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l-tryptophan

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https://www.readbyqxmd.com/read/28511073/preparation-and-evaluation-of-l-and-d-5-18-f-fluorotryptophan-as-pet-imaging-probes-for-indoleamine-and-tryptophan-2-3-dioxygenases
#1
Tang Tang, Herman S Gill, Annie Ogasawara, Jeff N Tinianow, Alexander N Vanderbilt, Simon-Peter Williams, Georgia Hatzivassiliou, Sharla White, Wendy Sandoval, Kevin DeMent, Mengling Wong, Jan Marik
Indoleamine and tryptophan 2,3-dioxygenases (IDO1 and TDO2) are pyrrolases catalyzing the oxidative cleavage of the 2,3-double bond of L-tryptophan in kynurenine pathway. In the tumor microenvironment, their increased activity prevents normal immune function, i.e. tumor cell recognition and elimination by cytotoxic T-cells. Consequently, inhibition of the kynurenine pathway may enhance the activity of cancer immunotherapeutics by reversing immune dysfunction. We sought to investigate the properties of radiolabeled 5-[(18)F]fluorotryptophan with respect to its ability for measuring IDO1 and TDO2 activity by positron emission tomography (PET)...
May 5, 2017: Nuclear Medicine and Biology
https://www.readbyqxmd.com/read/28510485/metabolomic-response-to-huanglongbing-role-of-carboxylic-compounds-in-citrus-sinensis-response-to-candidatus-liberibacter-asiaticus-and-its-vector-diaphorina-citri
#2
Nabil Killiny, Yasser Nehela
Huanglongbing, a destructive disease of citrus, is caused by the fastidious bacterium, Candidatus Liberibacter asiaticus (CLas), and transmitted by Asian citrus psyllid, Diaphorina citri. The impact of CLas-infection and/or D. citri-infestation on Valencia sweet orange (Citrus sinensis) leaf metabolites was investigated using GC-MS, followed by gene expression analysis for 37 genes involved in jasmonic acid (JA), salicylic acid (SA), and proline-glutamine pathways. The total amino acid abundance increased after CLas-infection, while the total fatty acids increased dramatically after infestation with D...
May 16, 2017: Molecular Plant-microbe Interactions: MPMI
https://www.readbyqxmd.com/read/28495383/zinc-complex-of-tryptophan-appended-1-4-7-10-tetraazacyclododecane-as-potential-anticancer-agent-synthesis-and-evaluation
#3
Anupriya Adhikari, Neelam Kumari, Manish Adhikari, Nitin Kumar, Anjani K Tiwari, Abha Shukla, Anil K Mishra, Anupama Datta
With the rising incidences of cancer cases, the quest for new metal based anticancer drugs has led to extensive research in cancer biology. Zinc complexes of amino acid residue side chains are well recognized for hydrolysis of phosphodiester bond in DNA at faster rate. In the presented work, a Zn(II) complex of cyclen substituted with two l-tryptophan units, Zn(II)-Cyclen-(Trp)2 has been synthesized and evaluated for antiproliferative activity. Zn(II)-Cyclen-(Trp)2 was synthesized in ∼70% yield and its DNA binding potential was evaluated through QM/MM study which suggested good binding (G=-9...
April 29, 2017: Bioorganic & Medicinal Chemistry
https://www.readbyqxmd.com/read/28487998/effects-of-dietary-l-tryptophan-supplementation-on-intestinal-response-to-chronic-unpredictable-stress-in-broilers
#4
Yunshuang Yue, Yuming Guo, Ying Yang
Stress has been recognized as a critical risk factor for gastrointestinal diseases in both humans and animals. However, nutritional strategies to attenuate stress-induced intestinal barrier function and underlying mechanisms remain largely unknown. This study tested the hypothesis that L-tryptophan enhanced intestinal barrier function by regulating mucosal serotonin metabolism in chronic unpredictable stress-exposed broilers. One-day-old male broilers (Arbor Acres) were fed a basal diet supplemented with or without L-tryptophan in the absence or presence of chronic unpredictable stress...
May 9, 2017: Amino Acids
https://www.readbyqxmd.com/read/28485502/indole-enhances-the-survival-of-pantoea-ananatis-yj76-in-face-of-starvation-conditions
#5
Jing Zheng, Jiajia Yu, Mengqi Jia, Liping Zheng, Yongjun Feng
Pantoea ananatis YJ76 is an indole-producing predominant diazotrophic endophyte isolated from rice having multiple growth-promoting effects on host plant. As a decomposition metabolite of L-tryptophan (L-Trp), indole is confirmed to regulate various physiological processes of bacteria. In this research, we found that indole significantly improves the survival of YJ76 in face of starvation conditions and the promoting effect is related to the glycogen accumulation promoted by indole, which is much more significant in the middle decline phase than in other growth phases...
