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L-methyl tryptophan

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https://www.readbyqxmd.com/read/29666372/brain-serotonin-synthesis-capacity-in-obsessive-compulsive-disorder-effects-of-cognitive-behavioral-therapy-and-sertraline
#1
Jennifer I Lissemore, Debbie Sookman, Paul Gravel, Alexandre Berney, Amir Barsoum, Mirko Diksic, Thomas E Nordahl, Gilbert Pinard, Igor Sibon, Jean Cottraux, Marco Leyton, Chawki Benkelfat
Cognitive behavioral therapy (CBT) and selective serotonin reuptake inhibitors (SSRIs) are both effective treatments for some patients with obsessive-compulsive disorder (OCD), yet little is known about the neurochemical changes related to these treatment modalities. Here, we used positron emission tomography and the α-[11 C]methyl-L-tryptophan tracer to examine the changes in brain regional serotonin synthesis capacity in OCD patients following treatment with CBT or SSRI treatment. Sixteen medication-free OCD patients were randomly assigned to 12 weeks of either CBT or sertraline treatment...
April 18, 2018: Translational Psychiatry
https://www.readbyqxmd.com/read/29605584/enzymatic-synthesis-of-methyl-derivatives-of-l-tryptophan-selectively-labeled-with-hydrogen-isotopes
#2
Elżbieta Winnicka, Marianna Kańska
We report the enzymatic synthesis of the derivatives of L-tryptophan methylated in indole moiety and labeled with deuterium and tritium in the 2-position of side chain. For kinetic studies twelve isotopomers, i.e., 1'-methyl-[2-2 H]-, 1'-methyl-[2-3 H]-, 1'-methyl-[2-2 H/3 H]-, 2'-methyl-[2-2 H]-, 2'-methyl-[2-3 H]-, 2'-methyl-[2-2 H/3 H]-, 5'-methyl-[2-2 H]-, 5'-methyl-[2-3 H]-, 5'-methyl-[2-2 H/3 H]-, 7'-methyl-[2-2 H]-, 7'-methyl-[2-3 H]-, and 7'-methyl-[2-2 H/3 H]-L-tryptophan are obtained by the enzymatic coupling of the appropriate methylated indole moiety with S-methyl-L-cysteine catalyzed by the enzyme tryptophanase...
March 27, 2018: Applied Radiation and Isotopes
https://www.readbyqxmd.com/read/29556427/purification-and-characterization-of-stenotrophomonas-maltophilia-derived-l-amino-acid-ester-hydrolase-for-synthesizing-dipeptide-isoleucyl-tryptophan
#3
Md Saddam Hossain, Takahiro Tanaka, Kazuyoshi Takagi, Junji Hayashi, Mamoru Wakayama
In the present study, we purified α-amino acid ester hydrolase (AEH) from cell-free extracts of the Stenotrophomonas maltophilia strain HS1. The approximately 70-kDa AEH from S. maltophilia HS1 (SmAEH) was homogeneous in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) analyses, and was present as a tetramer in gel-filtration experiments. The activity of the SmAEH enzyme was then determined by monitoring the synthesis of the antihypertensive agent dipeptide isoleucyl-tryptophan (Ile-Trp) from isoleucyl methyl ester (Ile-OMe) and tryptophan (Trp)...
March 2018: 3 Biotech
https://www.readbyqxmd.com/read/29552385/two-photon-absorption-spectra-of-fluorescent-isomorphic-dna-base-analogs
#4
Alexander Mikhaylov, Sophie de Reguardati, Jüri Pahapill, Patrik R Callis, Bern Kohler, Aleksander Rebane
Fluorescent DNA base analogs and intrinsic fluorophores are gaining importance for multiphoton microscopy and imaging, however, their quantitative nonlinear excitation properties have been poorly documented. Here we present the two-photon absorption (2PA) spectra of 2-aminopurine (2AP), 7-methyl guanosine (7MG), isoxanthopterin (IXP), 6-methyl isoxanthopterin (6MI), as well as L-tryptophan (L-trp) and 3-methylindole (3MI) in aqueous solution and some organic solvents measured in the wavelength range 550 - 810 nm using femtosecond two-photon excited fluorescence (2PEF) and nonlinear transmission (NLT) methods...
February 1, 2018: Biomedical Optics Express
https://www.readbyqxmd.com/read/29512370/indoleamine-2-3-dioxygenase-up-regulates-hypoxia-inducible-factor-1%C3%AE-expression-by-degrading-l-tryptophan-but-not-its-activity-in-human-alloreactive-t-cells
#5
Theodoros Eleftheriadis, Georgios Pissas, Vassilios Liakopoulos, Ioannis Stefanidis
Indoleamine 2, 3-dioxygenase (IDO) suppresses T-cell function at least in part by altering cell metabolism. Hypoxia-inducible factor-1 (HIF-1) increases upon T-cell activation and alters cell metabolism favoring their differentiation to effector cells. The effect of IDO on HIF-1α expression and activity was evaluated. For this purpose, mixed lymphocyte reaction (MLR) was performed using the IDO inhibitor 1-DL-methyl-tryptophan and the p53 inhibitor pifithrin-α. L-tryptophan degradation and cell proliferation were assessed by enzyme-linked immunosorbent assay, whereas the expression of proteins of interest by western blotting...
February 2018: Iranian Journal of Allergy, Asthma, and Immunology
https://www.readbyqxmd.com/read/29474084/georatusin-a-specific-antiparasitic-polyketide-peptide-hybrid-from-the-fungus-geomyces-auratus
#6
Yi-Ming Shi, Christian Richter, Victoria L Challinor, Peter Grün, Antonio Girela Del Rio, Marcel Kaiser, Anja Schüffler, Meike Piepenbring, Harald Schwalbe, Helge B Bode
Georatusin (1), featuring a highly reduced, methylated polyketide moiety fused to a tryptophan by an amide and ester bond forming a 13-membered ring, was produced by the soil fungus Geomyces auratus. An HMQC-COSY spectrum was measured to build up the connectivities despite the overlapping proton signals. DQF-COSY, HETLOC, J-HMBC, and ROESY were implemented to determine the relative configuration of the flexible moiety. Georatusin (1) shows specific antiparasitic activities against Leishmania donovani and Plasmodium falciparum without obvious cytotoxicity...
February 23, 2018: Organic Letters
https://www.readbyqxmd.com/read/29412668/total-synthesis-of-ecumicin
#7
Paige M E Hawkins, Andrew M Giltrap, Gayathri Nagalingam, Warwick J Britton, Richard J Payne
The first total synthesis of the potent anti-mycobacterial cyclic depsipeptide natural product ecumicin is described. Synthesis was achieved via a solid-phase strategy, incorporating the synthetic non-proteinogenic amino acids N-methyl-4-methoxy-l-tryptophan and threo-β-hydroxy-l-phenylalanine into the growing linear peptide chain. The synthesis employed key on-resin esterification and dimethylation steps as well as a final macrolactamization between the unusual N-methyl-4-methoxy-l-tryptophan unit and a bulky N-methyl-l-valine residue...
February 7, 2018: Organic Letters
https://www.readbyqxmd.com/read/29301550/role-of-the-indoleamine-2-3-dioxygenase-kynurenine-pathway-of-tryptophan-metabolism-in-behavioral-alterations-in-a-hepatic-encephalopathy-rat-model
#8
Xi Jiang, Lexing Xu, Lin Tang, Fuhe Liu, Ziwei Chen, Jiajia Zhang, Lei Chen, Cong Pang, Xuefeng Yu
BACKGROUND: This study aims to explore the role of indoleamine-2,3-dioxygenase (IDO)/kynurenine (KYN) pathway of tryptophan (TRY) metabolism in behavioral alterations observed in hepatic encephalopathy (HE) rats. METHODS: Expression levels of proinflammatory cytokines were tested by QT-PCR and ELISA, levels of IDOs were tested by QT-PCR and Western blot, and levels of 5-hydroxytryptamine (5-HT), KYN, TRY, 3-hydroxykynurenine (3-HK), and kynurenic acid (KA) in different brain regions were estimated using HPLC...
