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https://www.readbyqxmd.com/read/29442259/lc-ms-based-serum-metabolomics-reveals-a-distinctive-signature-in-patients-with-rheumatoid-arthritis
#1
Ju Li, Nan Che, Lingxiao Xu, Qian Zhang, Qi Wang, Wenfeng Tan, Miaojia Zhang
Metabolomics has been applied to explore altered metabolite profiles in disease and identify unique metabolic signatures in recent years. We aim to characterize the metabolic profile of rheumatoid arthritis patients and explore its underlying pathological processes using metabolomics approach. Serum samples from 30 rheumatoid arthritis (RA) patients, 30 primary Sjogren's syndrome (pSS) patients, and 32 healthy controls (HC) were collected. The sample was analyzed by ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UPLC-HRMS)...
February 13, 2018: Clinical Rheumatology
https://www.readbyqxmd.com/read/29433247/effect-of-different-buffer-systems-on-the-xanthine-oxidase-inhibitory-activity-of-tuna-katsuwonus-pelamis-protein-hydrolysate
#2
Guowan Su, Weiwei He, Mouming Zhao, Geoffrey I N Waterhouse, Dongxiao Sun-Waterhouse
This study systematically explored the effect of HEPES, Tris and sodium phosphate (PB) buffers on the xanthine oxidase (XO) inhibitory activity of tuna protein hydrolysate (TPH, containing over 90% of constituents with molecular weight below 5kDa). The greatest XO inhibition by TPH was observed in HEPES buffer. The optimal HEPES concentration was 100mmol/L. Tryptophan fluorescence and circular dichroism measurements revealed the comparable stability of XO and TPH in the three buffers. The buffers did not alter the majority of XO or TPH structure but induced slight modifications to specific domains (e...
March 2018: Food Research International
https://www.readbyqxmd.com/read/29433005/cytotoxic-activity-and-structural-features-of-ru-ii-phosphine-amino-acid-complexes
#3
Edjane R Dos Santos, Angelica E Graminha, Mario S Schultz, Isabel Correia, Heloisa S Selistre-de-Araújo, Rodrigo S Corrêa, Javier Ellena, Elisângela de Paula S Lacerda, João Costa Pessoa, Alzir A Batista
Thirteen new ruthenium amino acid complexes were synthesized and characterized. They were obtained by the reaction of α-amino acids (AA) with [RuCl2(P-P)(N-N)], where P-P=1,4-bis(diphenylphosphino)butane (dppb) or 1,3-bis(diphenylphosphino)propane (dppp) and N-N=4,4'-dimethyl-2,2'-bipyridine (4'-Mebipy), 5,5'-dimethyl-2,2'-bipyridine (5'-Mebipy) or 4,4'-Methoxy-2-2'-bipyridine (4'-MeObipy). This afforded a family of complexes formulated as [Ru(AA-H)(P-P)(N-N)]PF6, where AA=glycine (Gly), L-alanine (Ala), L-valine (Val), L-tyrosine (Tyr), L-tryptophan (Trp), L-histidine (His) and L-methionine (Met)...
December 23, 2017: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/29426665/phenotypic-genetic-and-symbiotic-characterization-of-erythrina-velutina-rhizobia-from-caatinga-dry-forest
#4
Dalila Ribeiro Rodrigues, Aleksandro Ferreira da Silva, Maria Idaline Pessoa Cavalcanti, Indra Elena Costa Escobar, Ana Carla Resende Fraiz, Paula Rose de Almeida Ribeiro, Reginaldo Alves Ferreira Neto, Ana Dolores Santiago de Freitas, Paulo Ivan Fernandes-Júnior
Erythrina velutina ("mulungu") is a legume tree from Caatinga that associates with rhizobia but the diversity and symbiotic ability of "mulungu" rhizobia are poorly understood. The aim of this study was to characterize "mulungu" rhizobia from Caatinga. Bacteria were obteined from Serra Talhada and Caruaru in Caatinga under natural regeneration. The bacteria were evaluated to the amplification of nifH and nodC and to metabolic characteristics. Ten selected bacteria identified by 16S rRNA sequences. They were tested in vitro to NaCl and temperature tolerance, auxin production and calcium phosphate solubilization...
