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https://www.readbyqxmd.com/read/28526263/n-stearoyl-l-tyrosine-inhibits-the-cell-senescence-and-apoptosis-induced-by-h2o2-in-hek293-tau-cells-via-the-cb2-receptor
#1
Yue Hu, Kai-Yi Zhou, Ze-Jian Wang, Yang Lu, Ming Yin
Although considerable energy and money have been spent trying to inhibit Aβ production and its related metabolic enzyme activities, there are still no drug treatments available to cure even slow for Alzheimer's disease. Therefore, tau protein has been focused recently as the new target for the treatment of Alzheimer's disease. The transfected human embryonic kidney 293 (HEK 293) cells with or without Tau 411 plasmid were used to evaluate the effect of tau protein on cell viability. H2O2 was added to simulate microenvironment of oxidative stress (OS) during aging...
May 16, 2017: Chemico-biological Interactions
https://www.readbyqxmd.com/read/28511681/chromosome-engineering-of-escherichia-coli-for-constitutive-production-of-salvianic-acid-a
#2
Liang Zhou, Qi Ding, Guo-Zhen Jiang, Zhen-Ning Liu, Hai-Yan Wang, Guang-Rong Zhao
BACKGROUND: Salvianic acid A (SAA), a valuable natural product from herbal plant Salvia miltiorrhiza, exhibits excellent antioxidant activities on food industries and efficacious therapeutic potential on cardiovascular diseases. Recently, production of SAA in engineered Escherichia coli was established via the artificial biosynthetic pathway of SAA on the multiple plasmids in our previous work. However, the plasmid-mediated system required to supplement expensive inducers and antibiotics during the fermentation process, restricting scale-up production of SAA...
May 16, 2017: Microbial Cell Factories
https://www.readbyqxmd.com/read/28493648/detection-of-localized-hepatocellular-amino-acid-kinetics-by-using-mass-spectrometry-imaging-of-stable-isotopes
#3
Martijn Arts, Zita Soons, Shane R Ellis, Keely A Pierzchalski, Benjamin Balluff, Gert B Eijkel, Ludwig J Dubois, Natasja G Lieuwes, Stijn M Agten, Tilman M Hackeng, Luc J C van Loon, Ron M A Heeren, Steven W M Olde Damink
Mass spectrometry imaging (MSI) simultaneously detects and identifies the spatial distribution of numerous molecules throughout tissues. Currently, MSI is limited to providing a static and ex vivo snapshot of highly dynamic systems in which molecules are constantly synthesized and consumed. Herein, we demonstrate an innovative MSI methodology to study dynamic molecular changes of amino acids within biological tissues by measuring the dilution and conversion of stable isotopes in a mouse model. We evaluate the method specifically on hepatocellular metabolism of the essential amino acid l-phenylalanine, associated with liver diseases...
May 11, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28477375/oral-l-tyrosine-supplementation-augments-the-vasoconstriction-response-to-whole-body-cooling-in-older-adults
#4
James A Lang, Kevin A Smaller
L-tyrosine is the primary substrate for noradrenaline biosynthesis within sympathetic axon terminals. Under stressful conditions requiring increased catecholamine production, axonal L-tyrosine concentration may limit the full expression of the sympathetic effector response and this may be particularly evident in older adults. We hypothesize that oral L-tyrosine supplementation will increase the sympathetic response to whole-body cooling and muscle metaboreflex activation. In a randomized, double-blind design, eleven young (Y = 24 ± 1 years) and eleven older (O = 68 ± 4 years) participants ingested either 150 mg kg(-1) of L-tyrosine or placebo prior to commencing 30 minutes of whole-body cooling to induce a gradual decline in skin temperature from 34 to 30...
May 5, 2017: Experimental Physiology
https://www.readbyqxmd.com/read/28459864/tyrosinase-inhibitory-activity-molecular-docking-studies-and-antioxidant-potential-of-chemotypes-of-lippia-origanoides-verbenaceae-essential-oils
#5
Alessandra P da Silva, Natália de F Silva, Eloísa Helena A Andrade, Tais Gratieri, William N Setzer, José Guilherme S Maia, Joyce Kelly R da Silva
The essential oils (EOs) of the aerial parts of Lippia origanoides (LiOr), collected in different localities of the Amazon region, were obtained by hydrodistillation and analyzed by GC and CG-MS. Principle component analysis (PCA) based on chemical composition grouped the oils in four chemotypes rich in mono- and sesquiterpenoids. Group I was characterized by 1,8-cineole and α-terpineol (LiOr-1 and LiOr-4) and group II by thymol (LiOr-2). The oil LiOr-3 showed β-caryophyllene, α-phellandrene and β-phellandrene as predominant and LiOr-5 was rich in (E)-nerolidol and β-caryophyllene...
