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l-tryptophan

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https://www.readbyqxmd.com/read/28214225/a-relay-pathway-between-arginine-and-tryptophan-metabolism-confers-immunosuppressive-properties-on-dendritic-cells
#1
Giada Mondanelli, Roberta Bianchi, Maria Teresa Pallotta, Ciriana Orabona, Elisa Albini, Alberta Iacono, Maria Laura Belladonna, Carmine Vacca, Francesca Fallarino, Antonio Macchiarulo, Stefano Ugel, Vincenzo Bronte, Federica Gevi, Lello Zolla, Auke Verhaar, Maikel Peppelenbosch, Emilia Maria Cristina Mazza, Silvio Bicciato, Yasmina Laouar, Laura Santambrogio, Paolo Puccetti, Claudia Volpi, Ursula Grohmann
Arginase 1 (Arg1) and indoleamine 2,3-dioxygenase 1 (IDO1) are immunoregulatory enzymes catalyzing the degradation of l-arginine and l-tryptophan, respectively, resulting in local amino acid deprivation. In addition, unlike Arg1, IDO1 is also endowed with non-enzymatic signaling activity in dendritic cells (DCs). Despite considerable knowledge of their individual biology, no integrated functions of Arg1 and IDO1 have been reported yet. We found that IDO1 phosphorylation and consequent activation of IDO1 signaling in DCs was strictly dependent on prior expression of Arg1 and Arg1-dependent production of polyamines...
February 13, 2017: Immunity
https://www.readbyqxmd.com/read/28211258/effects-of-a-wide-range-of-dietary-nicotinamide-riboside-nr-concentrations-on-metabolic-flexibility-and-white-adipose-tissue-wat-of-mice-fed-a-mildly-obesogenic-diet
#2
Wenbiao Shi, Maria A Hegeman, Dorien A M van Dartel, Jing Tang, Manuel Suarez, Hans Swarts, Bart van der Hee, Lluis Arola, Jaap Keijer
SCOPE: Metabolic flexibility is the ability to switch metabolism between carbohydrate oxidation (CHO) and fatty acid oxidation (FAO) and is a biomarker for metabolic health. The effect on metabolic health of nicotinamide riboside (NR) as an exclusive source of vitamin B3 is unknown and is examined here for a wide range of NR. DESIGN AND METHODS: Nine-week-old male C57BL/6JRcc mice received a semi-purified mildly obesogenic (40 en% fat) diet containing 0.14% L-tryptophan and either 5, 15, 30, 180 or 900 mg NR per kg diet for 15 weeks...
February 16, 2017: Molecular Nutrition & Food Research
https://www.readbyqxmd.com/read/28195396/development-of-a-validated-strategy-for-the-determination-of-tryptamine-in-human-cerebrospinal-fluid-in-the-presence-of-competitors-using-molecularly-imprinted-polymers
#3
Piotr Luliński, Magdalena Bamburowicz-Klimkowska, Mariusz Dana, Dorota Maciejewska
This study presents a validated strategy for the determination of tryptamine in the presence of its competitors, which involves the molecularly imprinted solid-phase extractions combined with high-performance liquid chromatography coupled with fluorimetric detection Tryptamine-imprinted microscale sorbent was produced from 4-vinylbenzoic acid and ethylene glycol dimethacrylate in methanol by precipitation polymerization, and its imprinting factor was equal to 15.4 in static experiments or 18.6 in dynamic binding experiments...
February 14, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28193333/heterologous-expression-of-%C3%AE-glutamyl-transpeptidase-from-bacillus-atrophaeus-gs-16-and-its-application-in-the-synthesis-of-%C3%AE-d-glutamyl-l-tryptophan-a-known-immunomodulatory-peptide
#4
Meenu Saini, Shruti Bindal, Rani Gupta
Gamma-glutamyl transpeptidase from a mesophilic bacterium Bacillus atrophaeus GS-16 (BaGGT) was expressed heterologously in E. coli using pET-51b vector. Maximum production of BaGGT was obtained at 16°C after 16h of IPTG induction and the protein, in its native conformation, was active as a heterooctamer which was composed of four heterodimeric units combined together. One heterodimeric unit constituted two subunits with molecular masses of 45kDa and 21kDa, respectively. The recombinant enzyme was purified by one step His-tag affinity purification protocol with a specific activity of 90U/mg and 5...
