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  1 / 39313 MEDLINE  
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[PMID]:28837875
[Au] Autor:Molnár Á; Feigl G; Trifán V; Ördög A; Szollosi R; Erdei L; Kolbert Z
[Ad] Endereço:Department of Plant Biology, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary. Electronic address: molnara@bio.u-szeged.hu.
[Ti] Título:The intensity of tyrosine nitration is associated with selenite and selenate toxicity in Brassica juncea L.
[So] Source:Ecotoxicol Environ Saf;147:93-101, 2018 Jan.
[Is] ISSN:1090-2414
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Selenium phytotoxicity involves processes like reactive nitrogen species overproduction and nitrosative protein modifications. This study evaluates the toxicity of two selenium forms (selenite and selenate at 0µM, 20µM, 50µM and 100µM concentrations) and its correlation with protein tyrosine nitration in the organs of hydroponically grown Indian mustard (Brassica juncea L.). Selenate treatment resulted in large selenium accumulation in both Brassica organs, while selenite showed slight root-to-shoot translocation resulting in a much lower selenium accumulation in the shoot. Shoot and root growth inhibition and cell viability loss revealed that Brassica tolerates selenate better than selenite. Results also show that relative high amounts of selenium are able to accumulate in Brassica leaves without obvious visible symptoms such as chlorosis or necrosis. The more severe phytotoxicity of selenite was accompanied by more intense protein tyrosine nitration as well as alterations in nitration pattern suggesting a correlation between the degree of Se forms-induced toxicities and nitroproteome size, composition in Brassica organs. These results imply the possibility of considering protein tyrosine nitration as novel biomarker of selenium phytotoxicity, which could help the evaluation of asymptomatic selenium stress of plants.
[Mh] Termos MeSH primário: Mostardeira/efeitos dos fármacos
Nitrocompostos/metabolismo
Espécies Reativas de Nitrogênio/metabolismo
Ácido Selênico/toxicidade
Ácido Selenioso/toxicidade
Tirosina/metabolismo
[Mh] Termos MeSH secundário: Transporte Biológico
Relação Dose-Resposta a Droga
Hidroponia
Mostardeira/metabolismo
Ácido Selênico/metabolismo
Ácido Selenioso/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Nitro Compounds); 0 (Reactive Nitrogen Species); 42HK56048U (Tyrosine); F6A27P4Q4R (Selenious Acid); HV0Y51NC4J (Selenic Acid)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180309
[Lr] Data última revisão:
180309
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170825
[St] Status:MEDLINE


  2 / 39313 MEDLINE  
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[PMID]:28460646
[Au] Autor:Markusic DM; Nichols TC; Merricks EP; Palaschak B; Zolotukhin I; Marsic D; Zolotukhin S; Srivastava A; Herzog RW
[Ad] Endereço:Department of Pediatrics, University of Florida, Gainesville, FL, 32610, USA. dmarkusic@ufl.edu.
[Ti] Título:Evaluation of engineered AAV capsids for hepatic factor IX gene transfer in murine and canine models.
[So] Source:J Transl Med;15(1):94, 2017 May 01.
[Is] ISSN:1479-5876
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Adeno-associated virus (AAV) gene therapy vectors have shown the best outcomes in human clinical studies for the treatment of genetic diseases such as hemophilia. However, these pivotal investigations have also identified several challenges. For example, high vector doses are often used for hepatic gene transfer, and cytotoxic T lymphocyte responses against viral capsid may occur. Therefore, achieving therapy at reduced vector doses and other strategies to reduce capsid antigen presentation are desirable. METHODS: We tested several engineered AAV capsids for factor IX (FIX) expression for the treatment of hemophilia B by hepatic gene transfer. These capsids lack potential phosphorylation or ubiquitination sites, or had been generated through molecular evolution. RESULTS: AAV2 capsids lacking either a single lysine residue or 3 tyrosine residues directed substantially higher coagulation FIX expression in mice compared to wild-type sequence or other mutations. In hemophilia B dogs, however, expression from the tyrosine-mutant vector was merely comparable to historical data on AAV2. Evolved AAV2-LiC capsid was highly efficient in hemophilia B mice but lacked efficacy in a hemophilia B dog. CONCLUSIONS: Several alternative strategies for capsid modification improve the in vivo performance of AAV vectors in hepatic gene transfer for correction of hemophilia. However, capsid optimization solely in mouse liver may not predict efficacy in other species and thus is of limited translational utility.
