Displaying publications 1 - 20 of 53 in total

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  1. Tryptophan-tagged peptide from serine threonine-protein kinase of Channa striatus improves antioxidant defence in L6 myotubes and attenuates caspase 3-dependent apoptotic response in zebrafish larvae
    Issac PK, Lite C, Guru A, Velayutham M, Kuppusamy G, Saraswathi NT, et al.
    Fish Physiol Biochem, 2021 Apr;47(2):293-311.
    PMID: 33394283 DOI: 10.1007/s10695-020-00912-7
    This study reports the antioxidant property and molecular mechanism of a tryptophan-tagged peptide derived from a teleost fish Channa striatus of serine threonine-protein kinase (STPK). The peptide was tagged with tryptophan to enhance the antioxidant property of STPK and named as IW13. The antioxidant activity of IW13 peptide was investigated using in vitro methods such as DPPH, ABTS, superoxide anion radical scavenging and hydrogen peroxide scavenging assay. Furthermore, to investigate the toxicity and dose response of IW13 peptide on antioxidant defence in vitro, L6 myotubes were induced with generic oxidative stress due to exposure of hydrogen peroxide (H2O2). IW13 peptide exposure was found to be non-cytotoxic to L6 cells in the tested concentration (10, 20, 30, 40 and 50 μM). Also, the pre-treatment of IW13 peptide decreased the lipid peroxidation level and increased glutathione enzyme activity. IW13 peptide treatment upregulated the antioxidant enzyme genes: GPx (glutathione peroxidase), GST (glutathione S transferase) and GCS (glutamine cysteine synthase), in vitro in L6 myotubes and in vivo in zebrafish larvae against the H2O2-induced oxidative stress. The results demonstrated that IW13 renders protection against the H2O2-induced oxidative stress through a cellular antioxidant defence mechanism by upregulating the gene expression, thus enhancing the antioxidant activity in the cellular or organismal level. The findings exhibited that the tryptophan-tagged IW13 peptide from STPK of C. striatus could be a promising candidate for the treatment of oxidative stress-associated diseases.
    Matched MeSH terms: Tryptophan
  2. Fulltext Tryptophan-metabolizing gut microbes regulate adult neurogenesis via the aryl hydrocarbon receptor
    Wei GZ, Martin KA, Xing PY, Agrawal R, Whiley L, Wood TK, et al.
    Proc Natl Acad Sci U S A, 2021 Jul 06;118(27).
    PMID: 34210797 DOI: 10.1073/pnas.2021091118
    While modulatory effects of gut microbes on neurological phenotypes have been reported, the mechanisms remain largely unknown. Here, we demonstrate that indole, a tryptophan metabolite produced by tryptophanase-expressing gut microbes, elicits neurogenic effects in the adult mouse hippocampus. Neurogenesis is reduced in germ-free (GF) mice and in GF mice monocolonized with a single-gene tnaA knockout (KO) mutant Escherichia coli unable to produce indole. External administration of systemic indole increases adult neurogenesis in the dentate gyrus in these mouse models and in specific pathogen-free (SPF) control mice. Indole-treated mice display elevated synaptic markers postsynaptic density protein 95 and synaptophysin, suggesting synaptic maturation effects in vivo. By contrast, neurogenesis is not induced by indole in aryl hydrocarbon receptor KO (AhR-/-) mice or in ex vivo neurospheres derived from them. Neural progenitor cells exposed to indole exit the cell cycle, terminally differentiate, and mature into neurons that display longer and more branched neurites. These effects are not observed with kynurenine, another AhR ligand. The indole-AhR-mediated signaling pathway elevated the expression of β-catenin, Neurog2, and VEGF-α genes, thus identifying a molecular pathway connecting gut microbiota composition and their metabolic function to neurogenesis in the adult hippocampus. Our data have implications for the understanding of mechanisms of brain aging and for potential next-generation therapeutic opportunities.