April 2017: Enzyme and Microbial Technology
https://www.readbyqxmd.com/read/28192306/a-molecularly-imprinted-polymer-coated-cdte-quantum-dot-nanocomposite-for-tryptophan-recognition-based-on-the-f%C3%A3-rster-resonance-energy-transfer-process
#5
Antonio Tirado-Guizar, Francisco Paraguay-Delgado, Georgina E Pina-Luis
A new 'turn-on' Förster resonance energy transfer (FRET) nanosensor for l-tryptophan based on molecularly imprinted quantum dots (QDs) is proposed. The approach combines the advantages of the molecular imprinting technique, the fluorescent characteristics of the QDs and the energy transfer process. Silica-coated CdTe QDs were first synthesized and then molecularly imprinted using a sol-gel process without surfactants. The final composite presents stable fluorescence which increases with the addition of l-tryptophan...
November 17, 2016: Methods and Applications in Fluorescence
https://www.readbyqxmd.com/read/28166207/structure-and-specificity-of-a-permissive-bacterial-c-prenyltransferase
#6
Sherif I Elshahawi, Hongnan Cao, Khaled A Shaaban, Larissa V Ponomareva, Thangaiah Subramanian, Mark L Farman, H Peter Spielmann, George N Phillips, Jon S Thorson, Shanteri Singh
This study highlights the biochemical and structural characterization of the L-tryptophan C6 C-prenyltransferase (C-PT) PriB from Streptomyces sp. RM-5-8. PriB was found to be uniquely permissive to a diverse array of prenyl donors and acceptors including daptomycin. Two additional PTs also produced novel prenylated daptomycins with improved antibacterial activities over the parent drug.
February 6, 2017: Nature Chemical Biology
https://www.readbyqxmd.com/read/28161804/tryptophan-depletion-under-conditions-that-imitate-insulin-resistance-enhances-fatty-acid-oxidation-and-induces-endothelial-dysfunction-through-reactive-oxygen-species-dependent-and-independent-pathways
#7
Theodoros Eleftheriadis, Georgios Pissas, Maria Sounidaki, Georgia Antoniadi, Christos Rountas, Vassilios Liakopoulos, Loannis Stefanidis
In atherosclerosis-associated pathologic entities characterized by malnutrition and inflammation, L-tryptophan (TRP) levels are low. Insulin resistance is an independent cardiovascular risk factor and induces endothelial dysfunction by increasing fatty acid oxidation. It is also associated with inflammation and low TRP levels. Low TRP levels have been related to worse cardiovascular outcome. This study evaluated the effect of TRP depletion on endothelial dysfunction under conditions that imitate insulin resistance...
February 4, 2017: Molecular and Cellular Biochemistry
https://www.readbyqxmd.com/read/28161779/interactions-of-amino-acids-with-aluminum-octacarboxyphthalocyanine-hydroxide-experimental-and-dft-studies
#8
Marta Kliber-Jasik, Małgorzata A Broda, Anna Maroń, Joanna Nackiewicz
The influence of albumin and amino acids (L-serine, glycine, L-histidine, L-tryptophan, L-cysteine) on the properties of aluminum octacarboxyphthalocyanine hydroxide (Al(OH)PcOC) was investigated in a phosphate buffer (pH 8.0). Particular attention was paid to the spectroscopic properties and photostability of Al(OH)PcOC. The effect of albumin or amino acids on the photodegradation of Al(OH)PcOC was examined in water using red light: 685 nm and daylight irradiation. Analysis of kinetic curves indicated that interaction with those molecules increases the photostability of Al(OH)PcOC...
