalamic-pituitary-adrenal axis, with resulting cortisol production inducing tryptophan 2,3-dioxygenase (TDO) activation. In secondary depression, caused by inflammation, infection, or oxidative stress, indoleamine 2,3-dioxygenase (IDO) is activated. In both reactive and secondary depression, the balance between 3-hydroxykynurenine (3-HK) and kynurenic acid may shift towards 3-HK production via kynurenine-3-monooxygenase (KMO) activation. By shifting the equilibrium position of key enzymes of tryptophan

  1. Functional genomic analysis supports conservation of function among cellulose synthase-like a gene family members and suggests diverse roles of mannans in plants

    DEFF Research Database (Denmark)

    Liepman, Aaron H; Nairn, C Joseph; Willats, William G T

    2007-01-01

    from Arabidopsis (Arabidopsis thaliana), guar (Cyamopsis tetragonolobus), and Populus trichocarpa catalyze beta-1,4-mannan and glucomannan synthase reactions in vitro. Mannan polysaccharides and homologs of CslA genes appear to be present in all lineages of land plants analyzed to date. In many plants......, the CslA genes are members of extended multigene families; however, it is not known whether all CslA proteins are glucomannan synthases. CslA proteins from diverse land plant species, including representatives of the mono- and dicotyledonous angiosperms, gymnosperms, and bryophytes, were produced...... they are prevalent at cell junctions and in buds. Taken together, these results demonstrate that members of the CslA gene family from diverse plant species encode glucomannan synthases and support the hypothesis that mannans function in metabolic networks devoted to other cellular processes in addition to cell wall...

  2. CTP synthase forms cytoophidia in the cytoplasm and nucleus

    International Nuclear Information System (INIS)

    Gou, Ke-Mian; Chang, Chia-Chun; Shen, Qing-Ji; Sung, Li-Ying; Liu, Ji-Long

    2014-01-01

    CTP synthase is an essential metabolic enzyme responsible for the de novo synthesis of CTP. Multiple studies have recently showed that CTP synthase protein molecules form filamentous structures termed cytoophidia or CTP synthase filaments in the cytoplasm of eukaryotic cells, as well as in bacteria. Here we report that CTP synthase can form cytoophidia not only in the cytoplasm, but also in the nucleus of eukaryotic cells. Both glutamine deprivation and glutamine analog treatment promote formation of cytoplasmic cytoophidia (C-cytoophidia) and nuclear cytoophidia (N-cytoophidia). N-cytoophidia are generally shorter and thinner than their cytoplasmic counterparts. In mammalian cells, both CTP synthase 1 and CTP synthase 2 can form cytoophidia. Using live imaging, we have observed that both C-cytoophidia and N-cytoophidia undergo multiple rounds of fusion upon glutamine analog treatment. Our study reveals the coexistence of cytoophidia in the cytoplasm and nucleus, therefore providing a good opportunity to investigate the intracellular compartmentation of CTP synthase. - Highlights: • CTP synthase forms cytoophidia not only in the cytoplasm but also in the nucleus. • Glutamine deprivation and Glutamine analogs promotes cytoophidium formation. • N-cytoophidia exhibit distinct morphology when compared to C-cytoophidia. • Both CTP synthase 1 and CTP synthase 2 form cytoophidia in mammalian cells. • Fusions of cytoophidia occur in the cytoplasm and nucleus

  3. CTP synthase forms cytoophidia in the cytoplasm and nucleus

    Energy Technology Data Exchange (ETDEWEB)

    Gou, Ke-Mian [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT (United Kingdom); State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193 (China); Chang, Chia-Chun [Institute of Biotechnology, National Taiwan University, Taipei, Taiwan, ROC (China); Shen, Qing-Ji [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT (United Kingdom); Sung, Li-Ying, E-mail: liyingsung@ntu.edu.tw [Institute of Biotechnology, National Taiwan University, Taipei, Taiwan, ROC (China); Agricultural Biotechnology Research Center, Academia Sinica, Taipei 115, Taiwan, ROC (China); Liu, Ji-Long, E-mail: jilong.liu@dpag.ox.ac.uk [MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT (United Kingdom)

    2014-04-15

    CTP synthase is an essential metabolic enzyme responsible for the de novo synthesis of CTP. Multiple studies have recently showed that CTP synthase protein molecules form filamentous structures termed cytoophidia or CTP synthase filaments in the cytoplasm of eukaryotic cells, as well as in bacteria. Here we report that CTP synthase can form cytoophidia not only in the cytoplasm, but also in the nucleus of eukaryotic cells. Both glutamine deprivation and glutamine analog treatment promote formation of cytoplasmic cytoophidia (C-cytoophidia) and nuclear cytoophidia (N-cytoophidia). N-cytoophidia are generally shorter and thinner than their cytoplasmic counterparts. In mammalian cells, both CTP synthase 1 and CTP synthase 2 can form cytoophidia. Using live imaging, we have observed that both C-cytoophidia and N-cytoophidia undergo multiple rounds of fusion upon glutamine analog treatment. Our study reveals the coexistence of cytoophidia in the cytoplasm and nucleus, therefore providing a good opportunity to investigate the intracellular compartmentation of CTP synthase. - Highlights: • CTP synthase forms cytoophidia not only in the cytoplasm but also in the nucleus. • Glutamine deprivation and Glutamine analogs promotes cytoophidium formation. • N-cytoophidia exhibit distinct morphology when compared to C-cytoophidia. • Both CTP synthase 1 and CTP synthase 2 form cytoophidia in mammalian cells. • Fusions of cytoophidia occur in the cytoplasm and nucleus.

  4. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    2012-10-06

    Oct 6, 2012 ... Anyhow, the 'multi-isotope' ansatz is needed to compensate for matrix element ... The neccessary half-life requirement to touch this ... site energy depositions (like double beta decay) and multiple site interactions (most of.

  5. Beta-Carotene

    Science.gov (United States)

    ... disease (COPD). It is also used to improve memory and muscle strength. Some people use beta-carotene ... to reduce the chance of death and night blindness during pregnancy, as well as diarrhea and fever ...

  6. Double beta decay: experiments

    International Nuclear Information System (INIS)

    Fiorini, Ettore

    2006-01-01

    The results obtained so far and those of the running experiments on neutrinoless double beta decay are reviewed. The plans for second generation experiments, the techniques to be adopted and the expected sensitivities are compared and discussed

  7. The Effects of Tryptophan on Everyday Interpersonal Encounters and Social Cognitions in Individuals with a Family History of Depression

    NARCIS (Netherlands)

    Hogenelst, Koen; Schoevers, Robert A.; Rot, Marije Aan Het

    2015-01-01

    Background: Individuals with a family history of depression show subtle abnormalities in the processing of social stimuli. This could negatively affect their interpersonal functioning and contribute to their depression risk. Repeated administration of the serotonin precursor tryptophan has

  8. Cognition following acute tryptophan depletion : Difference between first-degree relatives of bipolar disorder patients and matched healthy control volunteers

    NARCIS (Netherlands)

    Sobczak, S; Riedel, W J; Booij, I; Aan Het Rot, M; Deutz, N E P; Honig, A

    BACKGROUND: Serotonergic circuits have been proposed to mediate cognitive processes, particularly learning and memory. Cognitive impairment is often seen in bipolar disorders in relation to a possible lowered serotonergic turnover. METHODS: We investigated the effects of acute tryptophan depletion

  9. Reduction of cerebral blood flow in subclinical hepatic encephalopathy and its correlation with plasma-free tryptophan

    International Nuclear Information System (INIS)

    Rodriguez, G.; Testa, R.; Celle, G.; Gris, A.; Marenco, S.; Nobili, F.; Novellone, G.; Rosadini, G.

    1987-01-01

    Cerebral blood flow (CBF), measured by the noninvasive xenon-133 inhalation method, EEG, and plasma levels of ammonia (NH 3 ) and free tryptophan were determined in 18 hospitalized cirrhotic patients affected with subclinical hepatic encephalopathy, as diagnosed by the Kurtz test. CBF results were significantly lower (p less than 0.001) in the patients' group as compared with a sex- and age-matched normal control population, although seven patients had values in the normal range. NH 3 was increased only in six, while free tryptophan was increased in all but two patients. A significant negative correlation (p = 0.02) between CBF and free tryptophan was found, even though it appears to be difficult to interpret. We suggest that CBF impairment in some cirrhotic patients with subclinical hepatic encephalopathy may be related to the systemic metabolic derangement caused by the liver disease; free tryptophan could have some implication in producing CBF reduction

  10. Membrane interaction and secondary structure of de novo designed arginine-and tryptophan peptides with dual function

    KAUST Repository

    Rydberg, Hanna A.; Carlsson, Nils; Nordé n, Bengt

    2012-01-01

    of arg/trp peptides and investigated how the position and number of tryptophans affect cellular uptake. Here we explore the antimicrobial properties and the interaction with lipid model membranes of these peptides, using minimal inhibitory concentrations

  11. Metabolism of carbon-14 labelled l-tryptophan, l-kynerenine and hydroxy-l-kynerenine in miners with scleroderma

    International Nuclear Information System (INIS)

    Hankes, L.V.; De Bruin, E.; Jansen, C.R.; Voster, L.; Schmaeler, M.

    1977-01-01

    Six South African white miners were studied with the 2-g l-tryptophan load test and tracer doses of L-tryptophan-7a-carbon-14, L-kynurenine-keto-carbon-14 and hydroxy-L-kynerenine-keto-carbon-14. The breath 14 CO 2 and 14 urinary metabolites were measured. When they were compared with a previous study of American women with scleroderma, similar 14 CO 2 and tryptophan metabolite excretion patterns were observed in the data from the miners. The labelled quinolinic acid excretion was more significantly elevated in the South African miners' urine than in the urine of the American women. The data from both studies suggest that some patients with scleroderma have an altered step in the tryptophan metabolic pathway after hydroxy-anthranilic acid. What relationship exists between the induction of pulmonary silicosis and the subsequent development of scleroderma, requires additional human studies

  12. UVB-induced photoperoxidation of lipids of human low and high density lipoproteins. A possible role of tryptophan residues

    International Nuclear Information System (INIS)

    Salmon, S.; Maziere, J.C.; Santus, R.; Bouchemal, N.; Morliere, P.

    1990-01-01

    Ultraviolet radiation of the UVB region readily destroys tryptophan (Trp) residues of low (LDL) and high (HDL) density lipoproteins. The photooxidation of tryptophan residues is accompanied by peroxidation of low and high density lipoproteins unsaturated fatty acids, as measured by thiobarbituric acid assay. Moreover, low and high density lipoproteins are natural carriers of vitamin E and carotenoids. These two antioxidants are also rapidly bleached by UVB. The UVA radiation promotes neither tryptophan residue destruction nor lipid photoperoxidation. The redox cycling Cu 2+ ions considerably increase lipid photoperoxidation. The synergistic action of photo and auto (Cu 2+ -induced) peroxidation induces marked post-irradiation modifications of apolipoproteins as illustrated by degradation of most tryptophan residues after overnight incubation in the dark of pre-irradiated samples. (author)

  13. {beta} - amyloid imaging probes

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jae Min [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    Imaging distribution of {beta} - amyloid plaques in Alzheimer's disease is very important for early and accurate diagnosis. Early trial of the {beta} -amyloid plaques includes using radiolabeled peptides which can be only applied for peripheral {beta} - amyloid plaques due to limited penetration through the blood brain barrier (BBB). Congo red or Chrysamine G derivatives were labeled with Tc-99m for imaging {beta} - amyloid plaques of Alzheimer patient's brain without success due to problem with BBB penetration. Thioflavin T derivatives gave breakthrough for {beta} - amyloid imaging in vivo, and a benzothiazole derivative [C-11]6-OH-BTA-1 brought a great success. Many other benzothiazole, benzoxazole, benzofuran, imidazopyridine, and styrylbenzene derivatives have been labeled with F-18 and I-123 to improve the imaging quality. However, [C-11]6-OH-BTA-1 still remains as the best. However, short half-life of C-11 is a limitation of wide distribution of this agent. So, it is still required to develop an Tc-99m, F-18 or I-123 labeled agent for {beta} - amyloid imaging agent.

  14. Tryptophan-Assisted Synthesis Reduces Bimetallic Gold/Silver Nanoparticle Cytotoxicity and Improves Biological Activity

    Directory of Open Access Journals (Sweden)

    Igor O. Shmarakov

    2014-10-01

    Full Text Available Aiming to reduce the potential in vivo hepato-and nephrotoxicity of Ag/Au bimetallic nanoparticles (NPs stabilized by sodium dodecyl sulphate (SDS, an approach involving a simultaneous reduction of silver nitrate and tetrachlorauratic acid using tryptophan (Trp as a reducing/stabilizing agent was applied during NP synthesis. The obtained Ag/Au/Trp NPs (5–15 nm sized were able to form stable aggregates with an average size of 370–450 nm and were potentially less toxic than Ag/Au/SDS in relation to a mouse model system based on clinical biochemical parameters and oxidative damage product estimation. Ag/Au/Trp NPs were shown to exhibit anticancer activity in relation to a Lewis lung carcinoma model. The data generated from the present study support the fact that the use of tryptophan in NP synthesis is effective in attenuating the potential hepatotoxicity and nephrotoxicity of NPs during their in vivo application.

  15. Effects of biogenic aldehydes and aldehyde dehydrogenase inhibitors on rat brain tryptophan hydroxylase activity in vitro.

    Science.gov (United States)

    Nilsson, G E; Tottmar, O

    1987-04-21

    The effect of indole-3-acetaldehyde, 5-hydroxyindole-3-acetaldehyde, disulfiram, diethyldithiocarbamate, coprine, and 1-amino-cyclopropanol on tryptophan hydroxylase activity was studied in vitro using high performance liquid chromatography with electro-chemical detection. With the analytical method developed, 5-hydroxytryptophan, serotonin, and 5-hydroxyindole-3-acetic acid could be measured simultaneously. Indole-3-acetaldehyde (12-1200 microM) was found to cause a 6-33% inhibition of the enzyme. Dependent upon the nature of the sulfhydryl- or reducing-agent (dithiotreitol, glutathione, or ascorbate) present in the incubates, the degree of inhibition by disulfiram varied, probably due to the formation of various mixed disulfides. Also the presence of diethyldithiocarbamate (160-1600 microM) was found to inhibit tryptophan hydroxylase (28-91%), while 5-hydroxyindole-3-acetaldehyde, coprine, or 1-aminocyclopropanol appeared to have no effect on the enzyme activity.

  16. Formation of tryptophan radicals in irradiated aqueous solutions of hexachloroplatinate(IV): a flash photolysis study.

    Science.gov (United States)

    Zang, L; Rodgers, M A

    1999-10-01

    The oxidation of tryptophan photosensitized by PtCl6(2-) has been investigated in aqueous solutions at different pH using nanosecond laser flash photolysis. Cationic and neutral radicals of tryptophan were detected at pH 2.8 and 8.5, respectively. The generation of the radical was attributed to oxidation by Cl2- that was formed from the homolytic bond cleavage in the excited state of PtCl6(2-). The bimolecular rate constant derived from the kinetics analysis, 2.8 +/- 0.2 x 10(9) M-1 s-1, is in good agreement with the value obtained in earlier pulse radiolysis studies. Both the cationic and neutral radicals decayed by second-order kinetics, consistent with the dimerization process.

  17. Enzymatic syntheses of some 11C-labelled analogues of L-tyrosine and L-tryptophan

    International Nuclear Information System (INIS)

    Bjurling, P.; Malmborg, P.; Langstroem, B.

    1990-01-01

    In the elucidation of biochemical processes by use of positron emission tomography (PET), the multi-tracer approach can be valuable. In previous work, the authors have been studying the dopaminergic and serotonergic neurosystems by use of 11 C-labelled L-DOPA and 5-hydroxy-L-tryptophan, respectively. They have now developed the syntheses of several analogues of tyrosine and tryptophan, labelled with 11 C in the β-position, which are of interest for use in similar applications

  18. Tryptophan-enriched antioxidant cereals improve sleep in children with autistic spectrum and attention deficit hyperactivity disorders

    OpenAIRE

    Galán, Carmen; Sánchez, Soledad; Franco, Lourdes; Bravo, Rafael; Rivero, Montserrat; Rodríguez, Ana Beatriz; Barriga, Carmen

    2017-01-01

    Theintake of foods rich in tryptophan produces beneficial effects on sleep. Themajority of children with neurological disorders like autistic spectrum disorder(ASD), cerebral palsy or attention deficit hyperactivity disorder (ADHD) havesleep problems. To evaluate the effect of tryptophan-enriched cereal intake onsleep of children with neurological disorders. Involving 7 children with ASD, 9children with cerebral palsy and 6 children with ADHD. They carried a wrist actimeterto record activity....

  19. Multiresponse optimization of a UPLC method for the simultaneous determination of tryptophan and 15 tryptophan-derived compounds using a Box-Behnken design with a desirability function.

    Science.gov (United States)

    Setyaningsih, Widiastuti; Saputro, Irfan E; Carrera, Ceferino A; Palma, Miguel; Barroso, Carmelo G

    2017-06-15

    A Box-Behnken design was used in conjunction with multiresponse optimization based on the desirability function to carry out the simultaneous separation of tryptophan and 15 derivatives by Ultra Performance Liquid Chromatography. The gradient composition of the mobile phase and the flow rate were optimized with respect to the resolution of severely overlapping chromatographic peaks and the total run time. Two different stationary phases were evaluated (hybrid silica and a solid-core-based C 18 column). The methods were validated and a suitable sensitivity was found for all compounds in the concentration range 1-100μgL -1 (R 2 >0.999). High levels of repeatability and intermediate precision (CV less than 0.25% and 1.7% on average for the retention time and the signal area, respectively) were obtained. The new method was applied to the determination tryptophan and its derivatives in black pigmented glutinous and non-glutinous rice grain samples. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. An X11alpha/FSBP complex represses transcription of the GSK3beta gene promoter.

    LENUS (Irish Health Repository)

    Lau, Kwok-Fai

    2010-08-04

    X11alpha is a neuronal adaptor protein that interacts with the amyloid precursor protein (APP) through a centrally located phosphotyrosine binding domain to inhibit the production of Abeta peptide that is deposited in Alzheimer\\'s disease brains. X11alpha also contains two C-terminal postsynaptic density-95, large discs, zona occludens 1 (PDZ) domains, and we show here that through its PDZ domains, X11alpha interacts with a novel transcription factor, fibrinogen silencer binding protein. Moreover, we show that an X11alpha\\/fibrinogen silencer binding protein complex signals to the nucleus to repress glycogen synthase kinase-3beta promoter activity. Glycogen synthase kinase-3beta is a favoured candidate kinase for phosphorylating tau in Alzheimer\\'s disease. Our findings show a new function for X11alpha that may impact on Alzheimer\\'s disease pathogenesis.

  1. Serum Levels of Tryptophan, 5-Hydroxytryptophan and Serotonin in Patients Affected with Different Forms of Amenorrhea

    Directory of Open Access Journals (Sweden)

    S. Comai

    2010-01-01

    Full Text Available Tryptophan (Trp is present in the serum, partly bound to albumine and in the free form. The unbound portion of circulating tryptophan has the property of crossing the hematoencephalic barrier and being converted within the brain into serotonin (5-HT through the enzymatic processes of hydroxylation and decarboxylation. The serotoninergic system plays an important role in neuroendocrine control of reproductive hormone secretion, and in particular, it may influence GnRH pulsatility, a function essential for reproductive processes. In this study, we analysed serum levels of tryptophan, serotonin and 5-hydroxytryptophan (5-HTP in women with three different forms of amenorrhea: 16 patients were diagnosed with anorexia nervosa, 60 patients with functional hypothalamic amenorrhea, and 14 patients with hyperprolactinemia. Data were compared with those of a group of 25 healthy women. Serum Trp levels were significantly (P ≤ 0.05 lower in the anorexic (11.64 ± 0.53 μg/ml, mean ± S.E. than in the control (12.98 ± 0.37 μg/ml groups. In addition, in the anorexic group a statistical dispersion of Trp values was shown indicating a bimodal data distribution suggesting the existence of two different subgroups of patients. Regarding 5-HTP, an increase of its serum level was observed in all the groups with amenorrhea with the highest value in hyperprolactinemic patients. On the contrary, no statistical differences in serum 5-HT levels among the four analyzed groups were observed. This study shows that women affected by various forms of amenorrhea present an altered metabolism of tryptophan via serotonin and, in particular, markedly high differences are observed between the two subgroups of anorexic patients.

  2. Serum Levels of Tryptophan, 5-Hydroxytryptophan and Serotonin in Patients Affected with Different Forms of Amenorrhea

    Directory of Open Access Journals (Sweden)

    S. Comai

    2010-06-01

    Full Text Available Tryptophan (Trp is present in the serum, partly bound to albumine and in the free form. The unbound portion of circulating tryptophan has the property of crossing the hematoencephalic barrier and being converted within the brain into serotonin (5-HT through the enzymatic processes of hydroxylation and decarboxylation. The serotoninergic system plays an important role in neuroendocrine control of reproductive hormone secretion, and in particular, it may influence GnRH pulsatility, a function essential for reproductive processes. In this study, we analysed serum levels of tryptophan, serotonin and 5-hydroxytryptophan (5-HTP in women with three different forms of amenorrhea: 16 patients were diagnosed with anorexia nervosa, 60 patients with functional hypothalamic amenorrhea, and 14 patients with hyperprolactinemia. Data were compared with those of a group of 25 healthy women. Serum Trp levels were significantly (P ≤ 0.05 lower in the anorexic (11.64 ± 0.53 µg/ml, mean ± S.E. than in the control (12.98 ± 0.37 µg/ml groups. In addition, in the anorexic group a statistical dispersion of Trp values was shown indicating a bimodal data distribution suggesting the existence of two different subgroups of patients. Regarding 5-HTP, an increase of its serum level was observed in all the groups with amenorrhea with the highest value in hyperprolactinemic patients. On the contrary, no statistical differences in serum 5-HT levels among the four analyzed groups were observed. This study shows that women affected by various forms of amenorrhea present an altered metabolism of tryptophan via serotonin and, in particular, markedly high differences are observed between the two subgroups of anorexic patients.

  3. Uremic anorexia: a consequence of persistently high brain serotonin levels? The tryptophan/serotonin disorder hypothesis.

    Science.gov (United States)

    Aguilera, A; Selgas, R; Codoceo, R; Bajo, A

    2000-01-01

    Anorexia is a frequent part of uremic syndrome, contributing to malnutrition in dialysis patients. Many factors have been suggested as responsible for uremic anorexia. In this paper we formulate a new hypothesis to explain the appetite disorders in dialysis patients: "the tryptophan/serotonin disorder hypothesis." We review current knowledge of normal hunger-satiety cycle control and the disorders described in uremic patients. There are four phases in food intake regulation: (1) the gastric phase, during which food induces satiety through gastric distention and satiety peptide release; (2) the post absorptive phase, during which circulating compounds, including glucose and amino acids, cause satiety by hepatic receptors via the vagus nerve; (3) the hepatic phase, during which adenosine triphosphate (ATP) concentration is the main stimulus inducing hunger or satiety, with cytokines inhibiting ATP production; and (4) the central phase, during which appetite is regulated through peripheral (circulating plasma substances and neurotransmitters) and brain stimuli. Brain serotonin is the final target for peripheral mechanisms controlling appetite. High brain serotonin levels and a lower serotonin/dopamine ratio cause anorexia. Plasma and brain amino acid concentrations are recognized factors involved in neurotransmitter synthesis and appetite control. Tryptophan is the substrate of serotonin synthesis. High plasma levels of anorectics such as tryptophan (plasma and brain), cholecystokinin, tumor necrosis factor alpha, interleukin-1, and leptin, and deficiencies of nitric oxide and neuropeptide Y have been described in uremia; all increase intracerebral serotonin. We suggest that brain serotonin hyperproduction due to a uremic-dependent excess of tryptophan may be the final common pathway involved in the genesis of uremic anorexia. Various methods of ameliorating anorexia by decreasing the central effects of serotonin are proposed.

  4. Dynamic Allostery Mediated by a Conserved Tryptophan in the Tec Family Kinases.

    Directory of Open Access Journals (Sweden)

    Nikita Chopra

    2016-03-01

    Full Text Available Bruton's tyrosine kinase (Btk is a Tec family non-receptor tyrosine kinase that plays a critical role in immune signaling and is associated with the immunological disorder X-linked agammaglobulinemia (XLA. Our previous findings showed that the Tec kinases are allosterically activated by the adjacent N-terminal linker. A single tryptophan residue in the N-terminal 17-residue linker mediates allosteric activation, and its mutation to alanine leads to the complete loss of activity. Guided by hydrogen/deuterium exchange mass spectrometry results, we have employed Molecular Dynamics simulations, Principal Component Analysis, Community Analysis and measures of node centrality to understand the details of how a single tryptophan mediates allostery in Btk. A specific tryptophan side chain rotamer promotes the functional dynamic allostery by inducing coordinated motions that spread across the kinase domain. Either a shift in the rotamer population, or a loss of the tryptophan side chain by mutation, drastically changes the coordinated motions and dynamically isolates catalytically important regions of the kinase domain. This work also identifies a new set of residues in the Btk kinase domain with high node centrality values indicating their importance in transmission of dynamics essential for kinase activation. Structurally, these node residues appear in both lobes of the kinase domain. In the N-lobe, high centrality residues wrap around the ATP binding pocket connecting previously described Catalytic-spine residues. In the C-lobe, two high centrality node residues connect the base of the R- and C-spines on the αF-helix. We suggest that the bridging residues that connect the catalytic and regulatory architecture within the kinase domain may be a crucial element in transmitting information about regulatory spine assembly to the catalytic machinery of the catalytic spine and active site.

  5. No Tryptophan, Tyrosine and Phenylalanine Abnormalities in Children with Attention-Deficit/Hyperactivity Disorder

    OpenAIRE

    Bergwerff, C.E.; Luman, M.; Blom, H.J.; Oosterlaan, J.

    2016-01-01

    Background The aim of the current study was to explore the role of aromatic amino acids (AAAs) in blood in relation to attention-deficit/hyperactivity disorder (ADHD). Given their impact on the synthesis of serotonin and dopamine, decreased concentrations of the AAAs tryptophan, tyrosine and phenylalanine in blood may contribute to the expression of ADHD symptoms. Decreased AAA blood concentrations, in turn, may be related to lowered dietary protein intake or to abnormal AAA catabolism, as ev...

  6. Effects of Acute Tryptophan Depletion on Three Different Types of Behavioral Impulsivity

    Directory of Open Access Journals (Sweden)

    Donald M. Dougherty

    2010-01-01

    Full Text Available Introduction While central nervous system serotonin has been implicated in a variety of problematic impulsive behaviors, biological manipulation of brain serotonin using acute tryptophan depletion for studying changes in impulsive behavior has received little attention. Methods Using identical treatment conditions, we examined the effects of reduced serotonin synthesis for each of three matched groups using acute tryptophan depletion. Thirty healthy men and women (ages 18–45 were assigned to perform one of three tasks assessing different types of behavioral impulsivity: response initiation, response inhibition, and consequence sensitivity ( N = 90. Participants completed two experimental days during which each consumed either a tryptophan-depletion or balanced-placebo amino-acid formulation and completed 5 sessions of their respective tasks at 0.25 h before and 1.5, 4.0, 5.0, and 6.0 h after beverage consumption. Results During peak effectiveness (5.0 h to 6.0 h following amino-acid consumption, depletion produced selective differences dependent on the type of impulsivity being tested. Specifically, relative to baseline testing (pre-depletion, response initiation impulsivity was significantly increased during the peak effects of depletion. And, when compared to placebo control, both response initiation and consequence sensitivity impulsivity were increased during the peak effects of depletion. Conclusion Though response initiation and consequence sensitivity impulsivity were affected by tryptophan depletion, response inhibition impulsivity was not, suggesting that other biological processes may underlie this specific component of impulsivity. Future research in other populations or using different pharmacological agents is warranted to further examine the biological processes underlying these components of impulsivity.