    Matched MeSH terms: Tryptophan/metabolism*
  3. Fulltext Tryptophan-catabolizing enzymes - party of three
    Ball HJ, Jusof FF, Bakmiwewa SM, Hunt NH, Yuasa HJ
    Front Immunol, 2014;5:485.
    PMID: 25346733 DOI: 10.3389/fimmu.2014.00485
    Indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) are tryptophan-degrading enzymes that have independently evolved to catalyze the first step in tryptophan catabolism via the kynurenine pathway (KP). The depletion of tryptophan and formation of KP metabolites modulates the activity of the mammalian immune, reproductive, and central nervous systems. IDO and TDO enzymes can have overlapping or distinct functions depending on their expression patterns. The expression of TDO and IDO enzymes in mammals differs not only by tissue/cellular localization but also by their induction by distinct stimuli. To add to the complexity, these genes also have undergone duplications in some organisms leading to multiple isoforms of IDO or TDO. For example, many vertebrates, including all mammals, have acquired two IDO genes via gene duplication, although the IDO1-like gene has been lost in some lower vertebrate lineages. Gene duplications can allow the homologs to diverge and acquire different properties to the original gene. There is evidence for IDO enzymes having differing enzymatic characteristics, signaling properties, and biological functions. This review analyzes the evolutionary convergence of IDO and TDO enzymes as tryptophan-catabolizing enzymes and the divergent evolution of IDO homologs to generate an enzyme family with diverse characteristics not possessed by TDO enzymes, with an emphasis on the immune system.
    Matched MeSH terms: Tryptophan; Tryptophan Oxygenase
  4. Fulltext Tryptophan metabolism-related gene expression patterns: unveiling prognostic insights and immune landscapes in uveal melanoma
    Wang J, Zhao T, Li B, Wei W
    Aging (Albany NY), 2023 Oct 13;15(20):11201-11216.
    PMID: 37844995 DOI: 10.18632/aging.205122
    Uveal melanoma (UVM) remains the leading intraocular malignancy in adults, with a poor prognosis for those with metastatic disease. Tryptophan metabolism plays a pivotal role in influencing cancerous properties and modifying the tumor's immune microenvironment. In this study, we explore the relationship between tryptophan metabolism-related gene (TRMG) expression and the various features of UVM, including prognosis and tumor microenvironment. Our analysis included 143 patient samples sourced from public databases. Using K-means clustering, we categorized UVM patients into two distinct clusters. Further, we developed a prognostic model based on five essential genes, effectively distinguishing between low-risk and high-risk patients. This distinction underscores the importance of TRMGs in UVM prognostication. Combining TRMG data with gender to create nomograms demonstrated exceptional accuracy in predicting UVM patient outcomes. Moreover, our analysis reveals correlations between risk assessments and immune cell infiltrations. Notably, the low-risk group displayed a heightened potential response to immune checkpoint inhibitors. In conclusion, our findings underscore the dynamic relationship between TRMG expression and various UVM characteristics, presenting a novel prognostic framework centered on TRMGs. The deep connection between TRMGs and UVM's tumor immune microenvironment emphasizes the crucial role of tryptophan metabolism in shaping the immune landscape. Such understanding paves the way for designing targeted immunotherapy strategies for UVM patients.
    Matched MeSH terms: Tryptophan*
  5. Fulltext The methanolic extract of Garcinia atroviridis (MeGa) reduces body weight and food intake, and improves lipid profiles by altering the lipid metabolism: a rat model
    Lim WF, Nasir SM, Teh LK, James RJ, Izhar MHM, Salleh MZ
    Turk J Biol, 2020;44(6):437-448.