February 2, 2018: Brazilian Journal of Microbiology: [publication of the Brazilian Society for Microbiology]
https://www.readbyqxmd.com/read/29412935/chirality-detection-of-amino-acid-enantiomers-by-organic-electrochemical-transistor
#5
Lijun Zhang, Guiheng Wang, Can Xiong, Lei Zheng, Jianbo He, Yunsheng Ding, Hongbo Lu, Guobing Zhang, Kilwon Cho, Longzhen Qiu
Chiral recognition of α-amino acids is attracting increasing interest due to the importance of α-amino acids in protein metabolism as well as in food products and pharmaceuticals. Organic electrochemical transistors (OECTs) with gate electrodes modified with molecularly imprinted polymer (MIP) films were fabricated and successfully used as highly selective and sensitive chiral recognition biosensors for d/l-tryptophan (d/l-Trp) and d/l-tyrosine (d/l-Tyr). The MIP films, which can specifically recognize and has an electrocatalytic effect on the oxidation of Trp and Tyr, together with the amplification function of an OECT, provide a highly sensitive and selective OECT biosensor...
May 15, 2018: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/29412668/total-synthesis-of-ecumicin
#6
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/29368666/tryptophan-supplementation-and-serotonin-function-genetic-variations-in-behavioural-effects
#7
E L Gibson
The neurotransmitter serotonin has a role in affective disorders such as depression and anxiety, as well as sleep, cognitive function and appetite. This review examines the evidence that serotonin-related genotypes may moderate the behavioural effects of supplementation with the serotonin precursor amino acid l-tryptophan (TRP), on which synthesis of serotonin (or 5-hydroxytryptamine; 5-HT) depends. However, 95 % of serotonin is synthesised and used in the periphery, and TRP is also metabolised via non-5-HT routes such as the kynurenine pathway...
January 25, 2018: Proceedings of the Nutrition Society
https://www.readbyqxmd.com/read/29363948/electrochemical-sensor-coating-based-on-electrophoretic-deposition-of-au-doped-self-assembled-nanoparticles
#8
Rongli Zhang, Ye Zhu, Jing Huang, Sheng Xu, Jing Luo, Xiaoya Liu
Electrophoretic deposition (EPD) of self-assembled nanoparticles (NPs) on the surface of electrode is a new strategy for preparing sensor coating. Through simply changing the deposition conditions, the electrochemical response for analyte of deposited NPs-based coating can be controlled. This advantage can decrease the difference between different batches of sensor coating and ensure the reproducibility of each sensor. This paper investigated the effects of deposition conditions (including deposition voltage, pH value of suspension and deposition time) on the structure and the electrochemical response for L-tryptophan of sensor coating formed from Au doped poly(sodium γ-glutamate) with pendant dopamine units nanohybrids (Au/γ-PGA-DA NBs) via EPD method...
January 24, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29350728/dual-chain-extension-effect-and-antibacterial-properties-of-biomolecules-interleaved-within-ldh-dispersed-into-pbs-by-in-situ-polymerization
#9
Grazia Totaro, Laura Sisti, Annamaria Celli, Irene Aloisio, Diana Di Gioia, Adam A Marek, Vincent Verney, Fabrice Leroux
Nanocomposites based on poly(butylene succinate) (PBS) and hydrotalcite-type anionic clays (HTs) organo-modified with biomolecules characterized by antibacterial and/or antioxidant activities, such as l-ascorbic acid (ASA), phloretic acid (HPP), l-tyrosine (TYR) and l-tryptophan (TRP), have been prepared by in situ polymerization. From XRD analysis and rheology experiments in a molten polymer state, intercalated HT hybrid platelets acting here as a hybrid filler are found to be well dispersed into polymers while providing a chain extension effect on PBS...
January 19, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29340478/the-long-and-successful-journey-of-electrochemically-active-amino-acids-from-fundamental-adsorption-studies-to-potential-surface-engineering-tools
#10
André H B Dourado, Fabián C Pastrián, Susana I Córdoba DE Torresi
Proteins have been the subject of electrochemical studies. It is possible to apply electrochemical techniques to obtain information about their structure due to the presence of five electroactive amino acids that can be oriented to the outside of the peptidic chain. These amino acids are L-Tryptophan (L-Trp), L-Tyrosine (L-Tyr), L-Histidine (L-His), L-Methionine (L-Met) and L-Cysteine (L-Cys); their electrochemical behavior being subject of extensive research, but it is still controversial. No spectroscopic investigations have been reported on L-Trp, and due to the short life time of the intermediates, ex situ techniques cannot be employed, leading to a never-ending discussion about possible intermediates...