February 2017: Journal of Molecular Modeling
https://www.readbyqxmd.com/read/28138057/biochemical-and-chemical-biology-study-of-rice-ostar1-revealed-that-tryptophan-aminotransferase-is-involved-in-auxin-biosynthesis-identification-of-a-potent-ostar1-inhibitor-pyruvamine2031
#9
Yusuke Kakei, Ayako Nakamura, Mitsuhiro Yamamoto, Yosuke Ishida, Chiaki Yamazaki, Akiko Sato, Megumi Narukawa-Nara, Kazuo Soeno, Yukihisa Shimada
Indole-3-acetic acid (IAA), a major form of auxin, is biosynthesized from L-tryptophan via the indole-3-pyruvic acid (IPyA) pathway in Arabidopsis Tryptophan aminotransferases (TAA1/TARs) catalyze the first step from L-tryptophan to IPyA. In rice, the importance of TAA/TARs or YUC homologs in auxin biosynthesis has been suggested, but the enzymatic activities and involvement of the intermediate IPyA in auxin biosynthesis remain elusive. In this study, we obtained biochemical evidence that the rice tryptophan aminotransferase OsTAR1 converts L-tryptophan to IPyA, and has a Km of 82...
January 30, 2017: Plant & Cell Physiology
https://www.readbyqxmd.com/read/28095360/enzyme-catalyzed-michael-addition-for-the-synthesis-of-warfarin-and-its-determination-via-fluorescence-quenching-of-l-tryptophan
#10
Yusheng Yuan, Liu Yang, Shaopu Liu, Jidong Yang, Hui Zhang, Jingjing Yan, Xiaoli Hu
A sensitive fluorescence sensor for warfarin was proposed via quenching the fluorescence of l-tryptophan due to the interaction between warfarin and l-tryptophan. Warfarin, as one of the most effective anticoagulants, was designed and synthesized via lipase from porcine pancreas (PPL) as a biocatalyst to catalyze the Michael addition of 4-hydroxycoumarin to α, β-unsaturated enones in organic medium in the presence of water. Furthermore, the spectrofluorometry was used to detect the concentration of warfarin with a linear range and detection limit (3σ/k) of 0...
January 9, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28089858/glucose-amino-acids-and-fatty-acids-directly-regulate-ghrelin-and-nucb2-nesfatin-1-in-the-intestine-and-hepatopancreas-of-goldfish-carassius-auratus-in-vitro
#11
Juan Ignacio Bertucci, Ayelén Melisa Blanco, Luis Fabián Canosa, Suraj Unniappan
Ghrelin and nesfatin-1 are two peptidyl hormones primarily involved in food intake regulation. We previously reported that the amount of dietary carbohydrates, protein and lipids modulates the expression of these peptides in goldfish in vivo. In the present work, we aimed to characterize the effects of single nutrients on ghrelin and nesfatin-1 in the intestine and hepatopancreas. First, immunolocalization of ghrelin and NUCB2/nesfatin-1 in goldfish hepatopancreas cells was studied by immunohistochemistry. Second, the effects of 2 and 4hour-long exposures of cultured intestine and hepatopancreas sections to glucose, l-tryptophan, oleic acid, linolenic acid (LNA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on ghrelin and nesfatin-1 gene and protein expression were studied...