    PMID: 33402870 DOI: 10.3906/biy-2005-2
    Garcinia species are widely used for their slimming effects via increased fat burning and suppression of satiety. However, scientific evidence for the biological effects of Garcinia atroviridis (GA) is lacking. We investigated the phytochemical composition, safety profiles, and antioxidant and antiobesity effects of methanolic extracts of Garcinia atroviridis (MeGa) in obese female rats. Repeated dose toxicity studies were conducted according to the OECD guidelines. Upon sacrifice, haematological, biochemical, lipid profile, and serum-based metabolomics analyses were performed to evaluate metabolic expression changes and their related pathways. MeGa contains several phytochemical groups and GA fruit acids. MeGa was found to be nontoxic in both male and female rats with an oral lethal dose (LD50) of 2000 mg/kg. After 9 weeks of treatment, MeGa-treated obese rats had lower weight gain and better lipid profiles (cholesterol and triglyceride), which correlated with the altered metabolic pathways involved in the metabolism of lipid (glycerophospholipid) and biosynthesis of unsaturated fatty acid. In addition, MeGa caused differential metabolism pathways of arachidonic acid and tryptophan that affect the inflammatory response and suppression of appetite. We concluded that MeGa is safe, and its slimming effects are due to the differential metabolism of lipids.
    Matched MeSH terms: Tryptophan
  6. Fulltext The antimalarial drug quinine interferes with serotonin biosynthesis and action
    Islahudin F, Tindall SM, Mellor IR, Swift K, Christensen HE, Fone KC, et al.
    Sci Rep, 2014 Jan 09;4:3618.
    PMID: 24402577 DOI: 10.1038/srep03618
    The major antimalarial drug quinine perturbs uptake of the essential amino acid tryptophan, and patients with low plasma tryptophan are predisposed to adverse quinine reactions; symptoms of which are similar to indications of tryptophan depletion. As tryptophan is a precursor of the neurotransmitter serotonin (5-HT), here we test the hypothesis that quinine disrupts serotonin function. Quinine inhibited serotonin-induced proliferation of yeast as well as human (SHSY5Y) cells. One possible cause of this effect is through inhibition of 5-HT receptor activation by quinine, as we observed here. Furthermore, cells exhibited marked decreases in serotonin production during incubation with quinine. By assaying activity and kinetics of the rate-limiting enzyme for serotonin biosynthesis, tryptophan hydroxylase (TPH2), we showed that quinine competitively inhibits TPH2 in the presence of the substrate tryptophan. The study shows that quinine disrupts both serotonin biosynthesis and function, giving important new insight to the action of quinine on mammalian cells.
    Matched MeSH terms: Tryptophan Hydroxylase/antagonists & inhibitors
  7. The Lichen Flavin-Dependent Halogenase, DnHal: Identification, Heterologous Expression and Functional Characterization
    Hasan NS, Ling JG, Bakar MFA, Seman WMKW, Murad AMA, Bakar FDA, et al.
    Appl Biochem Biotechnol, 2023 Nov;195(11):6708-6736.
    PMID: 36913095 DOI: 10.1007/s12010-022-04304-w
    Enzymatic halogenation captures scientific interest considering its feasibility in modifying compounds for chemical diversity. Currently, majority of flavin-dependent halogenases (F-Hals) were reported from bacterial origin, and as far as we know, none from lichenized fungi. Fungi are well-known producers of halogenated compounds, so using available transcriptomic dataset of Dirinaria sp., we mined for putative gene encoding for F-Hal. Phylogenetic-based classification of the F-Hal family suggested a non-tryptophan F-Hals, similar to other fungal F-Hals, which mainly act on aromatic compounds. However, after the putative halogenase gene from Dirinaria sp., dnhal was codon-optimized, cloned, and expressed in Pichia pastoris, the ~63 kDa purified enzyme showed biocatalytic activity towards tryptophan and an aromatic compound methyl haematommate, which gave the tell-tale isotopic pattern of a chlorinated product at m/z 239.0565 and 241.0552; and m/z 243.0074 and 245.0025, respectively. This study is the start of understanding the complexities of lichenized fungal F-hals and its ability to halogenate tryptophan and other aromatic. compounds which can be used as green alternatives for biocatalysis of halogenated compounds.