January 11, 2018: Anais da Academia Brasileira de Ciências
https://www.readbyqxmd.com/read/29339338/the-phytotoxicities-of-decabromodiphenyl-ether-bde-209-to-different-rice-cultivars-oryza-sativa-l
#11
Kelun Li, Jie Chen, Lizhong Zhu
Decabromodiphenyl ether (BDE-209), as a major component of brominated flame retardants, has been detected in the agricultural soil in considerable amount. Given that BDE-209 is toxic, ubiquitous and persistent, BDE-209 might induce toxic effects on rice cultivars planted in contaminated soil. A comparative study was conducted on phytotoxicities and GC-MS based antioxidant-related metabolite levels to investigate the differences of phytotoxicities of BDE-209 to rice cultivars in Yangtze River Delta of China...
January 12, 2018: Environmental Pollution
https://www.readbyqxmd.com/read/29331348/effects-of-l-tryptophan-on-the-growth-intestinal-enzyme-activities-and-non-specific-immune-response-of-sea-cucumber-apostichopus-japonicus-selenka-exposed-to-crowding-stress
#12
Endong Zhang, Shuanglin Dong, Fang Wang, Xiangli Tian, Qinfeng Gao
In order to reveal the effects of l-tryptophan (Trp) on the physiology and immune response of sea cucumber (Apostichopus japonicus Selenka) exposed to crowding stress, four density groups of sea cucumbers (i.e. 4, 8, 16 and 32 individuals per 40 L water, represented as L, ML, MH and H) were fed with diets containing 0, 1, 3 and 5% l-tryptophan respectively for 75 days. The results showed that the specific growth rates (SGR) of the sea cucumber fed with diet with 3% Trp (L, 2.1; ML, 1.76; MH, 1.2; H, 0.7) were significantly higher than those fed with basal diet without Trp supplementation (P < ...
January 10, 2018: Fish & Shellfish Immunology
https://www.readbyqxmd.com/read/29327587/conformational-impact-on-amino-acid-surface-%C3%AF-%C3%AF-interactions-on-a-7-7-single-walled-carbon-nanotube-a-molecular-mechanics-approach
#13
Linda Grabill, Andreas Riemann
A study of π-π interactions between a (7,7) single-walled carbon nanotube (SWNT) and three different aromatic amino acids (AAA), namely L-Tyrosine (Tyr), L-Tryptophan (Trp), and L-Phenylalanine (Phe) was conducted with a Molecular Mechanics (MM) approach. For each of the amino acids we investigated the behavior of six different conformers. We examined the impact of the so-called edge effects by testing the parameters of the built-in switching function in MM. We found the optimal SWNT length to be approximately 80Å for the size of the molecules in our conformational studies...
January 12, 2018: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/29316507/the-%C3%AE-carbonic-anhydrase-from-the-pathogenic-bacterium-vibrio-cholerae-is-potently-activated-by-amines-and-amino-acids
#14
Andrea Angeli, Sonia Del Prete, William A Donald, Clemente Capasso, Claudiu T Supuran
The γ-class carbonic anhydrase (CAs, EC 4.2.1.1) from the pathogenic bacterium Vibrio cholerae, VchCAγ, was investigated for its activation with a panel of natural and non-natural amino acids and amines. The enzyme was effectively activated by l-tryptophan, 1-(2-minoethyl)-piperazine and 4-(2-aminoethyl)-morpholine, in the low nanomolar range (KAs 8-71 nM). In contrast, l-/d-Phe, l-/d-DOPA, d-Trp, l-/d-Tyr, 4-amino-l-Phe, histamine, dopamine, serotonin, some pyridyl-alkylamines, as well as l-adrenaline were submicromolar activators (KAs between 0...