2017: PloS One
https://www.readbyqxmd.com/read/28456625/effects-of-matsutake-mushroom-scent-compounds-on-tyrosinase-and-murine-b16-f10-melanoma-cells
#6
Hiroki Satooka, Philip Cerda, Hae-Jung Kim, William F Wood, Isao Kubo
Tyrosinase-catalyzed l-tyrosine oxidation is a key step in melanogenesis, and intense melanin formation is often a problem in chemotherapies or food preservation. Here we report that methyl cinnamate one of the constituents characterized from mycelium and sporocarp of American matsutake mushroom Tricholoma magnivelare inhibits both enzymatic and cellular melanin formation. Methyl cinnamate inhibits mushroom tyrosinase-catalyzed l-tyrosine oxidation while the oxidation of l-3,4-dihydroxyphenylalanine (l-DOPA) was not inhibited...
June 10, 2017: Biochemical and Biophysical Research Communications
https://www.readbyqxmd.com/read/28445766/inhibitory-effect-of-emulsifiers-in-sedds-on-protease-activity-just-an-illusion
#7
Noemi Lupo, Una Fidahic, Gergely Hetényi, Janine Griesser, Andreas Bernkop-Schnürch
AIM: Evaluation of inhibitory effect of emulsifiers on pancreatic trypsin and α-chymotrypsin. METHODS: The inhibitory effect of Cremophor EL, Cremophor RH 40, Brij O10, Tween 20, polyethylene glycol 8000, polyethylene glycol 400, Carbitol, Pemulen TR-1, Pemulen TR-2, Carbopol Ultrez 20 and Carbopol Ultrez 21 on pancreatic trypsin and α-chymotrypsin was tested. BAEE (Nα-Benzoyl-l-arginine ethyl ester), BTEE (N-Benzoyl-l-tyrosine ethyl ester), casein and insulin were used as substrates for trypsin and α-chymotrypsin...
April 23, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28435719/crystal-structure-of-o-benzyl-l-tyrosine-n-carb-oxy-anhydride
#8
Aya Inada, Hitoshi Kanazawa
In the title compound, C17H15NO4 (alternative name; O-benzyl-l-tyrosine N-carb-oxy anhydride), the oxazolidine ring is planer, with an r.m.s. deviation of 0.039 Å. The benz-yloxy and benzyl rings are almost coplanar, making a dihedral angle of 0.078 (10)°, and are inclined to the oxazolidine ring by 59.16 (11) and 58.42 (11)°, respectively. In the crystal, mol-ecules are linked by N-H⋯O and C-H⋯O hydrogen bonds, forming ribbons propagating along [010]. The ribbons are linked by C-H⋯π inter-actions, forming a three-dimensional supra-molecular structure...
April 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28430025/synthesis-of-dopamine-in-e-coli-using-plasmid-based-expression-system-and-its-marked-effect-on-host-growth-profiles
#9
Arunangshu Das, Anita Verma, Krishna J Mukherjee
L-Dopa and dopamine are important pathway intermediates towards the synthesis of catecholamine like epinephrine and norepinephrine from amino acid L-tyrosine. Dopamine, secreted from dopaminergic nerve cells, serves as an important neurotransmitter. We report the synthesis of dopamine by extending the aromatic amino acid pathway of E.coli DH5α by expression of 4-hydroxyphenylacetate-3-hydrolase (HpaBC) from E.coli and an engineered dopa decarboxylase (DDC) from pig kidney cell. The activity of HpaBC and DDC require 200 µM iron supplementation and 50 µM vitamin B6 respectively as additives to the growth media...