    Matched MeSH terms: Tryptophan/metabolism
  8. The Cytokines CXCL10 and CCL2 and the Kynurenine Metabolite Anthranilic Acid Accurately Predict Patients at Risk of Developing Dengue With Warning Signs
    Jusof FF, Lim CK, Aziz FN, Soe HJ, Raju CS, Sekaran SD, et al.
    J Infect Dis, 2022 Nov 28;226(11):1964-1973.
    PMID: 35767283 DOI: 10.1093/infdis/jiac273
    BACKGROUND: The resolution or aggravation of dengue infection depends on the patient's immune response during the critical phase. Cytokines released by immune cells increase with the worsening severity of dengue infections. Cytokines activate the kynurenine pathway (KP) and the extent of KP activation then influences disease severity.

    METHODS: KP metabolites and cytokines in plasma samples of patients with dengue infection (dengue without warning signs [DWS-], dengue with warning signs [DWS+], or severe dengue) were analyzed. Cytokines (interferon gamma [IFN-ɣ], tumor necrosis factor, interleukin 6, CXCL10/interferon-inducile protein 10 [IP-10], interleukin 18 [IL-18], CCL2/monocyte chemoattractant protein-1 [MCP-1], and CCL4/macrophage inflammatory protein-1beta [MIP-1β] were assessed by a Human Luminex Screening Assay, while KP metabolites (tryptophan, kynurenine, anthranilic acid [AA], picolinic acid, and quinolinic acid) were assessed by ultra-high-performance liquid chromatography and Gas Chromatography Mass Spectrophotometry [GCMS] assays.

    RESULTS: Patients with DWS+ had increased activation of the KP where kynurenine-tryptophan ratio, anthranilic acid, and picolinic acid were elevated. These patients also had higher levels of the cytokines IFN-ɣ, CXCL10, CCL4, and IL-18 than those with DWS-. Further receiver operating characteristic analysis identified 3 prognostic biomarker candidates, CXCL10, CCL2, and AA, which predicted patients with higher risks of developing DWS+ with an accuracy of 97%.

    CONCLUSIONS: The data suggest a unique biochemical signature in patients with DWS+. CXCL10 and CCL2 together with AA are potential prognostic biomarkers that discern patients with higher risk of developing DWS+ at earlier stages of infection.

    Matched MeSH terms: Tryptophan/metabolism
  9. Studies of the chemical composition of a healing skin wound in rats, and of the concentrations of some constituents of tissues distant from the healing wound
    Candlish J, Chandra N
    Biochem. J., 1967 Mar;102(3):767-73.
    PMID: 16742493
    1. A skin lesion was made in rats by dorsal incision and the insertion of a polythene tube. 2. Over a period of 25 days after wounding, assays were performed for ascorbic acid, DNA, hydroxyproline, methionine, tryptophan, tyrosine and free amino acids in the lesion tissue. 3. The neutral-salt-soluble proteins of the lesion tissue were fractionated on DEAE-Sephadex, with the separation of fibrinogen and gamma-globulin from a serum protein fraction. 4. Over a period of 20 days after wounding, in wounded rats and in controls, assays were conducted for: ascorbic acid in lens and liver, hydroxyproline, soluble protein, methionine and water in muscle and tendon, and free amino acids in muscle. 5. Relative to controls there was a decrease in lens and liver ascorbic acid, a rise in tendon hydroxyproline, a rise in muscle free amino acids, a fall in muscle protein and a rise in tendon and muscle water.
    Matched MeSH terms: Tryptophan
  10. Fulltext Rapid Evaluation and Optimization of Medium Components Governing Tryptophan Production by Pediococcus acidilactici TP-6 Isolated from Malaysian Food via Statistical Approaches
    Lim YH, Foo HL, Loh TC, Mohamad R, Abdul Rahim R
    Molecules, 2020 Feb 11;25(4).