January 4, 2018: Bioorganic Chemistry
https://www.readbyqxmd.com/read/29302832/a-fluorescent-sensor-of-3-aminobenzeneboronic-acid-functionalized-hydrothermal-carbon-spheres-for-facility-detection-of-l-tryptophan
#15
Rui Zhang, Li-Xia Wang, Yun-Di Zhang, Chun-Hua Ge, Jia-Ping Wang, Ying Zhang, Xiang-Dong Zhang
In the paper, hydrothermal carbon spheres (HTCs) are functionalized by the 3-aminobenzeneboronic acid (3-APBA) as a fluorescence sensor. The modification carbon spheres (3-APBA-HTCs) have shown excellent selectivity and sensitivity for efficient determination of L-tryptophan (L-Trp). The fluorescence sensor can selectively achieve the "On-Off" switchable functionality for L-Trp at an extremely low detection limit of 0.50 × 10- 5 mol/L.
January 4, 2018: Journal of Fluorescence
https://www.readbyqxmd.com/read/29302770/modulating-tumor-immunology-by-inhibiting-indoleamine-2-3-dioxygenase-ido-recent-developments-and-first-clinical-experiences
#16
Diwakar Davar, Nathan Bahary
Indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) catalyze the first rate-limiting step in the oxidative metabolism of compounds containing indole rings, including the transformation of the essential amino acid L-tryptophan to N-formyl-L-kynurenine. Through direct and indirect means, IDO exerts both tolerogenic and pro-inflammatory effects and has a profound immunoregulatory role in the tumor microenvironment. Although the role of IDO in mediating peripheral acquired immunologic tolerance has been known for some time, its role in tumorigenesis and the subversion of anti-tumor immunity have only recently been appreciated...
January 4, 2018: Targeted Oncology
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
#17
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/29299913/tracking-hyaluronan-molecularly-imprinted-polymer-coated-carbon-dots-for-cancer-cell-targeting-and-imaging
#18
Bilal Demir, Michael Lemberger, Maria Panagiotopoulou, Paulina Medina-Rangel, Suna Timur, Thomas Hirsch, Bernadette Tse Sum Bui, Joachim Wegener, Karsten Haupt
War against cancer constantly requires new affinity tools to selectively detect, localize and quantify biomarkers for diagnosis or prognosis. Herein, carbon nanodots (CDs), an emerging class of fluorescent nanomaterials, coupled with molecularly imprinted polymers (MIPs), are employed as a biocompatible optical imaging tool for probing cancer biomarkers. First, N-doped CDs were prepared by hydrothermal synthesis using starch as carbon source, and L-tryptophan as nitrogen atom provider to achieve a high quantum yield of (25...
January 4, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29288638/a-single-amino-acid-residue-regulates-the-substrate-affinity-and-specificity-of-indoleamine-2-3-dioxygenase
#19
Hajime J Yuasa, Mayumi Sugiura, Terue Harumoto
Indoleamine 2,3-dioxygenase (IDO) is a heme-containing enzyme that catalyses the oxidative cleavage of L-Trp. The ciliate Blepharisma stoltei has four IDO genes (IDO-I, -II, -III and -IV), which seem to have evolved via two sequential gene duplication events. Each IDO enzyme has a distinct enzymatic property, where IDO-III ha-s a high affinity for L-Trp, whereas the affinity of the other three isoforms for L-Trp is low. IDO-I also exhibits a significant catalytic activity with another indole compound: 5-hydroxy-L-tryptophan (5-HTP)...
December 27, 2017: Archives of Biochemistry and Biophysics
https://www.readbyqxmd.com/read/29284209/calcium-sensing-receptor-mediated-l-tryptophan-induced-secretion-of-cholecystokinin-and-glucose-dependent-insulinotropic-peptide-in-swine-duodenum
#20
Xiuying Zhao, Yihan Xian, Chao Wang, Liren Ding, Xianglong Meng, Weiyun Zhu, Suqin Hang
This study aimed to understand the effect of Tryptophan (Trp) on gut hormones secretion as well as the roles of the CaSR and its downstream signaling pathway in gut hormones secretion using swine duodenal perfusion in vitro. Swine duodenum was perfused with Krebs-Henseleit buffers (KHB) as a basal solution. Various concentrations (0, 10 mM and 20 mM) of Trp were applied to investigate the effect of Trp on gut hormones secretion. A CaSR antagonist was used to detect the involvement of CaSR and its signal molecules...
December 28, 2017: Journal of Veterinary Science
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