January 13, 2017: Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology
https://www.readbyqxmd.com/read/28076364/ifn%C3%AE-regulates-activated-v%C3%AE-2-t-cells-through-a-feedback-mechanism-mediated-by-mesenchymal-stem-cells
#12
Karoline Fechter, Akaitz Dorronsoro, Emma Jakobsson, Izaskun Ferrin, Valérie Lang, Pilar Sepulveda, Daniel J Pennington, César Trigueros
γδ T cells play a role in a wide range of diseases such as autoimmunity and cancer. The majority of circulating human γδ T lymphocytes express a Vγ9Vδ2+ (Vδ2+) T cell receptor (TCR) and following activation release pro-inflammatory cytokines. In this study, we show that IFNγ, produced by Vδ2+ cells, activates mesenchymal stem cell (MSC)-mediated immunosupression, which in turn exerts a negative feedback mechanism on γδ T cell function ranging from cytokine production to proliferation. Importantly, this modulatory effect is limited to a short period of time (<24 hours) post-T cell activation, after which MSCs can no longer exert their immunoregulatory capacity...
2017: PloS One
https://www.readbyqxmd.com/read/28032983/two-flavoenzymes-catalyze-the-post-translational-generation-of-5-chlorotryptophan-and-2-aminovinyl-cysteine-during-nai-107-biosynthesis
#13
Manuel A Ortega, Dillon P Cogan, Subha Mukherjee, Neha Garg, Bo Li, Gabrielle N Thibodeaux, Sonia I Maffioli, Stefano Donadio, Margherita Sosio, Jerome Escano, Leif Smith, Satish K Nair, Wilfred A van der Donk
Lantibiotics are ribosomally synthesized and post-translationally modified antimicrobial peptides containing thioether rings. In addition to these cross-links, the clinical candidate lantibiotic NAI-107 also possesses a C-terminal S-[(Z)-2-aminovinyl]-d-cysteine (AviCys) and a unique 5-chloro-l-tryptophan (ClTrp) moiety linked to its potent bioactivity. Bioinformatic and genetic analyses on the NAI-107 biosynthetic gene cluster identified mibH and mibD as genes encoding flavoenzymes responsible for the formation of ClTrp and AviCys, respectively...
February 17, 2017: ACS Chemical Biology
https://www.readbyqxmd.com/read/27998091/tryptophan-lyase-nosl-a-cornucopia-of-5-deoxyadenosyl-radical-mediated-transformations
#14
Dhananjay M Bhandari, Dmytro Fedoseyenko, Tadhg P Begley
Tryptophan lyase (NosL) is a radical S-adenosyl-l-methionine (SAM) enzyme that catalyzes the formation of 3-methyl-2-indolic acid from l-tryptophan. In this paper, we demonstrate that the 5'-deoxyadenosyl radical is considerably more versatile in its chemistry than previously anticipated: hydrogen atom abstraction from Nα-cyclopropyltryptophan occurs at Cα rather than the amino group with NosL Y90A and replacing the substrate amine with a ketone or an alkene changes the chemistry from hydrogen atom abstraction to double bond addition...
December 21, 2016: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/27997749/inhibition-of-platelet-aggregation-and-thrombosis-by-indole-alkaloids-isolated-from-the-edible-insect-protaetia-brevitarsis-seulensis-kolbe
#15
JungIn Lee, Wonhwa Lee, Mi-Ae Kim, Jae Sam Hwang, MinKyun Na, Jong-Sup Bae
Protaetia brevitarsis seulensis (Kolbe) has been temporarily registered as a food material by the Ministry of Food and Drug Safety of Korea (MFDS). The current study aimed to discover small antithrombotic molecules from this edible insect. Five indole alkaloids, 5-hydroxyindolin-2-one (1), (1R,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (2), (1S,3S)-1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (3), (3S)-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (4) and L-tryptophan (5), were isolated from the insect...
December 20, 2016: Journal of Cellular and Molecular Medicine
https://www.readbyqxmd.com/read/27994758/fused-heterocyclic-compounds-as-potent-indoleamine-2-3-dioxygenase-1-inhibitors
#16
Subhankar Panda, Ashalata Roy, Suman Jyoti Deka, Vishal Trivedi, Debasis Manna
Uncontrolled metabolism of l-tryptophan (l-Trp) in the immune system has been recognized as a critical cellular process in immune tolerance. Indoleamine 2,3-dioxygenase 1 (IDO1) enzyme plays an important role in the metabolism of a local l-Trp through the kynurenine pathway in the immune systems. In this regard, IDO1 has emerged as a therapeutic target for the treatment of diseases that are associated with immune suppression like chronic infections, cancer, and others. In this study, we synthesized a series of pyridopyrimidine, pyrazolopyranopyrimidine, and dipyrazolopyran derivatives...
