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L-methyl tryptophan

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https://www.readbyqxmd.com/read/28820583/processing-2-methyl-l-tryptophan-through-tandem-transamination-and-selective-oxygenation-initiates-indole-ring-expansion-in-the-biosynthesis-of-thiostrepton
#1
Zhi Lin, Jia Ji, Shuaixiang Zhou, Fang Zhang, Jiequn Wu, Yinlong Guo, Wen Liu
Thiostrepton (TSR), an archetypal member of the family of ribosomally synthesized and post-translationally modified thiopeptide antibiotics, possesses a biologically important quinaldic acid (QA) moiety within the side-ring system of its characteristic thiopeptide framework. QA is derived from an independent L-Trp residue; however, its associated transformation process remains poorly understood. We here report that during the formation of QA, the key expansion of an indole to a quinoline relies on the activities of the pyridoxal-5'-phosphate-dependent protein TsrA and the flavoprotein TsrE...
August 18, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28782636/embryo-yolk-sac-membrane-kynurenine-formamidase-of-l-tryptophan-to-nad-pathway-as-a-primary-target-for-organophosphorus-insecticides-opi-in-opi-induced-nad-associated-avian-teratogenesis
#2
Josef Seifert
The objective of this study was to provide in ovo evidence for the proposed role of kynurenine formamidase of l-tryptophan to NAD(+) pathway in embryo yolk sac membranes as a primary target for organophosphorus insecticide (OPI) teratogens in OPI-induced NAD-associated avian teratogenesis. Slices prepared from yolk sac membranes or embryo livers of chicken eggs treated with the OPI dicrotophos and/or methyl parathion were incubated with l-tryptophan. Yolk sac membrane slices metabolized l-tryptophan in the pathway to NAD(+) before that function was established in livers...
August 4, 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
https://www.readbyqxmd.com/read/28771838/human-regulatory-macrophages-are-potent-in-suppression-of-the-xenoimmune-response-via-indoleamine-2-3-dioxygenase-involved-mechanism-s
#3
Fei Guo, Min Hu, Dandan Huang, Yuanfei Zhao, Benjamin Heng, Gilles Guillemin, Chai K Lim, Wayne J Hawthorne, Shounan Yi
BACKGROUND: For xenotransplantation to truly succeed, we must develop immunomodulatory strategies to suppress the xenoimmune response but by minimizing immunosuppression over the long term. Regulatory macrophages (Mreg) have been shown to suppress polyclonal T-cell proliferation in vitro and prolong allograft survival in vivo. However, the question of whether they are capable of suppressing xenoimmune responses remains unknown. This study assessed the potential of human Mreg to be used as an effective immunomodulatory method in xenotransplantation...
August 2, 2017: Xenotransplantation
https://www.readbyqxmd.com/read/28763571/enzymatic-synthesis-of-psilocybin
#4
Janis Fricke, Felix Blei, Dirk Hoffmeister
Psilocybin is the psychotropic tryptamine-derived natural product of Psilocybe carpophores, the so-called "magic mushrooms". Although its structure has been known for 60 years, the enzymatic basis of its biosynthesis has remained obscure. We characterized four psilocybin biosynthesis enzymes. These include i) PsiD which represents a new class of fungal l-tryptophan decarboxylases, ii) PsiK, that catalyzes the phosphotransfer step, iii) the methyl transferase PsiM, catalyzing iterative N-methyltransfer as terminal biosynthetic step, and iv) PsiH, a monooxygenase...
August 1, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28747433/efficient-methylation-of-c2-in-l-tryptophan-by-the-cobalamin-dependent-radical-s-adenosylmethionine-methylase-tsrm-requires-an-unmodified-n1-amine
#5
Anthony J Blaszczyk, Bo Wang, Alexey Silakov, Jackson V Ho, Squire J Booker
TsrM catalyzes the methylation of C2 in Ltryptophan (Trp). This reaction is the first step in the biosynthesis of the quinaldic acid moiety of the thiopeptide antibiotic thiostrepton, which exhibits potent activity against Gram-positive pathogens. TsrM is a member of the radical S-adenosylmethionine (SAM) superfamily of enzymes, but does not catalyze formation of 5'-deoxyadenosin-5'-yl or any other SAM-derived radical. In addition to a [4Fe-4S] cluster, TsrM contains a cobalamin cofactor that serves as an intermediate methyl carrier in its reaction...