  7. Effects of Acute Tryptophan Depletion on Three Different Types of Behavioral Impulsivity

    Directory of Open Access Journals (Sweden)

    Donald M. Dougherty

    2010-06-01

    Full Text Available Introduction: While central nervous system serotonin has been implicated in a variety of problematic impulsive behaviors, biological manipulation of brain serotonin using acute tryptophan depletion for studying changes in impulsive behavior has received little attention. Methods: Using identical treatment conditions, we examined the effects of reduced serotonin synthesis for each of three matched groups using acute tryptophan depletion. Thirty healthy men and women (ages 18–45 were assigned to perform one of three tasks assessing different types of behavioral impulsivity: response initiation, response inhibition, and consequence sensitivity (N = 90. Participants completed two experimental days during which each consumed either a tryptophan-depletion or balanced-placebo amino-acid formulation and completed 5 sessions of their respective tasks at 0.25 h before and 1.5, 4.0, 5.0, and 6.0 h after beverage consumption. Results: During peak effectiveness (5.0 h to 6.0 h following amino-acid consumption, depletion produced selective differences dependent on the type of impulsivity being tested. Specifically, relative to baseline testing (pre-depletion, response initiation impulsivity was significantly increased during the peak effects of depletion. And, when compared to placebo control, both response initiation and consequence sensitivity impulsivity were increased during the peak effects of depletion. Conclusion: Though response initiation and consequence sensitivity impulsivity were affected by tryptophan depletion, response inhibition impulsivity was not, suggesting that other biological processes may underlie this specific component of impulsivity. Future research in other populations or using different pharmacological agents is warranted to further examine the biological processes underlying these components of impulsivity.

  8. Alpha and beta adrenergic effects on metabolism in contracting, perfused muscle

    DEFF Research Database (Denmark)

    Richter, Erik; Ruderman, N B; Galbo, H

    1982-01-01

    The role of alpha- and beta-adrenergic receptor stimulation for the effect of epinephrine on muscle glycogenolysis, glucose- and oxygen uptake and muscle performance was studied in the perfused rat hindquarter at rest and during electrical stimulation (60 contractions/min). Adrenergic stimulation...... was obtained by epinephrine in a physiological concentration (2.4 X 10(-8) M) and alpha- and beta-adrenergic blockade by 10(-5) M phentolamine and propranolol, respectively. Epinephrine enhanced net glycogenolysis during contractions most markedly in slow-twitch red fibers. In these fibers the effect...... was mediated by alpha- as well as by beta-adrenergic stimulation, the latter involving production of cAMP, phosphorylase activation and synthase inactivation. In contrast, in fast-twitch fibers only beta-adrenergic mechanisms were involved in the glycogenolytic effect of epinephrine. Moreover, inactivation...

  9. The role of adrenal hormones in the activation of tryptophan 2,3-dioxygenase by nicotinic acid in rat liver.

    Science.gov (United States)

    Sainio, E L

    1997-09-01

    In this study, our previous finding that nicotinic acid activates tryptophan 2,3-dioxygenase as strongly as tryptophan was investigated in further detail. This study focused on the role of the adrenals in the activation process. Adrenalectomy abolished the activation due to nicotinic acid, but not the activation caused by tryptophan. The role of corticoids and/or adrenomedullary hormones in the enzyme activation was studied, by supplementing these hormones in adrenalectomized rats using minipumps implanted under the skin. The results showed that the enhanced activity of tryptophan 2,3-dioxygenase caused by nicotinic acid was partly restored by adrenaline following adrenalectomy but not by corticosterone supplementation. The results were supported by further experiments in which the rats were treated with adrenaline or corticosterone intraperitoneally before nicotinic acid administration. The conclusion that adrenaline participates in the regulation of tryptophan 2,3-dioxygenase should promote further study to determine whether adrenaline is a general modulator of this enzyme. This experimental model generated new information on the activation mechanism of tryptophan 2,3-dioxygenase by nicotinic acid.

  10. l-Tryptophan Radical Cation Electron Spin Resonance Studies: Connecting Solution-derived Hyperfine Coupling Constants with Protein Spectral Interpretations

    Science.gov (United States)

    Connor, Henry D.; Sturgeon, Bradley E.; Mottley, Carolyn; Sipe, Herbert J.; Mason, Ronald P.

    2009-01-01

    Fast-flow electron spin resonance (ESR) spectroscopy has been used to detect a free radical formed from the reaction of l-tryptophan with Ce4+ in an acidic aqueous environment. Computer simulations of the ESR spectra from l-tryptophan and several isotopically modified forms strongly support the conclusion that the l-tryptophan radical cation has been detected by ESR for the first time. The hyperfine coupling constants (HFCs) determined from the well-resolved isotropic ESR spectra support experimental and computational efforts to understand l-tryptophan's role in protein catalysis of oxidation-reduction processes. l-tryptophan HFCs facilitated the simulation of fast-flow ESR spectra of free radicals from two related compounds, tryptamine and 3-methylindole. Analysis of these three compounds' β-methylene hydrogen HFC data along with equivalent l-tyrosine data has led to a new computational method that can distinguish between these two amino acid free radicals in proteins without dependence on isotope labeling, electron nuclear double resonance or high-field ESR. This approach also produces geometric parameters (dihedral angles for the β-methylene hydrogens) which should facilitate protein site assignment of observed l-tryptophan radicals as has been done for l-tyrosine radicals. PMID:18433127

  11. Stable isotope labeling, in vivo, of D- and L-tryptophan pools in lemna gibba and the low incorporation of label into indole-3-acetic acid

    International Nuclear Information System (INIS)

    Baldi, B.G.; Maher, B.R.; Slovin, J.P.; Cohen, J.D.

    1991-01-01

    The authors present evidence that the role of tryptophan and other potential intermediates in the pathways that could lead to indole derivatives needs to be reexamined. Two lines of Lemna gibba were tested for uptake of [ 15 N-indole]-labeled tryptophan isomers and incorporation of that label into free indole-3-acetic acid (IAA). Both lines required levels of L-[ 15 N]tryptophan 2 to 3 orders of magnitude over endogenous levels in order to obtain measurable incorporation of label into IAA. Labeled L-tryptophan was extractable from plant tissue after feeding and showed no measurable isomerization into D-tryptophan. D-[ 15 N]trytophan supplied to Lemna at rates of approximately 400 times excess of endogenous D-tryptophan levels (to yield an isotopic enrichment equal to that which allowed detection of the incorporation of L-tryptophan into IAA), did not result in measurable incorporation of label into free IAA. These results demonstrate that L-tryptophan is a more direct precursor to IAA than the D isomer and suggest (a) that the availability of tryptophan in vivo is not a limiting factor in the biosynthesis of IAA, thus implying that other regulatory mechanisms are in operation and (b) that L-tryptophan also may not be a primary precursor to IAA in plants

  12. Candida glabrata tryptophan-based pigment production via the Ehrlich pathway.

    Science.gov (United States)

    Brunke, Sascha; Seider, Katja; Almeida, Ricardo Sergio; Heyken, Antje; Fleck, Christian Benjamin; Brock, Matthias; Barz, Dagmar; Rupp, Steffen; Hube, Bernhard

    2010-04-01

    Pigments contribute to the pathogenicity of many fungi, mainly by protecting fungal cells from host defence activities. Here, we have dissected the biosynthetic pathway of a tryptophan-derived pigment of the human pathogen Candida glabrata, identified key genes involved in pigment production and have begun to elucidate the possible biological function of the pigment. Using transcriptional analyses and a transposon insertion library, we have identified genes associated with pigment production. Targeted deletion mutants revealed that the pigment is a by-product of the Ehrlich pathway of tryptophan degradation: a mutant lacking a tryptophan-upregulated aromatic aminotransferase (Aro8) displayed significantly reduced pigmentation and a recombinantly expressed version of this protein was sufficient for pigment production in vitro. Pigment production is tightly regulated as the synthesis is affected by the presence of alternative nitrogen sources, carbon sources, cyclic AMP and oxygen. Growth of C. glabrata on pigment inducing medium leads to an increased resistance to hydrogen peroxide, an effect which was not observed with a mutant defective in pigmentation. Furthermore, pigmented yeast cells had a higher survival rate when exposed to human neutrophils and caused increased damage in a monolayer model of human epithelia, indicating a possible role of pigmentation during interactions with host cells.

  13. The Potential Role of Cannabinoids in Modulating Serotonergic Signaling by Their Influence on Tryptophan Metabolism

    Directory of Open Access Journals (Sweden)

    Dietmar Fuchs

    2010-08-01

    Full Text Available Phytocannabinoids present in Cannabis plants are well known to exert potent anti-inflammatory and immunomodulatory effects. Previously, we have demonstrated that the psychoactive D9-tetrahydrocannabinol (THC and the non-psychotropic cannabidiol (CBD modulate mitogen-induced Th1-type immune responses in peripheral blood mononuclear cells (PBMC. The suppressive effect of both cannabinoids on mitogen-induced tryptophan degradation mediated by indoleamine-2,3-dioxygenase (IDO, suggests an additional mechanism by which antidepressive effects of cannabinoids might be linked to the serotonergic system. Here, we will review the role of tryptophan metabolism in the course of cell mediated immune responses and the relevance of cannabinoids in serotonergic signaling. We conclude that in particular the non-psychotropic CBD might be useful for the treatment of mood disorders in patients with inflammatory diseases, since this cannabinoid seems to be safe and its effects on activation-induced tryptophan degradation by CBD were more potent as compared to THC.

  14. Application of Tryptophan Fluorescence Bandwidth-Maximum Plot in Analysis of Monoclonal Antibody Structure.

    Science.gov (United States)

    Huang, Cheng-Yen; Hsieh, Ming-Ching; Zhou, Qinwei

    2017-04-01

    Monoclonal antibodies have become the fastest growing protein therapeutics in recent years. The stability and heterogeneity pertaining to its physical and chemical structures remain a big challenge. Tryptophan fluorescence has been proven to be a versatile tool to monitor protein tertiary structure. By modeling the tryptophan fluorescence emission envelope with log-normal distribution curves, the quantitative measure can be exercised for the routine characterization of monoclonal antibody overall tertiary structure. Furthermore, the log-normal deconvolution results can be presented as a two-dimensional plot with tryptophan emission bandwidth vs. emission maximum to enhance the resolution when comparing samples or as a function of applied perturbations. We demonstrate this by studying four different monoclonal antibodies, which show the distinction on emission bandwidth-maximum plot despite their similarity in overall amino acid sequences and tertiary structures. This strategy is also used to demonstrate the tertiary structure comparability between different lots manufactured for one of the monoclonal antibodies (mAb2). In addition, in the unfolding transition studies of mAb2 as a function of guanidine hydrochloride concentration, the evolution of the tertiary structure can be clearly traced in the emission bandwidth-maximum plot.

  15. Ultrafast quenching of tryptophan fluorescence in proteins: Interresidue and intrahelical electron transfer

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Weihong; Li Tanping; Zhang Luyuan; Yang Yi; Kao Yating; Wang Lijuan [Department of Physics, Chemistry, and Biochemistry, Program of Biophysics, Chemical Physics, and Biochemistry, Ohio State University, Columbus, OH 43210 (United States); Zhong Dongping [Department of Physics, Chemistry, and Biochemistry, Program of Biophysics, Chemical Physics, and Biochemistry, Ohio State University, Columbus, OH 43210 (United States)], E-mail: dongping@mps.ohio-state.edu

    2008-06-23

    Quenching of tryptophan fluorescence in proteins has been critical to the understanding of protein dynamics and enzyme reactions using tryptophan as a molecular optical probe. We report here our systematic examinations of potential quenching residues with more than 40 proteins. With site-directed mutation, we placed tryptophan to desired positions or altered its neighboring residues to screen quenching groups among 20 amino acid residues and of peptide backbones. With femtosecond resolution, we observed the ultrafast quenching dynamics within 100 ps and identified two ultrafast quenching groups, the carbonyl- and sulfur-containing residues. The former is glutamine and glutamate residues and the later is disulfide bond and cysteine residue. The quenching by the peptide-bond carbonyl group as well as other potential residues mostly occurs in longer than 100 ps. These ultrafast quenching dynamics occur at van der Waals distances through intraprotein electron transfer with high directionality. Following optimal molecular orbital overlap, electron jumps from the benzene ring of the indole moiety in a vertical orientation to the LUMO of acceptor quenching residues. Molecular dynamics simulations were invoked to elucidate various correlations of quenching dynamics with separation distances, relative orientations, local fluctuations and reaction heterogeneity. These unique ultrafast quenching pairs, as recently found to extensively occur in high-resolution protein structures, may have significant biological implications.

  16. Caspase recruitment domain 9, microbiota, and tryptophan metabolism: dangerous liaisons in inflammatory bowel diseases.

    Science.gov (United States)

    Lamas, Bruno; Richard, Mathias L; Sokol, Harry

    2017-07-01

    Inflammatory bowel diseases (IBDs) develop as a result of a combination of genetic predisposition, dysbiosis of the gut microbiota, and environmental influences. Here, we describe an example of how caspase recruitment domain 9 (CARD9), one of the numerous IBD susceptibility genes, participate to colitis susceptibility by shaping gut microbiota to produce tryptophan metabolites. Recent study showed that CARD9 mice are more susceptible to colitis as a result of impaired interleukin 22 signaling pathway. Furthermore, aryl hydrocarbon receptor (AhR) ligands from tryptophan metabolism by the gut microbiota participate to intestinal homeostasis by inducing production of interleukin 22 by intestinal immune cells. These data suggest an interaction between CARD9 and the ability of gut microbiota to produce AhR ligands. The microbiota from CARD9 mice fails to metabolize tryptophan leading to defective AhR activation which contributes to the susceptibility of mice to colitis by decreased interleukin 22 production. These effects were abrogated in the presence of AhR agonist. Reduced production of AhR ligands is also observed in the microbiota from individuals with IBD, particularly in those with CARD9 risk alleles associated with IBD. Correcting impaired microbiota functions, such as ability to produce AhR ligands, is an attractive strategy in IBD.

  17. Tryptophan derivatives regulate the transcription of Oct4 in stem-like cancer cells.

    Science.gov (United States)

    Cheng, Jie; Li, Wenxin; Kang, Bo; Zhou, Yanwen; Song, Jiasheng; Dan, Songsong; Yang, Ying; Zhang, Xiaoqian; Li, Jingchao; Yin, Shengyong; Cao, Hongcui; Yao, Hangping; Zhu, Chenggang; Yi, Wen; Zhao, Qingwei; Xu, Xiaowei; Zheng, Min; Zheng, Shusen; Li, Lanjuan; Shen, Binghui; Wang, Ying-Jie

    2015-06-10

    The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor that responds to environmental toxicants, is increasingly recognized as a key player in embryogenesis and tumorigenesis. Here we show that a variety of tryptophan derivatives that act as endogenous AhR ligands can affect the transcription level of the master pluripotency factor Oct4. Among them, ITE enhances the binding of the AhR to the promoter of Oct4 and suppresses its transcription. Reduction of endogenous ITE levels in cancer cells by tryptophan deprivation or hypoxia leads to Oct4 elevation, which can be reverted by administration with synthetic ITE. Consequently, synthetic ITE induces the differentiation of stem-like cancer cells and reduces their tumorigenic potential in both subcutaneous and orthotopic xenograft tumour models. Thus, our results reveal a role of tryptophan derivatives and the AhR signalling pathway in regulating cancer cell stemness and open a new therapeutic avenue to target stem-like cancer cells.

  18. Clinical significance of Phosphatidyl Inositol Synthase overexpression in oral cancer

    International Nuclear Information System (INIS)

    Kaur, Jatinder; Sawhney, Meenakshi; DattaGupta, Siddartha; Shukla, Nootan K; Srivastava, Anurag; Ralhan, Ranju

    2010-01-01

    We reported increased levels of Phosphatidyl Inositol synthase (PI synthase), (enzyme that catalyses phosphatidyl inositol (PI) synthesis-implicated in intracellular signaling and regulation of cell growth) in smokeless tobacco (ST) exposed oral cell cultures by differential display. This study determined the clinical significance of PI synthase overexpression in oral squamous cell carcinoma (OSCC) and premalignant lesions (leukoplakia), and identified the downstream signaling proteins in PI synthase pathway that are perturbed by smokeless tobacco (ST) exposure. Tissue microarray (TMA) Immunohistochemistry, Western blotting, Confocal laser scan microscopy, RT-PCR were performed to define the expression of PI synthase in clinical samples and in oral cell culture systems. Significant increase in PI synthase immunoreactivity was observed in premalignant lesions and OSCCs as compared to oral normal tissues (p = 0.000). Further, PI synthase expression was significantly associated with de-differentiation of OSCCs, (p = 0.005) and tobacco consumption (p = 0.03, OR = 9.0). Exposure of oral cell systems to smokeless tobacco (ST) in vitro confirmed increase in PI synthase, Phosphatidylinositol 3-kinase (PI3K) and cyclin D1 levels. Collectively, increased PI synthase expression was found to be an early event in oral cancer and a target for smokeless tobacco

  19. Genomic Analysis of Terpene Synthase Family and Functional Characterization of Seven Sesquiterpene Synthases from Citrus sinensis

    Directory of Open Access Journals (Sweden)

    Berta Alquézar

    2017-08-01

    Full Text Available Citrus aroma and flavor, chief traits of fruit quality, are derived from their high content in essential oils of most plant tissues, including leaves, stems, flowers, and fruits. Accumulated in secretory cavities, most components of these oils are volatile terpenes. They contribute to defense against herbivores and pathogens, and perhaps also protect tissues against abiotic stress. In spite of their importance, our understanding of the physiological, biochemical, and genetic regulation of citrus terpene volatiles is still limited. The availability of the sweet orange (Citrus sinensis L. Osbeck genome sequence allowed us to characterize for the first time the terpene synthase (TPS family in a citrus type. CsTPS is one of the largest angiosperm TPS families characterized so far, formed by 95 loci from which just 55 encode for putative functional TPSs. All TPS angiosperm families, TPS-a, TPS-b, TPS-c, TPS-e/f, and TPS-g were represented in the sweet orange genome, with 28, 18, 2, 2, and 5 putative full length genes each. Additionally, sweet orange β-farnesene synthase, (Z-β-cubebene/α-copaene synthase, two β-caryophyllene synthases, and three multiproduct enzymes yielding β-cadinene/α-copaene, β-elemene, and β-cadinene/ledene/allo-aromandendrene as major products were identified, and functionally characterized via in vivo recombinant Escherichia coli assays.

  20. Chrysanthemyl diphosphate synthase operates in planta as a bifunctional enzyme with chrysanthemol synthase activity

    DEFF Research Database (Denmark)

    Yang, Ting; Gao, Liping; Hu, Hao

    2014-01-01

    Chrysanthemyl diphosphate synthase (CDS) is the first path-way-specific enzyme in the biosynthesis of pyrethrins, the most widely used plant-derived pesticide. CDS catalyzes c1′-2-3 cyclopropanation reactions of two molecules of dimethylallyl diphosphate (DMAPP) to yield chrysanthemyl diphosphate...

  1. Effects of tryptophan depletion on selective serotonin reuptake inhibitor-remitted patients with obsessive compulsive disorder.

    Science.gov (United States)

    Hood, Sean D; Broyd, Annabel; Robinson, Hayley; Lee, Jessica; Hudaib, Abdul-Rahman; Hince, Dana A

    2017-12-01

    Serotonergic antidepressants are first-line medication therapies for obsessive-compulsive disorder, however it is not known if synaptic serotonin availability is important for selective serotonin reuptake inhibitor efficacy. The present study tested the hypothesis that temporary reduction in central serotonin transmission, through acute tryptophan depletion, would result in an increase in anxiety in selective serotonin reuptake inhibitor-remitted obsessive-compulsive disorder patients. Eight patients (four males) with obsessive-compulsive disorder who showed sustained clinical improvement with selective serotonin reuptake inhibitor treatment underwent acute tryptophan depletion in a randomized, double-blind, placebo-controlled, within-subjects design, over two days one week apart. Five hours after consumption of the depleting/sham drink the participants performed a personalized obsessive-compulsive disorder symptom exposure task. Psychological responses were measured using the Spielberger State Anxiety Inventory, Yale-Brown Obsessive Compulsive Scale and Visual Analogue Scales. Free plasma tryptophan to large neutral amino acid ratio decreased by 93% on the depletion day and decreased by 1% on the sham day, as anticipated. Psychological rating scores as measured by Visual Analogue Scale showed a significant decrease in perceived control and increase in interfering thoughts at the time of provocation on the depletion day but not on the sham day. A measure of convergent validity, namely Visual Analogue Scale Similar to past, was significantly higher at the time of provocation on both the depletion and sham days. Both the depletion and time of provocation scores for Visual Analogue Scale Anxiety, Spielberger State Anxiety Inventory, Yale-Brown Obsessive Compulsive Scale and blood pressure were not significant. Acute tryptophan depletion caused a significant decrease in perceived control and increase in interfering thoughts at the time of provocation. Acute tryptophan

  2. Boosted beta regression.

    Directory of Open Access Journals (Sweden)

    Matthias Schmid

    Full Text Available Regression analysis with a bounded outcome is a common problem in applied statistics. Typical examples include regression models for percentage outcomes and the analysis of ratings that are measured on a bounded scale. In this paper, we consider beta regression, which is a generalization of logit models to situations where the response is continuous on the interval (0,1. Consequently, beta regression is a convenient tool for analyzing percentage responses. The classical approach to fit a beta regression model is to use maximum likelihood estimation with subsequent AIC-based variable selection. As an alternative to this established - yet unstable - approach, we propose a new estimation technique called boosted beta regression. With boosted beta regression estimation and variable selection can be carried out simultaneously in a highly efficient way. Additionally, both the mean and the variance of a percentage response can be modeled using flexible nonlinear covariate effects. As a consequence, the new method accounts for common problems such as overdispersion and non-binomial variance structures.

  3. Labelling of. beta. -endorphin (. beta. -END) and. beta. -lipotropin (. beta. -LPH) by /sup 125/I

    Energy Technology Data Exchange (ETDEWEB)

    Deby-Dupont, G.; Joris, J.; Franchimont, P. (Universite de Liege (Belgique)); Reuter, A.M.; Vrindts-Gevaert, Y. (Institut des Radioelements, Fleurus (Belgique))

    1983-01-01

    5 ..mu..g of human ..beta..-endorphin were labelled with 2 mCi /sup 125/I by the chloramine T technique. After two gel filtrations on Sephadex G-15 and on Sephadex G-50 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer was obtained with a specific activity about 150 ..mu..Ci/..mu..g.Kept at + 4/sup 0/C, the tracer remained utilizable for 30 days without loss of immunoreactivity. The labelling with lactoperoxydase and the use of another gel filtration method (filtration on Aca 202) gave a /sup 125/I ..beta..-END tracer with the same immunoreactivity. The binding of this tracer to the antibody of an anti-..beta..-END antiserum diluted at 1/8000 was 32% with a non specific binding of 2%. 5 ..mu..g of human ..beta..-lipotropin were labelled with 0.5 mCi /sup 125/I by the lactoperoxydase method. After two gel filtrations on Sephadex G-25 and on Sephadex G-75 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer with a specific activity of 140 ..mu..Ci/..mu..g was obtained. It remained utilizable for 30 days when kept at + 4/sup 0/C. Gel filtration on Aca 202 did not give good purification, while gel filtration on Aca 54 was good but slower than on Sephadex G-75. The binding to antibody in absence of unlabelled ..beta..-LPH was 32% for an anti-..beta..-LPH antiserum diluted at 1/4000. The non specific binding was 2.5%.

  4. Antioxidative properties of harmane and beta-carboline alkaloids.

    Science.gov (United States)

    Tse, S Y; Mak, I T; Dickens, B F

    1991-07-15

    beta-Carboline alkaloids are derived as a result of condensation between indoleamine (e.g. tryptamine) and short-chain carboxylic acid (e.g. pyruvic acid) or aldehyde (e.g. acetaldehyde), a reaction that occurs readily at room temperature. These compounds have been found endogenously in human and animal tissues and may be formed as a byproduct of secondary metabolism: their endogenous functions however, are not well understood. Indoles and tryptophan derivatives exhibit antioxidative actions by scavenging free radicals and forming resonance stabilized indolyl radicals. Harmane and related compounds exhibited concentration-dependent inhibition of lipid peroxidation (measured as thiobarbiturate reactive products) in a hepatic microsomal preparation incubated with either enzymatic dependent (Fe3+ ADP/NADPH) or non-enzymatic dependent (Fe3+ ADP/dihydroxyfumarate) oxygen radical producing systems. Alkaloids with hydroxyl substitution and a partially desaturated pyridyl ring were found to have the highest antioxidative potencies. Substitution of a hydroxyl group by a methoxyl group at the 6-position resulted in a decrease of greater than 10-fold in the antioxidative activities. Harmane showed high efficacy in an enzymatic system but low efficacy in a non-enzymatic system. The antioxidative effects of harmane in the former system may be attributed to its ability to inhibit oxidative enzymes in the microsomal system. These results suggest that beta-carbolines may also serve as endogenous antioxidants.

  5. Homocystinuria due to cystathionine beta-synthase (CBS deficiency in Russia: Molecular and clinical characterization

    Directory of Open Access Journals (Sweden)

    Elena Voskoboeva

    2018-03-01

    Full Text Available We present the results of the 45-year clinical observation of 27 Russian homocystinuria patients. We made a mutation analysis of the CBS gene for thirteen patients from eleven unrelated genealogies. All patients except for the two were compound heterozygotes for the mutations detected. The most frequent mutation in the cohort investigated was splice mutation IVS11-2a->c. We detected one new nonsense mutation, one new missense-mutation and three novel small deletions. We also report the clinical case of the B6-responsive patient genotyped as Ile278Thr/Cys109Arg.

  6. Plasma beta HCG determination

    International Nuclear Information System (INIS)

    Amaral, L.B.D.; Pinto, J.C.M.; Linhares, E.; Linhares, Estevao

    1981-01-01

    There are three important indications for the early diagnosis of pregnancy through the determination of the beta sub-unit of chorionic gonadotrophin using radioimmunoassay: 1) some patient's or doctor's anxiety to discover the problem; 2) when it will be necessary to employ diagnostic or treatment procedures susceptible to affect the ovum; and 3) in the differential diagnosis of amenorrhoea, uterine hemorrhage and abdominal tumors. Other user's are the diagnosis of missed absortion, and the diagnosis and follow-up of chrorioncarcinoma. The AA. studied 200 determinations of plasma beta-HCG, considering the main difficulties occuring in the clinical use of this relevant laboratory tool in actual Obstetrics. (author) [pt

  7. Relation between the 2{nu}{beta}{beta} and 0{nu}{beta}{beta} nuclear matrix elements

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, Petr [Kellogg Radiation Laboratory, Caltech, Pasadena, CA 91125 (United States); Simkovic, Fedor [Department of Nuclear Physics and Biophysics, Comenius University, Mlynska dolina F1, SK-84248 Bratislava (Slovakia)

    2011-12-16

    A formal relation between the GT part of the nuclear matrix elements M{sub GT}{sup 0{nu}} of 0{nu}{beta}{beta} decay and the closure matrix elements M{sub cl}{sup 2{nu}} of 2{nu}{beta}{beta} decay is established. This relation is based on the integral representation of these quantities in terms of their dependence on the distance r between the two nucleons undergoing transformation. We also discuss the difficulties in determining the correct values of the closure 2{nu}{beta}{beta} decay matrix elements.

  8. Dysbiosis of the Vaginal Microbiota and Higher Vaginal Kynurenine/Tryptophan Ratio Reveals an Association with Chlamydia trachomatis Genital Infections

    Directory of Open Access Journals (Sweden)

    Noa Ziklo

    2018-01-01

    Full Text Available The natural course of Chlamydia trachomatis urogenital tract infections varies between individuals. While protective immunity can occur, some women can become reinfected, contributing to the development of severe pathology. While the reasons for these differences are unknown, an individual's response to induced interferon-γ (IFN-γ is suggested to be critical. IFN-γ induction of the enzyme indoleamine 2,3-dioxygenase, which depletes tryptophan, may be the key. One hypothesis suggests that indole-producing bacteria in the vaginal microbiota can provide a substrate for the Chlamydia to synthesize tryptophan, rescuing the Chlamydia from host IFN-γ attack. We studied a cohort of 25 women who were either, Chlamydia negative, Chlamydia positive with a single infection, or Chlamydia positive with repeated infection, to test our hypothesis. We characterized their vaginal microbiota, cytokine response, as well as their tryptophan, kynurenine and indole concentrations directly in vaginal secretions. We found that C. trachomatis urogenital tract infections either initial or repeat infections, were associated with elevated vaginal kynurenine/tryptophan ratios, primarily as a result of elevated kynurenine levels. In addition, vaginal microbiota of community state type (CST IV showed significantly lower vaginal tryptophan levels compared to CST I and III, which might be related to a higher abundance of indole producers found within this group. Furthermore, we found a higher abundance of indole producers in women who cleared their Chlamydia infection post antibiotic treatment. This study demonstrates for the first time in vivo, the association between high vaginal kynurenine/tryptophan ratios and C. trachomatis infections. In addition, tryptophan depletion was associated with vaginal microbiota of CST IV.