December 8, 2016: ACS Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/27988124/increased-serum-serotonin-improves-parturient-calcium-homeostasis-in-dairy-cows
#17
Lorenzo E Hernández-Castellano, Laura L Hernandez, Samantha Weaver, Rupert M Bruckmaier
Hypocalcemia in dairy cows is caused by the sudden increase in calcium demand by the mammary gland for milk production at the onset of lactation. Serotonin (5-HT) is a key factor for calcium homeostasis, modulating calcium concentration in blood. Therefore, it is hypothesized that administration of 5-hydroxy-l-tryptophan (5-HTP), a 5-HT precursor, can increase 5-HT concentrations in blood and, in turn, induce an increase in blood calcium concentration. In this study, 20 Holstein dairy cows were randomly assigned to 2 experimental groups...
February 2017: Journal of Dairy Science
https://www.readbyqxmd.com/read/27951658/analysis-of-reaction-intermediates-in-tryptophan-2-3-dioxygenase-a-comparison-with-indoleamine-2-3-dioxygenase
#18
Jaswir Basran, Elizabeth S Booth, Michael Lee, Sandeep Handa, Emma L Raven
Indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) are heme-containing enzymes that catalyze the O2-dependent oxidation of l-tryptophan (l-Trp) in biological systems. Although many decades have passed since their discovery, the mechanism of tryptophan oxidation has not been established. It has been widely assumed that IDO and TDO react using the same mechanism, although there is no evidence that they do. For IDO, a Compound II (ferryl) species accumulates in the steady state and is implicated in the mechanism; in TDO, no such species has ever been observed...
December 13, 2016: Biochemistry
https://www.readbyqxmd.com/read/27943428/synthesis-of-2-mercaptoacetyl-l-2-14-c-tryptophan-as-a-selective-metallo-%C3%AE-lactamase-inhibitor-via-2-14-c-indole-based-on-chiral-pool-strategy
#19
Gholamhossein Shirvani, Abbas Shockravi, Mohsen Amini, Nader Saemian
Metallo-beta-lactamase enzymes make bacteria resistant to a broad range of commonly used beta-lactam antibiotics. Several thiol derivatives of L-amino acids have been shown their inhibitory effects against the metallo-β-lactamase IMP-1. In this study, (2-mercaptoacetyl)-L-tryptophan as a new inhibitor of metallo-β-lactamases labeled with carbon-14 in the 2-position of the indole ring was prepared from [2-(14) C]indole as a key synthetic intermediate based on chiral pool strategy. The overall synthesis was performed in 10 steps with the overall radiochemical yield 3...
December 12, 2016: Journal of Labelled Compounds & Radiopharmaceuticals
https://www.readbyqxmd.com/read/27942644/chiral-organocatalysts-based-on-lipopeptide-micelles-for-aldol-reactions-in-water
#20
B M Soares, A M Aguilar, E R Silva, M D Coutinho-Neto, I W Hamley, M Reza, J Ruokolainen, W A Alves
A comprehensive study of the self-assembly in water of a lipopeptide consisting of a sequence of l-proline, l-arginine and l-tryptophan with a hydrocarbon chain has been performed. Fluorescence assays were used to determine the critical aggregation concentration. In situ small-angle X-ray scattering (SAXS) and molecular dynamics simulations showed the presence of spherical micelles with diameters around 6 nm. In agreement with these results, cryo-TEM images showed globular aggregates with diameters ranging from ≈4 nm up to ≈9 nm...
January 4, 2017: Physical Chemistry Chemical Physics: PCCP
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