July 26, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28732132/entrapment-of-amino-acids-in-gas-phase-surfactant-assemblies-the-case-of-tryptophan-confined-in-positively-charged-1r-2s-dodecyl-2-hydroxy-1-methyl-2-phenylethyl-dimethylammonium-bromide-aggregates
#6
David Bongiorno, Valentina Calabrese, Leopoldo Ceraulo, Serena Indelicato, Vincenzo Turco Liveri
The ability of positively charged aggregates of the surfactant (1R,2S)-Dodecyl(2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium bromide (DMEB) to incorporate D- or L-tryptophan in the gas-phase has been investigated by electrospray ion mobility mass spectrometry (ESI-IM-MS). Strongly impacted by the pH of the electrosprayed solutions, both protonated (T(+) ) and deprotonated (T(-) ) tryptophan are effectively included into the aggregates whereas, tryptophan in zwitterionic (T(0) ) form is practically absent in singly charged DMEB aggregates but can be found in multiply charged ones...
July 21, 2017: Journal of Mass Spectrometry: JMS
https://www.readbyqxmd.com/read/28688912/inhibition-of-the-kynurenine-pathway-protects-against-reactive-microglial-associated-reductions-in-the-complexity-of-primary-cortical-neurons
#7
Katherine O'Farrell, Eimear Fagan, Thomas J Connor, Andrew Harkin
Brain glia possess the rate limiting enzyme indoleamine 2, 3-dioxygenase (IDO) which catalyses the conversion of tryptophan to kynurenine. Microglia also express kynurenine monooxygenase (KMO) and kynureninase (KYNU) which lead to the production of the free radical producing metabolites, 3-hydroxykynurenine and 3-hydroxyanthranillic acid respectively and subsequently production of the NMDA receptor agonist quinolinic acid. The aim of this study was to examine the effect of IFNγ-stimulated kynurenine pathway (KP) induction in microglia on neurite outgrowth and complexity, and to determine whether alterations could be abrogated using pharmacological inhibitors of the KP...
September 5, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28656203/1-methyl-l-tryptophan-promotes-the-apoptosis-of-hepatic-stellate-cells-arrested-by-interferon-%C3%AE-by-increasing-the-expression-of-ifn-%C3%AE-r%C3%AE-irf-1-and-fas
#8
Ji Eun Oh, Kwang Yong Shim, Jong In Lee, Soo In Choi, Soon Koo Baik, Young Woo Eom
Liver fibrosis, a precursor to cirrhosis, is the result of the deposition of extracellular matrix (ECM) proteins and is mediated primarily by activated hepatic stellate cells (HSCs). In this study, we investigated the anti-fibrotic effects of interferon (IFN)-γ in activated HSCs in vitro and whether cell viability would be decreased by the inhibition of indoleamine 2,3-dioxygemase (IDO), which is responsible for cell cycle arrest. Following treatment with IFN-γ, cell signaling pathways and DNA content were analyzed to assess the inactivation of HSCs or the decrease in HSC proliferation...
June 26, 2017: International Journal of Molecular Medicine
https://www.readbyqxmd.com/read/28611277/association-of-rasgrf1-methylation-with-epileptic-seizures
#9
Xiaoni Chen, Xi Peng, Liang Wang, Xinwei Fu, Ji Xiu Zhou, Binglin Zhu, Jing Luo, Xuefeng Wang, Zheng Xiao
DNA methylation, one of the mechanisms of epigenetic regulation, has been suggested to be related with epilepsy. RASgrf1 is a paternally imprinted gene and has a differentially methylated region (DMR) at the promoter that can silence gene expression. We have previously observed the down-regulation of RASgrf1 in the temporal neocortex of epilepsy patients and in the hippocampus of epileptic animals. Here, we further explored the dynamic change (1-day acute period, 10-day latent period and 45-day chronic phase) of DNA methylation and RASgrf1 expression after acute epileptic seizures in kainic acid (KA)-treated mice, and we observed the impact of N-phthalyl-L-tryptophan (RG108), a DNA methyltransferase (DNMT) inhibitor, on an acute epileptic model by polymerase chain reaction (PCR), western blotting, and bisulfite sequencing PCR (BSP)...
July 11, 2017: Oncotarget
https://www.readbyqxmd.com/read/28529635/synthesis-of-5-18-f-fluoro-%C3%AE-methyl-tryptophan-new-trp-based-pet-agents
#10
Benjamin C Giglio, Haiyang Fei, Mengzhe Wang, Hui Wang, Liu He, Huijuan Feng, Zhanhong Wu, Hongjian Lu, Zibo Li
Indoleamine 2,3-dioxygenase (IDO1) plays a special role in the biology of various cancer types, because it breaks down the essential amino acid tryptophan for immune cell activation. Upregulation of IDO1 significantly correlates with the number of various T cell types in tumor tissues in melanoma and other cancers, suggesting that IDO expression is linked with effective and ineffective ('exhausted') immune response in cancer. Based on the reported IDO inhibitors (α-Methylated and indole-N-methylated tryptophan (Trp)), here we report the synthesis of potential IDO1 imaging agents through direct introduction of (18)F into the tryptophan aromatic ring...