[Mh] Termos MeSH primário: Capsídeo/metabolismo
Dependovirus/genética
Fator IX/genética
Técnicas de Transferência de Genes
Engenharia Genética
[Mh] Termos MeSH secundário: Animais
Cães
Vetores Genéticos/metabolismo
Hemofilia B/genética
Hepatócitos/metabolismo
Fígado/metabolismo
Lisina/genética
Masculino
Camundongos Endogâmicos BALB C
Camundongos Endogâmicos C57BL
Modelos Animais
Mutação/genética
Transdução Genética
Tirosina/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
42HK56048U (Tyrosine); 9001-28-9 (Factor IX); K3Z4F929H6 (Lysine)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180305
[Lr] Data última revisão:
180305
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170503
[St] Status:MEDLINE
[do] DOI:10.1186/s12967-017-1200-1


  3 / 39313 MEDLINE  
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[PMID]:29362733
[Au] Autor:Mancini O; Wellbrock T; Rolinski OJ; Kubiak-Ossowska K; Mulheran PA
[Ad] Endereço:Department of Chemical Engineering and Process Engineering, University of Strathclyde, Glasgow, G1 1XJ, UK. paul.mulheran@strath.ac.uk.
[Ti] Título:Probing beta amyloid aggregation using fluorescence anisotropy: experiments and simulation.
[So] Source:Phys Chem Chem Phys;20(6):4216-4225, 2018 Feb 07.
[Is] ISSN:1463-9084
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The aggregation of beta amyloid (Ab) protein is associated with the development of Alzheimer's disease. In this work we monitor Ab aggregation using fluorescence anisotropy, a technique that provides information on the rotational diffusion of the fluorescing tyrosine (Tyr) side chains. We also perform Monte Carlo (MC) and fully atomistic Molecular Dynamics (MD) simulations to interpret the experiments. The experimental results show that there are two different rotational timescales contributing to the anisotropy. Our MC simulation captures this behaviour in a coarse-scale manner, and, more importantly, shows that the Tyr side chains must have their movements restricted in order to reproduce the anisotropy. The MD simulations provide a molecular scale view, and indeed show that aggregation restricts the Try side chains to yield anisotropy in line with the experimental results. This combination of experiment and simulation therefore provides a unique insight into the aggregation process, and we suggest how this approach might be used to gain further information on aggregating protein systems.
[Mh] Termos MeSH primário: Peptídeos beta-Amiloides/química
Simulação de Dinâmica Molecular
[Mh] Termos MeSH secundário: Polarização de Fluorescência
Método de Monte Carlo
Estrutura Secundária de Proteína
Tirosina/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amyloid beta-Peptides); 42HK56048U (Tyrosine)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180226
[Lr] Data última revisão:
180226
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180125
[St] Status:MEDLINE
[do] DOI:10.1039/c7cp08217g


  4 / 39313 MEDLINE  
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[PMID]:29311464
[Au] Autor:Sato S; Tsushima M; Nakamura K; Nakamura H
[Ad] Endereço:Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology.
[Ti] Título:[Development and Application of Catalytic Tyrosine Modification].
[So] Source:Yakugaku Zasshi;138(1):39-46, 2018.