    PMID: 32054138 DOI: 10.3390/molecules25040779
    Tryptophan is one of the most extensively used amino acids in livestock industry owing to its effectiveness in enhancing the growth performance of animals. Conventionally, the production of tryptophan relies heavily on genetically modified Escherichia coli but its pathogenicity is a great concern. Our recent study demonstrated that a lactic acid bacterium (LAB), Pediococcus acidilactici TP-6 that isolated from Malaysian food was a promising tryptophan producer. However, the tryptophan production must enhance further for viable industrial application. Hence, the current study evaluated the effects of medium components and optimized the medium composition for tryptophan production by P. acidilactici TP-6 statistically using Plackett-Burman Design, and Central Composite Design. The optimized medium containing molasses (14.06 g/L), meat extract (23.68 g/L), urea (5.56 g/L) and FeSO4 (0.024 g/L) significantly enhanced the tryptophan production by 150% as compared to the control de Man, Rogosa and Sharpe medium. The findings obtained in this study revealed that rapid evaluation and effective optimization of medium composition governing tryptophan production by P. acidilactici TP-6 were feasible via statistical approaches. Additionally, the current findings reveal the potential of utilizing LAB as a safer alternative tryptophan producer and provides insight for future exploitation of various amino acid productions by LAB.
    Matched MeSH terms: Tryptophan/biosynthesis*
  11. Quinine interactions with tryptophan and tyrosine in malaria patients, and implications for quinine responses in the clinical setting
    Islahudin F, Pleass RJ, Avery SV, Ting KN
    J Antimicrob Chemother, 2012 Oct;67(10):2501-5.
    PMID: 22763566 DOI: 10.1093/jac/dks253
    OBJECTIVES: Recent work with the yeast model revealed that the antiprotozoal drug quinine competes with tryptophan for uptake via a common transport protein, causing cellular tryptophan starvation. In the present work, it was hypothesized that similar interactions may occur in malaria patients receiving quinine therapy.

    PATIENTS AND METHODS: A direct observational study was conducted in which plasma levels of drug and amino acids (tryptophan, tyrosine and phenylalanine) were monitored during quinine treatment of malaria patients with Plasmodium falciparum infections.

    RESULTS: Consistent with competition for uptake from plasma into cells, plasma tryptophan and tyrosine levels increased ≥2-fold during quinine therapy. Plasma quinine levels in individual plasma samples were significantly and positively correlated with tryptophan and tyrosine in the same samples. Control studies indicated no effect on phenylalanine. Chloroquine treatment of Plasmodium vivax-infected patients did not affect plasma tryptophan or tyrosine. During quinine treatment, plasma tryptophan was significantly lower (and quinine significantly higher) in patients experiencing adverse drug reactions.

    CONCLUSIONS: Plasma quinine levels during therapy are related to patient tryptophan and tyrosine levels, and these interactions can determine patient responses to quinine. The study also highlights the potential for extrapolating insights directly from the yeast model to human malaria patients.

    Matched MeSH terms: Tryptophan/antagonists & inhibitors*; Tryptophan/metabolism
  12. Fulltext Purple urine bag syndrome: a startling phenomenon of purple urine in a urine drainage bag. A primary care approach and literature review
    Wong, Y.W.E., Abdullah, N.
    Malaysian Family Physician, 2018;13(2):42-44.
    MyJurnal
    Purple urine bag syndrome (PUBs) is a rare and startling phenomenon of purple discolouration
    in the urine or urinary catheter and bag. It is reported in chronically debilitated elderly patients,
    mostly in women on long-term urinary catheters. Its prevalence is strikingly more common in
    nursing home residents. Several factors contribute to the formation of indigo (blue) and indirubin
    (red) pigments from a breakdown of dietary tryptophan, which stains the urine purple. These
    factors include constipation, dysmotility of the bowel, bowel bacterial overgrowth, dehydration, and
    urinary tract infection. The presence of purple urine may cause undue alarm to both the patient and
    the doctor. Thus, we present this case report on an 86-year-old woman, a nursing home resident
    on a long-term urinary catheter, who presented to the primary care clinic. Her urine cleared
    after antibiotic therapy, replacement of her urinary catheter, and supportive management, which
    included hydration and nutrition. In addition to these measures, reducing the time between urinary
    catheter changes was recommended to prevent recurrence of this condition.