May 9, 2017: Journal of Basic Microbiology
https://www.readbyqxmd.com/read/28481310/effects-of-melatonin-and-its-analogues-on-pancreatic-inflammation-enzyme-secretion-and-tumorigenesis
#6
REVIEW
Jolanta Jaworek, Anna Leja-Szpak, Katarzyna Nawrot-Porąbka, Joanna Szklarczyk, Michalina Kot, Piotr Pierzchalski, Marta Góralska, Piotr Ceranowicz, Zygmunt Warzecha, Artur Dembinski, Joanna Bonior
Melatonin is an indoleamine produced from the amino acid l-tryptophan, whereas metabolites of melatonin are known as kynuramines. One of the best-known kynuramines is N¹-acetyl-N¹-formyl-5-methoxykynuramine (AFMK). Melatonin has attracted scientific attention as a potent antioxidant and protector of tissue against oxidative stress. l-Tryptophan and kynuramines share common beneficial features with melatonin. Melatonin was originally discovered as a pineal product, has been detected in the gastrointestinal tract, and its receptors have been identified in the pancreas...
May 8, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28473296/crystallographic-analysis-of-the-ternary-complex-of-octanoate-and-n-acetyl-l-methionine-with-human-serum-albumin-reveals-the-mode-of-their-stabilizing-interactions
#7
Akito Kawai, Victor T G Chuang, Yosuke Kouno, Keishi Yamasaki, Shuichi Miyamoto, Makoto Anraku, Masaki Otagiri
During pasteurization and storage of albumin products, Sodium octanoate (Oct) and N-acethyl-L-tryptophan (N-AcTrp) are used as the thermal stabilizer and the antioxidant for human serum albumin (HSA), respectively. We recently reported that N-acethyl-L-methionine (N-AcMet) is an antioxidant for HSA, which is superior to N-AcTrp when it is especially exposed to light during storage. The objective of the present study is to clarify the molecular mechanism responsible for the HSA protective effect of Oct and N-AcMet based on their ternary complex structure...
May 1, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28467025/zinc-coordinated-hierarchical-organization-of-ligand-stabilized-gold-nanoclusters-for-chiral-recognition-supplemented-with-separation
#8
Arun Chattopadhyay, Srestha Basu, Anumita Paul
Three dimensional organization of D or L tryptophan and mercaptopropionic acid stabilized gold nanoclusters has been achieved by complexation reaction involving the ligands stabilizing gold nanoclusters and zinc ions. Powder X ray diffraction and transmission electron microscopy analyses substantiated the crystalline nature of the assembly of atomic nanoclusters. The hierarchical arrangement of the nanoclusters exhibited superior optical properties (namely, enhanced photoluminescence and excited state lifetime) as compared to the non-assembled nanoclusters...
May 3, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28456034/synthesis-and-cytotoxicity-of-a-novel-series-of-saframycin-ecteinascidin-analogs-containing-tetrahydro-%C3%AE-carboline-moieties
#9
Xiangran Lu, Xuan Pan, Ying Yang, Ming Ji, Xiaoguang Chen, Zhiyan Xiao, Zhanzhu Liu
A novel bistetrahydrocarboline heptacyclic skeleton and its twenty derivatives were prepared from l-tryptophan through a 15-step stereospecific route. The cytotoxicities of these compounds were tested against six human cancer cell lines including HCT-116, HepG2, BGC-823, MCF-7, A2780, and HT-29. Most of the derivatives with amide side chain exhibited the IC50 values at the level of 10(-7) M, and a preliminary structure-activity relationship (SAR) was discussed. Both compound 30 with 2-pyridine amide side chain and compound 14 with phthalamide side chain showed the most potent and broad cytotoxicity towards all six cell lines with the IC50 values at the level of 10(-8) M...
April 24, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28450405/unique-and-novel-urinary-metabolomic-features-in-malignant-versus-benign-adrenal-neoplasms
#10
Dhaval Patel, Matthew D Thompson, Soumen K Manna, Kristopher W Krausz, Lisa Zhang, Naris Nilbuol, Frank J Gonzalez, Electron Kebebew
Purpose: <p>Adrenal incidentalomas must be differentiated from adrenocortical cancer (ACC). Currently, size, growth, and imaging characteristics determine the potential for malignancy but are imperfect. The aim was to evaluate whether urinary small molecules (<800 Da) are associated with ACC.</p> <p>Experimental Design:</p> <p>Preoperative fasting urine specimens from patients with ACC (n=19) and benign adrenal tumors (n=46) were analyzed by unbiased ultra performance liquid chromatography/mass spectrometry...