[Is] ISSN:1347-5231
[Cp] País de publicação:Japan
[La] Idioma:jpn
[Ab] Resumo:The chemical labeling of proteins with synthetic probes is a key technique used in chemical biology, protein-based therapy, and material science. Much of the chemical labeling of native proteins, however, depends on the labeling of lysine and cysteine residues. While those methods have significantly contributed to native protein labeling, alternative methods that can modify different amino acid residues are still required. Herein we report the development of a novel methodology of tyrosine labeling, inspired by the luminol chemiluminescence reaction. Tyrosine residues are often exposed on a protein's surface and are thus expected to be good targets for protein functionalization. In our studies so far, we have found that 1) hemin oxidatively activates luminol derivatives as a catalyst, 2) N-methyl luminol derivative specifically forms a covalent bond with a tyrosine residue among the 20 kinds of natural amino acid residues, and 3) the efficiency of tyrosine labeling with N-methyl luminol derivative is markedly improved by using horseradish peroxidase (HRP) as a catalyst. We were able to use molecular oxygen as an oxidant under HRP/NADH conditions. By using these methods, the functionalization of purified proteins was carried out. Because N-methyl luminol derivative is an excellent protein labeling reagent that responds to the activation of peroxidase, this new method is expected to open doors to such biological applications as the signal amplification of HRP-conjugated antibodies and the detection of protein association in combination with peroxidase-tag technology.
[Mh] Termos MeSH primário: Tirosina/química
[Mh] Termos MeSH secundário: Catálise
Heme/química
Hemeproteínas/química
Luminescência
Luminol/química
Peroxidase/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Hemeproteins); 42HK56048U (Tyrosine); 42VZT0U6YR (Heme); 5EXP385Q4F (Luminol); EC 1.11.1.7 (Peroxidase)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180226
[Lr] Data última revisão:
180226
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180110
[St] Status:MEDLINE
[do] DOI:10.1248/yakushi.17-00186-1


  5 / 39313 MEDLINE  
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[PMID]:28468956
[Au] Autor:Jasnovidova O; Krejcikova M; Kubicek K; Stefl R
[Ad] Endereço:CEITEC - Central European Institute of Technology, Masaryk University, Brno, Czech Republic olga.jasnovidova@ceitec.muni.cz richard.stefl@ceitec.muni.cz.
[Ti] Título:Structural insight into recognition of phosphorylated threonine-4 of RNA polymerase II C-terminal domain by Rtt103p.
[So] Source:EMBO Rep;18(6):906-913, 2017 Jun.
[Is] ISSN:1469-3178
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Phosphorylation patterns of the C-terminal domain (CTD) of largest subunit of RNA polymerase II (called the CTD code) orchestrate the recruitment of RNA processing and transcription factors. Recent studies showed that not only serines and tyrosines but also threonines of the CTD can be phosphorylated with a number of functional consequences, including the interaction with yeast transcription termination factor, Rtt103p. Here, we report the solution structure of the Rtt103p CTD-interacting domain (CID) bound to Thr4 phosphorylated CTD, a poorly understood letter of the CTD code. The structure reveals a direct recognition of the phospho-Thr4 mark by Rtt103p CID and extensive interactions involving residues from three repeats of the CTD heptad. Intriguingly, Rtt103p's CID binds equally well Thr4 and Ser2 phosphorylated CTD A doubly phosphorylated CTD at Ser2 and Thr4 diminishes its binding affinity due to electrostatic repulsion. Our structural data suggest that the recruitment of a CID-containing CTD-binding factor may be coded by more than one letter of the CTD code.
[Mh] Termos MeSH primário: RNA Polimerase II/química
Proteínas de Saccharomyces cerevisiae/química
Treonina/química
Fatores de Transcrição/química
[Mh] Termos MeSH secundário: Fosforilação
Ligação Proteica
Proteínas Quinases/metabolismo
Estrutura Terciária de Proteína
Proteólise
RNA Polimerase II/metabolismo
Proteínas de Saccharomyces cerevisiae/metabolismo
Serina/metabolismo
Treonina/metabolismo
Fatores de Transcrição/metabolismo
Transcrição Genética
Tirosina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Rtt103 protein, S cerevisiae); 0 (Saccharomyces cerevisiae Proteins); 0 (Transcription Factors); 2ZD004190S (Threonine); 42HK56048U (Tyrosine); 452VLY9402 (Serine); EC 2.7.- (Protein Kinases); EC 2.7.7.- (RNA Polymerase II)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180223
[Lr] Data última revisão:
180223
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170505
[St] Status:MEDLINE
[do] DOI:10.15252/embr.201643723


  6 / 39313 MEDLINE  
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[PMID]:29365103
[Au] Autor:Bemena LD; Mukama O; Wang N; Gao XD; Nakanishi H
[Ad] Endereço:Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
[Ti] Título:Characterization of a yeast sporulation-specific P450 family protein, Dit2, using an in vitro assay to crosslink formyl tyrosine.