April 21, 2017: Preparative Biochemistry & Biotechnology
https://www.readbyqxmd.com/read/28419111/time-resolved-and-label-free-monitoring-of-extracellular-metabolites-by-surface-enhanced-raman-spectroscopy
#10
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/28418050/reversible-helical-chirality-of-perylene-bisimide-aggregates-amino-acid-directed-chiral-transfer-and-chiral-inversion
#11
Yizhi Liu, Xinpei Gao, Fei Lu, Mei Hu, Lijuan Shi, Liqiang Zheng
Through the formation of dynamic covalent bonds, we succeeded, for the first time, in achieving a reversible chiral transfer from amino acids to perylene bisimide aggregates in aqueous solutions. Two opposite helical aggregations are induced with l-phenylalanine and l-tyrosine, respectively. It is possible that the change in configurations of phenyl groups in amino acids leads to the chiral inversion of BAPBI arrangements.
May 3, 2017: Soft Matter
https://www.readbyqxmd.com/read/28392322/manipulation-of-dopamine-metabolism-contributes-to-attenuating-innate-high-locomotor-activity-in-icr-mice
#12
Takeshi Yamaguchi, Mao Nagasawa, Hiromi Ikeda, Momoko Kodaira, Kimie Minaminaka, Vishwajit S Chowdhury, Shinobu Yasuo, Mitsuhiro Furuse
Attention-deficit hyperactivity disorder (ADHD) is defined as attention deficiency, restlessness and distraction. The main characteristics of ADHD are hyperactivity, impulsiveness and carelessness. There is a possibility that these abnormal behaviors, in particular hyperactivity, are derived from abnormal dopamine (DA) neurotransmission. To elucidate the mechanism of high locomotor activity, the relationship between innate activity levels and brain monoamines and amino acids was investigated in this study. Differences in locomotor activity between ICR, C57BL/6J and CBA/N mice were determined using the open field test...
April 6, 2017: Behavioural Brain Research
https://www.readbyqxmd.com/read/28384480/l-tyrosine-administration-modulates-the-effect-of-transcranial-direct-current-stimulation-on-working-memory-in-healthy-humans
#13
Bryant J Jongkees, Roberta Sellaro, Christian Beste, Michael A Nitsche, Simone Kühn, Lorenza S Colzato
BACKGROUND: Transcranial direct current stimulation (tDCS) is an increasingly popular method of modulating cognitive functions in humans. However, some doubt its efficacy as findings are inconsistent or remain unreplicated. It is speculated dopamine (DA) might play an important role in this inconsistency, by determining the direction and strength of the cognitive-behavioral effects of tDCS. However, so far evidence for this hypothesis has been correlational in nature, precluding definitive conclusions...
March 10, 2017: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
https://www.readbyqxmd.com/read/28381091/differential-off-line-lc-nmr-dolc-nmr-metabolomics-to-monitor-tyrosine-induced-metabolome-alterations-in-saccharomyces-cerevisiae
#14
Richard Hammerl, Oliver Frank, Thomas Hofmann
A novel differential off-line LC-NMR approach (DOLC-NMR) was developed to capture and quantify nutrient-induced metabolome alterations in Saccharomyces cerevisiae. Off-line coupling of HPLC separation and (1)H NMR spectroscopy supported by automated comparative bucket analyses, followed by quantitative (1)H NMR using ERETIC 2 (electronic reference to access in vivo concentrations), has been successfully used to quantitatively record changes in the metabolome of S. cerevisiae upon intervention with the aromatic amino acid l-tyrosine...
April 10, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28338341/natural-product-inhibitors-of-carbonic-anhydrase-i-and-ii-isoenzymes-osajin-and-pomiferin
#15
Esra Dilek, Hüseyin Serkan Erol, Ahmet Cakir, Murat Koc, Mesut Bünyami Halici
The aim of this study is to purify carbonic anhydrase I and II isoenzymes from human erythrocyte, isolate two natural products osajin (OSJ) and pomiferin (PMF) from Maclura pomifera fruits, and evaluate the in vitro effect of these natural metabolites on these isoenzymes. These natural products may be used as starting points for drug discovery (like drugs used in several therapeutic applications, including antiglaucoma activity). For the purification procedure, the Sepharose-4B-l-tyrosine-sulphonamide affinity chromatography was used...
March 24, 2017: Archives of Physiology and Biochemistry
https://www.readbyqxmd.com/read/28335103/correlation-between-gastric-emptying-and-gastric-adaptive-relaxation-influenced-by-amino-acids
#16
Masayuki Uchida, Orie Kobayashi, Chizuru Saito
Background/Aims: Amino acids have many physiological activities. We report the correlation between gastric emptying and gastric adaptive relaxation using tryptophan and amino acids with a straight alkyl chain, hydroxylated chain, and branched chain. Here we sought to further clarify the correlation between gastric emptying and gastric adaptive relaxation by using other amino acids. Methods: In Sprague-Dawley rats, gastric emptying was evaluated by a breath test using [1-¹³C] acetic acid...
