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l-tryptophan

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https://www.readbyqxmd.com/read/28633643/enhancement-of-thermoalkaliphilic-xylanase-production-by-pichia-pastoris-through-novel-fed-batch-strategy-in-high-cell-density-fermentation
#1
Tingting Shang, Dayong Si, Dongyan Zhang, Xuhui Liu, Longmei Zhao, Cong Hu, Yu Fu, Rijun Zhang
BACKGROUND: Xylanase degrades xylan into monomers of various sizes by catalyzing the endohydrolysis of the 1,4-β-D-xylosidic linkage randomly, possessing potential in wide industrial applications. Most of xylanases are susceptible to be inactive when suffering high temperature and high alkaline process. Therefore, it is necessary to develop a high amount of effective thermoalkaliphilic xylanases. This study aims to enhance thermoalkaliphilic xylanase production in Pichia pastoris through fermentation parameters optimization and novel efficient fed-batch strategy in high cell-density fermentation...
June 21, 2017: BMC Biotechnology
https://www.readbyqxmd.com/read/28625179/dietary-l-tryptophan-leaves-a-lasting-impression-on-the-brain-and-the-stress-response
#2
Erik Höglund, Øyvind Øverli, Madelene Å Andersson, Patricia Silva, Danielle Caroline Laursen, Maria M Moltesen, Åshild Krogdahl, Joachim Schjolden, Svante Winberg, Marco A Vindas, Ian Mayer, Marie Hillestad
Comparative models suggest that effects of dietary tryptophan (Trp) on brain serotonin (5-hydroxytryptamine; 5-HT) neurochemistry and stress responsiveness are present throughout the vertebrate lineage. Moreover, hypothalamic 5-HT seems to play a central role in control of the neuroendocrine stress axis in all vertebrates. Still, recent fish studies suggest long-term effects of dietary Trp on stress responsiveness, which are independent of hypothalamic 5-HT. Here, we investigated if dietary Trp treatment may result in long-lasting effects on stress responsiveness, including changes in plasma cortisol levels and 5-HT neurochemistry in the telencephalon and hypothalamus of Atlantic salmon...
June 19, 2017: British Journal of Nutrition
https://www.readbyqxmd.com/read/28622378/gene-modification-of-the-acetate-biosynthesis-pathway-in-escherichia-coli-and-implementation-of-the-cell-recycling-technology-to-increase-l-tryptophan-production
#3
Qingyang Xu, Fang Bai, Ning Chen, Gang Bai
The implementation of a novel cell recycling technology based on a special disk centrifuge during microbial fermentation process can continuously separate the product and harmful intermediates, while maintaining the cell viability owing to the installed cooling system. Acetate accumulation is an often encountered problem in L-tryptophan fermentation by Escherichia coli. To extend our previous studies, the current study deleted the key genes underlying acetate biosynthesis to improve l-tryptophan production...
2017: PloS One
https://www.readbyqxmd.com/read/28611277/association-of-rasgrf1-methylation-with-epileptic-seizures
#4
Xiaoni Chen, Xi Peng, Liang Wang, Xinwei Fu, Ji Xiu Zhou, Binglin Zhu, Jing Luo, Xuefeng Wang, Zheng Xiao
DNA methylation, one of the mechanisms of epigenetic regulation, has been suggested to be related with epilepsy. RASgrf1 is a paternally imprinted gene and has a differentially methylated region (DMR) at the promoter that can silence gene expression. We have previously observed the down-regulation of RASgrf1 in the temporal neocortex of epilepsy patients and in the hippocampus of epileptic animals. Here, we further explored the dynamic change (1-day acute period, 10-day latent period and 45-day chronic phase) of DNA methylation and RASgrf1 expression after acute epileptic seizures in kainic acid (KA)-treated mice, and we observed the impact of N-phthalyl-L-tryptophan (RG108), a DNA methyltransferase (DNMT) inhibitor, on an acute epileptic model by polymerase chain reaction (PCR), western blotting, and bisulfite sequencing PCR (BSP)...
May 19, 2017: Oncotarget
https://www.readbyqxmd.com/read/28599706/quantitative-chiral-analysis-of-amino-acids-in-solution-using-enantiomer-selective-photodissociation-of-cold-gas-phase-tryptophan-via-chiral-recognition
#5
Akimasa Fujihara, Naoto Maeda
To explore the origin of biomolecule homochirality in interstellar molecular clouds, enantiomer-selective photodissociation via chiral recognition between amino acids in the gas phase was examined using a tandem mass spectrometer containing an electrospray ionization source and a cold ion trap. Ultraviolet photodissociation mass spectra of cold gas-phase noncovalent complexes of sodiated l-tryptophan ion, Na(+)(l-Trp), with an amino acid such as serine (Ser), threonine (Thr), or alanine (Ala) were obtained by the photo-excitation of l-Trp in the noncovalent complexes...