[So] Source:J Biochem;163(2):123-131, 2018 Feb 01.
[Is] ISSN:1756-2651
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The outermost layer of the yeast Saccharomyces cerevisiae spore, termed the dityrosine layer, is primarily composed of bisformyl dityrosine. Bisformyl dityrosine is produced in the spore cytosol by crosslinking of two formyl tyrosine molecules, after which it is transported to the nascent spore wall and assembled into the dityrosine layer by an unknown mechanism. A P450 family protein, Dit2, is believed to mediate the crosslinking of bisformyl dityrosine molecules. To characterize Dit2 and gain insight into the biological process of dityrosine layer formation, we performed an in vitro assay to crosslink formyl tyrosine with using permeabilized cells. For an unknown reason, the production of bisformyl dityrosine could not be confirmed under our experimental conditions, but dityrosine was detected in acid hydrolysates of the reaction mixtures in a Dit2 dependent manner. Thus, Dit2 mediated the crosslinking of formyl tyrosine in vitro. Dityrosine was detected when formyl tyrosine, but not tyrosine, was used as a substrate and the reaction required NADPH as a cofactor. Intriguingly, apart from Dit2, we found that the spore wall, but not the vegetative cell wall, contains bisformyl dityrosine crosslinking activity. This activity may be involved in the assembly of the dityrosine layer.
[Mh] Termos MeSH primário: Proteínas Fúngicas/metabolismo
Saccharomyces cerevisiae/metabolismo
Esporos Fúngicos/metabolismo
Tirosina/análogos & derivados
[Mh] Termos MeSH secundário: Reagentes para Ligações Cruzadas/química
Reagentes para Ligações Cruzadas/metabolismo
Proteínas Fúngicas/química
Proteínas Fúngicas/genética
Saccharomyces cerevisiae/genética
Tirosina/química
Tirosina/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cross-Linking Reagents); 0 (Fungal Proteins); 42HK56048U (Tyrosine); 980-21-2 (dityrosine)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180220
[Lr] Data última revisão:
180220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180125
[St] Status:MEDLINE
[do] DOI:10.1093/jb/mvx067


  7 / 39313 MEDLINE  
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[PMID]:27777102
[Au] Autor:Mumaw CL; Surace M; Levesque S; Kodavanti UP; Kodavanti PRS; Royland JE; Block ML
[Ad] Endereço:Department of Anatomy and Cell Biology, The Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
[Ti] Título:Atypical microglial response to biodiesel exhaust in healthy and hypertensive rats.
[So] Source:Neurotoxicology;59:155-163, 2017 03.
[Is] ISSN:1872-9711
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Accumulating evidence suggests a deleterious role for urban air pollution in central nervous system (CNS) diseases and neurodevelopmental disorders. Microglia, the resident innate immune cells and sentinels in the brain, are a common source of neuroinflammation and are implicated in air pollution-induced CNS effects. While renewable energy, such as soy-based biofuel, is of increasing public interest, there is little information on how soy biofuel may affect the brain, especially in people with preexisting disease conditions. To address this, male spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats were exposed to 100% Soy-based Biodiesel Exhaust (100SBDE; 0, 50, 150 and 500µg/m ) by inhalation, 4h/day for 4 weeks (5 days/week). Ionized calcium-binding adapter molecule-1 (IBA-1) staining of microglia in the substantia nigra revealed significant changes in morphology with 100SBDE exposure in rats from both genotypes, where SHR were less sensitive. Aconitase activity was inhibited in the frontal cortex and cerebellum of WKY rats exposed to 100SBDE. No consistent changes occurred in pro-inflammatory cytokine expression, nitrated protein, or arginase1 expression in brain regions from either rat strain exposed to 100SBDE. However, while IBA-1 mRNA expression was not modified, CX3CR1 mRNA expression was lower in the striatum of 100SBDE exposed rats regardless of genotype, suggesting a downregulation of the fractalkine receptor on microglia in this brain region. Together, these data indicate that while microglia are detecting and responding to 100SBDE exposure with changes in morphology, there is reduced expression of CX3CR1 regardless of genetic background and the activation response is atypical without traditional inflammatory markers of M1 or M2 activation in the brain.