  9. Revisiting the tryptophan-serotonin deficiency and the inflammatory hypotheses of major depression in a biopsychosocial approach

    Directory of Open Access Journals (Sweden)

    Andreas Baranyi

    2017-11-01

    Full Text Available Background The aim of this cross-sectional study was to identify important biopsychosocial correlates of major depression. Biological mechanisms, including the inflammatory and the tryptophan-serotonin deficiency hypotheses of major depression, were investigated alongside health-related quality of life, life satisfaction, and social support. Methods The concentrations of plasma tryptophan, plasma kynurenine, plasma kynurenic acid, serum quinolinic acid, and the tryptophan breakdown to kynurenine were determined alongside health-related quality of life (Medical Outcome Study Form, SF-36, life satisfaction (Life Satisfaction Questionnaire, FLZ, and social support (Social Support Survey, SSS in 71 depressive patients at the time of their in-patient admittance and 48 healthy controls. Results Corresponding with the inflammatory hypothesis of major depression, our study results suggest a tryptophan breakdown to kynurenine in patients with major depression, and depressive patients had a lower concentration of neuroprotective kynurenic acid in comparison to the healthy controls (Mann–Whitney-U: 1315.0; p = 0.046. Contradicting the inflammatory theory, the concentrations of kynurenine (t: −0.945; df = 116; p = 0.347 and quinolinic acid (Mann-Whitney-U: 1376.5; p = 0.076 in depressive patients were not significantly different between depressed and healthy controls. Our findings tend to support the tryptophan-serotonin deficiency hypothesis of major depression, as the deficiency of the serotonin precursor tryptophan in depressive patients (t: −3.931; df = 116; p < 0.001 suggests dysfunction of serotonin neurotransmission. A two-step hierarchical linear regression model showed that low tryptophan concentrations, low social support (SSS, occupational requirements (FLZ, personality traits (FLZ, impaired physical role (SF-36, and impaired vitality (SF-36 predict higher Beck Depression Inventory (BDI-II scores. Discussion Our study results

  10. Sequence analysis of cereal sucrose synthase genes and isolation ...

    African Journals Online (AJOL)

    SERVER

    2007-10-18

    Oct 18, 2007 ... sequencing of sucrose synthase gene fragment from sor- ghum using primers designed at their conserved exons. MATERIALS AND METHODS. Multiple sequence alignment. Sucrose synthase gene sequences of various cereals like rice, maize, and barley were accessed from NCBI Genbank database.

  11. Prostaglandin H synthase immunoreactivity in human gut. An immunohistochemical study

    DEFF Research Database (Denmark)

    Mikkelsen, H B; Rumessen, J J; Qvortrup, Klaus

    1991-01-01

    Prostaglandins exhibit a variety of actions on intestinal smooth muscle depending upon the type, dose and muscle layer studied. As the cellular origin of prostaglandin H (PGH) synthase has not been established with certainty in the human gut wall, we studied the localization of PGH synthase...

  12. Localization of nitric oxide synthase in human skeletal muscle

    DEFF Research Database (Denmark)

    Frandsen, Ulrik; Lopez-Figueroa, M.; Hellsten, Ylva

    1996-01-01

    The present study investigated the cellular localization of the neuronal type I and endothelial type III nitric oxide synthase in human skeletal muscle. Type I NO synthase immunoreactivity was found in the sarcolemma and the cytoplasm of all muscle fibres. Stronger immunoreactivity was expressed...

  13. Regular moderate or intense exercise prevents depression-like behavior without change of hippocampal tryptophan content in chronically tryptophan-deficient and stressed mice.

    Directory of Open Access Journals (Sweden)

    Hosung Lee

    Full Text Available Regular exercise has an antidepressant effect in human subjects. Studies using animals have suggested that the antidepressant effect of exercise is attributable to an increase of brain 5-hydroxytryptamine (5-HT; however, the precise mechanism underlying the antidepressant action via exercise is unclear. In contrast, the effect of 5-HT on antidepressant activity has not been clarified, in part because the therapeutic response to antidepressant drugs has a time lag in spite of the rapid increase of brain 5-HT upon administration of these drugs. This study was designed to investigate the contribution of brain 5-HT to the antidepressant effect of exercise. Mice were fed a tryptophan-deficient diet and stressed using chronic unpredictable stress (CUS for 4 weeks with or without the performance of either moderate or intense exercise on a treadmill 3 days per week. The findings demonstrated that the onset of depression-like behavior is attributable not to chronic reduction of 5-HT but to chronic stress. Regular exercise, whether moderate or intense, prevents depression-like behavior with an improvement of adult hippocampal cell proliferation and survival and without the recovery of 5-HT. Concomitantly, the mice that exercised showed increased hippocampal noradrenaline. Regular exercise prevents the impairment of not long-term memory but short-term memory in a 5-HT-reduced state. Together, these findings suggest that: (1 chronic reduction of brain 5-HT may not contribute to the onset of depression-like behavior; (2 regular exercise, whether moderate or intense, prevents the onset of chronic stress-induced depression-like behavior independent of brain 5-HT and dependent on brain adrenaline; and (3 regular exercise prevents chronic tryptophan reduction-induced impairment of not long-term but short-term memory.

  14. Metabolic and functional effects of beta-hydroxy-beta-methylbutyrate (HMB) supplementation in skeletal muscle.

    Science.gov (United States)

    Pinheiro, Carlos Hermano da Justa; Gerlinger-Romero, Frederico; Guimarães-Ferreira, Lucas; de Souza, Alcione Lescano; Vitzel, Kaio Fernando; Nachbar, Renato Tadeu; Nunes, Maria Tereza; Curi, Rui

    2012-07-01

    Beta-hydroxy-beta-methylbutyrate (HMB) is a metabolite derived from leucine. The anti-catabolic effect of HMB is well documented but its effect upon skeletal muscle strength and fatigue is still uncertain. In the present study, male Wistar rats were supplemented with HMB (320 mg/kg per day) for 4 weeks. Placebo group received saline solution only. Muscle strength (twitch and tetanic force) and resistance to acute muscle fatigue of the gastrocnemius muscle were evaluated by direct electrical stimulation of the sciatic nerve. The content of ATP and glycogen in red and white portions of gastrocnemius muscle were also evaluated. The effect of HMB on citrate synthase (CS) activity was also investigated. Muscle tetanic force was increased by HMB supplementation. No change was observed in time to peak of contraction and relaxation time. Resistance to acute muscle fatigue during intense contractile activity was also improved after HMB supplementation. Glycogen content was increased in both white (by fivefold) and red (by fourfold) portions of gastrocnemius muscle. HMB supplementation also increased the ATP content in red (by twofold) and white (1.2-fold) portions of gastrocnemius muscle. CS activity was increased by twofold in red portion of gastrocnemius muscle. These results support the proposition that HMB supplementation have marked change in oxidative metabolism improving muscle strength generation and performance during intense contractions.

  15. Induced nuclear beta decay

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1986-01-01

    Certain nuclear beta decay transitions normally inhibited by angular momentum or parity considerations can be induced to occur by the application of an electromagnetic field. Such decays can be useful in the controlled production of power, and in fission waste disposal

  16. Trichoderma .beta.-glucosidase

    Science.gov (United States)

    Dunn-Coleman, Nigel; Goedegebuur, Frits; Ward, Michael; Yao, Jian

    2006-01-03

    The present invention provides a novel .beta.-glucosidase nucleic acid sequence, designated bgl3, and the corresponding BGL3 amino acid sequence. The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding BGL3, recombinant BGL3 proteins and methods for producing the same.

  17. Applied Beta Dosimetry

    International Nuclear Information System (INIS)

    Rich, B.L.

    1986-01-01

    Measurements of beta and/or nonpenetrating exposure results is complicated and past techniques and capabilities have resulted in significant inaccuracies in recorded results. Current developments have resulted in increased capabilities which make the results more accurate and should result in less total exposure to the work force. Continued development of works in progress should provide equivalent future improvements

  18. Beta thalassemia - a review

    Directory of Open Access Journals (Sweden)

    R Jha

    2014-09-01

    Full Text Available Thalassemia is a globin gene disorder that results in a diminished rate of synthesis of one or more of the globin chains. About 1.5% of the global population (80 to 90 million people are carriers of beta Thalassemia. More than 200 mutations are described in beta thalassemia. However not all mutations are common in different ethnic groups. The only effective way to reduce burden of thalassemia is to prevent birth of homozygotes. Diagnosis of beta thalassemia can be done by fetal DNA analysis for molecular defects of beta thalassemia or by fetal blood analysis. Hematopoietic stem cell transplantation is the only available curative approach for Thalassemia. Many patients with thalassemia in underdeveloped nations die in childhood or adolescence. Programs that provide acceptable care, including transfusion of safe blood and supportive therapy including chelation must be established.DOI: http://dx.doi.org/10.3126/jpn.v4i8.11609 Journal of Pathology of Nepal; Vol.4,No. 8 (2014 663-671

  19. Double Beta Decay Experiments

    International Nuclear Information System (INIS)

    Piepke, A.

    2005-01-01

    The experimental observation of neutrino oscillations and thus neutrino mass and mixing gives a first hint at new particle physics. The absolute values of the neutrino mass and the properties of neutrinos under CP-conjugation remain unknown. The experimental investigation of the nuclear double beta decay is one of the key techniques for solving these open problems

  20. A Comparison of the Effects of Neuronal Nitric Oxide Synthase and Inducible Nitric Oxide Synthase Inhibition on Cartilage Damage

    Directory of Open Access Journals (Sweden)

    Nevzat Selim Gokay

    2016-01-01

    Full Text Available The objective of this study was to investigate the effects of selective inducible nitric oxide synthase and neuronal nitric oxide synthase inhibitors on cartilage regeneration. The study involved 27 Wistar rats that were divided into five groups. On Day 1, both knees of 3 rats were resected and placed in a formalin solution as a control group. The remaining 24 rats were separated into 4 groups, and their right knees were surgically damaged. Depending on the groups, the rats were injected with intra-articular normal saline solution, neuronal nitric oxide synthase inhibitor 7-nitroindazole (50 mg/kg, inducible nitric oxide synthase inhibitor amino-guanidine (30 mg/kg, or nitric oxide precursor L-arginine (200 mg/kg. After 21 days, the right and left knees of the rats were resected and placed in formalin solution. The samples were histopathologically examined by a blinded evaluator and scored on 8 parameters. Although selective neuronal nitric oxide synthase inhibition exhibited significant (P=0.044 positive effects on cartilage regeneration following cartilage damage, it was determined that inducible nitric oxide synthase inhibition had no statistically significant effect on cartilage regeneration. It was observed that the nitric oxide synthase activation triggered advanced arthrosis symptoms, such as osteophyte formation. The fact that selective neuronal nitric oxide synthase inhibitors were observed to have mitigating effects on the severity of the damage may, in the future, influence the development of new agents to be used in the treatment of cartilage disorders.

  1. Beta cell adaptation in pregnancy

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    2016-01-01

    Pregnancy is associated with a compensatory increase in beta cell mass. It is well established that somatolactogenic hormones contribute to the expansion both indirectly by their insulin antagonistic effects and directly by their mitogenic effects on the beta cells via receptors for prolactin...... and growth hormone expressed in rodent beta cells. However, the beta cell expansion in human pregnancy seems to occur by neogenesis of beta cells from putative progenitor cells rather than by proliferation of existing beta cells. Claes Hellerström has pioneered the research on beta cell growth for decades...... in the expansion of the beta cell mass in human pregnancy, and the relative roles of endocrine factors and nutrients....

  2. Effect of surface roughness and surface modification of indium tin oxide electrode on its potential response to tryptophan

    International Nuclear Information System (INIS)

    Khan, Md. Zaved Hossain; Nakanishi, Takuya; Kuroiwa, Shigeki; Hoshi, Yoichi; Osaka, Tetsuya

    2011-01-01

    Highlights: → We examine factors affecting potential response of ITO electrode to tryptophan. → Surface roughness of ITO electrode affects the stability of its rest potential. → Surface modification is effective for ITO electrode with a certain roughness. → Optimum values of work function exist for potential response of ITO to tryptophan. - Abstract: The effect of surface modification of indium tin oxide (ITO) electrode on its potential response to tryptophan was investigated for ITO substrates with different surface roughness. It was found that a small difference in surface roughness, between ∼1 and ∼2 nm of R a evaluated by atomic force microscopy, affects the rest potential of ITO electrode in the electrolyte. A slight difference in In:Sn ratio at the near surface of the ITO substrates, measured by angle-resolved X-ray photoelectron spectrometry and Auger electron spectroscopy is remarkable, and considered to relate with surface roughness. Interestingly, successive modification of the ITO surface with aminopropylsilane and disuccinimidyl suberate, of which essentiality to the potential response to indole compounds we previously reported, improved the stability of the rest potential and enabled the electrodes to respond to tryptophan in case of specimens with R a values ranging between ∼2 and ∼3 nm but not for those with R a of ∼1 nm. It was suggested that there are optimum values of effective work function of ITO for specific potential response to tryptophan, which can be obtained by the successive modification of ITO surface.

  3. Meal Pattern of Male Rats Maintained on Amino Acid Supplemented Diets: The Effect of Tryptophan, Lysine, Arginine, Proline and Threonine

    Directory of Open Access Journals (Sweden)

    Raghad Ayaso

    2014-07-01

    Full Text Available The macronutrient composition of the diet has been shown to affect food intake, with proteins having distinct effects. The present study investigated the effect of diet supplementation with individual amino acids (tryptophan, lysine, arginine, proline and threonine on meal pattern among male rats. Meal pattern and body weight were monitored for two weeks. Proline and threonine had minimal effects on meal pattern, while the most pronounced changes were observed in the tryptophan group. Both tryptophan and lysine decreased overall food intake, which was translated into a reduction in body weight. The reduced food intake of the tryptophan group was associated with an increase in meal size, intermeal intervals (IMI and meal time and a decrease in meal number. The decrease in the food intake of the lysine group was associated with a reduction in both IMI and meal number, and this was accompanied by an increase in meal time. Arginine increased meal number, while decreasing IMI. Proline and threonine had a minimal effect on meal pattern. Lysine seems to increase satiety, and arginine seems to decrease it, while tryptophan seems to increase satiety and decrease satiation. Accordingly, changes in meal patterns are associated with the type of amino acid added to the diet.

  4. Correlation between breakfast tryptophan content and morning-evening in Japanese infants and students aged 0-15 yrs.

    Science.gov (United States)

    Harada, Tetsuo; Hirotani, Masaaki; Maeda, Mari; Nomura, Hiromi; Takeuchi, Hitomi

    2007-03-01

    Tryptophan can be metabolized via 5-hydroxytryptamine=serotonin to melatonin by a series of 4 enzymes in pineal body. Lack of serotonin in body fluid in the brain during daytime can lead to several psychiatric disorders, while shortage of plasma-melatonin at night can be related to sleep disorders. The Morning-Evening (M-E) questionnaire and the original questionnaire including questions on sleep habits, mental symptoms, and contents of meals were administered to 1055 infants aged 0-6 yrs, 751 students attending an elementary school, and 473 students attending junior high school in Kochi City (33 degrees N). The index of tryptophan taken at breakfast (Trp-Index) was calculated as tryptophan amount per one meal based on the tryptophan included in each 100 g of the foods and a standard amount of food per one meal. A significant positive-correlation between M-E scores and Trp-Index was not shown by relatively older students, aged 9-15 yrs (Pearson's test, r=0.044-0.123, p=0.071-0.505), whereas a significant positive correlation was shown by infants and young elementary school students aged 0-8 yrs (r=0.180, 0.258, phigh quality of sleep, and indirectly good mental health, presumably, through the metabolism of tryptophan to serotonin in daytime and further to melatonin at night.

  5. Effects of Tranilast on the Urinary Excretion of Kynurenic and Quinolinic Acid under Conditions of L Tryptophan Loading

    Directory of Open Access Journals (Sweden)

    Rowland R. Noakes

    2013-01-01

    Full Text Available The pathogenesis of morphea and other cutaneous sclerosing disorders remain poorly understood. Although they are considered to be autoimmune disorders, abnormal tryptophan metabolism may be involved. Current therapy is directed to supressing the autoimmune response. Demonstration of a therapeutic response to manipulation of the kynurenine pathway would both support a role for abnormal tryptophan metabolism and offer additional targets for therapy. Tranilast is a 3-hydroxyanthranilic acid derivative known to target the kynurenine pathway. The aim of this study was to see if tranilast lowered the urinary excretion of the kynurenine metabolites kynurenic and quinolinic acid under condition of L tryptophan loading in a volunteer. Mean baseline value for kynurenic acid and quinolinic acid were 1.1 and 2.1 mmol/mol creatinine, respectively. This rose to 5.6 and 3.8 mmol/mol creatinine respectively under conditions of L tryptophan loading 2 grams daily. Adding 1 g of tranilast daily lowered the values to 2.0 and 2.9 mmol/mol creatinine, respectively. These data suggest that tranilast acts as a competitive inhibitor of either indoleamine 2, 3-dioxygenase (IDO, tryptophan 2, 3 di-oxygenase (TDO or both. As it involved only 1 subject, the results may not be representative of the larger population and must be considered preliminary.

  6. Tumor-produced, active Interleukin-1 {beta} regulates gene expression in carcinoma-associated fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Dudas, Jozsef, E-mail: Jozsef.Dudas@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Fullar, Alexandra, E-mail: fullarsz@gmail.com [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); 1st Institute of Pathology and Experimental Cancer Research, Semmelweis University, Ulloei ut 26, H-1085 Budapest (Hungary); Bitsche, Mario, E-mail: Mario.Bitsche@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Schartinger, Volker, E-mail: Volker.Schartinger@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Kovalszky, Ilona, E-mail: koval@korb1.sote.hu [1st Institute of Pathology and Experimental Cancer Research, Semmelweis University, Ulloei ut 26, H-1085 Budapest (Hungary); Sprinzl, Georg Mathias, E-mail: Georg.Sprinzl@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria); Riechelmann, Herbert, E-mail: Herbert.Riechelmann@i-med.ac.at [Department of Otorhinolaryngology, Medical University Innsbruck, Anichstrasse 35, A-6020 Innsbruck (Austria)

    2011-09-10

    Recently we described a co-culture model of periodontal ligament (PDL) fibroblasts and SCC-25 lingual squamous carcinoma cells, which resulted in conversion of normal fibroblasts into carcinoma-associated fibroblasts (CAFs), and in epithelial-mesenchymal transition (EMT) of SCC-25 cells. We have found a constitutive high interleukin-1{beta} (IL1-{beta}) expression in SCC-25 cells in normal and in co-cultured conditions. In our hypothesis a constitutive IL1-{beta} expression in SCC-25 regulates gene expression in fibroblasts during co-culture. Co-cultures were performed between PDL fibroblasts and SCC-25 cells with and without dexamethasone (DEX) treatment; IL1-{beta} processing was investigated in SCC-25 cells, tumor cells and PDL fibroblasts were treated with IL1-{beta}. IL1-{beta} signaling was investigated by western blot and immunocytochemistry. IL1-{beta}-regulated genes were analyzed by real-time qPCR. SCC-25 cells produced 16 kD active IL1-{beta}, its receptor was upregulated in PDL fibroblasts during co-culture, which induced phosphorylation of interleukin-1 receptor-associated kinase-1 (IRAK-1), and nuclear translocalization of NF{kappa}B{alpha}. Several genes, including interferon regulatory factor 1 (IRF1) interleukin-6 (IL-6) and prostaglandin-endoperoxide synthase 2 (COX-2) were induced in CAFs during co-culture. The most enhanced induction was found for IL-6 and COX-2. Treatment of PDL fibroblasts with IL1-{beta} reproduced a time- and dose-dependent upregulation of IL1-receptor, IL-6 and COX-2. A further proof was achieved by DEX inhibition for IL1-{beta}-stimulated IL-6 and COX-2 gene expression. Constitutive expression of IL1-{beta} in the tumor cells leads to IL1-{beta}-stimulated gene expression changes in tumor-associated fibroblasts, which are involved in tumor progression. -- Graphical abstract: SCC-25 cells produce active, processed IL1-{beta}. PDL fibroblasts possess receptor for IL1-{beta}, and its expression is increased 4.56-times in the

  7. Nitric oxide synthase modulates CFA-induced thermal hyperalgesia through cytokine regulation in mice.

    Science.gov (United States)

    Chen, Yong; Boettger, Michael K; Reif, Andreas; Schmitt, Angelika; Uçeyler, Nurcan; Sommer, Claudia

    2010-03-02

    Although it has been largely demonstrated that nitric oxide synthase (NOS), a key enzyme for nitric oxide (NO) production, modulates inflammatory pain, the molecular mechanisms underlying these effects remain to be clarified. Here we asked whether cytokines, which have well-described roles in inflammatory pain, are downstream targets of NO in inflammatory pain and which of the isoforms of NOS are involved in this process. Intraperitoneal (i.p.) pretreatment with 7-nitroindazole sodium salt (7-NINA, a selective neuronal NOS inhibitor), aminoguanidine hydrochloride (AG, a selective inducible NOS inhibitor), L-N(G)-nitroarginine methyl ester (L-NAME, a non-selective NOS inhibitor), but not L-N(5)-(1-iminoethyl)-ornithine (L-NIO, a selective endothelial NOS inhibitor), significantly attenuated thermal hyperalgesia induced by intraplantar (i.pl.) injection of complete Freund's adjuvant (CFA). Real-time reverse transcription-polymerase chain reaction (RT-PCR) revealed a significant increase of nNOS, iNOS, and eNOS gene expression, as well as tumor necrosis factor-alpha (TNF), interleukin-1 beta (IL-1beta), and interleukin-10 (IL-10) gene expression in plantar skin, following CFA. Pretreatment with the NOS inhibitors prevented the CFA-induced increase of the pro-inflammatory cytokines TNF and IL-1beta. The increase of the anti-inflammatory cytokine IL-10 was augmented in mice pretreated with 7-NINA or L-NAME, but reduced in mice receiving AG or L-NIO. NNOS-, iNOS- or eNOS-knockout (KO) mice had lower gene expression of TNF, IL-1beta, and IL-10 following CFA, overall corroborating the inhibitor data. These findings lead us to propose that inhibition of NOS modulates inflammatory thermal hyperalgesia by regulating cytokine expression.

  8. Neopterin, kynurenine and tryptophan as new biomarkers for early detection of rectal anastomotic leakage.

    Science.gov (United States)

    Dusek, Tomas; Orhalmi, Julius; Sotona, Otakar; Krcmova, Lenka Kujovska; Javorska, Lenka; Dolejs, Josef; Paral, Jiri

    2018-03-01

    At present, there are no strong predictors, nor a useful scoring system, that clearly identifies patients at risk for anastomotic leakage. This study aimed to investigate a new method that assesses this risk by monitoring levels of neopterin, tryptophan, and kynurenine, in bodily fluids. This prospective study included patients who underwent elective rectal resection for carcinoma. The basic condition for inclusion was rectal anastomosis using the double-stapling technique. Preoperative levels of neopterin, tryptophan, kynurenine, and their ratios, were assessed with blood and urine samples. These levels were then monitored for 6 postoperative days in venous blood, urine, and abdominal drainage fluid. A total of 42 patients were enrolled in the study. Thirty-six patients underwent a laparoscopic resection and 6 patients had an open procedure. No differences were found among neopterin, tryptophan, and kynurenine serum levels. However, the groups were observed to have significant differences in the urinary neopterin/creatinine ratio: the preoperative neopterin/creatinine ratio was 139.5 μmol/mol in the group with leakage, vs 114.8 μmol/mol in the group without complications, p = 0.037. The same results were observed during the postoperative period, p = 0.012. Additionally, the group with complications had a higher mean value of neopterin in drainage fluid, p = 0.048. Our study demonstrated that high preoperative levels of urinary neopterin could be interpreted as a risk for anastomotic leakage. Moreover, pathological levels of neopterin in urine and abdominal drainage fluid could be useful for early identification of anastomotic leakage during the postoperative period prior to its clinical development.

  9. The Role of Amino Acid Permeases and Tryptophan Biosynthesis in Cryptococcus neoformans Survival.

    Directory of Open Access Journals (Sweden)

    João Daniel Santos Fernandes

    Full Text Available Metabolic diversity is an important factor during microbial adaptation to different environments. Among metabolic processes, amino acid biosynthesis has been demonstrated to be relevant for survival for many microbial pathogens, whereas the association between pathogenesis and amino acid uptake and recycling are less well-established. Cryptococcus neoformans is an opportunistic fungal pathogen with many habitats. As a result, it faces frequent metabolic shifts and challenges during its life cycle. Here we studied the C. neoformans tryptophan biosynthetic pathway and found that the pathway is essential. RNAi indicated that interruptions in the biosynthetic pathway render strains inviable. However, auxotroph complementation can be partially achieved by tryptophan uptake when a non preferred nitrogen source and lower growth temperature are applied, suggesting that amino acid permeases may be the target of nitrogen catabolism repression (NCR. We used bioinformatics to search for amino acid permeases in the C. neoformans and found eight potential global permeases (AAP1 to AAP8. The transcriptional profile of them revealed that they are subjected to regulatory mechanisms which are known to respond to nutritional status in other fungi, such as (i quality of nitrogen (Nitrogen Catabolism Repression, NCR and carbon sources (Carbon Catabolism Repression, CCR, (ii amino acid availability in the extracellular environment (SPS-sensing and (iii nutritional deprivation (Global Amino Acid Control, GAAC. This study shows that C. neoformans has fewer amino acid permeases than other model yeasts, and that these proteins may be subjected to complex regulatory mechanisms. Our data suggest that the C. neoformans tryptophan biosynthetic pathway is an excellent pharmacological target. Furthermore, inhibitors of this pathway cause Cryptococcus growth arrest in vitro.

  10. Homospermidine synthase, the first pathway-specific enzyme of pyrrolizidine alkaloid biosynthesis, evolved from deoxyhypusine synthase

    Science.gov (United States)

    Ober, Dietrich; Hartmann, Thomas

    1999-01-01

    Pyrrolizidine alkaloids are preformed plant defense compounds with sporadic phylogenetic distribution. They are thought to have evolved in response to the selective pressure of herbivory. The first pathway-specific intermediate of these alkaloids is the rare polyamine homospermidine, which is synthesized by homospermidine synthase (HSS). The HSS gene from Senecio vernalis was cloned and shown to be derived from the deoxyhypusine synthase (DHS) gene, which is highly conserved among all eukaryotes and archaebacteria. DHS catalyzes the first step in the activation of translation initiation factor 5A (eIF5A), which is essential for eukaryotic cell proliferation and which acts as a cofactor of the HIV-1 Rev regulatory protein. Sequence comparison provides direct evidence for the evolutionary recruitment of an essential gene of primary metabolism (DHS) for the origin of the committing step (HSS) in the biosynthesis of pyrrolizidine alkaloids. PMID:10611289

  11. Misleading Betas: An Educational Example

    Science.gov (United States)

    Chong, James; Halcoussis, Dennis; Phillips, G. Michael

    2012-01-01

    The dual-beta model is a generalization of the CAPM model. In the dual-beta model, separate beta estimates are provided for up-market and down-market days. This paper uses the historical "Anscombe quartet" results which illustrated how very different datasets can produce the same regression coefficients to motivate a discussion of the…

  12. Cysteine and tryptophan anomalies found when scanning all the binding sites in the Protein Data Bank.

    Science.gov (United States)

    Iván, Gábor; Szabadka, Zoltán; Grolmusz, Vince

    2010-01-01

    The Protein Data Bank (PDB) is one of the richest sources of structural biological information in the World. It started to exist as the computer-readable depository of crystallographic data complementing printed papers. The proper interpretation of the content of the individual files in the PDB still needs the detailed information found in the citing publication. An advanced graph theoretical method is presented here for automatically repairing, re-organising and re-structuring PDB data yielding the identification of all the protein-ligand complexes and all the binding sites in the PDB. As an application, we identified strong cysteine and tryptophan irregularities in the data.

  13. Gold-catalyzed direct alkynylation of tryptophan in peptides using TIPS-EBX

    Directory of Open Access Journals (Sweden)

    Gergely L. Tolnai

    2016-04-01

    Full Text Available The selective functionalization of peptides containing only natural amino acids is important for the modification of biomolecules. In particular, the installation of an alkyne as a useful handle for bioconjugation is highly attractive, but the use of a carbon linker is usually required. Herein, we report the gold-catalyzed direct alkynylation of tryptophan in peptides using the hypervalent iodine reagent TIPS-EBX (1-[(triisopropylsilylethynyl]-1,2-benziodoxol-3(1H-one. The reaction proceeded in 50–78% yield under mild conditions and could be applied to peptides containing other nucleophilic and aromatic amino acids, such as serine, phenylalanine or tyrosine.

  14. Converging evidence for central 5-HT effects in acute tryptophan depletion

    DEFF Research Database (Denmark)

    Crockett, Molly; Clark, Luke; Roiser, Jonathan

    2012-01-01

    the validity of ATD.2 Although we agree that ATD's effects on 5-HT activity at the molecular level need further clarification, van Donkelaar et al.2 goes too far in challenging whether ATD exerts its effects through serotonergic mechanisms. There is strong evidence that ATD reduces brain 5-HT and disrupts......Acute tryptophan depletion (ATD), a dietary technique for manipulating brain serotonin (5-HT) function, has advanced our understanding of 5-HT mechanisms in the etiology and treatment of depression and other affective disorders.1 A recent review article in Molecular Psychiatry questioned...

  15. Involvement of tryptophan hydroxylase 2 gene polymorphisms in susceptibility to tic disorder in Chinese Han population

    OpenAIRE

    Zheng, Ping; Li, Erzhen; Wang, Jianhua; Cui, Xiaodai; Wang, Liwen

    2013-01-01

    Abstract Background Tryptophan hydroxylase-2 (TPH2) is a potential candidate gene for screening tic disorder (TD). Methods A case–control study was performed to examine the association between the TPH2 gene and TD. The Sequenom® Mass ARRAY iPLEX GOLD System was used to genotype two single nucleotide polymorphisms (SNPs) of the TPH2 gene in 149 TD children and in 125 normal controls. Results For rs4565946, individuals with the TT genotype showed a significantly higher risk of TD than those wit...

  16. Introduction of a unique tryptophan residue into various positions of Bacillus licheniformis DnaK.

    Science.gov (United States)

    Chen, Bo-En; Lin, Min-Guan; Lo, Huei-Fen; Wang, Tzu-Fan; Chi, Meng-Chun; Lin, Long-Liu

    2013-01-01

    Site-directed mutagenesis together with biochemical and biophysical techniques were used to probe effects of single-tryptophan-incorporated mutations on a bacterial molecular chaperone, Bacillus licheniformis DnaK (BlDnaK). Specifically, five phenylalanine residues (Phe(120), Phe(174), Phe(186), Phe(378) and Phe(396)) of BlDnaK were individually replaced by single tryptophans, thus creating site-specific probes for the fluorescence analysis of the protein. The steady-state ATPase activity for BlDnaK, F120W, F174W, F186W, F378W, and F396W was determined to be 76.01, 52.82, 25.32, 53.31, 58.84, and 47.53 nmol Pi/min/mg, respectively. Complementation test revealed that the single mutation at codons 120, 186, and 378 of the dnaK gene still allowed an Escherichia coli dnaK756-Ts strain to grow at a stringent temperature of 44°C. Simultaneous addition of co-chaperones and NR-peptide did not synergistically stimulate the ATPase activity of F174W and F396W, and these two proteins were unable to assist the refolding of GdnHCl-denatured luciferase. The heat-induced denaturation of all variants could be fitted adequately to a three-state model, in agreement with the observation for the wild-type protein. By CD spectral analysis, GdnHCl-induced unfolding transition for BlDnaK was 1.51 M corresponding to ΔG(N-U) of 1.69 kcal/mol; however, the transitions for mutant proteins were 1.07-1.55 M equivalent to ΔG(N-U) of 0.94-2.93 kcal/mol. The emission maximum of single-tryptophan-incorporated variants was in the range of 333.2-335.8 nm. Acrylamide quenching analysis showed that the mutant proteins had a dynamic quenching constant of 3.0-4.2 M(-1). Taken together, these results suggest that the molecular properties of BlDnaK have been significantly changed upon the individual replacement of selected phenylalanine residues by tryptophan. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Nitric oxide synthase gene G298 allele

    International Nuclear Information System (INIS)

    Nagib El-Kilany, Galal E.; Nayel, Ehab; Hazzaa, Sahar

    2004-01-01

    Background: Nitric oxide (NO) has an important effect on blood pressure, arterial wall, and the basal release of endothelial NO in hypertension (HPN) may be reduced. Until now, there is no solid data revealing the potential role of the polymorphism of the nitric oxide synthase gene (NOS) in patients with HPN and microvascular angina. Aim: The aim of the present study is to investigate the gene of endothelial nitric oxide synthase (eNOS), as the polymorphism of this gene may be a putative candidate for HPN and initiate the process of atherosclerosis. Methods: Sixty participants were recruited for this study; 50 were hypertensive patients complaining of chest pain [30 of them have electrocardiogram (EKG) changes of ischemia], 20 had isolated HPN, and 10 healthy volunteers served as control. All patients underwent stress myocardial perfusion imaging (MPI) and coronary angiography. Genotyping of eNOS for all patients and controls was performed. The linkages between HPN, microvascular angina and eNOS gene polymorphism were investigated. Results: MPI and coronary angiography revealed that 15 patients had chest pain with true ischemia and reversible myocardial perfusion defects (multiple and mild) but normal epicardial coronary arteries (microvascular angina), while 15 patients had significant coronary artery disease (CAD), and 20 hypertensive patients showed normal perfusion scan and coronary angiography. The prevalence of the NOS G 298 allele was higher in the hypertensive group with microvascular angina (documented by MPI) than it was among the control participants (P<.005). The eNOS allele was significantly higher in the hypertensive group than in the control participants, but there was no significant difference in homozygote mutants among hypertensive participants, x-syndrome and patients with CAD. Conclusion: eNOS gene polymorphism is proved to be an important etiology in microvascular angina (x-syndrome) among hypertensive patients. In addition, the eNOS mutant

  18. Interaction with beta-arrestin determines the difference in internalization behavor between beta1- and beta2-adrenergic receptors.

    Science.gov (United States)

    Shiina, T; Kawasaki, A; Nagao, T; Kurose, H

    2000-09-15

    The beta(1)-adrenergic receptor (beta(1)AR) shows the resistance to agonist-induced internalization. As beta-arrestin is important for internalization, we examine the interaction of beta-arrestin with beta(1)AR with three different methods: intracellular trafficking of beta-arrestin, binding of in vitro translated beta-arrestin to intracellular domains of beta(1)- and beta(2)ARs, and inhibition of betaAR-stimulated adenylyl cyclase activities by beta-arrestin. The green fluorescent protein-tagged beta-arrestin 2 translocates to and stays at the plasma membrane by beta(2)AR stimulation. Although green fluorescent protein-tagged beta-arrestin 2 also translocates to the plasma membrane, it returns to the cytoplasm 10-30 min after beta(1)AR stimulation. The binding of in vitro translated beta-arrestin 1 and beta-arrestin 2 to the third intracellular loop and the carboxyl tail of beta(1)AR is lower than that of beta(2)AR. The fusion protein of beta-arrestin 1 with glutathione S-transferase inhibits the beta(1)- and beta(2)AR-stimulated adenylyl cyclase activities, although inhibition of the beta(1)AR-stimulated activity requires a higher concentration of the fusion protein than that of the beta(2)AR-stimulated activity. These results suggest that weak interaction of beta(1)AR with beta-arrestins explains the resistance to agonist-induced internalization. This is further supported by the finding that beta-arrestin can induce internalization of beta(1)AR when beta-arrestin 1 does not dissociate from beta(1)AR by fusing to the carboxyl tail of beta(1)AR.

  19. Intrinsic Tryptophan Fluorescence in the Detection and Analysis of Proteins: A Focus on Förster Resonance Energy Transfer Techniques

    Directory of Open Access Journals (Sweden)

    Amar B. T. Ghisaidoobe

    2014-12-01

    Full Text Available F resonance energy transfer (FRET occurs when the distance between a donor fluorophore and an acceptor is within 10 nm, and its application often necessitates fluorescent labeling of biological targets. However, covalent modification of biomolecules can inadvertently give rise to conformational and/or functional changes. This review describes the application of intrinsic protein fluorescence, predominantly derived from tryptophan (\\(\\uplambda_{\\textsc{ex}}\\sim\\ nm, \\(\\uplambda_{\\textsc{em}}\\sim\\ 350 nm, in protein-related research and mainly focuses on label-free FRET techniques. In terms of wavelength and intensity, tryptophan fluorescence is strongly influenced by its (or the proteinlocal environment, which, in addition to fluorescence quenching, has been applied to study protein conformational changes. Intrinsic F resonance energy transfer (iFRET, a recently developed technique, utilizes the intrinsic fluorescence of tryptophan in conjunction with target-specific fluorescent probes as FRET donors and acceptors, respectively, for real time detection of native proteins.

  20. Low-beta investment strategies

    OpenAIRE

    Korn, Olaf; Kuntz, Laura-Chloé

    2015-01-01

    This paper investigates investment strategies that exploit the low-beta anomaly. Although the notion of buying low-beta stocks and selling high-beta stocks is natural, a choice is necessary with respect to the relative weighting of high-beta stocks and low-beta stocks in the investment portfolio. Our empirical results for US large-cap stocks show that this choice is very important for the risk-return characteristics of the resulting portfolios and their sensitivities to common risk factors. W...

  1. Structure of the ent -Copalyl Diphosphate Synthase PtmT2 from Streptomyces platensis CB00739, a Bacterial Type II Diterpene Synthase

    Energy Technology Data Exchange (ETDEWEB)

    Rudolf, Jeffrey D.; Dong, Liao-Bin; Cao, Hongnan; Hatzos-Skintges, Catherine; Osipiuk, Jerzy; Endres, Michael; Chang, Chin-Yuan; Ma, Ming; Babnigg, Gyorgy; Joachimiak, Andrzej; Phillips, George N.; Shen, Ben

    2016-08-31

    Terpenoids are the largest and most structurally diverse family of natural products found in nature, yet their presence in bacteria is underappreciated. The carbon skeletons of terpenoids are generated through carbocation-dependent cyclization cascades catalyzed by terpene synthases (TSs). Type I and type II TSs initiate cyclization via diphosphate ionization and protonation, respectively, and protein structures of both types are known. Most plant diterpene synthases (DTSs) possess three alpha-helical domains (alpha beta gamma), which are thought to have arisen from the fusion of discrete, ancestral bacterial type I TSs (alpha) and type II TSs (beta gamma). Type II DTSs of bacterial origin, of which there are no structurally characterized members, are a missing piece in the structural evolution of TSs. Here, we report the first crystal structure of a type II DTS from bacteria. PtnaT2 from Streptomyces platensis CB00739 was verified as an ent-copalyl diphosphate synthase involved in the biosynthesis of platensimycin and platencin. The crystal structure of PtmT2 was solved at a resolution of 1.80 angstrom, and docking studies suggest the catalytically active conformation of geranylgeranyl diphosphate (GGPP). Site-directed mutagenesis confirmed residues involved in binding the diphosphate moiety of GGPP and identified DxxxxE as a potential Mg2+-binding motif for type II DTSs of bacterial origin. Finally, both the shape and physicochemical properties of the active sites are responsible for determining specific catalytic outcomes of TSs. The structure of PtmT2 fundamentally advances the knowledge of bacterial TSs, their mechanisms, and their role in the evolution of TSs.

  2. Glycogen synthase activation by sugars in isolated hepatocytes.

    Science.gov (United States)

    Ciudad, C J; Carabaza, A; Bosch, F; Gòmez I Foix, A M; Guinovart, J J

    1988-07-01

    We have investigated the activation by sugars of glycogen synthase in relation to (i) phosphorylase a activity and (ii) changes in the intracellular concentration of glucose 6-phosphate and adenine nucleotides. All the sugars tested in this work present the common denominator of activating glycogen synthase. On the other hand, phosphorylase a activity is decreased by mannose and glucose, unchanged by galactose and xylitol, and increased by tagatose, glyceraldehyde, and fructose. Dihydroxyacetone exerts a biphasic effect on phosphorylase. These findings provide additional evidence proving that glycogen synthase can be activated regardless of the levels of phosphorylase a, clearly establishing that a nonsequential mechanism for the activation of glycogen synthase occurs in liver cells. The glycogen synthase activation state is related to the concentrations of glucose 6-phosphate and adenine nucleotides. In this respect, tagatose, glyceraldehyde, and fructose deplete ATP and increase AMP contents, whereas glucose, mannose, galactose, xylitol, and dihydroxyacetone do not alter the concentration of these nucleotides. In addition, all these sugars, except glyceraldehyde, increase the intracellular content of glucose 6-phosphate. The activation of glycogen synthase by sugars is reflected in decreases on both kinetic constants of the enzyme, M0.5 (for glucose 6-phosphate) and S0.5 (for UDP-glucose). We propose that hepatocyte glycogen synthase is activated by monosaccharides by a mechanism triggered by changes in glucose 6-phosphate and adenine nucleotide concentrations which have been described to modify glycogen synthase phosphatase activity. This mechanism represents a metabolite control of the sugar-induced activation of hepatocyte glycogen synthase.

  3. Neutrophil beta-2 microglobulin: an inflammatory mediator

    DEFF Research Database (Denmark)

    Bjerrum, O W; Nissen, Mogens Holst; Borregaard, N

    1990-01-01

    Beta-2 microglobulin (beta 2m) constitutes the light invariant chain of HLA class I antigen, and is a constituent of mobilizable compartments of neutrophils. Two forms of beta 2m exist: native beta 2m and proteolytically modified beta 2m (Des-Lys58-beta 2m), which shows alpha mobility in crossed ...

  4. Beta and muon decays

    International Nuclear Information System (INIS)

    Galindo, A.; Pascual, P.

    1967-01-01

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  5. Beta-thalassemia

    Directory of Open Access Journals (Sweden)

    Origa Raffaella

    2010-05-01

    Full Text Available Abstract Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands, dilated myocardiopathy, liver fibrosis and cirrhosis. Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes, gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely

  6. Beta and Gamma Gradients

    DEFF Research Database (Denmark)

    Løvborg, Leif; Gaffney, C. F.; Clark, P. A.

    1985-01-01

    Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions...... of differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears...... that the present practice of avoiding samples above a depth of 0.3 m may be over-cautious...

  7. Beta and muon decays

    Energy Technology Data Exchange (ETDEWEB)

    Galindo, A; Pascual, P

    1967-07-01

    These notes represent a series of lectures delivered by the authors in the Junta de Energia Nuclear, during the Spring term of 1965. They were devoted to graduate students interested in the Theory of Elementary Particles. Special emphasis was focussed into the computational problems. Chapter I is a review of basic principles (Dirac equation, transition probabilities, final state interactions.) which will be needed later. In Chapter II the four-fermion punctual Interaction is discussed, Chapter III is devoted to the study of beta-decay; the main emphasis is given to the deduction of the formulae corresponding to electron-antineutrino correlation, electron energy spectrum, lifetimes, asymmetry of electrons emitted from polarized nuclei, electron and neutrino polarization and time reversal invariance in beta decay. In Chapter IV we deal with the decay of polarized muons with radiative corrections. Chapter V is devoted to an introduction to C.V.C. theory. (Author)

  8. Effects of L-tryptophan, Fructan, and Casein on Reducing Ammonia, Hydrogen Sulfide, and Skatole in Fermented Swine Manure

    Directory of Open Access Journals (Sweden)

    Q. K. Sheng

    2015-08-01

    Full Text Available The effects of daily dietary Bacillus subtilis (Bs, and adding L-tryptophan, fructan, or casein to fecal fermentation broths were investigated as means to reduce the production of noxious gas during manure fermentation caused by ammonia, hydrogen sulfide (H2S, and 3-methylindole (skatole. Eighty swine (50.0±0.5 kg were equally apportioned to an experimental group given Bs in daily feed, or a control group without Bs. After 6 weeks, fresh manure was collected from both groups for fermentation studies using a 3×3 orthogonal array, in which tryptophan, casein, and fructan were added at various concentrations. After fermentation, the ammonia, H2S, L-tryptophan, skatole, and microflora were measured. In both groups, L-tryptophan was the principle additive increasing skatole production, with significant correlation (r = 0.9992. L-tryptophan had no effect on the production of ammonia, H2S, or skatole in animals fed Bs. In both groups, fructan was the principle additive that reduced H2S production (r = 0.9981. Fructan and Bs significantly interacted in H2S production (p = 0.014. Casein was the principle additive affecting the concentration of ammonia, only in the control group. Casein and Bs significantly interacted in ammonia production (p = 0.039. The predominant bacteria were Bacillus spp. CWBI B1434 (26% in the control group, and Streptococcus alactolyticus AF201899 (36% in the experimental group. In summary, daily dietary Bs reduced ammonia production during fecal fermentation. Lessening L-tryptophan and increasing fructan in the fermentation broth reduced skatole and H2S.

  9. Altered tryptophan and alanine transport in fibroblasts from boys with attention-deficit/hyperactivity disorder (ADHD: an in vitro study

    Directory of Open Access Journals (Sweden)

    Vumma Ravi

    2011-09-01

    Full Text Available Abstract Background The catecholaminergic and serotonergic neurotransmitter systems are implicated in the pathophysiology of attention-deficit/hyperactivity disorder (ADHD. The amino acid tyrosine is the precursor for synthesis of the catecholamines dopamine and norepinephrine, while tryptophan is the precursor of serotonin. A disturbed transport of tyrosine, as well as other amino acids, has been found in a number of other psychiatric disorders, such as schizophrenia, bipolar disorder and autism, when using the fibroblast cell model. Hence, the aim of this study was to explore whether children with ADHD may have disturbed amino acid transport. Methods Fibroblast cells were cultured from skin biopsies obtained from 14 boys diagnosed with ADHD and from 13 matching boys without a diagnosis of a developmental disorder. Transport of the amino acids tyrosine, tryptophan and alanine across the cell membrane was measured by the cluster tray method. The kinetic parameters, maximal transport capacity (Vmax and affinity constant (Km were determined. Any difference between the two groups was analyzed by Student's unpaired t-test or the Mann Whitney U test. Results The ADHD group had significantly decreased Vmax (p = 0.039 and Km (increased affinity (p = 0.010 of tryptophan transport in comparison to controls. They also had a significantly higher Vmaxof alanine transport (p = 0.031, but the Km of alanine transport did not differ significantly. There were no significant differences in any of the kinetic parameters regarding tyrosine transport in fibroblasts for the ADHD group. Conclusions Tryptophan uses the same transport systems in both fibroblasts and at the blood brain barrier (BBB. Hence, a decreased transport capacity of tryptophan implies that less tryptophan is being transported across the BBB in the ADHD group. This could lead to deficient serotonin access in the brain that might cause disturbances in both the serotonergic and the catecholaminergic

  10. Generation and Functional Evaluation of Designer Monoterpene Synthases.

    Science.gov (United States)

    Srividya, N; Lange, I; Lange, B M

    2016-01-01

    Monoterpene synthases are highly versatile enzymes that catalyze the first committed step in the pathways toward terpenoids, the structurally most diverse class of plant natural products. Recent advancements in our understanding of the reaction mechanism have enabled engineering approaches to develop mutant monoterpene synthases that produce specific monoterpenes. In this chapter, we are describing protocols to introduce targeted mutations, express mutant enzyme catalysts in heterologous hosts, and assess their catalytic properties. Mutant monoterpene synthases have the potential to contribute significantly to synthetic biology efforts aimed at producing larger amounts of commercially attractive monoterpenes. © 2016 Elsevier Inc. All rights reserved.

  11. Geranylfarnesyl diphosphate synthase from Methanosarcina mazei: Different role, different evolution

    International Nuclear Information System (INIS)

    Ogawa, Takuya; Yoshimura, Tohru; Hemmi, Hisashi

    2010-01-01

    The gene of (all-E) geranylfarnesyl diphosphate synthase that is responsible for the biosynthesis of methanophenazine, an electron carrier utilized for methanogenesis, was cloned from a methanogenic archaeon Methanosarcina mazei Goe1. The properties of the recombinant enzyme and the results of phylogenetic analysis suggest that the enzyme is closely related to (all-E) prenyl diphosphate synthases that are responsible for the biosynthesis of respiratory quinones, rather than to the enzymes involved in the biosynthesis of archaeal membrane lipids, including (all-E) geranylfarnesyl diphosphate synthase from a thermophilic archaeon.

  12. Regulation of beta cell replication

    DEFF Research Database (Denmark)

    Lee, Ying C; Nielsen, Jens Høiriis

    2008-01-01

    Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

  13. High beta experiments in CHS

    International Nuclear Information System (INIS)

    Okamura, S.; Matsuoka, K.; Nishimura, K.

    1994-09-01

    High beta experiments were performed in the low-aspect-ratio helical device CHS with the volume-averaged equilibrium beta up to 2.1 %. These values (highest for helical systems) are obtained for high density plasmas in low magnetic field heated with two tangential neutral beams. Confinement improvement given by means of turning off gas puffing helped significantly to make high betas. Magnetic fluctuations increased with increasing beta, but finally stopped to increase in the beta range > 1 %. The coherent modes appearing in the magnetic hill region showed strong dependence on the beta values. The dynamic poloidal field control was applied to suppress the outward plasma movement with the plasma pressure. Such an operation gave fixed boundary operations of high beta plasmas in helical systems. (author)

  14. Beta rays and neutrinos

    International Nuclear Information System (INIS)

    Adams, S.F.

    1992-01-01

    It was over 30 years between the first observation of the enigmatic process of beta decay and the first postulation of the neutrino. It took a further 26 years until the first neutrino was detected and yet another 27 until the electroweak theory was confirmed by the discovery of W and Z particles. This article traces some of the puzzles and paradoxes associated with the history of the neutrino. (author)

  15. Coroutine Sequencing in BETA

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun; Madsen, Ole Lehrmann; Møller-Pedersen, Birger

    In object-oriented programming, a program execution is viewed as a physical model of some real or imaginary part of the world. A language supporting object-oriented programming must therefore contain comprehensive facilities for modeling phenomena and concepts form the application domain. Many...... applications in the real world consist of objects carrying out sequential processes. Coroutines may be used for modeling objects that alternate between a number of sequential processes. The authors describe coroutines in BETA...

  16. COM Support in BETA

    DEFF Research Database (Denmark)

    Madsen, Ole Lehrmann

    1999-01-01

    Component technologies based on binary units of independent production are some of the most important contributions to software architecture and reuse during recent years. Especially the COM technologies and the CORBA standard from the Object Management Group have contributed new and interesting...... principles for software architecture, and proven to be useful in parctice. In this paper ongoing work with component support in the BETA language is described....

  17. Role of quaternary structure in muscle creatine kinase stability: tryptophan 210 is important for dimer cohesion.

    Science.gov (United States)

    Perraut, C; Clottes, E; Leydier, C; Vial, C; Marcillat, O

    1998-07-01

    A mutant of the dimeric rabbit muscle creatine kinase (MM-CK) in which tryptophan 210 was replaced has been studied to assess the role of this residue in dimer cohesion and the importance of the dimeric state for the native enzyme stability. Wild-type protein equilibrium unfolding induced by guanidine hydrochloride occurs through intermediate states with formation of a molten globule and a premolten globule. Unlike the wild-type enzyme, the mutant inactivates at lower denaturant concentration and the loss of enzymatic activity is accompanied by the dissociation of the dimer into two apparently compact monomers. However, the Stokes radius of the monomer increases with denaturant concentration as determined by size exclusion chromatography, indicating that, upon monomerization, the protein structure is destabilized. Binding of 8-anilinonaphthalene-1-sulfonate shows that the dissociated monomer exposes hydrophobic patches at its surface, suggesting that it could be a molten globule. At higher denaturant concentrations, both wild-type and mutant follow similar denaturation pathways with formation of a premolten globule around 1.5-M guanidine, indicating that tryptophan 210 does not contribute to a large extent to the monomer conformational stability, which may be ensured in the dimeric state through quaternary interactions.

  18. Effects of Ultrasound, Tryptophan and Proline on embryogenesis and regeneration of grape (Vitis vinifera L.

    Directory of Open Access Journals (Sweden)

    Yousef Farokhzad

    2016-10-01

    Full Text Available Genetic improvement of Grape is limited by traditional methods. An effective regeneration system for tissues culture of transgenic adult plants could facilitate genetic modification of them. So it is necessary to develop and improve embryogenesis and regeneration systems in plants. Accordingly the aim of the present study was to evaluate the effects of ultrasound (0 (as control, 60, 120 and 240 second, tryptophan (0 (as control, 50,100, 200 µM and proline content (0 (as control, 50, 100 and 200 µM on grape stem internodes explants in Kodori cultivar. This project was performed in factorial experiment (two factors in the basis of completely randomized design with three replications at tissue culture laboratory of Shahed University of Tehran. Results showed that both ultrasound and two explained amino acids had significant effects on studied characteristics such as callus frequency, callus length and width, fresh weight, embryo numbers in each callus and their germination percentage. Generally, using 100 µM tryptophan and proline coincide with 120 second ultrasound had highest positive effects on the most studied characteristics.

  19. Lack of tryptophan hydroxylase-1 in mice results in gait abnormalities.

    Science.gov (United States)

    Suidan, Georgette L; Duerschmied, Daniel; Dillon, Gregory M; Vanderhorst, Veronique; Hampton, Thomas G; Wong, Siu Ling; Voorhees, Jaymie R; Wagner, Denisa D

    2013-01-01

    The role of peripheral serotonin in nervous system development is poorly understood. Tryptophan hydroxylase-1 (TPH1) is expressed by non-neuronal cells including enterochromaffin cells of the gut, mast cells and the pineal gland and is the rate-limiting enzyme involved in the biosynthesis of peripheral serotonin. Serotonin released into circulation is taken up by platelets via the serotonin transporter and stored in dense granules. It has been previously reported that mouse embryos removed from Tph1-deficient mothers present abnormal nervous system morphology. The goal of this study was to assess whether Tph1-deficiency results in behavioral abnormalities. We did not find any differences between Tph1-deficient and wild-type mice in general motor behavior as tested by rotarod, grip-strength test, open field and beam walk. However, here we report that Tph1 (-/-) mice display altered gait dynamics and deficits in rearing behavior compared to wild-type (WT) suggesting that tryptophan hydroxylase-1 expression has an impact on the nervous system.

  20. IDO chronic immune activation and tryptophan metabolic pathway: A potential pathophysiological link between depression and obesity.

    Science.gov (United States)

    Chaves Filho, Adriano José Maia; Lima, Camila Nayane Carvalho; Vasconcelos, Silvânia Maria Mendes; de Lucena, David Freitas; Maes, Michael; Macedo, Danielle

    2018-01-03

    Obesity and depression are among the most pressing health problems in the contemporary world. Obesity and depression share a bidirectional relationship, whereby each condition increases the risk of the other. By inference, shared pathways may underpin the comorbidity between obesity and depression. Activation of cell-mediated immunity (CMI) is a key factor in the pathophysiology of depression. CMI cytokines, including IFN-γ, TNFα and IL-1β, induce the catabolism of tryptophan (TRY) by stimulating indoleamine 2,3-dioxygenase (IDO) resulting in the synthesis of kynurenine (KYN) and other tryptophan catabolites (TRYCATs). In the CNS, TRYCATs have been related to oxidative damage, inflammation, mitochondrial dysfunction, cytotoxicity, excitotoxicity, neurotoxicity and lowered neuroplasticity. The pathophysiology of obesity is also associated with a state of aberrant inflammation that activates aryl hydrocarbon receptor (AHR), a pathway involved in the detection of intracellular or environmental changes as well as with increases in the production of TRYCATs, being KYN an agonists of AHR. Both AHR and TRYCATS are involved in obesity and related metabolic disorders. These changes in the TRYCAT pathway may contribute to the onset of neuropsychiatric symptoms in obesity. This paper reviews the role of immune activation, IDO stimulation and increased TRYCAT production in the pathophysiology of depression and obesity. Here we suggest that increased synthesis of detrimental TRYCATs is implicated in comorbid obesity and depression and is a new drug target to treat both diseases. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. MUTANT STRAIN of Bacillus subtilis IFBG MC-1 WITH INCREASED TRYPTOPHAN SYNTHESIS

    Directory of Open Access Journals (Sweden)

    A. F. Tkachenko

    2013-12-01

    Full Text Available Scientific research of essential amino acids biotechnology is directed both to create optimum conditions for producer’s cultivation and economically viable raw materials selection for these technologies, so as breeding the more productive microorganisms strains capable of extracellular producing amino acids. For successful microbial synthesis it is necessary to have an excellent crop’s metabolism knowledge and ensure that the composition of growth medium have no repressing substances. Bacterial cultures from «Collection microorganism’s stains and plants line for food and agriculture biotechnology» from Institute of Food Biotechnology and Genomics of National Academy of Sciences of Ukraine have been studied. Tryptophan producer Bacillus subtilis have been selected, which accumulated the greatest amount of this amino acid in the cultivation liquid. The optimal culture producer conditions were selected. Using selection methods, namely mutagenesis with UV irradiation and sequential stepwise selection, mutant strain Bacillus subtilis IFBG MC-1 were obtained which produced nearly 50% more tryptophan (13.9 g/l than the parent strain.