    Matched MeSH terms: Tryptophan
  13. Fulltext Purple urine bag syndrome: A startling phenomenon of purple urine in a urine drainage bag. A primary care approach and literature review
    Wong Y, Abdullah N
    Malays Fam Physician, 2018;13(2):42-44.
    PMID: 30302185
    Purple urine bag syndrome (PUBs) is a rare and startling phenomenon of purple discolouration in the urine or urinary catheter and bag. It is reported in chronically debilitated elderly patients, mostly in women on long-term urinary catheters. Its prevalence is strikingly more common in nursing home residents. Several factors contribute to the formation of indigo (blue) and indirubin (red) pigments from a breakdown of dietary tryptophan, which stains the urine purple. These factors include constipation, dysmotility of the bowel, bowel bacterial overgrowth, dehydration, and urinary tract infection. The presence of purple urine may cause undue alarm to both the patient and the doctor. Thus, we present this case report on an 86-year-old woman, a nursing home resident on a long-term urinary catheter, who presented to the primary care clinic. Her urine cleared after antibiotic therapy, replacement of her urinary catheter, and supportive management, which included hydration and nutrition. In addition to these measures, reducing the time between urinary catheter changes was recommended to prevent recurrence of this condition.
    Matched MeSH terms: Tryptophan
  14. Physical properties, storage stability, and consumer acceptability for sourdough bread produced using encapsulated kombucha sourdough starter culture
    Mohd Roby BH, Muhialdin BJ, Abadl MMT, Mat Nor NA, Marzlan AA, Lim SAH, et al.
    J Food Sci, 2020 Aug;85(8):2286-2295.
    PMID: 32691422 DOI: 10.1111/1750-3841.15302
    This study aimed to produce sourdough bread using an encapsulated kombucha sourdough starter culture without the addition of baker's yeast. The bioactive metabolites of kombucha sourdough starter and sourdough starter without kombucha were identified using 1 H-NMR analysis with multivariate analysis. The physical properties, including loaf volume, specific loaf volume, firmness, and water activity were determined following standard methods. The shelf life and consumer acceptability of the bread were also being evaluated. The principal component analyses showed the presence of 15 metabolites in kombucha sourdough starter. The major compounds that contributed to the differences from sourdough starter without kombucha were alpha-aminobutyric acid, alanine, acetic acid, riboflavin, pyridoxine, anserine, tryptophan, gluconic acid, and trehalose. The encapsulated kombucha sourdough starter increased the loaf volume (976.7 ± 25.2 mL) and specific loaf volume (4.38 ± 0.12 mL/g) compared to yeast bread. Thus, significant (P
    Matched MeSH terms: Tryptophan
  15. Fulltext Optimization of culture conditions for flexirubin production by Chryseobacterium artocarpi CECT 8497 using response surface methodology
    Venil CK, Zakaria ZA, Ahmad WA
    Acta Biochim. Pol., 2015;62(2):185-90.
    PMID: 25979288 DOI: 10.18388/abp.2014_870
    Flexirubins are the unique type of bacterial pigments produced by the bacteria from the genus Chryseobacterium, which are used in the treatment of chronic skin disease, eczema etc. and may serve as a chemotaxonomic marker. Chryseobacterium artocarpi CECT 8497, an yellowish-orange pigment producing strain was investigated for maximum production of pigment by optimizing medium composition employing response surface methodology (RSM). Culture conditions affecting pigment production were optimized statistically in shake flask experiments. Lactose, l-tryptophan and KH2PO4 were the most significant variables affecting pigment production. Box Behnken design (BBD) and RSM analysis were adopted to investigate the interactions between variables and determine the optimal values for maximum pigment production. Evaluation of the experimental results signified that the optimum conditions for maximum production of pigment (521.64 mg/L) in 50 L bioreactor were lactose 11.25 g/L, l-tryptophan 6 g/L and KH2PO4 650 ppm. Production under optimized conditions increased to 7.23 fold comparing to its production prior to optimization. Results of this study showed that statistical optimization of medium composition and their interaction effects enable short listing of the significant factors influencing maximum pigment production from Chryseobacterium artocarpi CECT 8497. In addition, this is the first report optimizing the process parameters for flexirubin type pigment production from Chryseobacterium artocarpi CECT 8497.
    Matched MeSH terms: Tryptophan/metabolism
  16. Nutrition and immunity: the effects of the combination of arginine and tryptophan on growth performance, serum parameters and immune response in broiler chickens challenged with infectious bursal disease vaccine
    Emadi M, Jahanshiri F, Kaveh K, Hair-Bejo M, Ideris A, Alimon AR
    Avian Pathol, 2011 Feb;40(1):63-72.
    PMID: 21331949 DOI: 10.1080/03079457.2010.539590
    To explore the effects of the combination of tryptophan (Trp) and arginine (Arg) on growth performance, serum parameters and immune response of broiler chickens challenged with intermediate plus strain of infectious bursal disease virus vaccine, an in vivo experiment was conducted. A corn-soybean meal-based diet containing different levels of Arg and Trp was used. Cobb500 male broiler chickens from 0 to 49 days of age were subjected to a diet supplemented with the combination of Trp and Arg. Growth performance parameters and serum parameters were measured at 27 and 49 days of age. To evaluate the immunomodulatory effects of the combination of Trp and Arg on the challenged chickens, we measured the serum levels of interferon-α, interferon-γ and immunoglobulin G at 27, 35, 42, and 49 days of age. The results showed that the three evaluated immune system parameters including interferon-α, interferon-γ and immunoglobulin G were significantly enhanced after treatment. This enhancement resulted in the recovery of infectious bursal disease virus-infected chickens compared with controls as confirmed by histopathological examinations. Moreover, serum parameters such as albumin and total protein increased, whereas the treatment decreased (P<0.05) the feed:gain ratio, aspartate amino-transferase, alkaline phosphatase, lactic dehydrogenase, triglyceride and cholesterol. These findings suggest that the combination of Arg and Trp has a regulatory effect on growth performance. Moreover, it modulates the systemic immune response against infectious bursal disease.
    Matched MeSH terms: Tryptophan/administration & dosage*
  17. Fulltext Multifunctional Tyrosinase Inhibitor Peptides with Copper Chelating, UV-Absorption and Antioxidant Activities: Kinetic and Docking Studies
    Yap PG, Gan CY
    Foods, 2021 Mar 22;10(3).
    PMID: 33810046 DOI: 10.3390/foods10030675
    Nature-derived tyrosinase inhibitors are of great industrial interest. Three monophenolase inhibitor peptides (MIPs) and three diphenolase inhibitor peptides (DIPs) from a previous study were investigated for their in vitro tyrosinase inhibitory effects, mode of inhibition, copper-chelating activity, sun protection factor (SPF) and antioxidant activities. DIP1 was found to be the most potent tyrosinase inhibitor (IC50 = 3.04 ± 0.39 mM), which could be due to the binding interactions between its aromatic amino acid residues (Y2 and D7) with tyrosinase hotspots (H85, V248, H258, H263, F264, R268, V283 and E322) and its ability to chelate copper ion within the substrate-binding pocket. The conjugated planar rings of tyrosine and tryptophan may interact with histidine within the active site to provide stability upon enzyme-peptide binding. This postulation was later confirmed as the Lineweaver-Burk analysis had identified DIP1 as a competitive inhibitor and DIP1 also showed 36.27 ± 1.17% of copper chelating activity. In addition, DIP1 provided the highest SPF value (11.9 ± 0.04) as well as ferric reducing antioxidant power (FRAP) (5.09 ± 0.13 mM FeSO4), 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) (11.34 ± 0.90%) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) (29.14 ± 1.36%) free radical scavenging activities compared to other peptides. These results demonstrated that DIP1 could be a multifunctional anti-tyrosinase agent with pharmaceutical and cosmeceutical applications.
    Matched MeSH terms: Tryptophan
  18. Meta-analysis of polymorphisms in TPH2 gene and suicidal behavior
    Choong MY, Tee SF, Tang PY
    Psychiatry Res, 2014 Dec 30;220(3):1163-6.
    PMID: 25219619 DOI: 10.1016/j.psychres.2014.07.076
    Matched MeSH terms: Tryptophan Hydroxylase/genetics*
  19. Materials and Techniques for Implantable Nutrient Sensing Using Flexible Sensors Integrated with Metal-Organic Frameworks
    Ling W, Liew G, Li Y, Hao Y, Pan H, Wang H, et al.
    Adv Mater, 2018 Jun;30(23):e1800917.
    PMID: 29633379 DOI: 10.1002/adma.201800917
    The combination of novel materials with flexible electronic technology may yield new concepts of flexible electronic devices that effectively detect various biological chemicals to facilitate understanding of biological processes and conduct health monitoring. This paper demonstrates single- or multichannel implantable flexible sensors that are surface modified with conductive metal-organic frameworks (MOFs) such as copper-MOF and cobalt-MOF with large surface area, high porosity, and tunable catalysis capability. The sensors can monitor important nutriments such as ascorbicacid, glycine, l-tryptophan (l-Trp), and glucose with detection resolutions of 14.97, 0.71, 4.14, and 54.60 × 10-6 m, respectively. In addition, they offer sensing capability even under extreme deformation and complex surrounding environment with continuous monitoring capability for 20 d due to minimized use of biological active chemicals. Experiments using live cells and animals indicate that the MOF-modified sensors are biologically safe to cells, and can detect l-Trp in blood and interstitial fluid. This work represents the first effort in integrating MOFs with flexible sensors to achieve highly specific and sensitive implantable electrochemical detection and may inspire appearance of more flexible electronic devices with enhanced capability in sensing, energy storage, and catalysis using various properties of MOFs.
    Matched MeSH terms: Tryptophan
  20. Localization and characterization of val-opsin isoform-expressing cells in the brain of adult zebrafish
    Hang CY, Kitahashi T, Parhar IS
    J. Comp. Neurol., 2014 Dec 1;522(17):3847-60.
    PMID: 25043553 DOI: 10.1002/cne.23645
    In addition to vision, light information is used to regulate a range of animal physiology. Such nonimage-forming functions of light are mediated by nonvisual photoreceptors expressed in distinct neurons in the retina and the brain in most vertebrates. A nonvisual photoreceptor vertebrate ancient long opsin (VAL-opsin) possesses two functional isoforms in the zebrafish, encoded by valopa and valopb, which has received little attention. To delineate the neurochemical identities of valop cells and to test for colocalization of the valop isoforms, we used in situ hybridization to characterize the expression of the valop genes along with that of neurotransmitters and a neuropeptide known to be present at the sites of valop expression. Double labeling showed that the thalamic valop population coexpresses valopa and valopb. All the thalamic valop cells overlapped with a GABAergic cell mass that continues from the anterior nucleus to the intercalated thalamic nucleus. A novel valopa cell population found in the superior raphe was serotonergic in nature. A valopb cell population in the Edinger-Westphal nucleus was identified as containing thyrotropin-releasing hormone. Valopb cells localized in the hindbrain intermediate reticular formation were noncholinergic in nature (nonmotorneurons). Thus, the presence of valop cell populations in different brain regions with coexpression of neurotransmitters and neuropeptides and the colocalization of valop isoforms in the thalamic cell population indicate regulatory and functional complexity of VAL-opsin in the brain of the zebrafish.
    Matched MeSH terms: Tryptophan Hydroxylase/genetics; Tryptophan Hydroxylase/metabolism
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