[Mh] Termos MeSH primário: Biocombustíveis/toxicidade
Quimiocina CX3CL1/metabolismo
Hipertensão/fisiopatologia
Microglia/efeitos dos fármacos
Substância Negra/patologia
Emissões de Veículos/toxicidade
[Mh] Termos MeSH secundário: Aconitato Hidratase/metabolismo
Animais
Antioxidantes/metabolismo
Proteínas de Ligação ao Cálcio/metabolismo
Citocinas/metabolismo
Relação Dose-Resposta a Droga
Hipertensão/genética
Hipertensão/patologia
Masculino
Proteínas dos Microfilamentos/metabolismo
Microglia/classificação
Estresse Oxidativo/efeitos dos fármacos
RNA Mensageiro/metabolismo
Ratos
Ratos Endogâmicos SHR
Ratos Endogâmicos WKY
Tirosina/análogos & derivados
Tirosina/metabolismo
Tirosina 3-Mono-Oxigenase/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Aif1 protein, rat); 0 (Antioxidants); 0 (Biofuels); 0 (Calcium-Binding Proteins); 0 (Chemokine CX3CL1); 0 (Cytokines); 0 (Microfilament Proteins); 0 (RNA, Messenger); 0 (Vehicle Emissions); 3604-79-3 (3-nitrotyrosine); 42HK56048U (Tyrosine); EC 1.14.16.2 (Tyrosine 3-Monooxygenase); EC 4.2.1.3 (Aconitate Hydratase)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:180209
[Lr] Data última revisão:
180209
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161026
[St] Status:MEDLINE


  8 / 39313 MEDLINE  
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[PMID]:28469016
[Au] Autor:Sterkel M; Oliveira PL
[Ad] Endereço:Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil msterkel29@gmail.com.
[Ti] Título:Developmental roles of tyrosine metabolism enzymes in the blood-sucking insect .
[So] Source:Proc Biol Sci;284(1854), 2017 May 17.
[Is] ISSN:1471-2954
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The phenylalanine/tyrosine degradation pathway is frequently described as a catabolic pathway that funnels aromatic amino acids into citric acid cycle intermediates. Previously, we demonstrated that the accumulation of tyrosine generated during the hydrolysis of blood meal proteins in is potentially toxic, a harmful outcome that is prevented by the action of the first two enzymes in the tyrosine degradation pathway. In this work, we further evaluated the relevance of all other enzymes involved in phenylalanine/tyrosine metabolism in the physiology of this insect. The knockdown of most of these enzymes produced a wide spectrum of distinct phenotypes associated with reproduction, development and nymph survival, demonstrating a highly pleiotropic role of tyrosine metabolism. The phenotypes obtained for two of these enzymes, homogentisate dioxygenase and fumarylacetoacetase, have never before been described in any arthropod. To our knowledge, this report is the first comprehensive gene-silencing analysis of an amino acid metabolism pathway in insects. Amino acid metabolism is exceptionally important in haematophagous arthropods due to their particular feeding behaviour.
[Mh] Termos MeSH primário: Monofenol Mono-Oxigenase/genética
Rhodnius/enzimologia
Tirosina/metabolismo
[Mh] Termos MeSH secundário: Animais
Inativação Gênica
Redes e Vias Metabólicas
Fenótipo
Rhodnius/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
42HK56048U (Tyrosine); EC 1.14.18.1 (Monophenol Monooxygenase)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180131
[Lr] