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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
#1
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
#2
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
#3
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.
April 18, 2017: Soft Matter
https://www.readbyqxmd.com/read/28392322/manipulation-of-dopamine-metabolism-contributes-to-attenuating-innate-high-locomotor-activity-in-icr-mice
#4
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
#5
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
#6
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
#7
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
#8
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
#9
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
#10
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
#11
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
#12
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
https://www.readbyqxmd.com/read/28276711/an-alternative-purification-method-for-human-serum-paraoxonase-1-and-its-interaction-with-methidathion
#13
Nahit Gençer, Emre Yavuz
In this study, an alternative purification method for human Paraoxonase 1 (hPON1) enzyme was developed using two-step procedures, namely ammonium sulphate precipitation and Sepharose-4B-L-tyrosine-1-aminoanthracene hydrophobic interaction chromatography. SDS-polyacrylamide gel electrophoresis of the enzyme indicates a single band with an apparent MW of 43 kDa. The enzyme was purified 674-fold with a yield of 16%. Furthermore, we examined the in vitro effect of methidathion on the enzyme activity to understand the better inhibitory properties of the compound...
February 14, 2017: Archives of Physiology and Biochemistry
https://www.readbyqxmd.com/read/28236182/endoscopic-management-of-a-low-grade-thalamic-glioma-a-safe-alternative-to-open-microsurgery
#14
Benjamin Brokinkel, Murat Yavuz, Nils Warneke, Angela Brentrup, Katharina Hess, Caroline Bleimüller, Johannes Wölfer, Walter Stummer
BACKGROUND: Despite considerable advances in preoperative and intraoperative imaging and neuronavigation, resection of thalamic gliomas remains challenging. Although both endoscopic biopsy and third ventriculostomy (ETV) for the treatment of secondary hydrocephalus are commonly performed, endoscopic resection of thalamic gliomas has been very sparsely described. METHOD: We report and illustrate the surgical procedure and patient's outcome after full endoscopic resection of a thalamic glioma and to discuss this approach as an alternative to open microsurgery...
February 24, 2017: Acta Neurochirurgica
https://www.readbyqxmd.com/read/28204572/o-2-18f-fluoroethyl-l-tyrosine-pet-for-evaluation-of-brain-metastasis-recurrence-after-radiotherapy-an-effectiveness-and-cost-effectiveness-analysis
#15
Alexander Heinzel, Dirk Müller, Sareh Said Yekta-Michael, Garry Ceccon, Karl-Josef Langen, Felix M Mottaghy, Martin Wiesmann, Martin Kocher, Elke Hattingen, Norbert Galldiks
No abstract text is available yet for this article.
February 13, 2017: Neuro-oncology
https://www.readbyqxmd.com/read/28202018/de-novo-biosynthesis-of-pterostilbene-in-an-escherichia-coli-strain-using-a-new-resveratrol-o-methyltransferase-from-arabidopsis
#16
Kyung Taek Heo, Sun-Young Kang, Young-Soo Hong
BACKGROUND: Pterostilbene, a structural analog of resveratrol, has higher oral bioavailability and bioactivity than that of the parent compound; but is far less abundant in natural sources. Thus, to efficiently obtain this bioactive resveratrol analog, it is necessary to develop new bioproduction systems. RESULTS: We identified a resveratrol O-methyltransferase (ROMT) function from a multifunctional caffeic acid O-methyltransferase (COMT) originating from Arabidopsis, which catalyzes the transfer of a methyl group to resveratrol resulting in pterostilbene production...
February 15, 2017: Microbial Cell Factories
https://www.readbyqxmd.com/read/28192140/action-of-2-2-4-4-tetrahydroxybenzophenone-in-the-biosynthesis-pathway-of-melanin
#17
Antonio Garcia-Jimenez, Jose Antonio Teruel-Puche, Pedro Antonio Garcia-Ruiz, Jose Berna, Jose Neptuno Rodríguez-López, Jose Tudela, Francisco Garcia-Canovas
2,2',4,4'-tetrahydroxybenzophenone (Uvinul D50), a sunscreen used in cosmetics, has two effects in the melanin biosynthesis pathway. On the one hand, it acts a weak inhibitor of tyrosinase and on the other, it accelerates the conversion of dopachrome to melanin. Uvinul D50 was seen to behave as a weak competitive inhibitor: apparent constant inhibition=2.02±0.09mM and IC50=3.82±0.39mM established in this work. These values are higher than those in the bibliography, which tend to be undersetimated. This discrepancy could be explained by the reaction of Uvinul D50 with the dopachrome produced from l-tyrosine or l-dopa, which would interfere in the measurement...
May 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28187333/localization-of-cl-35-nuclei-in-biological-solids-using-rotational-echo-double-resonance-experiments
#18
D Iuga, P Rossi, J Herzfeld, R G Griffin
Chloride ions play important roles in many chemical and biological processes. This paper investigates the possibility of localizing (35)Cl nuclei using solid-state NMR. It demonstrates that distances shorter than 3.8Å, between (13)C atoms and (35)Cl atoms in 10% uniformly labeled (13)C L-tyrosine·HCl and natural abundance Glycine·HCl can be measured using rotational-echo (adiabatic passage) double-resonance (RE(AP)DOR). Furthermore the effect of quadrupolar interaction on the REDOR/REAPDOR experiment is quantified...
April 2017: Solid State Nuclear Magnetic Resonance
https://www.readbyqxmd.com/read/28153956/influence-of-bevacizumab-on-blood-brain-barrier-permeability-and-o-2-18f-fluoroethyl-l-tyrosine-uptake-in-rat-gliomas
#19
Carina Stegmayr, Dennis Oliveira, Nicole Niemietz, Antje Willuweit, Philipp Lohmann, Norbert Galldiks, N Jon Shah, Johannes Ermert, Karl-Josef Langen
PURPOSE: Restoration of the blood-brain barrier (BBB) following antiangiogenic therapy of gliomas using Bevacizumab may result in a decrease of contrast enhancement in magnet resonance imaging (MRI) despite tumor progression. This so called pseudoresponse is difficult to differentiate from true tumor response with conventional MRI. First patient studies have indicated that positron emission tomography (PET) using O-(2-(18)F-fluoroethyl)-L-tyrosine ((18)F-FET) may be helpful to solve this diagnostic problem...
February 2, 2017: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
https://www.readbyqxmd.com/read/28150904/rationally-developed-organic-salts-of-tolfenamic-acid-and-its-%C3%AE-alanine-derivatives-for-dual-purposes-as-an-anti-inflammatory-topical-gel-and-anticancer-agent
#20
Rumana Parveen, Bommagani Sravanthi, Parthasarathi Dastidar
A new series of primary ammonium monocarboxylate (PAM) salts of a nonsteroidal anti-inflammatory drug (NSAID), namely, tolfenamic acid (TA), and its β-alanine derivatives were generated. Nearly 67 % of the salts in the series showed gelling abilities with various solvents, including water (biogenic solvent) and methyl salicylate (typically used for topical gel formulations). Gels were characterized by rheology, electron microscopy, and so forth. Structure-property correlations based on single-crystal and powder XRD data of several gelator and nongelator salts revealed intriguing insights...
February 2, 2017: Chemistry, An Asian Journal
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