  2. Non-invasive tryptophan fluorescence measurements as a novel method of grading cataract

    DEFF Research Database (Denmark)

    Erichsen, Jesper Høiberg; Mensah, Aurore; Kessel, Line

    2017-01-01

    . All cataracts were age-related. Lens material from 16 eyes of 14 patients was included in the study. Cataracts were preoperatively graded in categories 1, 2 and 3. No lenses were category 4. For nuclear cataracts mean values of F-factor were 52.9 (SD 12.2), 61.7 (SD 5.3) and 75.7 (SD 8.9......) for categories 1, 2 and 3 respectively. Linear regression on F-factor as a function of preoperative grading category showed increasing values of F-factor with increasing preoperative grading category, R2 = 0.515. Our experiment showed that preoperative optical grading of cataracts by Scheimpflug imaging may......Development of non-invasive treatments for cataract calls for a sensitive diagnostic assay. We conducted a study to test whether the ratio of folded tryptophan to non-tryptophan fluorescence emission (F-factor) may be used for grading cataracts in human lenses. The F-factor was measured...

  3. Bright ambient light conditions reduce the effect of tryptophan depletion in healthy females.

    Science.gov (United States)

    Defrancesco, Michaela; Niederstätter, Harald; Parson, Walther; Kemmler, Georg; Hinterhuber, Hartmann; Marksteiner, Josef; Deisenhammer, Eberhard A

    2013-11-30

    Tryptophan depletion (TD) is an established method to influence the serotonergic system and mood. The purpose of this study was to examine the effect of TD under different ambient light conditions, measured through serotonin-associated plasma levels and a visual analog scale (VAS), on healthy females. Thirty-eight healthy female s-allele carriers of the serotonin transporter promoter gene (5-HTTLPR) were administered a TD under dim light conditions (75 lx). A sub-group of 8 participants repeated the procedure randomized in two additional light conditions (585 lx and 1530 lx respectively). Prior to, and 5h following administration of TD, various variables (serotonin-associated plasma levels, VAS) were measured. Due to not normal distributed data, non-parametric statistical tests were used. Overall analysis showed a significant mood lowering effect of TD. Moreover, TD decreased all measured serotonin-associated plasma levels significantly. Significant differences in varying light conditions were found for the VAS and plasma tryptophan, with the greatest effect of TD in the 75 lx condition. Results of our study showed an influence of even slight differences in ambient light intensity on the effect of TD concerning mood as well as on the serotonergic system. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  4. Tryptophan-2,3-dioxygenase (TDO) inhibition ameliorates neurodegeneration by modulation of kynurenine pathway metabolites.

    Science.gov (United States)

    Breda, Carlo; Sathyasaikumar, Korrapati V; Sograte Idrissi, Shama; Notarangelo, Francesca M; Estranero, Jasper G; Moore, Gareth G L; Green, Edward W; Kyriacou, Charalambos P; Schwarcz, Robert; Giorgini, Flaviano

    2016-05-10

    Metabolites of the kynurenine pathway (KP) of tryptophan (TRP) degradation have been closely linked to the pathogenesis of several neurodegenerative disorders. Recent work has highlighted the therapeutic potential of inhibiting two critical regulatory enzymes in this pathway-kynurenine-3-monooxygenase (KMO) and tryptophan-2,3-dioxygenase (TDO). Much evidence indicates that the efficacy of KMO inhibition arises from normalizing an imbalance between neurotoxic [3-hydroxykynurenine (3-HK); quinolinic acid (QUIN)] and neuroprotective [kynurenic acid (KYNA)] KP metabolites. However, it is not clear if TDO inhibition is protective via a similar mechanism or if this is instead due to increased levels of TRP-the substrate of TDO. Here, we find that increased levels of KYNA relative to 3-HK are likely central to the protection conferred by TDO inhibition in a fruit fly model of Huntington's disease and that TRP treatment strongly reduces neurodegeneration by shifting KP flux toward KYNA synthesis. In fly models of Alzheimer's and Parkinson's disease, we provide genetic evidence that inhibition of TDO or KMO improves locomotor performance and ameliorates shortened life span, as well as reducing neurodegeneration in Alzheimer's model flies. Critically, we find that treatment with a chemical TDO inhibitor is robustly protective in these models. Consequently, our work strongly supports targeting of the KP as a potential treatment strategy for several major neurodegenerative disorders and suggests that alterations in the levels of neuroactive KP metabolites could underlie several therapeutic benefits.

  5. Optimization of Photosensitized Tryptophan Oxidation in the Presence of Dimegin-Polyvinylpyrrolidone-Chitosan Systems.

    Science.gov (United States)

    Solovieva, Anna B; Kardumian, Valeria V; Aksenova, Nadezhda A; Belovolova, Lyudmila V; Glushkov, Mikhail V; Bezrukov, Evgeny A; Sukhanov, Roman B; Kotova, Svetlana L; Timashev, Peter S

    2018-05-23

    By the example of a model process of tryptophan photooxidation in the aqueous medium in the presence of a three-component photosensitizing complex (porphyrin photosensitizer-polyvinylpyrrolidone- chitosan, PPS-PVP-CT) in the temperature range of 20-40 °С, we have demonstrated a possibility of modification of such a process by selecting different molar ratios of the components in the reaction mixture. The actual objective of this selection is the formation of a certain PPS-PVP-CT composition in which PVP macromolecules would coordinate with PPS molecules and at the same time practically block the complex binding of PPS molecules with chitosan macromolecules. Such blocking allows utilization of the bactericidal properties of chitosan to a greater extent, since chitosan is known to depress the PPS photosensitizing activity in PPS-PVP-CT complexes when using those in photodynamic therapy (PDT). The optimal composition of photosensitizing complexes appears to be dependent on the temperature at which the PDT sessions are performed. We have analyzed the correlations of the effective rate constants of tryptophan photooxidation with the photophysical characteristics of the formed complexes.

  6. Imaging C. elegans with thiolated tryptophan-based NIR fluorescent gold nanoclusters

    Energy Technology Data Exchange (ETDEWEB)

    Barman, Apurba Kr. [Indian Institute of Technology Kanpur, Department of Chemistry (India); Chaturbedi, Amaresh; Subramaniam, K. [Indian Institute of Technology Kanpur, Department of Biological Sciences and Bioengineering (India); Verma, Sandeep, E-mail: sverma@iitk.ac.in [Indian Institute of Technology Kanpur, Department of Chemistry (India)

    2013-11-15

    Multidentate, thiolated, tryptophan-containing peptide conjugates were synthesized for the preparation of gold nanoclusters (AuNCs). Precursor Au{sub 11}(PPh{sub 3}){sub 8}Cl{sub 3} was prepared by the reduction of HAuCl{sub 4}, followed by the use of tryptophan-containing peptide conjugates in ligand displacement reactions, to afford near-infrared fluorescent AuNCs. The emission maxima for these newly synthesized AuNCs were ∼715 nm. AuNCs were characterized with the help of UV–Vis, FTIR, fluorescence and MALDI analysis. FTIR spectra showed that the ligands bind to Au atoms through Au–S bonds, while MALDI mass spectra revealed that the clusters consisted of 20–23 Au atoms. Introduction of hydrophilic –COOH groups engendered water solubility to these AuNCs, enabling bioimaging applications. We demonstrate fluorescence imaging of the nematode C. elegans and confirm distribution of these AuNCs in nematode gut with the help of green fluorescent protein co-localization experiments.

  7. CARD9 impacts colitis by altering gut microbiota metabolism of tryptophan into aryl hydrocarbon receptor ligands.

    Science.gov (United States)

    Lamas, Bruno; Richard, Mathias L; Leducq, Valentin; Pham, Hang-Phuong; Michel, Marie-Laure; Da Costa, Gregory; Bridonneau, Chantal; Jegou, Sarah; Hoffmann, Thomas W; Natividad, Jane M; Brot, Loic; Taleb, Soraya; Couturier-Maillard, Aurélie; Nion-Larmurier, Isabelle; Merabtene, Fatiha; Seksik, Philippe; Bourrier, Anne; Cosnes, Jacques; Ryffel, Bernhard; Beaugerie, Laurent; Launay, Jean-Marie; Langella, Philippe; Xavier, Ramnik J; Sokol, Harry

    2016-06-01

    Complex interactions between the host and the gut microbiota govern intestinal homeostasis but remain poorly understood. Here we reveal a relationship between gut microbiota and caspase recruitment domain family member 9 (CARD9), a susceptibility gene for inflammatory bowel disease (IBD) that functions in the immune response against microorganisms. CARD9 promotes recovery from colitis by promoting interleukin (IL)-22 production, and Card9(-/-) mice are more susceptible to colitis. The microbiota is altered in Card9(-/-) mice, and transfer of the microbiota from Card9(-/-) to wild-type, germ-free recipients increases their susceptibility to colitis. The microbiota from Card9(-/-) mice fails to metabolize tryptophan into metabolites that act as aryl hydrocarbon receptor (AHR) ligands. Intestinal inflammation is attenuated after inoculation of mice with three Lactobacillus strains capable of metabolizing tryptophan or by treatment with an AHR agonist. Reduced production of AHR ligands is also observed in the microbiota from individuals with IBD, particularly in those with CARD9 risk alleles associated with IBD. Our findings reveal that host genes affect the composition and function of the gut microbiota, altering the production of microbial metabolites and intestinal inflammation.

  8. Au nanoparticles on tryptophan-functionalized graphene for sensitive detection of dopamine

    International Nuclear Information System (INIS)

    Lian, Qianwen; Luo, Ai; An, Zhenzhen; Li, Zhuang; Guo, Yongyang; Zhang, Dongxia; Xue, Zhonghua; Zhou, Xibin; Lu, Xiaoquan

    2015-01-01

    Graphical abstract: - Highlights: • A novel AuNPs/Trp-GR composite was fabricated by directly electrochemical deposition. • The composite exhibited excellent electrocatalytic activity towards DA. • The proposed method was applied to real samples. - Abstract: A novel and uniform gold nanoparticles/tryptophan-functionalized graphene nanocomposite (AuNPs/Trp-GR) has been successfully fabricated by directly electrochemical depositing gold onto the surface of tryptophan-functionalized graphene (Trp-GR). The nanostructure of AuNPs/Trp-GR was characterized by using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). It was demonstrated that Au nanoparticles were well dispersed on the surface of Trp-GR which might attribute to the more binding sites provided by Trp-GR for the formation of Au nanoparticles. The electrocatalytic activity of the AuNPs/Trp-GR towards the dopamine (DA) was systematically investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under optimum conditions, a wide and valuable linear range (0.5–411 μM), a low detection limit (0.056 μM, S/N = 3), good repeatability and stability were obtained for the determination of DA. Furthermore, the modified electrode was successfully applied to real samples analysis

  9. Au nanoparticles on tryptophan-functionalized graphene for sensitive detection of dopamine

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Qianwen; Luo, Ai; An, Zhenzhen; Li, Zhuang; Guo, Yongyang; Zhang, Dongxia [Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, 730070, Lanzhou (China); Xue, Zhonghua [College of Chemistry and Chemical Engineering, Northwest Normal University, 730070, Lanzhou (China); Zhou, Xibin, E-mail: zhouxb@nwnu.edu.cn [Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, 730070, Lanzhou (China); Lu, Xiaoquan, E-mail: Luxq@nwnu.edu.cn [College of Chemistry and Chemical Engineering, Northwest Normal University, 730070, Lanzhou (China)

    2015-09-15

    Graphical abstract: - Highlights: • A novel AuNPs/Trp-GR composite was fabricated by directly electrochemical deposition. • The composite exhibited excellent electrocatalytic activity towards DA. • The proposed method was applied to real samples. - Abstract: A novel and uniform gold nanoparticles/tryptophan-functionalized graphene nanocomposite (AuNPs/Trp-GR) has been successfully fabricated by directly electrochemical depositing gold onto the surface of tryptophan-functionalized graphene (Trp-GR). The nanostructure of AuNPs/Trp-GR was characterized by using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). It was demonstrated that Au nanoparticles were well dispersed on the surface of Trp-GR which might attribute to the more binding sites provided by Trp-GR for the formation of Au nanoparticles. The electrocatalytic activity of the AuNPs/Trp-GR towards the dopamine (DA) was systematically investigated using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under optimum conditions, a wide and valuable linear range (0.5–411 μM), a low detection limit (0.056 μM, S/N = 3), good repeatability and stability were obtained for the determination of DA. Furthermore, the modified electrode was successfully applied to real samples analysis.

  10. Tryptophan: the key to boosting brain serotonin synthesis in depressive illness.

    Science.gov (United States)

    Badawy, Abdulla A-B

    2013-10-01

    It has been proposed that focusing on brain serotonin synthesis can advance antidepressant drug development. Biochemical aspects of the serotonin deficiency in major depressive disorder (MDD) are discussed here in detail. The deficiency is caused by a decreased availability of the serotonin precursor tryptophan (Trp) to the brain. This decrease is caused by accelerated Trp degradation, most likely induced by enhancement of the hepatic enzyme tryptophan 2,3-dioxygenase (TDO) by glucocorticoids and/or catecholamines. Induction of the extrahepatic Trp-degrading enzyme indolylamine 2,3-dioxygenase (IDO) by the modest immune activation in MDD has not been demonstrated and, if it occurs, is unlikely to make a significant contribution. Liver TDO appears to be a target of many antidepressants, the mood stabilisers Li(+) and carbamazepine and possibly other adjuncts to antidepressant therapy. The poor, variable and modest antidepressant efficacy of Trp is due to accelerated hepatic Trp degradation, and efficacy can be restored or enhanced by combination with antidepressants or other existing or new TDO inhibitors. Enhancing Trp availability to the brain is thus the key to normalisation of serotonin synthesis and could form the basis for future antidepressant drug development.

  11. Interfacial Tryptophan Residues: A Role for the Cation-{pi} Effect?

    DEFF Research Database (Denmark)

    Petersen, Frederic Nicolas Rønne; Jensen, Morten Ø.; Helix Nielsen, Claus

    2005-01-01

    Integral membrane proteins are characterized by having a preference for aromatic residues, e.g., tryptophan (W), at the interface between the lipid bilayer core and the aqueous phase. The reason for this is not clear, but it seems that the preference is related to a complex interplay between steric...... between the nitrogen moiety of lipid molecule headgroups and the pi-electron distribution of gramicidin (gA) tryptophan residues (W(9), W(11), W(13), and W(15)) using molecular dynamics (MD) simulations of gA embedded in two hydrated lipid bilayers composed of 1-palmitoyl-2-oleoylphosphatidylethanolamine....... Our criteria for cation-pi interactions are based on distance and angular requirements, and the results from our model suggest that cation-pi interactions are relevant for W(PE)(11), W(PE)(13), W(PE)(15), and, to some extent, W(PC)(11) and W(PC)(13). In our model, W(9)does not seem to engage in cation...

  12. EFFECT OF DIETARY TRYPTOPHAN LEVELS ON GROWTH PERFORMANCE OF BROILER CHICKENS REARED IN THE HOT SEASON UNDER TROPICAL ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Emmanuel Opoola

    2017-12-01

    Full Text Available This study was conducted to evaluate the effect of dietary levels of tryptophan on growth performance of broiler chickens reared under tropical environment. At the starter phase, a total of two hundred and eighty five day old mixed sex Arbor Acres broiler chicks were randomly allotted to five dietary treatments with three replicates each having nineteen (19 chicks. At the finisher phase, two hundred and seventy broilers were also allotted to five dietary treatments with three replicates each having 18 broilers per replicate. The dietary tryptophan levels at the starter phase were 0.15, 0.19, 0.23, 0.27 and 0.31% respectively while the diets for the finisher phase contained 0.13, 0.17, 0.21, 0.25 and 0.29% dietary tryptophan respectively. All other nutrient levels were constant. The experiment was conducted at 0 to 28d (starter phase and 33 to 56d (finisher phase. Growth performance traits including weight gain, feed intake and feed conversion ratio were recorded at the end of each week. The results for the starter phase showed that chicks fed diet containing 0.23%, 0.27% and 0.31% dietary tryptophan had similar results in term of the weight gain, average daily weight gain, feed intake and average daily feed intake. For the finisher phase, the birds fed 0.21%, 0.25% and 0.29% tryptophan diets also had similar results in terms of final weight, weight gain, feed intake and average daily feed intake. Our results suggest that supplemental tryptophan was sufficient to have significant (P<0.05 effect on broiler performance. However, polynomial regression analysis reveals that the optimum performances were reached at 0.24% and 0.21% dietary tryptophan for the starter and finisher phases respectively. Therefore, it can be concluded that dietary tryptophan requirements during the hot season for the starter and finisher phases were 0.24% and 0.21%, respectively.

  13. Highly specific ''sensing'' of tryptophan by a luminescent europium(III) complex

    Energy Technology Data Exchange (ETDEWEB)

    Stubenrauch, Jan A.; Mevissen, Christian; Schulte, Marie F.; Bochenek, Steffen; Albrecht, Markus [RWTH Univ. Aachen (Germany). Inst. fuer Organische Chemie; Subramanian, Palani S. [Central Salt and Marine Chemicals, Research Institute (CSRI), Gujarat (India)

    2016-07-01

    The europium(III) complex 1-Cl{sub 3} (S,S-2,2{sup '}-(((1,10-phenanthroline-2,9-diyl)bis(methanylylidene))bis (azanylyliden e))bis(3-methylbutanamide)europiumtrichloride) undergoes, only in the presence of the amino acid tryptophan, a change of emission at 615 nm. In the presence of few equivalents of tryptophan, emission of the europium complex is enhanced while it disappears upon addition of large amounts. This behavior can be assigned to displacement of the sensitizing phenanthroline ligand of 1-Cl{sub 2} x Trp in the latter case.

  14. LHCb: $2\\beta_s$ measurement at LHCb

    CERN Multimedia

    Conti, G

    2009-01-01

    A measurement of $2\\beta_s$, the phase of the $B_s-\\bar{B_s}$ oscillation amplitude with respect to that of the ${\\rm b} \\rightarrow {\\rm c^{+}}{\\rm W^{-}}$ tree decay amplitude, is one of the key goals of the LHCb experiment with first data. In the Standard Model (SM), $2\\beta_s$ is predicted to be $0.0360^{+0.0020}_{-0.0016} \\rm rad$. The current constraints from the Tevatron are: $2\\beta_{s}\\in[0.32 ; 2.82]$ at 68$\\%$CL from the CDF experiment and $2\\beta_{s}=0.57^{+0.24}_{-0.30}$ from the D$\\oslash$ experiment. Although the statistical uncertainties are large, these results hint at the possible contribution of New Physics in the $B_s-\\bar{B_s}$ box diagram. After one year of data taking at LHCb at an average luminosity of $\\mathcal{L}\\sim2\\cdot10^{32}\\rm cm^{-2} \\rm s^{-1}$ (integrated luminosity $\\mathcal{L}_{\\rm int}\\sim 2 \\rm fb^{-1}$), the expected statistical uncertainty on the measurement is $\\sigma(2\\beta_s)\\simeq 0.03$. This uncertainty is similar to the $2\\beta_s$ value predicted by the SM.

  15. Crystal structure of 3,4-dihydroxy-2-butanone 4-phosphate synthase of riboflavin biosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Liao, D.-I.; Calabrese, J.C.; Wawrzak, Z.; Viitanen, P.V.; Jordan, D.B. (DuPont); (NWU)

    2010-03-05

    3,4-Dihydroxy-2-butanone-4-phosphate synthase catalyzes a commitment step in the biosynthesis of riboflavin. On the enzyme, ribulose 5-phosphate is converted to 3,4-dihydroxy-2-butanone 4-phosphate and formate in steps involving enolization, ketonization, dehydration, skeleton rearrangement, and formate elimination. The enzyme is absent in humans and an attractive target for the discovery of antimicrobials for pathogens incapable of acquiring sufficient riboflavin from their hosts. The homodimer of 23 kDa subunits requires Mg{sup 2+} for activity. The first three-dimensional structure of the enzyme was determined at 1.4 {angstrom} resolution using the multiwavelength anomalous diffraction (MAD) method on Escherichia coli protein crystals containing gold. The protein consists of an {alpha} + {beta} fold having a complex linkage of {beta} strands. Intersubunit contacts are mediated by numerous hydrophobic interactions and three hydrogen bond networks. A proposed active site was identified on the basis of amino acid residues that are conserved among the enzyme from 19 species. There are two well-separated active sites per dimer, each of which comprise residues from both subunits. In addition to three arginines and two threonines, which may be used for recognizing the phosphate group of the substrate, the active site consists of three glutamates, two aspartates, two histidines, and a cysteine which may provide the means for general acid and base catalysis and for coordinating the Mg{sup 2+} cofactor within the active site.

  16. Isolation of developing secondary xylem specific cellulose synthase ...

    Indian Academy of Sciences (India)

    The present study aimed at identifying developing secondary xylem specific cellulose synthase genes from .... the First strand cDNA synthesis kit (Fermentas, Pittsburgh,. USA). .... ing height of the rooted cutting, girth of the stem, leaf area.

  17. Cloning and expression of pineapple sucrose- phosphate synthase ...

    African Journals Online (AJOL)

    hope&shola

    2010-12-06

    Dec 6, 2010 ... phosphate; EDTA, ethylene diamine tetraacetic acid; Ivr, invertase; SS .... phenolics, tannins and artifacts due to differences of tissue composition ..... Banana sucrose-phosphate synthase gene expression during fruit ripening.

  18. PGC-1alpha and PGC-1beta have both similar and distinct effects on myofiber switching toward an oxidative phenotype

    DEFF Research Database (Denmark)

    Mortensen, Ole Hartvig; Frandsen, Lis; Schjerling, Peter

    2006-01-01

    Peroxisome proliferator-activated receptor-gamma coactivator-1alpha and -1beta (PGC-1alpha and PGC-1beta) were overexpressed by adenovirus-mediated gene transfer in cultures of primary rat skeletal muscle cells derived from neonatal myoblasts. Effects on muscle fiber type transition and metabolism...... an increase in the mRNA expression of TRB3, a negative regulator of insulin signaling. These results show that both PGC-1alpha and PGC-1beta are involved in the regulation of skeletal muscle fiber transition and metabolism and that they have both overlapping and differing effects....... were studied from days 5 to 22 of culture. PGC-1alpha and PGC-1beta overexpression caused a three- to fourfold increase in mRNA level, a doubling of enzymatic activity of citrate synthase, a slight increase in short-chain acyl-CoA dehydrogenase mRNA, a doubling of the mRNA level, and a 30-50% increase...

  19. Metabolic Availability of the Limiting Amino Acids Lysine and Tryptophan in Cooked White African Cornmeal Assessed in Healthy Young Men Using the Indicator Amino Acid Oxidation Technique.

    Science.gov (United States)

    Rafii, Mahroukh; Elango, Rajavel; Ball, Ronald O; Pencharz, Paul B; Courtney-Martin, Glenda

    2018-06-01

    Maize is a staple food in many regions of the world, particularly in Africa and Latin America. However, maize protein is limiting in the indispensable amino acids lysine and tryptophan, making its protein of poor quality. The main objective of this study was to determine the protein quality of white African cornmeal by determining the metabolic availability (MA) of lysine and tryptophan. To determine the MA of lysine, 4 amounts of l-lysine (10, 13, 16, and 18 mg · kg-1 · d-1 totaling 28.6%, 37.1%, 45.7%, and 51.4% of the mean lysine requirement of 35 mg · kg-1 · d-1, respectively) were studied in 6 healthy young men in a repeated-measures design. To determine the MA of tryptophan, 4 amounts of l-tryptophan (0.5, 1, 1.5, and 2 mg · kg-1 · d-1 totaling 12.5%, 25.0%, 37.5%, and 50.0% of the mean tryptophan requirement of 4 mg · kg-1 · d-1, respectively) were studied in 7 healthy young men in a repeated-measures design. The MAs of lysine and tryptophan were estimated by comparing the indicator amino acid oxidation (IAAO) response with varying intakes of lysine and tryptophan in cooked white cornmeal compared with the IAAO response to l-lysine and l-tryptophan intakes in the reference protein (crystalline amino acid mixture patterned after egg protein) with the use of the slope ratio method. The MAs of lysine and tryptophan from African cooked white cornmeal were 71% and 80%, respectively. Our study provides a robust estimate of the availability of lysine and tryptophan in African white maize to healthy young men. This estimate provides a basis for postproduction fortification or supplementation of maize-based diets. This trial was registered at www.clinicaltrials.gov as NCT02402179.

  20. Enantioselective synthesis of alpha,beta-disubstituted-beta-amino acids.

    Science.gov (United States)

    Sibi, Mukund P; Prabagaran, Narayanasamy; Ghorpade, Sandeep G; Jasperse, Craig P

    2003-10-01

    Highly diastereoselective and enantioselective addition of N-benzylhydroxylamine to imides 17 and 20-30 produces alpha,beta-trans-disubstituted N-benzylisoxazolidinones 19 and 31-41. These reactions proceed in 60-96% ee with 93-99% de's using 5 mol % of Mg(NTf2)2 and ligand 18. The product isoxazolidinones can be hydrogenolyzed directly to provide alpha,beta-disubstituted-beta-amino acids.

  1. Modulation of hyaluronan synthase activity in cellular membrane fractions

    OpenAIRE

    Vigetti, Davide; Genasetti, A; Karousou, Evgenia; Viola, Manuela; Clerici, M; Bartolini, B; Moretto, Paola; DE LUCA, Giancarlo; Hascall, Vc; Passi, Alberto

    2009-01-01

    Hyaluronan (HA), the only non-sulfated glycosaminoglycan, is involved in morphogenesis, wound healing, inflammation, angiogenesis, and cancer. In mammals, HA is synthesized by three homologous HA synthases, HAS1, HAS2, and HAS3, that polymerize the HA chain using UDP-glucuronic acid and UDP-N-acetylglucosamine as precursors. Since the amount of HA is critical in several pathophysiological conditions, we developed a non-radioactive assay for measuring the activity of HA synthases (HASs) in euk...

  2. Inhibitors of Fatty Acid Synthase for Prostate Cancer. Revision

    Science.gov (United States)

    2013-05-01

    acetyl- cholinesterase inhibitors have been developed, many with femtomolar binding affinities (7). This body of literature also confirms that the...AD_________________ Award Number: W81XWH-09-1-0204 TITLE: Inhibitors of Fatty Acid Synthase for...May 2013 2. REPORT TYPE Revised Final 3. DATES COVERED 01 May 2009-30 Apr 2013 4. TITLE AND SUBTITLE Inhibitors of Fatty Acid Synthase for

  3. Inhibitors of Fatty Acid Synthase for Prostate Cancer

    Science.gov (United States)

    2012-05-01

    compounds. For example, numerous classes of acetyl- cholinesterase inhibitors have been developed, m any with fe mtomolar binding affinities (7). This...AD_________________ Award Number: W81XWH-09-1-0204 TITLE: Inhibitors of Fatty Acid Synthase for...CONTRACT NUMBER Inhibitors of Fatty Acid Synthase for Prostate Cancer 5b. GRANT NUMBER W81XWH-09-1-0204 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR

  4. Cellular demise and inflammatory microglial activation during beta-amyloid toxicity are governed by Wnt1 and canonical signaling pathways.

    Science.gov (United States)

    Chong, Zhao Zhong; Li, Faqi; Maiese, Kenneth

    2007-06-01

    Initially described as a modulator of embryogenesis for a number of organ systems, Wnt1 has recently been linked to the development of several neurodegenerative disorders, none being of greater significance than Alzheimer's disease. We therefore examined the ability of Wnt1 to oversee vital pathways responsible for cell survival during beta-amyloid (Abeta1-42) exposure. Here we show that Wnt1 is critical for protection in the SH-SY5Y neuronal cell line against genomic DNA degradation, membrane phosphatidylserine (PS) exposure, and microglial activation, since these neuroprotective attributes of Wnt1 are lost during gene silencing of Wnt1 protein expression. Intimately tied to Wnt1 protection is the presence and activation of Akt1. Pharmacological inhibition of the PI 3-K pathway or gene silencing of Akt1 expression can abrogate the protective capacity of Wnt1. Closely aligned with Wnt1 and Akt1 are the integrated canonical pathways of synthase kinase-3beta (GSK-3beta) and beta-catenin. Through Akt1 dependent pathways, Wnt1 phosphorylates GSK-3beta and maintains beta-catenin integrity to insure its translocation from the cytoplasm to the nucleus to block apoptosis. Our work outlines a highly novel role for Wnt1 and its integration with Akt1, GSK-3beta, and beta-catenin to foster neuronal cell survival and repress inflammatory microglial activation that can identify new avenues of therapy against neurodegenerative disorders.