January 4, 2018: Journal of Neuroinflammation
https://www.readbyqxmd.com/read/29261637/amino-acid-pet-imaging-of-the-early-metabolic-response-during-tumor-treating-fields-ttfields-therapy-in-recurrent-glioblastoma
#9
Edit Bosnyák, Geoffrey R Barger, Sharon K Michelhaugh, Natasha L Robinette, Alit Amit-Yousif, Sandeep Mittal, Csaba Juhász
Tumor-treating fields (TTFields) therapy is a relatively new treatment approach for malignant gliomas. We evaluated if amino acid PET can detect an objective metabolic response to TTFields therapy in recurrent glioblastomas. PET scanning with alpha[C-11]-methyl-L-tryptophan (AMT) before and 2 to 3 months after the start of TTFields treatment showed an interval decrease of tryptophan uptake in the whole tumor (2 patients) or in a portion of the tumor (1 patient). These data demonstrate that TTFields therapy can induce an early metabolic response in recurrent glioblastoma, and this treatment response can be detected by amino acid PET...
March 2018: Clinical Nuclear Medicine
https://www.readbyqxmd.com/read/29232414/influence-of-trp-flipping-on-carbohydrate-binding-in-lectins-an-example-on-aleuria-aurantia-lectin-aal
#10
Josef Houser, Stanislav Kozmon, Deepti Mishra, Sushil K Mishra, Patrick R Romano, Michaela Wimmerová, Jaroslav Koča
Protein-carbohydrate interactions are very often mediated by the stacking CH-π interactions involving the side chains of aromatic amino acids such as tryptophan (Trp), tyrosine (Tyr) or phenylalanine (Phe). Especially suitable for stacking is the Trp residue. Analysis of the PDB database shows Trp stacking for 265 carbohydrate or carbohydrate like ligands in 5 208 Trp containing motives. An appropriate model system to study such an interaction is the AAL lectin family where the stacking interactions play a crucial role and are thought to be a driving force for carbohydrate binding...
2017: PloS One
https://www.readbyqxmd.com/read/29183598/tribenuron-methyl-resistance-and-mutation-diversity-of-the-ahas-gene-in-shepherd-s-purse-capsella-bursa-pastoris-l-medik-in-henan-province-china
#11
Lele Zhang, Wenlei Guo, Qi Li, Cuixia Wu, Ning Zhao, Weitang Liu, Jinxin Wang
Shepherd's purse is a troublesome dicot weed that occurs in the major wheat-producing areas in China. Twenty-eight shepherd's purse populations were collected from winter wheat-planting areas in Henan Province and used to evaluate tribenuron-methyl resistance and acetohydroxyacid synthase (AHAS) gene-mutation diversity. The results indicate that all 28 shepherd's purse populations were resistant to tribenuron-methyl at different levels compared with the susceptible population. Mutation of the 197 codon (CCT) changed proline (Pro) into tyrosine (Tyr), histidine (His), leucine (Leu), serine (Ser), arginine (Arg), alanine (Ala) and threonine (Thr), whereas mutation of the 574 codon (TGG) changed tryptophan (Trp) into leucine (Leu)...
November 2017: Pesticide Biochemistry and Physiology
https://www.readbyqxmd.com/read/29163899/design-crystal-structure-and-atomic-force-microscopy-study-of-thioether-ligated-d-l-cyclic-antimicrobial-peptides-against-multidrug-resistant-pseudomonas-aeruginosa
#12
Runze He, Ivan Di Bonaventura, Ricardo Visini, Bee-Ha Gan, Yongchun Fu, Daniel Probst, Alexandre Lüscher, Thilo Köhler, Christian van Delden, Achim Stocker, Wenjing Hong, Tamis Darbre, Jean-Louis Reymond
Here we report a new family of cyclic antimicrobial peptides (CAMPs) targeting MDR strains of Pseudomonas aeruginosa . These CAMPs are cyclized via a xylene double thioether bridge connecting two cysteines placed at the ends of a linear amphiphilic alternating d,l-sequence composed of lysines and tryptophans. Investigations by transmission electron microscopy (TEM), dynamic light scattering and atomic force microscopy (AFM) suggest that these peptide macrocycles interact with the membrane to form lipid-peptide aggregates...