2017: Theranostics
https://www.readbyqxmd.com/read/28488390/mesenchymal-stem-cells-protect-from-acute-liver-injury-by-attenuating-hepatotoxicity-of-liver-nkt-cells-in-inos-and-ido-dependent-manner
#11
Marina Gazdic, Bojana Simovic Markovic, Ljubica Vucicevic, Tamara Nikolic, Valentin Djonov, Nebojsa Arsenijevic, Vladimir Trajkovic, Miodrag L Lukic, Vladislav Volarevic
The effects of mesenchymal stem cells (MSCs) on phenotype and function of natural killer T (NKT) cells, is not understood. We used concanavalin A (ConA) - and α-galactosylceramide (α-GalCer)-induced liver injury to evaluate effects of MSCs on NKT-dependent hepatotoxicity. Mouse MSCs (mMSCs) significantly reduced Con A- and α-GalCer-mediated hepatitis in C57Bl/6 mice, as demonstrated by histopathological and biochemical analysis, attenuated influx of inflammatory (T-bet(+) TNF-α, IFN-γ producing and GATA3(+) , IL-4-producing) liver NKT cells and down-regulated TNF-α, IFN-γ and IL-4 levels in the sera...
May 9, 2017: Journal of Tissue Engineering and Regenerative Medicine
https://www.readbyqxmd.com/read/28485810/expression-of-indoleamine-2-3-dioxygenase-in-pregnant-mice-correlates-with-cd4-cd25-foxp3-t-regulatory-cells
#12
L-L Yu, Y-H Zhang, F-X Zhao
OBJECTIVE: Indoleamine 2,3-dioxygenase (IDO) initiated tryptophan degradation in the placenta has a role in the prevention of allogeneic fetus rejection by T-cells. The present study aimed to investigate the relationship between IDO and CD4+CD25+Foxp3+ T cells in pregnant mice. MATERIALS AND METHODS: The percentage of CD4+CD25+Foxp3+ T cells in peripheral blood mononuclear cells (PBMC) and IDO mRNA levels were detected in pregnant mice. The non-pregnant mice were used as control in this study...
April 2017: European Review for Medical and Pharmacological Sciences
https://www.readbyqxmd.com/read/28416218/dummy-molecularly-imprinted-microbeads-as-solid-phase-extraction-material-for-selective-determination-of-phthalate-esters-in-water
#13
Elif Tümay Özer, Bilgen Osman, Tuğçe Yazıcı
The aim of this study was to investigate the usability of newly synthesized dummy molecularly imprinted microbeads (DMIMs) as a solid phase extraction (SPE) material to determine six phthalate esters (PEs) in water by GC-MS analysis. Diethyl phthalate (DEP) was used as a dummy template to prepare poly(ethylene glycol dimethacrylate N-methacryloyl-l-tryptophan methyl ester) [PEMATrp)] DMIMs by using suspension polymerization. The PEMATrp DMIMs were characterized by using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM)...
April 9, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28344890/suppression-of-indoleamine-2-3-dioxygenase-1-expression-by-promoter-hypermethylation-in-er-positive-breast-cancer
#14
Dyah L Dewi, Soumya R Mohapatra, Saioa Blanco Cabañes, Isabell Adam, Luis F Somarribas Patterson, Bianca Berdel, Masroor Kahloon, Loreen Thürmann, Stefanie Loth, Katharina Heilmann, Dieter Weichenhan, Oliver Mücke, Ines Heiland, Pauline Wimberger, Jan Dominik Kuhlmann, Karl-Heinz Kellner, Sarah Schott, Christoph Plass, Michael Platten, Clarissa Gerhäuser, Saskia Trump, Christiane A Opitz
Kynurenine formation by tryptophan-catabolic indoleamine-2,3-dioxygenase 1 (IDO1) plays a key role in tumor immune evasion and inhibition of IDO1 is efficacious in preclinical models of breast cancer. As the response of breast cancer to immune checkpoint inhibitors may be limited, a better understanding of the expression of additional targetable immunomodulatory pathways is of importance. We therefore investigated the regulation of IDO1 expression in different breast cancer subtypes. We identified estrogen receptor α (ER) as a negative regulator of IDO1 expression...