  5. The Eucalyptus terpene synthase gene family.

    Science.gov (United States)

    Külheim, Carsten; Padovan, Amanda; Hefer, Charles; Krause, Sandra T; Köllner, Tobias G; Myburg, Alexander A; Degenhardt, Jörg; Foley, William J

    2015-06-11

    Terpenoids are abundant in the foliage of Eucalyptus, providing the characteristic smell as well as being valuable economically and influencing ecological interactions. Quantitative and qualitative inter- and intra- specific variation of terpenes is common in eucalypts. The genome sequences of Eucalyptus grandis and E. globulus were mined for terpene synthase genes (TPS) and compared to other plant species. We investigated the relative expression of TPS in seven plant tissues and functionally characterized five TPS genes from E. grandis. Compared to other sequenced plant genomes, Eucalyptus grandis has the largest number of putative functional TPS genes of any sequenced plant. We discovered 113 and 106 putative functional TPS genes in E. grandis and E. globulus, respectively. All but one TPS from E. grandis were expressed in at least one of seven plant tissues examined. Genomic clusters of up to 20 genes were identified. Many TPS are expressed in tissues other than leaves which invites a re-evaluation of the function of terpenes in Eucalyptus. Our data indicate that terpenes in Eucalyptus may play a wider role in biotic and abiotic interactions than previously thought. Tissue specific expression is common and the possibility of stress induction needs further investigation. Phylogenetic comparison of the two investigated Eucalyptus species gives insight about recent evolution of different clades within the TPS gene family. While the majority of TPS genes occur in orthologous pairs some clades show evidence of recent gene duplication, as well as loss of function.

  6. Beta measurement evaluation and upgrade

    International Nuclear Information System (INIS)

    Swinth, K.L.; Rathbun, L.A.; Roberson, P.L.; Endres, G.W.R.

    1986-01-01

    This program focuses on the resolution of problems associated with the field measurement of the beta dose component at Department of Energy (DOE) facilities. The change in DOE programs, including increased efforts in improved waste management and decontamination and decommissioning (D and D) of facilities, coupled with beta measurement problems identified at Three Mile Island has increased the need to improve beta measurements. In FY 1982, work was initiated to provide a continuing effort to identify problems associated with beta dose assessment at DOE facilities. The problems identified resulted in the development of this program. The investigation includes (1) an assessment of measurement systems now in use, (2) development of improved calibration systems and procedures, (3) application of innovative beta dosimetry concepts, (4) investigation of new instruments or concepts for monitoring and spectroscopy, and (5) development of recommendations to assure an adequate beta measurement program within DOE facilities

  7. Surplus dietary tryptophan reduces plasma cortisol and noradrenaline concentrations and enhances recovery after social stress in pigs

    NARCIS (Netherlands)

    Koopmans, S.J.; Ruis, M.A.W.; Dekker, R.A.; Diepen, van J.T.M.; Korte, S.M.; Mroz, Z.

    2005-01-01

    Social stress occurs in intensive pig farming due to aggressive behavior. This stress may be reduced at elevated dietary levels of tryptophan (TRP). In this study, we compared the effects of high (13.2%) vs. normal (3.4%) dietary TRP to large neutral amino acid (LNAA) ratios on behavior and stress

  8. Evaluation of acute tryptophan depletion and sham depletion with a gelatin-based collagen peptide protein mixture

    DEFF Research Database (Denmark)

    Stenbæk, Dea Siggaard; Einarsdottir, H S; Goregliad-Fjaellingsdal, T

    2016-01-01

    Acute Tryptophan Depletion (ATD) is a dietary method used to modulate central 5-HT to study the effects of temporarily reduced 5-HT synthesis. The aim of this study is to evaluate a novel method of ATD using a gelatin-based collagen peptide (CP) mixture. We administered CP-Trp or CP+Trp mixtures...

  9. Metabolic pathway interruption: CRISPR/Cas9-mediated knockout of tryptophan 2,3-oxygenase in Tribolium castaneum

    Science.gov (United States)

    The Tribolium castaneum vermilion gene encodes tryptophan 2,3-dioxygenase, a pivotal enzyme in the ommochrome pathway that is responsible for the black eye color. T. castaneum strains with a loss-of-function mutation, vermilion white (vw), lack both the promoter and the first 80% of the vermilion co...

  10. Neural and personality correlates of individual differences related to the effects of acute tryptophan depletion on future reward evaluation.

    Science.gov (United States)

    Demoto, Yoshihiko; Okada, Go; Okamoto, Yasumasa; Kunisato, Yoshihiko; Aoyama, Shiori; Onoda, Keiichi; Munakata, Ayumi; Nomura, Michio; Tanaka, Saori C; Schweighofer, Nicolas; Doya, Kenji; Yamawaki, Shigeto

    2012-01-01

    In general, humans tend to discount the value of delayed reward. An increase in the rate of discounting leads to an inability to select a delayed reward over a smaller immediate reward (reward-delay impulsivity). Although deficits in the serotonergic system are implicated in this reward-delay impulsivity, there is individual variation in response to serotonin depletion. The aim of the present study was to investigate whether the effects of serotonin depletion on the ability to evaluate future reward are affected by individual personality traits or brain activation. Personality traits were assessed using the NEO-Five Factor Inventory and Temperament and Character Inventory. The central serotonergic levels of 16 healthy volunteers were manipulated by dietary tryptophan depletion. Subjects performed a delayed reward choice task that required the continuous estimation of reward value during functional magnetic resonance imaging scanning. Discounting rates were increased in 9 participants, but were unchanged or decreased in 7 participants in response to tryptophan depletion. Participants whose discounting rate was increased by tryptophan depletion had significantly higher neuroticism and lower self-directedness. Furthermore, tryptophan depletion differentially affected the groups in terms of hemodynamic responses to the value of predicted future reward in the right insula. These results suggest that individuals who have high neuroticism and low self-directedness as personality traits are particularly vulnerable to the effect of low serotonin on future reward evaluation accompanied by altered brain activation patterns. Copyright © 2012 S. Karger AG, Basel.

  11. Evening dietary tryptophan improves post-sleep behavioral and brain measures of memory function in healthy subjects

    NARCIS (Netherlands)

    Markus, C.R.; Jonkman, L.M.; Lammers, J.H.C.M.; Deutz, N.E.P.

    2006-01-01

    Brain serotonin function has been implicated in the control of sleep and sleep related memory dysfunctions are attributed to deficient brain serotonin activity. Depletion of the serotonin precursor tryptophan reduces brain serotonin function and is found to cause sleep abnormalities and cognitive

  12. Indoleamine 2,3-dioxygenase-dependent tryptophan metabolites contribute to tolerance induction during allergen immunotherapy in a mouse model

    NARCIS (Netherlands)

    Taher, Yousef A.; Piavaux, Benoit J. A.; Gras, Renee; van Esch, Betty C. A. M.; Hofman, Gerard A.; Bloksma, Nanne; Henricks, Paul A. J.; van Oosterhout, Antoon J. M.

    Background: The tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase (IDO) has been implicated in immune suppression and tolerance induction. Objective: We examined (1) whether IDO activity is required during tolerance induction by allergen immunotherapy or for the subsequent suppressive

  13. Adsorption of the cysteine–tryptophan dipeptide at the Au(110)/liquid interface studied using reflection anisotropy spectroscopy

    DEFF Research Database (Denmark)

    Morozzo della Rocca, Blasco; Smith, C I; Tesauro, Cinzia

    2010-01-01

    The adsorption of a cysteine–tryptophan dipeptide has been monitored at a Au(110)/electrolyte interface using reflection anisotropy spectroscopy. At −0.6 V the dipeptide adsorbed through the formation of Au–S bonds and a link between the NH2 group at the Au surface. As the applied potential...

  14. Peptide-membrane interactions of arginine-tryptophan peptides probed using quartz crystal microbalance with dissipation monitoring.

    KAUST Repository

    Rydberg, Hanna A

    2014-04-18

    Membrane-active peptides include peptides that can cross cellular membranes and deliver macromolecular cargo as well as peptides that inhibit bacterial growth. Some of these peptides can act as both transporters and antibacterial agents. It is desirable to combine the knowledge from these two different fields of membrane-active peptides into design of new peptides with tailored actions, as transporters of cargo or as antibacterial substances, targeting specific membranes. We have previously shown that the position of the amino acid tryptophan in the peptide sequence of three arginine-tryptophan peptides affects their uptake and intracellular localization in live mammalian cells, as well as their ability to inhibit bacterial growth. Here, we use quartz crystal microbalance with dissipation monitoring to assess the induced changes caused by binding of the three peptides to supported model membranes composed of POPC, POPC/POPG, POPC/POPG/cholesterol or POPC/lactosyl PE. Our results indicate that the tryptophan position in the peptide sequence affects the way these peptides interact with the different model membranes and that the presence of cholesterol in particular seems to affect the membrane interaction of the peptide with an even distribution of tryptophans in the peptide sequence. These results give mechanistic insight into the function of these peptides and may aid in the design of membrane-active peptides with specified cellular targets and actions.

  15. Synthesis and biological evaluation of ¹⁸F-labeled fluoropropyl tryptophan analogs as potential PET probes for tumor imaging.

    Science.gov (United States)

    Chiotellis, Aristeidis; Mu, Linjing; Müller, Adrienne; Selivanova, Svetlana V; Keller, Claudia; Schibli, Roger; Krämer, Stefanie D; Ametamey, Simon M

    2013-01-01

    In the search for an efficient, fluorine-18 labeled amino acid based radiotracer for tumor imaging with positron emission tomography (PET), two new tryptophan analogs were synthesized and characterized in vitro and in vivo. Both are tryptophan alkyl-derivatives, namely 2-(3-[(18)F]fluoropropyl)-DL-tryptophan ([(18)F]2-FPTRP) and 5-(3-[(18)F]fluoro-propyl)-DL-tryptophan ([(18)F]5-FPTRP). Standard reference compounds and precursors were prepared by multi step approaches. Radiosynthesis was achieved by no-carrier-added nucleophilic [(18)F]fluorination in 29-34% decay corrected yields with radiochemical purity over 99%. In vitro cell uptake assays showed that both compounds are substrates for amino acid transport and enter small cell lung cancer cells (NCI-H69) most probably almost exclusively via large neutral amino acids transporter(s) (LAT). Small animal PET imaging with xenograft bearing mice revealed high tumor/background ratios for [(18)F]2-FPTRP comparable to the well established tyrosine analog O-(2-[(18)F]fluroethyl)-L-tyrosine ([(18)F]FET). Radiometabolite studies showed no evidence of involvement of a biotransformation step in tumor accumulation. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  16. Peptide-membrane interactions of arginine-tryptophan peptides probed using quartz crystal microbalance with dissipation monitoring.

    KAUST Repository

    Rydberg, Hanna A; Kunze, Angelika; Carlsson, Nils; Altgä rde, Noomi; Svedhem, Sofia; Nordé n, Bengt

    2014-01-01

    Membrane-active peptides include peptides that can cross cellular membranes and deliver macromolecular cargo as well as peptides that inhibit bacterial growth. Some of these peptides can act as both transporters and antibacterial agents. It is desirable to combine the knowledge from these two different fields of membrane-active peptides into design of new peptides with tailored actions, as transporters of cargo or as antibacterial substances, targeting specific membranes. We have previously shown that the position of the amino acid tryptophan in the peptide sequence of three arginine-tryptophan peptides affects their uptake and intracellular localization in live mammalian cells, as well as their ability to inhibit bacterial growth. Here, we use quartz crystal microbalance with dissipation monitoring to assess the induced changes caused by binding of the three peptides to supported model membranes composed of POPC, POPC/POPG, POPC/POPG/cholesterol or POPC/lactosyl PE. Our results indicate that the tryptophan position in the peptide sequence affects the way these peptides interact with the different model membranes and that the presence of cholesterol in particular seems to affect the membrane interaction of the peptide with an even distribution of tryptophans in the peptide sequence. These results give mechanistic insight into the function of these peptides and may aid in the design of membrane-active peptides with specified cellular targets and actions.

  17. Preparation and characterization of a novel epoxy based nanocomposite using tryptophan as an eco-friendly curing agent

    International Nuclear Information System (INIS)

    Motahari, Ahmad; Omrani, Abdollah; Rostami, Abbas Ali; Ehsani, Morteza

    2013-01-01

    Highlights: • Epoxy cured with tryptophan in the presence of 2,4,5-triphenylimidazole. • Kinetic study on the epoxy nanocomposite using advanced isoconversional method. • Structural study and characterization of nanocomposite using SEM, XRD, AFM and DMTA. - Abstract: In this study, kinetics of the curing reaction between DGEBA epoxy resin and tryptophan as an environmentally friendly curing agent in the presence of 2,4,5-triphenylimidazole was reported. The role of silica nanoparticles (SiNP) in changing the mechanism of the curing reaction was also studied. The optimum molar ratio of DGEBA/tryptophan and the optimum content of SiNP were determined by calorimetry analyses. Kinetic analysis using the advanced isoconversional method revealed that the system undergoes the vitrification. Thermogravimetric analysis demonstrated that addition of SiNP does not improve the thermal stability of the tryptophan based thermosets. Impedance spectroscopy and also the standard four-probe method were performed to investigate the effect of curing agent and SiNP loading level on the electrical properties of the cured epoxy. The structure and morphology of the nanocomposite were studied by X-ray diffraction analysis, atomic force microscopy and scanning electron microscopy imaging. Dynamic mechanical thermal analysis revealed that the crosslinking density cannot be significantly affected with the addition of SiNP

  18. [Environment of tryptophan residues in proteins--a factor for stability to oxidative nitrosylation. I. Analysis of primary structure].

    Science.gov (United States)

    Beda, N V; Nedospasov, A A

    2001-01-01

    Micellar catalysis under aerobic conditions effectively accelerates oxidative nitrosylation because of solubilization of NO and O2 by protein membranes and hydrophobic nuclei. Nitrosylating intermediates NOx (NO2, N2O3, N2O4) form mainly in the hydrophobic phase, and therefore their solubility in aqueous phase is low and hydrolysis is rapid, local concentration of NOx in the hydrophobic phase being essentially higher than in aqueous. Tryptophan is a hydrophobic residue and can nitrosylate with the formation of isomer N-nitrosotryptophans (NOW). Without denitrosylation mechanism, the accumulation of NOW in proteins of NO-synthesizing organisms would be constant, and long-living proteins would contain essential amounts of NOW, which is however not the case. Using Protein Data Bank (more than 78,000 sequences) we investigated the distribution of tryptophan residues environment (22 residues on each side of polypeptide chain) in proteins with known primary structure. Charged and polar residues (D, H, K, N, Q, R, S) are more incident in the immediate surrounding of tryptophan (-6, -5, -2, -1, 1, 2, 4) and hydrophobic residues (A, F, I, L, V, Y) are more rare than in remote positions. Hence, an essential part of tryptophan residues is situated in hydrophilic environment, which decreases the nitrosylation velocity because of lower NOx concentration in aqueous phase and allows the denitrosylation reactions course via nitrosonium ion transfer on nucleophils of functional groups of protein and low-molecular compounds in aqueous phase.

  19. Bioavailability of tryptophan from a single oral dose of a trytophan-enriched peptide mixture in healthy men

    NARCIS (Netherlands)

    Brink, E.J.; Boelsma, E.; Steijns, J.; Hendriks, H.F.J.

    2004-01-01

    The aim of the study was to investigate the bioavailability of tryptophan (Trp) from a Trp-enriched peptide mixture in healthy men. A second objective was to investigate the effect of this Trp-enriched protein hydrolysate on potential parameters of serotonergic activity. serum serotonim melatonin

  20. Conditional Betas and Investor Uncertainty

    OpenAIRE

    Fernando D. Chague

    2013-01-01

    We derive theoretical expressions for market betas from a rational expectation equilibrium model where the representative investor does not observe if the economy is in a recession or an expansion. Market betas in this economy are time-varying and related to investor uncertainty about the state of the economy. The dynamics of betas will also vary across assets according to the assets' cash-flow structure. In a calibration exercise, we show that value and growth firms have cash-flow structures...

  1. Dynamic returns of beta arbitrage

    OpenAIRE

    Nascimento, Mafalda

    2017-01-01

    This thesis studies the patterns of the abnormal returns of the beta strategy. The topic can be helpful for professional investors, who intend to achieve a better performance in their portfolios. Following the methodology of Lou, Polk, & Huang (2016), the COBAR measure is computed in order to determine the levels of beta arbitrage in the market in each point in time. It is argued that beta arbitrage activity can have impact on the returns of the beta strategy. In fact, it is demonstrated that...

  2. Integration of BETA with Eclipse

    DEFF Research Database (Denmark)

    Andersen, Peter; Madsen, Ole Lehrmann; Enevoldsen, Mads Brøgger

    2004-01-01

    This paper presents language interoperability issues appearing in order to implement support for the BETA language in the Java-based Eclipse integrated development environment. One of the challenges is to implement plug-ins in BETA and be able to load them in Eclipse. In order to do this, some fo...... it is possible to implement plug-ins in BETA and even inherit from Java classes. In the paper the two approaches are described together with part of the mapping from BETA to Java class files. http://www.sciencedirect.com/science/journal/15710661...

  3. Simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  4. Converting S-limonene synthase to pinene or phellandrene synthases reveals the plasticity of the active site.

    Science.gov (United States)

    Xu, Jinkun; Ai, Ying; Wang, Jianhui; Xu, Jingwei; Zhang, Yongkang; Yang, Dong

    2017-05-01

    S-limonene synthase is a model monoterpene synthase that cyclizes geranyl pyrophosphate (GPP) to form S-limonene. It is a relatively specific enzyme as the majority of its products are composed of limonene. In this study, we converted it to pinene or phellandrene synthases after introducing N345A/L423A/S454A or N345I mutations. Further studies on N345 suggest the polarity of this residue plays a critical role in limonene production by stabilizing the terpinyl cation intermediate. If it is mutated to a non-polar residue, further cyclization or hydride shifts occurs so the carbocation migrates towards the pyrophosphate, leading to the production of pinene or phellandrene. On the other hand, mutant enzymes that still possess a polar residue at this position produce limonene as the major product. N345 is not the only polar residue that may stabilize the terpinyl cation because it is not strictly conserved among limonene synthases across species and there are also several other polar residues in this area. These residues could form a "polar pocket" that may collectively play this stabilizing role. Our study provides important insights into the catalytic mechanism of limonene synthases. Furthermore, it also has wider implications on the evolution of terpene synthases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Radiation-induced mutagenicity and lethality in tryptophan-requiring auxotrophs of escherichia coli

    International Nuclear Information System (INIS)

    Xu Rong; Qian Hongwei; Yao Fenying; Gu Shuzhu; Xu Jiaxin; Bi Hekan; Liu Yuying

    1989-01-01

    Mutation and killing caused by X-ray radiation and 60 Co γ-ray radiation were studied in three different tryptophan-requiring auxotrophs (WP2, Wp2A, Cm 891) of Escherichia coli. These testers are sensitive to base pair substitution mutagens. Cm891 carries a R-factor and is more sensitive than WP2 and WP2A to radiation-induced mutation and lethality. The results of the study show that (1) ionizing radiation was mutagenic to E. coli, (2) the order of mutagenic sensitivity among three strains to ionizing radiation was Cm891 > WP2A > WP2, (3) the dose rate of γ-ray influences mutagenicity and lethalty of E. coli strain, (4) the toxicity and mutagenicity of γ-ray were similar to X-ray when Cm891 was tested, however, γ-ray was more toxic and mutagenic than X-ray to WP2A ang WP2

  6. Effect of Tryptophan on the corrosion behavior of low alloy steel in sulfamic acid

    Directory of Open Access Journals (Sweden)

    Hesham T.M. Abdel-Fatah

    2016-11-01

    Full Text Available Sulfamic acid is widely used in various industrial acid cleaning applications. In the present work, the inhibition effect of Tryptophan (Tryp on the corrosion of low alloy steel in sulfamic acid solutions at four different temperatures was studied. The investigations involved electrochemical methods (electrochemical impedance spectroscopy; EIS and the new technique electrochemical frequency modulation; EFM as well as gravimetric measurements. The inhibition efficiency and the apparent activation energy have been calculated in the presence and in the absence of Tryp. It is most probable that the inhibition property of Tryp was due to the electrostatic adsorption of the protonated form of Tryp on the steel surface. Adsorption of the inhibitor molecule, onto the steel surface followed the Temkin adsorption isotherm. The thermodynamic parameters of adsorption were determined and discussed. All of the obtained data from the three techniques were in close agreement, which confirmed that EFM technique can be used efficiently for monitoring the corrosion inhibition under the studied conditions.

  7. Kinetics of immobilisation and release of tryptophan, riboflavin and peptides from whey protein microbeads.

    Science.gov (United States)

    O'Neill, Graham J; Egan, Thelma; Jacquier, Jean Christophe; O'Sullivan, Michael; Dolores O'Riordan, E

    2015-08-01

    This study investigated the kinetics of immobilisation and release of riboflavin, amino acids and peptides from whey microbeads. Blank whey microbeads were placed in solutions of the compounds. As the volume of microbeads added to the solution was increased, the uptake of the compounds increased, to a maximum of 95% for the pentapeptide and 56%, 57% and 45% for the dipeptide, riboflavin and tryptophan respectively, however, the rate of uptake remained constant. The rate of uptake increased with increasing molecule hydrophobicity. The opposite was observed in the release studies, the more hydrophobic compounds had lower release rate constants (kr). When whey microbeads are used as sorbents, they show excellent potential to immobilise small hydrophobic molecules and minimise subsequent diffusion, even in high moisture environments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Role of NAD, Oxidative Stress, and Tryptophan Metabolism in Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Musthafa Mohamed Essa

    2013-01-01

    Full Text Available Autism spectrum disorder (ASD is a pervasive neuro-developmental disorder characterized by impaired social interaction, reduced/absent verbal and non-verbal communication, and repetitive behavior during early childhood. The etiology of this developmental disorder is poorly understood, and no biomarkers have been identified. Identification of novel biochemical markers related to autism would be advantageous for earlier clinical diagnosis and intervention. Studies suggest that oxidative stress-induced mechanisms and reduced antioxidant defense, mitochondrial dysfunction, and impaired energy metabolism (NAD + , NADH, ATP, pyruvate, and lactate, are major causes of ASD. This review provides renewed insight regarding current autism research related to oxidative stress, mitochondrial dysfunction, and altered tryptophan metabolism in ASD.

  9. To Cheat or Not To Cheat: Tryptophan Hydroxylase 2 SNP Variants Contribute to Dishonest Behavior.

    Science.gov (United States)

    Shen, Qiang; Teo, Meijun; Winter, Eyal; Hart, Einav; Chew, Soo H; Ebstein, Richard P

    2016-01-01

    Although, lying (bear false witness) is explicitly prohibited in the Decalogue and a focus of interest in philosophy and theology, more recently the behavioral and neural mechanisms of deception are gaining increasing attention from diverse fields especially economics, psychology, and neuroscience. Despite the considerable role of heredity in explaining individual differences in deceptive behavior, few studies have investigated which specific genes contribute to the heterogeneity of lying behavior across individuals. Also, little is known concerning which specific neurotransmitter pathways underlie deception. Toward addressing these two key questions, we implemented a neurogenetic strategy and modeled deception by an incentivized die-under-cup task in a laboratory setting. The results of this exploratory study provide provisional evidence that SNP variants across the tryptophan hydroxylase 2 (TPH2) gene, that encodes the rate-limiting enzyme in the biosynthesis of brain serotonin, contribute to individual differences in deceptive behavior.

  10. To cheat or not to cheat: Tryptophan hydroxylase 2 SNP variants contribute to dishonest behavior

    Directory of Open Access Journals (Sweden)

    Qiang eShen

    2016-05-01

    Full Text Available Although lying (bear false witness is explicitly prohibited in the Decalogue and a focus of interest in philosophy and theology, more recently the behavioral and neural mechanisms of deception are gaining increasing attention from diverse fields especially economics, psychology and neuroscience. Despite the considerable role of heredity in explaining individual differences in deceptive behavior, few studies have investigated which specific genes contribute to the heterogeneity of lying behavior across individuals. Also, little is known concerning which specific neurotransmitter pathways underlie deception. Towards addressing these two key questions, we implemented a neurogenetic strategy and modeled deception by an incentivized die-under-cup task in a laboratory setting. The results of this exploratory study provide provisional evidence that SNP variants across the tryptophan hydroxylase 2 (TPH2 gene, that encodes the rate-limiting enzyme in the biosynthesis of brain serotonin, contribute to individual differences in deceptive behavior.

  11. Substitution of Active Site Tyrosines with Tryptophan Alters the Free Energy for Nucleotide Flipping by Human Alkyladenine DNA Glycosylase†

    Science.gov (United States)

    Hendershot, Jenna M.; Wolfe, Abigail E.; O'Brien, Patrick J.

    2011-01-01

    Human alkyladenine DNA glycosylase (AAG) locates and excises a wide variety of structurally diverse alkylated and oxidized purine lesions from DNA to initiate the base excision repair pathway. Recognition of a base lesion requires flipping of the damaged nucleotide into a relatively open active site pocket between two conserved tyrosine residues, Y127 and Y159. We have mutated each of these amino acids to tryptophan and measured the kinetic effects on the nucleotide flipping and base excision steps. The Y127W and Y159W mutant proteins have robust glycosylase activity toward DNA containing 1,N6-ethenoadenine (εA), within 4-fold of that of the wildtype enzyme, raising the possibility that tryptophan fluorescence could be used to probe the DNA binding and nucleotide flipping steps. Stopped-flow fluorescence was used to compare the time-dependent changes in tryptophan fluorescence and εA fluorescence. For both mutants, the tryptophan fluorescence exhibited two-step binding with essentially identical rate constants as were observed for the εA fluorescence changes. These results provide evidence that AAG forms an initial recognition complex in which the active site pocket is perturbed and the stacking of the damaged base is disrupted. Upon complete nucleotide flipping, there is further quenching of the tryptophan fluorescence with coincident quenching of the εA fluorescence. Although these mutations do not have large effects on the rate constant for excision of εA, there are dramatic effects on the rate constants for nucleotide flipping that result in 40 to 100-fold decreases in the flipping equilibrium relative to wildtype. Most of this effect is due to an increased rate of unflipping, but surprisingly the Y159W mutation causes a 5-fold increase in the rate constant for flipping. The large effect on the equilibrium for nucleotide flipping explains the greater deleterious effects that these mutations have on the glycosylase activity toward base lesions that are in

  12. Identification of active anti-inflammatory principles of beta- beta ...

    African Journals Online (AJOL)

    chromatography. Components of the extracts were identified by thin layer chromatography (TLC) scanner and UV-visible spectroscopy, using scopoletin as standard. Results: ... basic coumarin skeleton ring structure reduce ... Figure 2: Thin-layer chromatogram: (1) Ethanol extract; (2) Dichloromethane fraction; (3) Beta-beta.

  13. Improved limits on beta(-) and beta(-) decays of Ca-48

    Czech Academy of Sciences Publication Activity Database

    Bakalyarov, A.; Balysh, A.; Barabash, AS.; Beneš, P.; Briancon, C.; Brudanin, V. B.; Čermák, P.; Egorov, V.; Hubert, F.; Hubert, P.; Korolev, NA.; Kosjakov, VN.; Kovalík, Alojz; Lebedev, NA.; Novgorodov, A. F.; Rukhadze, NI.; Štekl, NI.; Timkin, VV.; Veleshko, IE.; Vylov, T.; Umatov, VI.

    2002-01-01

    Roč. 76, č. 9 (2002), s. 545-547 ISSN 0021-3640 Institutional research plan: CEZ:AV0Z1048901 Keywords : beta decay * double beta decay * Ca-48 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.483, year: 2002

  14. Certain tryptophan photoproducts are inhibitors of cytochrome P450-dependent mutagenicity

    International Nuclear Information System (INIS)

    Rannug, U.; Agurell, E.; Cederberg, H.; Rannug, A.