August 1, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28585544/serotonin-modulates-a-depression-like-state-in-drosophila-responsive-to-lithium-treatment
#6
Ariane-Saskia Ries, Tim Hermanns, Burkhard Poeck, Roland Strauss
Major depressive disorder (MDD) affects millions of patients; however, the pathophysiology is poorly understood. Rodent models have been developed using chronic mild stress or unavoidable punishment (learned helplessness) to induce features of depression, like general inactivity and anhedonia. Here we report a three-day vibration-stress protocol for Drosophila that reduces voluntary behavioural activity. As in many MDD patients, lithium-chloride treatment can suppress this depression-like state in flies. The behavioural changes correlate with reduced serotonin (5-HT) release at the mushroom body (MB) and can be relieved by feeding the antidepressant 5-hydroxy-L-tryptophan or sucrose, which results in elevated 5-HT levels in the brain...
June 6, 2017: Nature Communications
https://www.readbyqxmd.com/read/28554057/the-immune-regulation-in-cancer-by-the-amino-acid-metabolizing-enzymes-arg-and-ido
#7
REVIEW
Giada Mondanelli, Stefano Ugel, Ursula Grohmann, Vincenzo Bronte
Some enzymes degrading amino acids have evolved in mammals to dampen immune responses and maintain peripheral tolerance. The enzymes metabolizing l-arginine and l-tryptophan are particularly powerful, contributing to restrain immunity towards fetal tissues and establish neonatal tolerance. Solid tumors can hijack these formidable pathways to construct a microenvironment highly unfavorable to anti-tumor T lymphocytes able to recognize them, one of mechanisms for their immune evasion. In this review, we analyze emerging concepts in the cross-talk between cells expressing these enzymes, their immune regulatory functions and pharmacological approaches that can target them to enhance cancer immunotherapy...
May 26, 2017: Current Opinion in Pharmacology
https://www.readbyqxmd.com/read/28549738/direct-actions-of-macronutrient-components-on-goldfish-hepatopancreas-in-vitro-to-modulate-the-expression-of-ghr-i-ghr-ii-igf-i-and-igf-ii-mrnas
#8
Juan Ignacio Bertucci, Ayelén Melisa Blanco, Luis Fabián Canosa, Suraj Unniappan
In mammals and fish, somatic growth and metabolism are coordinated by the GH-IGF axis, composed of growth hormone (GH), growth hormone receptors I and II (GHR-I and GHR-II), and the insulin-like growth factors I and II (IGF-I and IGF-II). In order to determine if dietary macronutrients regulate the hepatopancreatic expression of ghr-I, ghr-II, igf-I and igf-II independently of circulating GH, organ culture experiments were conducted. Briefly, goldfish hepatopancreas sections were incubated with different doses of glucose; L-tryptophan; oleic acid; linolenic acid (LNA); eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)...
May 24, 2017: General and Comparative Endocrinology
https://www.readbyqxmd.com/read/28540509/short-term-supplementation-of-isocaloric-meals-with-l-tryptophan-affects-pig-growth
#9
H N Liu, C-A A Hu, M M Bai, Gang Liu, M C B Tossou, K Xu, F N Li, P Liao, X F Kong, X Wu, Y L Yin
L-Tryptophan (Trp) and some of its metabolites regulate the circadian rhythm in mammals. We aimed to investigate the effects of short-term supplementation of Trp in isocaloric meals on growth performance using the parameters of multiple blood biomarkers and free amino acids in growing pigs. A total of 32 Landrace × Yorkshire barrows with a mean body weight of 8.64 (±1.13) kg were randomly assigned to four groups and then fed with various concentrations of Trp diets daily. Our results showed that sequential supplementation of different concentrations of Trp in isocaloric meals decreased the feed:gain (F:G) ratio (P = 0...
May 24, 2017: Amino Acids
https://www.readbyqxmd.com/read/28533791/jasmonoyl-l-tryptophan-disrupts-iaa-activity-through-the-aux1-auxin-permease
#10
Paul Staswick, Martha Rowe, Edgar P Spalding, Bessie L Splitt
Amide-linked conjugates between tryptophan (Trp) and jasmonic (JA) or indole-3-acetic (IAA) acids interfered with gravitropism and other auxin-dependent activities in Arabidopsis, but the mechanism was unclear. To identify structural features necessary for activity several additional Trp conjugates were synthesized. The phenylacetic acid (PAA) conjugate was active, while several others were not. Common features of active conjugates is that they have ring structures that are linked to Trp through an acetic acid side chain, while longer or shorter linkages are inactive or less active...
2017: Frontiers in Plant Science
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
#11
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
#12
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
#13
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...
July 1, 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
#14
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
#15
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
#16
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
#17
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...
August 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
#18
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
#19
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
#20
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
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