April 27, 2017: Clinical Cancer Research: An Official Journal of the American Association for Cancer Research
https://www.readbyqxmd.com/read/28434742/endocrine-and-metabolic-changes-in-transition-dairy-cows-are-affected-by-prepartum-infusions-of-a-serotonin-precursor
#11
Lorenzo E Hernández-Castellano, Laura L Hernandez, Helga Sauerwein, Rupert M Bruckmaier
Serotonin (5-HT) has been shown to be involved in calcium homeostasis, modulating calcium concentration in blood. In addition, 5-HT participates in a variety of metabolic pathways, mainly through the modulation of glucose and lipid metabolism. The hypothesis of the present study was that the prepartum administration of 5-hydroxy-l-tryptophan (5-HTP), a 5-HT precursor, would affect endocrine systems related to calcium homeostasis, and interact with other endocrine and metabolic pathways during the transition period...
April 20, 2017: Journal of Dairy Science
https://www.readbyqxmd.com/read/28419111/time-resolved-and-label-free-monitoring-of-extracellular-metabolites-by-surface-enhanced-raman-spectroscopy
#12
Victoria Shalabaeva, Laura Lovato, Rosanna La Rocca, Gabriele C Messina, Michele Dipalo, Ermanno Miele, Michela Perrone, Francesco Gentile, Francesco De Angelis
Metabolomics is an emerging field of cell biology that aims at the comprehensive identification of metabolite levels in biological fluids or cells in a specific functional state. Currently, the major tools for determining metabolite concentrations are mass spectrometry coupled with chromatographic techniques and nuclear magnetic resonance, which are expensive, time consuming and destructive for the samples. Here, we report a time resolved approach to monitor metabolite dynamics in cell cultures, based on Surface Enhanced Raman Scattering (SERS)...
2017: PloS One
https://www.readbyqxmd.com/read/28417340/preconditioning-of-primary-human-renal-proximal-tubular-epithelial-cells-without-tryptophan-increases-survival-under-hypoxia-by-inducing-autophagy
#13
Theodoros Eleftheriadis, Georgios Pissas, Maria Sounidaki, Nikolaos Antoniadis, Georgia Antoniadi, Vassilios Liakopoulos, Ioannis Stefanidis
PURPOSE: Hypoxia plays a significant role in the pathogenesis of acute kidney injury (AKI). Autophagy protects from AKI. Amino acid deprivation induces autophagy. The effect of L-tryptophan depletion on survival and autophagy in cultures of renal proximal tubular epithelial cells (RPTECs) under hypoxia was evaluated. METHODS: RPTECs were preconditioned in a medium containing or not tryptophan, following culture under hypoxia and treatment with or without the autophagy inhibitor chloroquine...
April 17, 2017: International Urology and Nephrology
https://www.readbyqxmd.com/read/28416218/dummy-molecularly-imprinted-microbeads-as-solid-phase-extraction-material-for-selective-determination-of-phthalate-esters-in-water
#14
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/28398659/hypaphorine-an-indole-alkaloid-isolated-from-caragana-korshinskii-kom-inhibites-3t3-l1-adipocyte-differentiation-and-improves-insulin-sensitivity-in-vitro
#15
Guangxiang Luan, Fangfang Tie, Zhenzhen Yuan, Gang Li, Jie He, Zhenhua Wang, Honglun Wang
Obesity, a major health problem worldwide, is a complex multifactorial chronic disease that increases the risk for insulin resistance, type 2 diabetes, coronary heart disease and hypertension. In this study, we assessed methods to isolate hypaphorine, a potent drug candidate for obesity and insulin resistance. Semi-preparative reversed-phase liquid chromatography (semi-preparative RPLC) was established as a method to separate three compounds, adenosine, L-tryptophan and hypaphorine, from the crude extracts of Caragana korshinskii Kom...