    1992-01-01

    Two photoproducts, derived from UV-irradiation of the amino acid L-tryptophan and with high Ah (TCDD) receptor binding affinity, were tested for genotoxic and antimutagenic effects. The two indolo[3,2-b]carbazole derivatives, with the molecular weights of 284 and 312, respectively, were tested in Saccharomyces cerevisiae strain D7 for mitotic gene conversion and reverse mutation and in strain RS112 for sister chromatid conversion and gene conversion. No significant (P > 0.05) genotoxic effects were found in strain D7, while strain RS112 showed a small but significant increase in the frequency of sister chromatid conversions. In Chinese hamster ovary (CHO) cells the two compounds induced a statistically significant but less than twofold increase in the frequency of sister chromatid exchanges (SCE). No mutations were detected when the compounds were tested in Salmonella tphimurium strains TA98 and TA100. However, both 284 and 312 acted as antimutagens on strain TA100+S9 in the presence of benzo(a)pyrene. The decrease in mutagenicity by the most potent compound 284 was 20 revertants/nmol. This effect could be explained by an inhibitory effect on the cytochrome P450-dependent ethoxyresorufin O-deethylase (EROD) activity as seen in rat hepatocytes. The two compounds were also tested with hamster cells expressing rat cytochrome P-4501A1. The results support the conclusion that this cytochrome P-450 isozyme is inhibited by the tryptophan photoproducts. Similar results were also seen with two other high affinity Ah receptor ligands the quinazolinocarboline alkaloids rutaecapine and dehydrorutaecarpine. 20 refs., 3 figs., 4 tabs

  15. In situ tryptophan-like fluorometers: assessing turbidity and temperature effects for freshwater applications.

    Science.gov (United States)

    Khamis, K; Sorensen, J P R; Bradley, C; Hannah, D M; Lapworth, D J; Stevens, R

    2015-04-01

    Tryptophan-like fluorescence (TLF) is an indicator of human influence on water quality as TLF peaks are associated with the input of labile organic carbon (e.g. sewage or farm waste) and its microbial breakdown. Hence, real-time measurement of TLF could be particularly useful for monitoring water quality at a higher temporal resolution than available hitherto. However, current understanding of TLF quenching/interference is limited for field deployable sensors. We present results from a rigorous test of two commercially available submersible tryptophan fluorometers (ex ∼ 285, em ∼ 350). Temperature quenching and turbidity interference were quantified in the laboratory and compensation algorithms developed. Field trials were then undertaken involving: (i) an extended deployment (28 days) in a small urban stream; and, (ii) depth profiling of an urban multi-level borehole. TLF was inversely related to water temperature (regression slope range: -1.57 to -2.50). Sediment particle size was identified as an important control on the turbidity specific TLF response, with signal amplification apparent 200 NTU for clay particles. Compensation algorithms significantly improved agreement between in situ and laboratory readings for baseflow and storm conditions in the stream. For the groundwater trial, there was an excellent agreement between laboratory and raw in situ TLF; temperature compensation provided only a marginal improvement, and turbidity corrections were unnecessary. These findings highlight the potential utility of real time TLF monitoring for a range of environmental applications (e.g. tracing polluting sources and monitoring groundwater contamination). However, in situations where high/variable suspended sediment loads or rapid changes in temperature are anticipated concurrent monitoring of turbidity and temperature is required and site specific calibration is recommended for long term, surface water monitoring.

  16. Simultaneous determination of ascorbic acid, dopamine and uric acid based on tryptophan functionalized graphene

    International Nuclear Information System (INIS)

    Lian, Qianwen; He, Zhifang; He, Qian; Luo, Ai; Yan, Kaiwang; Zhang, Dongxia; Lu, Xiaoquan; Zhou, Xibin

    2014-01-01

    Highlights: • Trp-GR was synthesized by utilizing a facile ultrasonic method. • The material as prepared had well dispersivity in water and better conductivity than pure GR. • Trp-GR/GCE showed excellent potential for the determination of AA, DA and UA. • The proposed method was applied for the analysis of AA, DA and UA in real samples. - Abstract: A new type of tryptophan-functionalized graphene nanocomposite (Trp-GR) was synthesized by utilizing a facile ultrasonic method via π–π conjugate action between graphene (GR) and tryptophan (Trp) molecule. The material as prepared had well dispersivity in water and better conductivity than pure GR. The surface morphology of Trp-GR was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA), and uric acid (UA) were investigated by cyclic voltammetry (CV) on the surface of Trp-GR. The separation of the oxidation peak potentials for AA–DA, DA–UA and UA–AA was about 182 mV, 125 mV and 307 mV, which allowed simultaneously determining AA, DA, and UA. Differential pulse voltammetery (DPV) was used for the determination of AA, DA, and UA in their mixture. Under optimum conditions, the linear response ranges for the determination of AA, DA, and UA were 0.2–12.9 mM, 0.5–110 μM, and 10–1000 μM, with the detection limits (S/N = 3) of 10.09 μM, 0.29 μM and 1.24 μM, respectively. Furthermore, the modified electrode was investigated for real sample analysis

  17. Simultaneous determination of ascorbic acid, dopamine and uric acid based on tryptophan functionalized graphene

    Energy Technology Data Exchange (ETDEWEB)

    Lian, Qianwen; He, Zhifang; He, Qian; Luo, Ai; Yan, Kaiwang; Zhang, Dongxia [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070 (China); Lu, Xiaoquan, E-mail: Luxq@nwnu.edu.cn [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, 730070 (China); Zhou, Xibin, E-mail: zhouxb@nwnu.edu.cn [Key Laboratory of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Geography and Environment Science, Northwest Normal University, Lanzhou, 730070 (China)

    2014-05-01

    Highlights: • Trp-GR was synthesized by utilizing a facile ultrasonic method. • The material as prepared had well dispersivity in water and better conductivity than pure GR. • Trp-GR/GCE showed excellent potential for the determination of AA, DA and UA. • The proposed method was applied for the analysis of AA, DA and UA in real samples. - Abstract: A new type of tryptophan-functionalized graphene nanocomposite (Trp-GR) was synthesized by utilizing a facile ultrasonic method via π–π conjugate action between graphene (GR) and tryptophan (Trp) molecule. The material as prepared had well dispersivity in water and better conductivity than pure GR. The surface morphology of Trp-GR was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. The electrochemical behaviors of ascorbic acid (AA), dopamine (DA), and uric acid (UA) were investigated by cyclic voltammetry (CV) on the surface of Trp-GR. The separation of the oxidation peak potentials for AA–DA, DA–UA and UA–AA was about 182 mV, 125 mV and 307 mV, which allowed simultaneously determining AA, DA, and UA. Differential pulse voltammetery (DPV) was used for the determination of AA, DA, and UA in their mixture. Under optimum conditions, the linear response ranges for the determination of AA, DA, and UA were 0.2–12.9 mM, 0.5–110 μM, and 10–1000 μM, with the detection limits (S/N = 3) of 10.09 μM, 0.29 μM and 1.24 μM, respectively. Furthermore, the modified electrode was investigated for real sample analysis.

  18. Ruminal tryptophan-utilizing bacteria degrade ergovaline from tall fescue seed extract.

    Science.gov (United States)

    Harlow, B E; Goodman, J P; Lynn, B C; Flythe, M D; Ji, H; Aiken, G E

    2017-02-01

    The objectives of this study were to evaluate degradation of ergovaline in a tall fescue [ (Schreb.) Darbysh.] seed extract by rumen microbiota ex vivo and to identify specific bacteria capable of ergovaline degradation in vitro. Rumen cell suspensions were prepared by harvesting rumen fluid from fistulated wether goats ( = 3), straining, and differential centrifugation. Suspensions were dispensed into anaerobic tubes with added Trypticase with or without extract (∼10 μg kg ergovaline). Suspensions were incubated for 48 h at 39°C. Samples were collected at 0, 24, and 48 h for ergovaline analysis and enumeration of hyper-ammonia producing (HAB) and tryptophan-utilizing bacteria. Ergovaline values were analyzed by repeated measures using the mixed procedure of SAS. Enumeration data were log transformed for statistical analysis. When suspensions were incubated with extract, 11 to 15% of ergovaline disappearance was observed over 48 h ( = 0.02). After 24 h, suspensions with added extract had 10-fold less HAB than controls ( = 0.04), but treatments were similar by 48 h ( = 1.00). However, after 24 h and 48 h, suspensions with extract had 10-fold more tryptophan-utilizing bacteria ( rumen pure cultures ( JB1, B159, HD4, B, F, MD1, SR) were evaluated for the ability to degrade ergovaline in vitro. Pure culture cell suspensions were incubated as described above and samples were taken at 0 and 48 h for ergovaline analysis. Data were analyzed using the ANOVA procedure of SAS. All HAB, including the isolates, tested degraded ergovaline (54 to 75%; bacteria tested did not degrade ergovaline. The results of this study indicate which rumen bacteria may play an important role in ergovaline degradation and that microbiological strategies for controlling their activity could have ramifications for fescue toxicosis and other forms of ergotism in ruminants.

  19. Conversion of beta-methylbutyric acid to beta-hydroxy-beta-methylbutyric acid by Galactomyces reessii.

    OpenAIRE

    Lee, I Y; Nissen, S L; Rosazza, J P

    1997-01-01

    beta-Hydroxy-beta-methylbutyric acid (HMB) has been shown to increase strength and lean mass gains in humans undergoing resistance-exercise training. HMB is currently marketed as a calcium salt of HMB, and thus, environmentally sound and inexpensive methods of manufacture are being sought. This study investigates the microbial conversion of beta-methylbutyric acid (MBA) to HMB by cultures of Galactomyces reessii. Optimal concentrations of MBA were in the range of 5 to 20 g/liter for HMB produ...

  20. The Tomato Terpene Synthase Gene Family1[W][OA

    Science.gov (United States)

    Falara, Vasiliki; Akhtar, Tariq A.; Nguyen, Thuong T.H.; Spyropoulou, Eleni A.; Bleeker, Petra M.; Schauvinhold, Ines; Matsuba, Yuki; Bonini, Megan E.; Schilmiller, Anthony L.; Last, Robert L.; Schuurink, Robert C.; Pichersky, Eran

    2011-01-01

    Compounds of the terpenoid class play numerous roles in the interactions of plants with their environment, such as attracting pollinators and defending the plant against pests. We show here that the genome of cultivated tomato (Solanum lycopersicum) contains 44 terpene synthase (TPS) genes, including 29 that are functional or potentially functional. Of these 29 TPS genes, 26 were expressed in at least some organs or tissues of the plant. The enzymatic functions of eight of the TPS proteins were previously reported, and here we report the specific in vitro catalytic activity of 10 additional tomato terpene synthases. Many of the tomato TPS genes are found in clusters, notably on chromosomes 1, 2, 6, 8, and 10. All TPS family clades previously identified in angiosperms are also present in tomato. The largest clade of functional TPS genes found in tomato, with 12 members, is the TPS-a clade, and it appears to encode only sesquiterpene synthases, one of which is localized to the mitochondria, while the rest are likely cytosolic. A few additional sesquiterpene synthases are encoded by TPS-b clade genes. Some of the tomato sesquiterpene synthases use z,z-farnesyl diphosphate in vitro as well, or more efficiently than, the e,e-farnesyl diphosphate substrate. Genes encoding monoterpene synthases are also prevalent, and they fall into three clades: TPS-b, TPS-g, and TPS-e/f. With the exception of two enzymes involved in the synthesis of ent-kaurene, the precursor of gibberellins, no other tomato TPS genes could be demonstrated to encode diterpene synthases so far. PMID:21813655

  1. Characterization of the human gene (TBXAS1) encoding thromboxane synthase.

    Science.gov (United States)

    Miyata, A; Yokoyama, C; Ihara, H; Bandoh, S; Takeda, O; Takahashi, E; Tanabe, T

    1994-09-01

    The gene encoding human thromboxane synthase (TBXAS1) was isolated from a human EMBL3 genomic library using human platelet thromboxane synthase cDNA as a probe. Nucleotide sequencing revealed that the human thromboxane synthase gene spans more than 75 kb and consists of 13 exons and 12 introns, of which the splice donor and acceptor sites conform to the GT/AG rule. The exon-intron boundaries of the thromboxane synthase gene were similar to those of the human cytochrome P450 nifedipine oxidase gene (CYP3A4) except for introns 9 and 10, although the primary sequences of these enzymes exhibited 35.8% identity each other. The 1.2-kb of the 5'-flanking region sequence contained potential binding sites for several transcription factors (AP-1, AP-2, GATA-1, CCAAT box, xenobiotic-response element, PEA-3, LF-A1, myb, basic transcription element and cAMP-response element). Primer-extension analysis indicated the multiple transcription-start sites, and the major start site was identified as an adenine residue located 142 bases upstream of the translation-initiation site. However, neither a typical TATA box nor a typical CAAT box is found within the 100-b upstream of the translation-initiation site. Southern-blot analysis revealed the presence of one copy of the thromboxane synthase gene per haploid genome. Furthermore, a fluorescence in situ hybridization study revealed that the human gene for thromboxane synthase is localized to band q33-q34 of the long arm of chromosome 7. A tissue-distribution study demonstrated that thromboxane synthase mRNA is widely expressed in human tissues and is particularly abundant in peripheral blood leukocyte, spleen, lung and liver. The low but significant levels of mRNA were observed in kidney, placenta and thymus.

  2. The best-beta CAPM

    NARCIS (Netherlands)

    Zou, L.

    2006-01-01

    The issue of 'best-beta' arises as soon as potential errors in the Sharpe-Lintner-Black capital asset pricing model (CAPM) are acknowledged. By incorporating a target variable into the investor preferences, this study derives a best-beta CAPM (BCAPM) that maintains the CAPM's theoretical appeal and

  3. Beta decay of Cu-56

    NARCIS (Netherlands)

    Borcea, R; Aysto, J; Caurier, E; Dendooven, P; Doring, J; Gierlik, M; Gorska, M; Grawe, H; Hellstrom, M; Janas, Z; Jokinen, A; Karny, M; Kirchner, R; La Commara, M; Langanke, K; Martinez-Pinedo, G; Mayet, P; Nieminen, A; Nowacki, F; Penttila, H; Plochocki, A; Rejmund, M; Roeckl, E; Schlegel, C; Schmidt, K; Schwengner, R; Sawicka, M

    2001-01-01

    The proton-rich isotope Cu-56 was produced at the GSI On-Line Mass Separator by means of the Si-28(S-32, p3n) fusion-evaporation reaction. Its beta -decay properties were studied by detecting beta -delayed gamma rays and protons. A half-Life of 93 +/- 3 ms was determined for Cu-56. Compared to the

  4. BETA SPECTRA. I. Negatrons spectra

    International Nuclear Information System (INIS)

    Grau Malonda, A.; Garcia-Torano, E.

    1978-01-01

    Using the Fermi theory of beta decay, the beta spectra for 62 negatrons emitters have been computed introducing a correction factor for unique forbidden transitions. These spectra are plotted vs. energy, once normal i sed, and tabulated with the related Fermi functions. The average and median energies are calculated. (Author)

  5. Review of the beta situation

    International Nuclear Information System (INIS)

    Sheffield, J.

    1982-01-01

    This note lists some of the possible causes of beta limitation in tokamak and discusses what is known and what is involved in investigating them. The motivation for preparing this note is the observed degradation of confinement with increasing beta poloidal β/sub p/ and beam power P/sub b/ in ISX-B

  6. GSK-3beta inhibition enhances sorafenib-induced apoptosis in melanoma cell lines.

    Science.gov (United States)

    Panka, David J; Cho, Daniel C; Atkins, Michael B; Mier, James W

    2008-01-11

    Glycogen synthase kinase-3beta (GSK-3beta) can participate in the induction of apoptosis or, alternatively, provide a survival signal that minimizes cellular injury. We previously demonstrated that the multikinase inhibitor sorafenib induces apoptosis in melanoma cell lines. In this report, we show that sorafenib activates GSK-3beta in multiple subcellular compartments and that this activation undermines the lethality of the drug. Pharmacologic inhibition and/or down-modulation of the kinase enhances sorafenib-induced apoptosis as determined by propidium iodide staining and by assessing the mitochondrial release of apoptosis-inducing factor and Smac/DIABLO. Conversely, the forced expression of a constitutively active form of the enzyme (GSK-3beta(S9A)) protects the cells from the apoptotic effects of the drug. This protective effect is associated with a marked increase in basal levels of Bcl-2, Bcl-x(L), and survivin and a diminution in the degree to which these anti-apoptotic proteins are down-modulated by sorafenib exposure. Sorafenib down-modulates the pro-apoptotic Bcl-2 family member Noxa in cells with high constitutive GSK-3beta activity. Pharmacologic inhibition of GSK-3beta prevents the disappearance of Noxa induced by sorafenib and enhances the down-modulation of Mcl-1. Down-modulation of Noxa largely eliminates the enhancing effect of GSK-3 inhibition on sorafenib-induced apoptosis. These data provide a strong rationale for the use of GSK-3beta inhibitors as adjuncts to sorafenib treatment and suggest that preservation of Noxa may contribute to their efficacy.

  7. RAVEN Beta Release

    International Nuclear Information System (INIS)

    Rabiti, Cristian; Alfonsi, Andrea; Cogliati, Joshua Joseph; Mandelli, Diego; Kinoshita, Robert Arthur; Wang, Congjian; Maljovec, Daniel Patrick; Talbot, Paul William

    2016-01-01

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  8. RAVEN Beta Release

    Energy Technology Data Exchange (ETDEWEB)

    Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Alfonsi, Andrea [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cogliati, Joshua Joseph [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kinoshita, Robert Arthur [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wang, Congjian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Maljovec, Daniel Patrick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Talbot, Paul William [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  9. Highly divergent mitochondrial ATP synthase complexes in Tetrahymena thermophila.

    Directory of Open Access Journals (Sweden)

    Praveen Balabaskaran Nina

    2010-07-01

    Full Text Available The F-type ATP synthase complex is a rotary nano-motor driven by proton motive force to synthesize ATP. Its F(1 sector catalyzes ATP synthesis, whereas the F(o sector conducts the protons and provides a stator for the rotary action of the complex. Components of both F(1 and F(o sectors are highly conserved across prokaryotes and eukaryotes. Therefore, it was a surprise that genes encoding the a and b subunits as well as other components of the F(o sector were undetectable in the sequenced genomes of a variety of apicomplexan parasites. While the parasitic existence of these organisms could explain the apparent incomplete nature of ATP synthase in Apicomplexa, genes for these essential components were absent even in Tetrahymena thermophila, a free-living ciliate belonging to a sister clade of Apicomplexa, which demonstrates robust oxidative phosphorylation. This observation raises the possibility that the entire clade of Alveolata may have invented novel means to operate ATP synthase complexes. To assess this remarkable possibility, we have carried out an investigation of the ATP synthase from T. thermophila. Blue native polyacrylamide gel electrophoresis (BN-PAGE revealed the ATP synthase to be present as a large complex. Structural study based on single particle electron microscopy analysis suggested the complex to be a dimer with several unique structures including an unusually large domain on the intermembrane side of the ATP synthase and novel domains flanking the c subunit rings. The two monomers were in a parallel configuration rather than the angled configuration previously observed in other organisms. Proteomic analyses of well-resolved ATP synthase complexes from 2-D BN/BN-PAGE identified orthologs of seven canonical ATP synthase subunits, and at least 13 novel proteins that constitute subunits apparently limited to the ciliate lineage. A mitochondrially encoded protein, Ymf66, with predicted eight transmembrane domains could be a

  10. Interactions between two beta-sheets. Energetics of beta/beta packing in proteins.

    Science.gov (United States)

    Chou, K C; Némethy, G; Rumsey, S; Tuttle, R W; Scheraga, H A

    1986-04-20

    The analysis of the interactions between regularly folded segments of the polypeptide chain contributes to an understanding of the energetics of protein folding. Conformational energy-minimization calculations have been carried out to determine the favorable ways of packing two right-twisted beta-sheets. The packing of two five-stranded beta-sheets was investigated, with the strands having the composition CH3CO-(L-Ile)6-NHCH3 in one beta-sheet and CH3CO-(L-Val)6-NHCH3 in the other. Two distinct classes of low-energy packing arrangements were found. In the class with lowest energies, the strands of the two beta-sheets are aligned nearly parallel (or antiparallel) with each other, with a preference for a negative orientation angle, because this arrangement corresponds to the best complementary packing of the two twisted saddle-shaped beta-sheets. In the second class, with higher interaction energies, the strands of the two beta-sheets are oriented nearly perpendicular to each other. While the surfaces of the two beta-sheets are not complementary in this arrangement, there is good packing between the corner of one beta-sheet and the interior part of the surface of the other, resulting in a favorable energy of packing. Both classes correspond to frequently observed orientations of beta-sheets in proteins. In proteins, the second class of packing is usually observed when the two beta-sheets are covalently linked, i.e. when a polypeptide strand passes from one beta-sheet to the other, but we have shown here that a large contribution to the stabilization of this packing arrangement arises from noncovalent interactions.

  11. Sucrose Phosphate Synthase and Sucrose Accumulation at Low Temperature 1

    Science.gov (United States)

    Guy, Charles L.; Huber, Joan L. A.; Huber, Steven C.

    1992-01-01

    The influence of growth temperature on the free sugar and sucrose phosphate synthase content and activity of spinach (Spinacia oleracea) leaf tissue was studied. When plants were grown at 25°C for 3 weeks and then transferred to a constant 5°C, sucrose, glucose, and fructose accumulated to high levels during a 14-d period. Predawn sugar levels increased from 14- to 20-fold over the levels present at the outset of the low-temperature treatment. Sucrose was the most abundant free sugar before, during, and after exposure to 5°C. Leaf sucrose phosphate synthase activity was significantly increased by the low-temperature treatment, whereas sucrose synthase and invertases were not. Synthesis of the sucrose phosphate synthase subunit was increased during and after low-temperature exposure and paralleled an increase in the steady-state level of the subunit. The increases in sucrose and its primary biosynthetic enzyme, sucrose phosphate synthase, are discussed in relation to adjustment of metabolism to low nonfreezing temperature and freezing stress tolerance. Images Figure 1 Figure 2 Figure 3 PMID:16652990

  12. Evolution of the F0F1 ATP synthase complex in light of the patchy distribution of different bioenergetic pathways across prokaryotes.

    Directory of Open Access Journals (Sweden)

    Vassiliki Lila Koumandou

    2014-09-01

    Full Text Available Bacteria and archaea are characterized by an amazing metabolic diversity, which allows them to persist in diverse and often extreme habitats. Apart from oxygenic photosynthesis and oxidative phosphorylation, well-studied processes from chloroplasts and mitochondria of plants and animals, prokaryotes utilize various chemo- or lithotrophic modes, such as anoxygenic photosynthesis, iron oxidation and reduction, sulfate reduction, and methanogenesis. Most bioenergetic pathways have a similar general structure, with an electron transport chain composed of protein complexes acting as electron donors and acceptors, as well as a central cytochrome complex, mobile electron carriers, and an ATP synthase. While each pathway has been studied in considerable detail in isolation, not much is known about their relative evolutionary relationships. Wanting to address how this metabolic diversity evolved, we mapped the distribution of nine bioenergetic modes on a phylogenetic tree based on 16S rRNA sequences from 272 species representing the full diversity of prokaryotic lineages. This highlights the patchy distribution of many pathways across different lineages, and suggests either up to 26 independent origins or 17 horizontal gene transfer events. Next, we used comparative genomics and phylogenetic analysis of all subunits of the F0F1 ATP synthase, common to most bacterial lineages regardless of their bioenergetic mode. Our results indicate an ancient origin of this protein complex, and no clustering based on bioenergetic mode, which suggests that no special modifications are needed for the ATP synthase to work with different electron transport chains. Moreover, examination of the ATP synthase genetic locus indicates various gene rearrangements in the different bacterial lineages, ancient duplications of atpI and of the beta subunit of the F0 subcomplex, as well as more recent stochastic lineage-specific and species-specific duplications of all subunits. We

  13. Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test.

    Science.gov (United States)

    Strekalova, Tatyana; Markova, Nataliia; Shevtsova, Elena; Zubareva, Olga; Bakhmet, Anastassia; Steinbusch, Harry M; Bachurin, Sergey; Lesch, Klaus-Peter

    2016-01-01

    While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta) mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome.

  14. Individual Differences in Behavioural Despair Predict Brain GSK-3beta Expression in Mice: The Power of a Modified Swim Test

    Directory of Open Access Journals (Sweden)

    Tatyana Strekalova

    2016-01-01

    Full Text Available While deficient brain plasticity is a well-established pathophysiologic feature of depression, little is known about disorder-associated enhanced cognitive processing. Here, we studied a novel mouse paradigm that potentially models augmented learning of adverse memories during development of a depressive-like state. We used a modification of the classic two-day protocol of a mouse Porsolt test with an additional session occurring on Day 5 following the initial exposure. Unexpectedly, floating behaviour and brain glycogen synthase kinase-3 beta (GSK-3beta mRNA levels, a factor of synaptic plasticity as well as a marker of distress and depression, were increased during the additional swimming session that was prevented by imipramine. Observed increases of GSK-3beta mRNA in prefrontal cortex during delayed testing session correlated with individual parameters of behavioural despair that was not found in the classic Porsolt test. Repeated swim exposure was accompanied by a lower pGSK-3beta/GSK-3beta ratio. A replacement of the second or the final swim sessions with exposure to the context of testing resulted in increased GSK-3beta mRNA level similar to the effects of swimming, while exclusion of the second testing prevented these changes. Together, our findings implicate the activation of brain GSK-3beta expression in enhanced contextual conditioning of adverse memories, which is associated with an individual susceptibility to a depressive syndrome.

  15. Derivatives of the Incomplete Beta Function

    Directory of Open Access Journals (Sweden)

    Robert J. Boik

    1998-03-01

    Full Text Available The incomplete beta function is defined as where Beta(p, q is the beta function. Dutka (1981 gave a history of the development and numerical evaluation of this function. In this article, an algorithm for computing first and second derivatives of Ix,p,q with respect to p and q is described. The algorithm is useful, for example, when fitting parameters to a censored beta, truncated beta, or a truncated beta-binomial model.

  16. Bornyl-diphosphate synthase from Lavandula angustifolia: A major monoterpene synthase involved in essential oil quality.

    Science.gov (United States)

    Despinasse, Yolande; Fiorucci, Sébastien; Antonczak, Serge; Moja, Sandrine; Bony, Aurélie; Nicolè, Florence; Baudino, Sylvie; Magnard, Jean-Louis; Jullien, Frédéric

    2017-05-01

    Lavender essential oils (EOs) of higher quality are produced by a few Lavandula angustifolia cultivars and mainly used in the perfume industry. Undesirable compounds such as camphor and borneol are also synthesized by lavender leading to a depreciated EO. Here, we report the cloning of bornyl diphosphate synthase of lavender (LaBPPS), an enzyme that catalyzes the production of bornyl diphosphate (BPP) and then by-products such as borneol or camphor, from an EST library. Compared to the BPPS of Salvia officinalis, the functional characterization of LaBPPS showed several differences in amino acid sequence, and the distribution of catalyzed products. Molecular modeling of the enzyme's active site suggests that the carbocation intermediates are more stable in LaBPPS than in SoBPPS leading probably to a lower efficiency of LaBPPS to convert GPP into BPP. Quantitative RT-PCR performed from leaves and flowers at different development stages of L. angustifolia samples show a clear correlation between transcript level of LaBPPS and accumulation of borneol/camphor, suggesting that LaBPPS is mainly responsible of in vivo biosynthesis of borneol/camphor in fine lavender. A phylogenetic analysis of terpene synthases (TPS) pointed out the basal position of LaBPPS in the TPSb clade, suggesting that LaBPPS could be an ancestor of others lavender TPSb. Finally, borneol could be one of the first monoterpenes to be synthesized in the Lavandula subgenus. Knowledge gained from these experiments will facilitate future studies to improve the lavender oils through metabolic engineering or plant breeding. Accession numbers: LaBPPS: KM015221. Copyright © 2017. Published by Elsevier Ltd.

  17. Neuroendocrine and Immune Responses Undertake Different Fates following Tryptophan or Methionine Dietary Treatment: Tales from a Teleost Model

    Directory of Open Access Journals (Sweden)

    Rita Azeredo

    2017-09-01

    Full Text Available Methionine and tryptophan appear to be fundamental in specific cellular pathways involved in the immune response mechanisms, including stimulation of T-regulatory cells by tryptophan metabolites or pro-inflammatory effects upon methionine supplementation. Thus, the aim of this study was to evaluate the immunomodulatory effect of these amino acids on the inflammatory and neuroendocrine responses in juveniles of European seabass, Dicentrarchus labrax. To achieve this, goal fish were fed for 14 days methionine and tryptophan-supplemented diets (MET and TRP, respectively, 2× dietary requirement level or a control diet meeting the amino acids requirement levels (CTRL. Fish were sampled for immune status assessment and the remaining fish were challenged with intraperitoneally injected inactivated Photobacterium damselae subsp. piscicida and sampled either 4 or 24 h post-injection. Respiratory burst activity, brain monoamines, plasma cortisol, and immune-related gene expression showed distinct and sometimes opposite patterns regarding the effects of dietary amino acids. While neuroendocrine intermediates were not affected by any dietary treatment at the end of the feeding trial, both supplemented diets led to increased levels of plasma cortisol after the inflammatory insult, while brain monoamine content was higher in TRP-fed fish. Peripheral blood respiratory burst was higher in TRP-fed fish injected with the bacteria inoculum but only compared to those fed MET. However, no changes were detected in total antioxidant capacity. Complement factor 3 was upregulated in MET-fed fish but methionine seemed to poorly affect other genes expression patterns. In contrast, fish fed MET showed increased immune cells numbers both before and after immune challenge, suggesting a strong enhancing effect of methionine on immune cells proliferation. Differently, tryptophan effects on inflammatory transcripts suggested an inhibitory mode of action. This, together

  18. Sesquiterpene Synthase-3-Hydroxy-3-Methylglutaryl Coenzyme A Synthase Fusion Protein Responsible for Hirsutene Biosynthesis in Stereum hirsutum.