March 23, 2017: Journal of Neurogastroenterology and Motility
https://www.readbyqxmd.com/read/28315992/omega-3-fatty-acid-supplementation-decreases-dna-damage-in-brain-of-rats-subjected-to-a-chemically-induced-chronic-model-of-tyrosinemia-type-ii
#17
Milena Carvalho-Silva, Lara M Gomes, Giselli Scaini, Joyce Rebelo, Adriani P Damiani, Maiara Pereira, Vanessa M Andrade, Fernanda F Gava, Samira S Valvassori, Patricia F Schuck, Gustavo C Ferreira, Emilio L Streck
Tyrosinemia type II is an inborn error of metabolism caused by a mutation in a gene encoding the enzyme tyrosine aminotransferase leading to an accumulation of tyrosine in the body, and is associated with neurologic and development difficulties in numerous patients. Because the accumulation of tyrosine promotes oxidative stress and DNA damage, the main aim of this study was to investigate the possible antioxidant and neuroprotective effects of omega-3 treatment in a chemically-induced model of Tyrosinemia type II in hippocampus, striatum and cerebral cortex of rats...
March 18, 2017: Metabolic Brain Disease
https://www.readbyqxmd.com/read/28299546/combinatorial-analysis-of-enzymatic-bottlenecks-of-l-tyrosine-pathway-by-p-coumaric-acid-production-in-saccharomyces-cerevisiae
#18
Jiwei Mao, Quanli Liu, Xiaofei Song, Hesuiyuan Wang, Hui Feng, Haijin Xu, Mingqiang Qiao
OBJECTIVE: To identify new enzymatic bottlenecks of L-tyrosine pathway for further improving the production of L-tyrosine and its derivatives. RESULT: When ARO4 and ARO7 were deregulated by their feedback resistant derivatives in the host strains, the ARO2 and TYR1 genes, coding for chorismate synthase and prephenate dehydrogenase were further identified as new important rate-limiting steps. The yield of p-coumaric acid in the feedback-resistant strain overexpressing ARO2 or TYR1, was significantly increased from 6...
March 15, 2017: Biotechnology Letters
https://www.readbyqxmd.com/read/28291661/evaluation-of-a-novel-system-for-analyzing-hydrophilic-blood-metabolites
#19
Shin Nishiumi, Keisuke Shima, Takeshi Azuma, Masaru Yoshida
Metabolomics has recently been developed, and there have been a considerable number of metabolomics-based biomarker studies in the medical research field. Therefore, as a first step toward the practical use of metabolite biomarkers, a simple and quick sample preparation method involving metabolite extraction, metabolite measurement, and data analysis needs to be developed. In this study, we evaluated whether the use of simpler metabolite extraction methods would facilitate the stable analysis of hydrophilic blood metabolites during liquid chromatography/triple quadrupole mass spectrometry (LC/QqQMS)-based metabolome analysis...
March 10, 2017: Journal of Bioscience and Bioengineering
https://www.readbyqxmd.com/read/28290392/potential-for-differentiation-of-glioma-recurrence-from-radionecrosis-using-integrated-18-f-fluoroethyl-l-tyrosine-fet-positron-emission-tomography-magnetic-resonance-imaging-a-prospective-evaluation
#20
Shanti K Sogani, Amarnath Jena, Sangeeta Taneja, Aashish Gambhir, Anil K Mishra, Maria M D'Souza, Sapna M Verma, Puja P Hazari, Pradeep Negi, Ganesh K R Jadhav
PURPOSE: To assess the utility of 18F-fluoroethyl-L-tyrosine (FET) positron emission tomography/magnetic resonance imaging (PET/MRI) in distinguishing recurrence from radionecrosis. MATERIALS AND METHODS: Thirty-two patients (25 males, 7 females) of glioma who had already undergone surgery/chemoradiotherapy and had enhancing brain lesions suspicious of recurrence were evaluated using integrated 18F-FET PET/MRI, and followed up with histopathology or clinical follow-up and/or MRI/PET/MRI imaging...
March 2017: Neurology India
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