April 11, 2017: Chemistry & Biodiversity
https://www.readbyqxmd.com/read/28397062/multi-metal-resistance-and-plant-growth-promotion-potential-of-a-wastewater-bacterium-pseudomonas-aeruginosa-and-its-synergistic-benefits
#16
Jayanta Kumar Biswas, Monojit Mondal, Jörg Rinklebe, Santosh Kumar Sarkar, Punarbasu Chaudhuri, Mahendra Rai, Sabry M Shaheen, Hocheol Song, Muhammad Rizwan
Water and soil pollution by toxic heavy metals (HMs) is increasing globally because of increase in population, industrialization and urbanization. It is a burning problem for the public, scientists, academicians and politicians how to tackle the toxic contaminants which jeopardize the environment. One possible solution for pollution abatement is a bioremediation-effective and innovative technology that uses biological systems for treatment of contaminants. Many bacteria synthesize indole-3-acetic acid (IAA) which is a product of L-tryptophan metabolism and belongs to the auxin class of plant growth-promoting hormone...
April 10, 2017: Environmental Geochemistry and Health
https://www.readbyqxmd.com/read/28388167/collective-hydration-dynamics-in-some-amino-acid-solutions-a-combined-ghz-thz-spectroscopic-study
#17
Nirnay Samanta, Debasish Das Mahanta, Samiran Choudhury, Anjan Barman, Rajib Kumar Mitra
A detailed understanding of hydration of amino acids, the building units of protein, is a key step to realize the overall solvation processes in proteins. In the present contribution, we have made a combined GHz (0.2-50) to THz (0.3-2.0) experimental spectroscopic study to investigate the dynamics of water at room temperature in the presence of different amino acids (glycine, L-serine, L-lysine, L-tryptophan, L-arginine, and L-aspartic acid). The THz absorption coefficient, α(ν), of amino acids follows a trend defined by their solvent accessible surface area...
March 28, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28362260/evolution-of-substrate-specificity-in-a-retained-enzyme-driven-by-gene-loss
#18
Ana Lilia Juárez-Vázquez, Janaka N Edirisinghe, Ernesto A Verduzco-Castro, Karolina Michalska, Chenggang Wu, Lianet Noda-García, Gyorgy Babnigg, Michael Endres, Sofía Medina-Ruíz, Julián Santoyo-Flores, Mauricio Carrillo-Tripp, Hung Ton-That, Andrzej Joachimiak, Christopher S Henry, Francisco Barona-Gómez
The connection between gene loss and the functional adaptation of retained proteins is still poorly understood. We apply phylogenomics and metabolic modeling to detect bacterial species that are evolving by gene loss, with the finding that Actinomycetaceae genomes from human cavities are undergoing sizable reductions, including loss of L-histidine and L-tryptophan biosynthesis. We observe that the dual-substrate phosphoribosyl isomerase A or priA gene, at which these pathways converge, appears to coevolve with the occurrence of trp and his genes...
March 31, 2017: ELife
https://www.readbyqxmd.com/read/28357780/targeting-tdo-in-cancer-immunotherapy
#19
REVIEW
Cheng-Peng Yu, Yun-Lei Song, Zheng-Ming Zhu, Bo Huang, Ying-Qun Xiao, Da-Ya Luo
Tryptophan-2,3-dioxygenase (TDO) is a homotetrameric heme-containing protein catalyzing the initial step in the kynurenine pathway, which oxidates the 2,3-double bond of the indole ring in L-tryptophan and catalyzes it into kynurenine (KYN). The upregulation of TDO results in a decrease in tryptophan and the accumulation of KYN and its metabolites. These metabolites can affect the proliferation of T cells. Increasing evidence demonstrates that TDO is a promising therapeutic target in the anti-tumor process...
May 2017: Medical Oncology
https://www.readbyqxmd.com/read/28353092/functional-and-phylogenetic-diversity-of-cultivable-rhizobacterial-endophytes-of-sorghum-sorghum-bicolor-l-moench
#20
Venkadasamy Govindasamy, Susheel Kumar Raina, Priya George, Mahesh Kumar, Jagadish Rane, Paramjit Singh Minhas, Kanuparthy Pandu Ranga Vittal
A diverse group of bacteria colonize the exo- and endo-rhizospheres of sorghum and play a critical role in its tolerance to drought and other abiotic stresses. Two hundred and eighty endophytic bacteria were isolated from the surface-sterilized roots of four sorghum cultivars that were grown on three soil types at three different phenological stages of growth. The isolates were subjected to in vitro screening for their plant growth promoting traits. Out of 280 isolates, 70 could produce Indole 3-Acetic Acid (IAA), 28 showed N-fixation, 28 could solubilize phosphate, 24 had ACC deaminase activity and 13 isolates were able to produce siderophores...
March 28, 2017: Antonie Van Leeuwenhoek
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