2017: Oncoimmunology
https://www.readbyqxmd.com/read/28302759/preclinical-evaluation-of-11-c-sarcosine-as-a-substrate-of-proton-coupled-amino-acid-transporters-and-first-human-application-in-prostate-cancer
#15
Morand Piert, Xia Shao, David M Raffel, Mathew S Davenport, Jeffrey Montgomery, Lakshmi Kunju, Brian G Hockley, Javed Siddiqui, Peter J H Scott, Arul Chinnaiyan, Thekkelnaycke Rajendiran
Sarcosine is a known substrate of proton-coupled amino acid transporters (PAT), which are overexpressed in selected tissues and solid tumors. Sarcosine, an N-methyl derivative of the amino acid glycine and a metabolic product of choline, plays an important role for prostate cancer aggressiveness and progression. Methods: Carbon-11 radiolabeled sarcosine ((11)C-sarcosine) was tested as a new positron emission tomography (PET) imaging probe in comparison with (11)C-choline in two prostate cancer tumor xenograft models (DU-145 and PC-3)...
March 16, 2017: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
https://www.readbyqxmd.com/read/28268250/antioxidant-effect-of-thiazolidine-molecules-in-cell-culture-media-improves-stability-and-performance
#16
Jennifer Kuschelewski, Alisa Schnellbaecher, Sascha Pering, Maria Wehsling, Aline Zimmer
The ability of cell culture media components to generate reactive species as well as their sensitivity to oxidative degradation, affects the overall stability of media and the behavior of cells cultured in vitro. This study investigates the influence of thiazolidine molecules, formed from the condensation between cysteine and alpha-ketoacids, on the stability of these complex mixtures and on the performance of cell culture processes aiming to produce therapeutically relevant monoclonal antibodies. Results presented in this study indicate that 2-methyl-1,3-thiazolidine-2,4-dicarboxylic acid and 2-(2-carboxyethyl)-1,3-thiazolidine-2,4-dicarboxylic acid, obtained by condensation of cysteine with pyruvate or alpha-ketoglutarate, respectively, are able to stabilize cell culture media formulations, in particular redox sensitive molecules like folic acid, thiamine, l-methionine (met) and l-tryptophan (trp)...
March 7, 2017: Biotechnology Progress
https://www.readbyqxmd.com/read/28221769/manipulation-of-the-precursor-supply-in-yeast-significantly-enhances-the-accumulation-of-prenylated-%C3%AE-carbolines
#17
Katja Backhaus, Lena Ludwig-Radtke, Xiulan Xie, Shu-Ming Li
The tryptophan derivative 1-methyl-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid (MTCA) is present in many plants and foods including fermentation products of the baker's yeast Saccharomyces cerevisiae. MTCA is formed from tryptophan and acetaldehyde via a Pictet-Spengler reaction. In this study, up to 9 mg/L of MTCA were detected as a mixture of (1S,3S) and (1R,3S) isomers in a ratio of 2.2:1 in Saccharomyces cerevisiae cultures. To the best of our knowledge, this is the first report on the presence of MTCA in laboratory baker's yeast cultures...
March 2, 2017: ACS Synthetic Biology
https://www.readbyqxmd.com/read/28208655/experimental-evidence-and-in-silico-identification-of-tryptophan-decarboxylase-in-citrus-genus
#18
Luigi De Masi, Domenico Castaldo, Domenico Pignone, Luigi Servillo, Angelo Facchiano
Plant tryptophan decarboxylase (TDC) converts tryptophan into tryptamine, precursor of indolealkylamine alkaloids. The recent finding of tryptamine metabolites in Citrus plants leads to hypothesize the existence of TDC activity in this genus. Here, we report for the first time that, in Citrus x limon seedlings, deuterium labeled tryptophan is decarboxylated into tryptamine, from which successively deuterated N,N,N-trimethyltryptamine is formed. These results give an evidence of the occurrence of the TDC activity and the successive methylation pathway of the tryptamine produced from the tryptophan decarboxylation...
February 11, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28195901/prognostic-molecular-and-imaging-biomarkers-in-primary-glioblastoma
#19
Edit Bosnyák, Sharon K Michelhaugh, Neil V Klinger, David O Kamson, Geoffrey R Barger, Sandeep Mittal, Csaba Juhász
PURPOSE: Several molecular glioma markers (including isocitrate dehydrogenase 1 [IDH1] mutation, amplification of the epidermal growth factor receptor [EGFR], and methylation of the O6-methylguanine-DNA methyltransferase [MGMT] promoter) have been associated with glioblastoma survival. In this study, we examined the association between tumoral amino acid uptake, molecular markers, and overall survival in patients with IDH1 wild-type (primary) glioblastoma. PATIENTS AND METHODS: Twenty-one patients with newly diagnosed IDH1 wild-type glioblastomas underwent presurgical MRI and PET scanning with alpha[C-11]-L-methyl-tryptophan (AMT)...
May 2017: Clinical Nuclear Medicine
https://www.readbyqxmd.com/read/27998091/tryptophan-lyase-nosl-a-cornucopia-of-5-deoxyadenosyl-radical-mediated-transformations
#20
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
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