November 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/28993242/a-distinct-microrna-expression-profile-is-associated-with-%C3%AE-11-c-methyl-l-tryptophan-amt-pet-uptake-in-epileptogenic-cortical-tubers-resected-from-patients-with-tuberous-sclerosis-complex
#13
Shruti Bagla, Daniela Cukovic, Eishi Asano, Sandeep Sood, Aimee Luat, Harry T Chugani, Diane C Chugani, Alan A Dombkowski
Tuberous sclerosis complex (TSC) is characterized by hamartomatous lesions in various organs and arises due to mutations in the TSC1 or TSC2 genes. TSC mutations lead to a range of neurological manifestations including epilepsy, cognitive impairment, autism spectrum disorders (ASD), and brain lesions that include cortical tubers. There is evidence that seizures arise at or near cortical tubers, but it is unknown why some tubers are epileptogenic while others are not. We have previously reported increased tryptophan metabolism measured with α[(11)C]-methyl-l-tryptophan (AMT) positron emission tomography (PET) in epileptogenic tubers in approximately two-thirds of patients with tuberous sclerosis and intractable epilepsy...
October 7, 2017: Neurobiology of Disease
https://www.readbyqxmd.com/read/28923384/synthesis-and-structure-elucidation-of-novel-salophen-based-dioxo-uranium-vi-complexes-in-vitro-and-in-silico-studies-of-their-dna-bsa-binding-properties-and-anticancer-activity
#14
S Yousef Ebrahimipour, Maryam Mohamadi, Masoud Torkzadeh Mahani, Jim Simpson, Joel T Mague, Iran Sheikhshoaei
The synthesis and characterization of three dioxo U(VI) complexes, [UO2(L(1))(OH2)], [UO2(L(2))DMF], and [UO2(L(2))DMSO], [L(1)](2-) = 1,1'-(4-methyl-1,2-phenylenebis (nitrilomethylidyne))di-2-naphtholate: [L(2)](2-) = 1,1'-(o-phenylenebis (nitrilomethylidyne)) di-2-naphtholate, are reported. Elemental analysis, FT-IR, (1)HNMR, UV-Vis spectroscopy, molar conductivity and single crystal X-ray diffraction were used to characterize the complexes. It was found that the complexes adopt a distorted pentagonal bipyramidal coordination geometry...
November 10, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28862845/structural-and-functional-analyses-of-periplasmic-5-methylthioadenosine-s-adenosylhomocysteine-nucleosidase-from-aeromonas-hydrophila
#15
Yongbin Xu, Lulu Wang, Jinli Chen, Jing Zhao, Shengdi Fan, Yuesheng Dong, Nam-Chul Ha, Chunshan Quan
The Gram-negative, rod-shaped bacterium Aeromonas hydrophila has two multifunctional 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase (MTAN) enzymes, MtaN-1 and MtaN-2, that differ from those in other bacteria. These proteins are essential for several metabolic pathways, including biological methylation, polyamine biosynthesis, methionine recycling, and bacterial quorum sensing. To gain insight into how these two proteins function, we determined four high-resolution crystal structures of MtaN-1 in its apo form and in complex with the substrates S-adenosyl-l-homocysteine, 5'-methylthioadenosine, and 5'-deoxyadenosine...
October 10, 2017: Biochemistry
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
#16
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 23, 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
#17
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...
October 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
#18
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
#19
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, namely i) PsiD, which represents a new class of fungal l-tryptophan decarboxylases, ii) PsiK, which catalyzes the phosphotransfer step, iii) the methyltransferase PsiM, catalyzing iterative N-methyl transfer as the terminal biosynthetic step, and iv) PsiH, a monooxygenase...
September 25, 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
#20
Anthony J Blaszczyk, Bo Wang, Alexey Silakov, Jackson V Ho, Squire J Booker
TsrM catalyzes the methylation of C2 in l-tryptophan (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 it does not catalyze the 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...
September 15, 2017: Journal of Biological Chemistry
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