    Science.gov (United States)

    Flynn, Christopher M; Schmidt-Dannert, Claudia

    2018-06-01

    The wood-rotting mushroom Stereum hirsutum is a known producer of a large number of namesake hirsutenoids, many with important bioactivities. Hirsutenoids form a structurally diverse and distinct class of sesquiterpenoids. No genes involved in hirsutenoid biosynthesis have yet been identified or their enzymes characterized. Here, we describe the cloning and functional characterization of a hirsutene synthase as an unexpected fusion protein of a sesquiterpene synthase (STS) with a C-terminal 3-hydroxy-3-methylglutaryl-coenzyme A (3-hydroxy-3-methylglutaryl-CoA) synthase (HMGS) domain. Both the full-length fusion protein and truncated STS domain are highly product-specific 1,11-cyclizing STS enzymes with kinetic properties typical of STSs. Complementation studies in Saccharomyces cerevisiae confirmed that the HMGS domain is also functional in vivo Phylogenetic analysis shows that the hirsutene synthase domain does not form a clade with other previously characterized sesquiterpene synthases from Basidiomycota. Comparative gene structure analysis of this hirsutene synthase with characterized fungal enzymes reveals a significantly higher intron density, suggesting that this enzyme may be acquired by horizontal gene transfer. In contrast, the HMGS domain is clearly related to other fungal homologs. This STS-HMGS fusion protein is part of a biosynthetic gene cluster that includes P450s and oxidases that are expressed and could be cloned from cDNA. Finally, this unusual fusion of a terpene synthase to an HMGS domain, which is not generally recognized as a key regulatory enzyme of the mevalonate isoprenoid precursor pathway, led to the identification of additional HMGS duplications in many fungal genomes, including the localization of HMGSs in other predicted sesquiterpenoid biosynthetic gene clusters. IMPORTANCE Hirsutenoids represent a structurally diverse class of bioactive sesquiterpenoids isolated from fungi. Identification of their biosynthetic pathways will provide

  19. Impaired glycogen synthase activity and mitochondrial dysfunction in skeletal muscle

    DEFF Research Database (Denmark)

    Højlund, Kurt; Beck-Nielsen, Henning

    2006-01-01

    Insulin resistance in skeletal muscle is a major hallmark of type 2 diabetes and an early detectable abnormality in the development of this disease. The cellular mechanisms of insulin resistance include impaired insulin-mediated muscle glycogen synthesis and increased intramyocellular lipid content......, whereas impaired insulin activation of muscle glycogen synthase represents a consistent, molecular defect found in both type 2 diabetic and high-risk individuals. Despite several studies of the insulin signaling pathway believed to mediate dephosphorylation and hence activation of glycogen synthase......, the molecular mechanisms responsible for this defect remain unknown. Recently, the use of phospho-specific antibodies in human diabetic muscle has revealed hyperphosphorylation of glycogen synthase at sites not regulated by the classical insulin signaling pathway. In addition, novel approaches such as gene...

  20. Class II recombinant phosphoribosyl diphosphate synthase from spinach

    DEFF Research Database (Denmark)

    Krath, B N; Hove-Jensen, B

    2001-01-01

    to other PRPP synthases the activity of spinach PRPP synthase isozyme 3 is independent of P(i), and the enzyme is inhibited by ribonucleoside diphosphates in a purely competitive manner, which indicates a lack of allosteric inhibition by these compounds. In addition spinach PRPP synthase isozyme 3 shows...... an unusual low specificity toward diphosphoryl donors by accepting dATP, GTP, CTP, and UTP in addition to ATP. The kinetic mechanism of the enzyme is an ordered steady state Bi Bi mechanism with K(ATP) and K(Rib-5-P) values of 170 and 110 micrometer, respectively, and a V(max) value of 13.1 micromol (min x...... mg of protein)(-1). The enzyme has an absolute requirement for magnesium ions, and maximal activity is obtained at 40 degrees C at pH 7.6....

  1. Beta-and gamma-turns in proteins revisited: a new set of amino acid turn-type dependent positional preferences and potentials.

    Science.gov (United States)

    Guruprasad, K; Rajkumar, S

    2000-06-01

    The number of beta-turns in a representative set of 426 protein three-dimensional crystal structures selected from the recent Protein Data Bank has nearly doubled and the number of gamma-turns in a representative set of 320 proteins has increased over seven times since the previous analysis. Beta-turns (7153) and gamma-turns (911) extracted from these proteins were used to derive a revised set of type-dependent amino acid positional preferences and potentials. Compared with previous results, the preference for proline, methionine and tryptophan has increased and the preference for glutamine, valine, glutamic acid and alanine has decreased for beta-turns. Certain new amino acid preferences were observed for both turn types and individual amino acids showed turn-type dependent positional preferences. The rationale for new amino acid preferences are discussed in the light of hydrogen bonds and other interactions involving the turns. Where main-chain hydrogen bonds of the type NH(i + 3) --> CO(i) were not observed for some beta-turns, other main-chain hydrogen bonds or solvent interactions were observed that possibly stabilize such beta-turns. A number of unexpected isolated beta-turns with proline at i + 2 position were also observed. The NH(i + 2) --> CO(i) hydrogen bond was observed for almost all gamma-turns. Nearly 20% classic gamma-turns and 43% inverse gamma-turns are isolated turns.

  2. Development of beta reference radiations

    International Nuclear Information System (INIS)

    Wan Zhaoyong; Cai Shanyu; Li Yanbo; Yin Wei; Feng Jiamin; Sun Yuhua; Li Yongqiang

    1997-09-01

    A system of beta reference radiation has been developed, that is composed of 740 MBq 147 Pm beta source, 74 MBq and 740 MBq 90 Sr + 90 Y β sources, compensation filters, a source handling tool, a source jig, spacing bars, a shutter, a control unit and a beta dose meter calibration stand. For 740 MBq 147 Pm and 74 MBq 90 Sr + 90 Y beta reference radiations with compensation filters and 740 MBq 90 Sr + 90 Y beta reference radiation without compensation filter, at 20 cm, 30 cm and 30 cm distance separately; the residual energy of maximum is 0.14 MeV, 1.98 MeV and 2.18 MeV separately; the absorbed dose to tissue D (0.07) is 1.547 mGy/h (1996-05-20), 5.037 mGy/h (1996-05-10) and 93.57 mGy/h (1996-05-15) separately; the total uncertainty is 3.0%, 1.7% and 1.7% separately. For the first and the second beta reference radiation, the dose rate variability in the area of 18 cm diameter in the plane perpendicular to the beta-ray beam axis is within +-6% and +-3% separately. (3 refs., 2 tabs., 8 figs.)

  3. A semiconductor beta ray spectrometer

    International Nuclear Information System (INIS)

    Bom, V.R.

    1987-01-01

    Measurement of energy spectra of beta particles emitted from nuclei in beta-decay processes provides information concerning the mass difference of these nuclei between initial and final state. Moreover, experimental beta spectra yield information on the feeding of the levels in the daughter nucleus. Such data are valuable in the construction and checking of the level schemes. This thesis describes the design, construction, testing and usage of a detector for the accurate measurement of the mentioned spectra. In ch. 2 the design and construction of the beta spectrometer, which uses a hyper-pure germanium crystal for energy determination, is described. A simple wire chamber is used to discriminate beta particles from gamma radiation. Disadvantages arise from the large amounts of scattered beta particles deforming the continua. A method is described to minimize the scattering. In ch. 3 some theoretical aspects of data analysis are described and the results of Monte-Carlo simulations of the summation of annihilation radiation are compared with experiments. Ch. 4 comprises the results of the measurements of the beta decay energies of 103-108 In. 87 refs.; 34 figs.; 7 tabs

  4. BETA (Bitter Electromagnet Testing Apparatus)

    Science.gov (United States)

    Bates, Evan M.; Birmingham, William J.; Rivera, William F.; Romero-Talamas, Carlos A.

    2017-10-01

    The Bitter Electromagnet Testing Apparatus (BETA) is a 1-Tesla (T) prototype of the 10-T Adjustable Long Pulse High-Field Apparatus (ALPHA). These water-cooled resistive magnets use high DC currents to produce strong uniform magnetic fields. Presented here is the successful completion of the BETA project and experimental results validating analytical magnet designing methods developed at the Dusty Plasma Laboratory (DPL). BETA's final design specifications will be highlighted which include electromagnetic, thermal and stress analyses. The magnet core design will be explained which include: Bitter Arcs, helix starters, and clamping annuli. The final version of the magnet's vessel and cooling system are also presented, as well as the electrical system of BETA, which is composed of a unique solid-state breaker circuit. Experimental results presented will show the operation of BETA at 1 T. The results are compared to both analytical design methods and finite element analysis calculations. We also explore the steady state maximums and theoretical limits of BETA's design. The completion of BETA validates the design and manufacturing techniques that will be used in the succeeding magnet, ALPHA.

  5. Wild-type phosphoribosylpyrophosphate synthase (PRS from Mycobacterium tuberculosis: a bacterial class II PRS?

    Directory of Open Access Journals (Sweden)

    Ardala Breda

    Full Text Available The 5-phospho-α-D-ribose 1-diphosphate (PRPP metabolite plays essential roles in several biosynthetic pathways, including histidine, tryptophan, nucleotides, and, in mycobacteria, cell wall precursors. PRPP is synthesized from α-D-ribose 5-phosphate (R5P and ATP by the Mycobacterium tuberculosis prsA gene product, phosphoribosylpyrophosphate synthase (MtPRS. Here, we report amplification, cloning, expression and purification of wild-type MtPRS. Glutaraldehyde cross-linking results suggest that MtPRS predominates as a hexamer, presenting varied oligomeric states due to distinct ligand binding. MtPRS activity measurements were carried out by a novel coupled continuous spectrophotometric assay. MtPRS enzyme activity could be detected in the absence of P(i. ADP, GDP and UMP inhibit MtPRS activity. Steady-state kinetics results indicate that MtPRS has broad substrate specificity, being able to accept ATP, GTP, CTP, and UTP as diphosphoryl group donors. Fluorescence spectroscopy data suggest that the enzyme mechanism for purine diphosphoryl donors follows a random order of substrate addition, and for pyrimidine diphosphoryl donors follows an ordered mechanism of substrate addition in which R5P binds first to free enzyme. An ordered mechanism for product dissociation is followed by MtPRS, in which PRPP is the first product to be released followed by the nucleoside monophosphate products to yield free enzyme for the next round of catalysis. The broad specificity for diphosphoryl group donors and detection of enzyme activity in the absence of P(i would suggest that MtPRS belongs to Class II PRS proteins. On the other hand, the hexameric quaternary structure and allosteric ADP inhibition would place MtPRS in Class I PRSs. Further data are needed to classify MtPRS as belonging to a particular family of PRS proteins. The data here presented should help augment our understanding of MtPRS mode of action. Current efforts are toward experimental structure

  6. Wild-Type Phosphoribosylpyrophosphate Synthase (PRS) from Mycobacterium tuberculosis: A Bacterial Class II PRS?

    Science.gov (United States)

    Breda, Ardala; Martinelli, Leonardo K. B.; Bizarro, Cristiano V.; Rosado, Leonardo A.; Borges, Caroline B.; Santos, Diógenes S.; Basso, Luiz A.

    2012-01-01

    The 5-phospho-α-D-ribose 1-diphosphate (PRPP) metabolite plays essential roles in several biosynthetic pathways, including histidine, tryptophan, nucleotides, and, in mycobacteria, cell wall precursors. PRPP is synthesized from α-D-ribose 5-phosphate (R5P) and ATP by the Mycobacterium tuberculosis prsA gene product, phosphoribosylpyrophosphate synthase (MtPRS). Here, we report amplification, cloning, expression and purification of wild-type MtPRS. Glutaraldehyde cross-linking results suggest that MtPRS predominates as a hexamer, presenting varied oligomeric states due to distinct ligand binding. MtPRS activity measurements were carried out by a novel coupled continuous spectrophotometric assay. MtPRS enzyme activity could be detected in the absence of Pi. ADP, GDP and UMP inhibit MtPRS activity. Steady-state kinetics results indicate that MtPRS has broad substrate specificity, being able to accept ATP, GTP, CTP, and UTP as diphosphoryl group donors. Fluorescence spectroscopy data suggest that the enzyme mechanism for purine diphosphoryl donors follows a random order of substrate addition, and for pyrimidine diphosphoryl donors follows an ordered mechanism of substrate addition in which R5P binds first to free enzyme. An ordered mechanism for product dissociation is followed by MtPRS, in which PRPP is the first product to be released followed by the nucleoside monophosphate products to yield free enzyme for the next round of catalysis. The broad specificity for diphosphoryl group donors and detection of enzyme activity in the absence of Pi would suggest that MtPRS belongs to Class II PRS proteins. On the other hand, the hexameric quaternary structure and allosteric ADP inhibition would place MtPRS in Class I PRSs. Further data are needed to classify MtPRS as belonging to a particular family of PRS proteins. The data here presented should help augment our understanding of MtPRS mode of action. Current efforts are toward experimental structure determination of Mt

  7. The association between the hypothalamic pituitary adrenal axis and tryptophan metabolism in persons with recurrent major depressive disorder and healthy controls

    NARCIS (Netherlands)

    Sorgdrager, F. J. H.; Doornbos, B.; Penninx, B. W. J. H.; de Jonge, P.; Kema, I. P.

    2017-01-01

    Objectives: Persistent changes in serotonergic and hypothalamic pituitary adrenal (HPA) axis functioning are implicated in recurrent types of major depressive disorder (MDD). Systemic tryptophan levels, which influence the rate of serotonin synthesis, are regulated by glucocorticoids produced along

  8. Metabolism of /sup 14/C-labelled L-tryptophan, L-kynurenine, and hydroxy-L-kynurenine in miners with scleroderma

    Energy Technology Data Exchange (ETDEWEB)

    Hankes, L.V.; De Bruin, E.; Jansen, C.R.; Vorster, L.; Schmaeler, M.

    1977-03-19

    Six South African white miners were studied with the 2-g L-tryptophan load test and tracer doses of L-tryptophan-7a-/sup 14/C, L-kynurenine-keto-/sup 14/C and hydroxy-L-kynurenine-keto-/sup 14/C. The breath /sup 14/CO/sub 2/ and 14 urinary metabolites were measured. When they were compared with a previous study of American women with scleroderma, similar /sup 14/CO/sub 2/ and tryptophan metabolite excretion patterns were observed in the data from the miners. The labelled quinolinic acid excretion was more significantly elevated in the South African miners' urine than in the urine of the American women. The data from both studies suggest that some patients with scleroderma have an altered step in the tryptophan metabolic pathway after hydroxy-anthranilic acid. What relationship exists between the induction of pulmonary silicosis and the subsequent development of scleroderma, requires additional human studies.

  9. Experiments on double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Busto, J [Neuchatel Univ. (Switzerland). Inst. de Physique

    1996-11-01

    The Double Beta Decay, and especially ({beta}{beta}){sub 0{nu}} mode, is an excellent test of Standard Model as well as of neutrino physics. From experimental point of view, a very large number of different techniques are or have been used increasing the sensitivity of this experiments quite a lot (the factor of 10{sup 4} in the last 20 years). In future, in spite of several difficulties, the sensitivity would be increased further, keeping the interest of this very important process. (author) 4 figs., 5 tabs., 21 refs.

  10. Preventive Effects of Beta-Hydroxy-Beta-Methyl Butyrate

    OpenAIRE

    N. Ravanbakhsh; N. Torabi; M. Foadoddini

    2016-01-01

    Aims: One of the major factors in sudden cardiac arrest is the initiation and continuation of deadly arrhythmias during ischemia. It is known that beta-hydroxy-beta-methylbutyrate (HMB) has useful effects such as anti-inflammatory and anti-apoptosis effects in the skeletal muscles. The aim of this study was to investigate the preventive effects of HMB on the ventricular arrhythmias due to the ischemia. Materials & Methods: In the experimental study, 30 Wistar male rats were randomly div...

  11. Dosimetry of {beta} extensive sources; Dosimetria de fuentes {beta} extensas

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E.L.; Lallena R, A.M. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain)

    2002-07-01

    In this work, we have been studied, making use of the Penelope Monte Carlo simulation code, the dosimetry of {beta} extensive sources in situations of spherical geometry including interfaces. These configurations are of interest in the treatment of the called cranealfaringyomes of some synovia leisure of knee and other problems of interest in medical physics. Therefore, its application can be extended toward problems of another areas with similar geometric situation and beta sources. (Author)

  12. Study on the interaction of tropisetron hydrochloride and L-tryptophan by spectrofluorimetry and its analytical application

    International Nuclear Information System (INIS)

    Zhu Xiashi; Gong Aiqin; Wang Baosheng; Yu Suhai

    2008-01-01

    A new method to determine tropisetron hydrochloride with L-tryptophan in the medium with pH=9.0 was studied, which is based on the fluorescence quenching effect of tropisetron hydrochloride on L-tryptophan. The fluorescence quenching mechanism and various factors influencing fluorescence quenching were discussed. Under the optimum conditions, the linear range and detection limit were 0.03-12.0 and 0.01 μg/mL (correlation coefficient r=0.9970), respectively. The calibration curve equation was ΔF=6.17+12.56 C (μg/mL). RSD was 3.4% (c=4.0 μg/mL, n=5); the detection limit estimated (S/N=3) was 0.01 μg/mL. The proposed method had been successfully applied to determine tropisetron hydrochloride in real samples and the obtained results were in good agreement with the results of the official method

  13. Computational Protocols for Prediction of Solute NMR Relative Chemical Shifts. A Case Study of L-Tryptophan in Aqueous Solution

    DEFF Research Database (Denmark)

    Eriksen, Janus J.; Olsen, Jógvan Magnus H.; Aidas, Kestutis

    2011-01-01

    to the results stemming from the conformations extracted from the MM conformational search in terms of replicating an experimental reference as well as in achieving the correct sequence of the NMR relative chemical shifts of L-tryptophan in aqueous solution. We find this to be due to missing conformations......In this study, we have applied two different spanning protocols for obtaining the molecular conformations of L-tryptophan in aqueous solution, namely a molecular dynamics simulation and a molecular mechanics conformational search with subsequent geometry re-optimization of the stable conformers...... using a quantum mechanically based method. These spanning protocols represent standard ways of obtaining a set of conformations on which NMR calculations may be performed. The results stemming from the solute–solvent configurations extracted from the MD simulation at 300 K are found to be inferior...

  14. Real-time detection of faecally contaminated drinking water with tryptophan-like fluorescence: defining threshold values.

    Science.gov (United States)

    Sorensen, James P R; Baker, Andy; Cumberland, Susan A; Lapworth, Dan J; MacDonald, Alan M; Pedley, Steve; Taylor, Richard G; Ward, Jade S T

    2018-05-01

    We assess the use of fluorescent dissolved organic matter at excitation-emission wavelengths of 280nm and 360nm, termed tryptophan-like fluorescence (TLF), as an indicator of faecally contaminated drinking water. A significant logistic regression model was developed using TLF as a predictor of thermotolerant coliforms (TTCs) using data from groundwater- and surface water-derived drinking water sources in India, Malawi, South Africa and Zambia. A TLF threshold of 1.3ppb dissolved tryptophan was selected to classify TTC contamination. Validation of the TLF threshold indicated a false-negative error rate of 15% and a false-positive error rate of 18%. The threshold was unsuccessful at classifying contaminated sources containing water globally. Copyright © 2017 Natural Environment Research Council (NERC), as represented by the British Geological Survey (BGS. Published by Elsevier B.V. All rights reserved.

  15. Remarkable Role of Indoleamine 2,3-Dioxygenase and Tryptophan Metabolites in Infectious Diseases: Potential Role in Macrophage-Mediated Inflammatory Diseases

    OpenAIRE

    Murakami, Yuki; Hoshi, Masato; Imamura, Yukio; Arioka, Yuko; Yamamoto, Yasuko; Saito, Kuniaki

    2013-01-01

    Indoleamine 2,3-dioxygenase 1 (IDO1), the L-tryptophan-degrading enzyme, plays a key role in the immunomodulatory effects on several types of immune cells. Originally known for its regulatory function during pregnancy and chronic inflammation in tumorigenesis, the activity of IDO1 seems to modify the inflammatory state of infectious diseases. The pathophysiologic activity of L-tryptophan metabolites, kynurenines, is well recognized. Therefore, an understanding of the regulation of IDO1 and th...

  16. Tryptophan Intake in the US Adult Population Is Not Related to Liver or Kidney Function but Is Associated with Depression and Sleep Outcomes.

    Science.gov (United States)

    Lieberman, Harris R; Agarwal, Sanjiv; Fulgoni, Victor L

    2016-12-01

    Tryptophan is an indispensable amino acid and is a precursor of the neurotransmitter serotonin. Tryptophan metabolites, such as serotonin and melatonin, are thought to participate in the regulation of mood and sleep and tryptophan is used to treat insomnia, sleep apnea, and depression. This study examined the intake of tryptophan and its associations with biochemical, behavioral, sleep, and health and safety outcomes in adults in a secondary analysis of a large, publicly available database of the US population. Data from the NHANES 2001-2012 (n = 29,687) were used to determine daily intakes of tryptophan and its associations with biochemical markers of health- and safety-related outcomes, self-reported depression, and sleep-related variables. Data were adjusted for demographic factors and protein intake. Linear trends were computed across deciles of intake for each outcome variable, and P-trends were determined. The usual tryptophan intake by US adults was 826 mg/d, severalfold higher than the Estimated Average Requirement for adults of 4 mg/(kg ⋅ d) (∼280 mg/d for a 70-kg adult). Most health- and safety-related biochemical markers of liver function, kidney function, and carbohydrate metabolism were not significantly (P-trend > 0.05) associated with deciles of tryptophan intake and were well within normal ranges, even for individuals in the 99th percentile of intake. Usual intake deciles of tryptophan were inversely associated with self-reported depression measured by the Patient Health Questionnaire raw score (0-27; P-trend depression, 5 = severe depression; P-trend depression and positively associated with sleep duration. © 2016 American Society for Nutrition.

  17. Sigma beta decay

    International Nuclear Information System (INIS)

    Newman, D.E.

    1975-01-01

    Describes an experiment to measure beta decays of the sigma particle. Sigmas produced by stopping a K - beam in a liquid hydrogen target decayed in the following reactions: Kp → Σπ; Σ → Neν. The electron and pion were detected by wire spark chambers in a magnetic spectrometer and by plastic scintillators, and were differentiated by a threshold gas Cherenkov counter. The neutron was detected by liquid scintillation counters. The data (n = 3) shell electrons or the highly excited electrons decay first. Instead, it is suggested that when there are two to five electrons in highly excited states immediately after a heavy ion--atom collision the first transitions to occur will be among highly excited Rydberg states in a cascade down to the 4s, 4p, and 3d-subshells. If one of the long lived states becomes occupied by electrons promoted during the collision or by electrons falling from higher levels, it will not decay until after the valence shell decays. LMM rates calculated to test the methods used are compared to previous works. The mixing coefficients are given in terms of the states 4s4p, 45sp+-, and 5s5p. The applicability of Cooper, Fano, and Prats' discussion of the energies and transition rates of doubly excited states is considered

  18. Double Beta Decay

    International Nuclear Information System (INIS)

    Fiorini, Ettore

    2008-01-01

    The importance of neutrinoless Double Beta Decay (DBD) is stressed in view of the recent results of experiments on neutrino oscillations which indicate that the difference between the squared masses of two neutrinos of different flavours is finite [For a recent review including neutrino properties and recent results see: Review of Particle Physics, J. of Phys. G: Nuclear and Particle Physics 33, 1]. As a consequence the mass of at least one neutrino has to be different from zero and it becomes imperative to determine its absolute value. The various experimental techniques to search for DBD are discussed together with the difficult problems of the evaluation of the corresponding nuclear matrix elements. The upper limits on neutrino mass coming from the results of the various experiments are reported together with the indication for a non zero value by one of them not confirmed so far. The two presently running experiments on neutrinoless DBD are briefly described together with the already approved or designed second generation searches aiming to reach the values on the absolute neutrino mass indicated by the results on neutrino oscillations

  19. Virtual Screening of Novel Glucosamine-6-Phosphate Synthase Inhibitors.

    Science.gov (United States)

    Lather, Amit; Sharma, Sunil; Khatkar, Anurag

    2018-01-01

    Infections caused by microorganisms are the major cause of death today. The tremendous and improper use of antimicrobial agents leads to antimicrobial resistance. Various currently available antimicrobial drugs are inadequate to control the infections and lead to various adverse drug reactions. Efforts based on computer-aided drug design (CADD) can excavate a large number of databases to generate new, potent hits and minimize the requirement of time as well as money for the discovery of newer antimicrobials. Pharmaceutical sciences also have made development with advances in drug designing concepts. The current research article focuses on the study of various G-6-P synthase inhibitors from literature cited molecular database. Docking analysis was conducted and ADMET data of various molecules was evaluated by Schrodinger Glide and PreADMET software, respectively. Here, the results presented efficacy of various inhibitors towards enzyme G-6-P synthase. Docking scores, binding energy and ADMET data of various molecules showed good inhibitory potential toward G-6-P synthase as compared to standard antibiotics. This novel antimicrobial drug target G-6-P synthase has not so extensively been explored for its application in antimicrobial therapy, so the work done so far proved highly essential. This article has helped the drug researchers and scientists to intensively explore about this wonderful antimicrobial drug target. The Schrodinger, Inc. (New York, USA) software was utilized to carry out the computational calculations and docking studies. The hardware configuration was Intel® core (TM) i5-4210U CPU @ 2.40GHz, RAM memory 4.0 GB under 64-bit window operating system. The ADMET data was calculated by using the PreADMET tool (PreADMET ver. 2.0). All the computational work was completed in the Laboratory for Enzyme Inhibition Studies, Department of Pharmaceutical Sciences, M.D. University, Rohtak, INDIA. Molecular docking studies were carried out to identify the binding

  20. Selective decrease of components of the creatine kinase system and ATP synthase complex in chronic Chagas disease cardiomyopathy.

    Directory of Open Access Journals (Sweden)

    Priscila Camillo Teixeira

    2011-06-01

    Full Text Available BACKGROUND: Chronic Chagas disease cardiomyopathy (CCC is an inflammatory dilated cardiomyopathy with a worse prognosis than other cardiomyopathies. CCC occurs in 30 % of individuals infected with Trypanosoma cruzi, endemic in Latin America. Heart failure is associated with impaired energy metabolism, which may be correlated to contractile dysfunction. We thus analyzed the myocardial gene and protein expression, as well as activity, of key mitochondrial enzymes related to ATP production, in myocardial samples of end-stage CCC, idiopathic dilated (IDC and ischemic (IC cardiomyopathies. METHODOLOGY/PRINCIPAL FINDINGS: Myocardium homogenates from CCC (N=5, IC (N=5 and IDC (N=5 patients, as well as from heart donors (N=5 were analyzed for protein and mRNA expression of mitochondrial creatine kinase (CKMit and muscular creatine kinase (CKM and ATP synthase subunits aplha and beta by immunoblotting and by real-time RT-PCR. Total myocardial CK activity was also assessed. Protein levels of CKM and CK activity were reduced in all three cardiomyopathy groups. However, total CK activity, as well as ATP synthase alpha chain protein levels, were significantly lower in CCC samples than IC and IDC samples. CCC myocardium displayed selective reduction of protein levels and activity of enzymes crucial for maintaining cytoplasmic ATP levels. CONCLUSIONS/SIGNIFICANCE: The selective impairment of the CK system may be associated to the loss of inotropic reserve observed in CCC. Reduction of ATP synthase alpha levels is consistent with a decrease in myocardial ATP generation through oxidative phosphorylation. Together, these results suggest that the energetic deficit is more intense in the myocardium of CCC patients than in the other tested dilated cardiomyopathies.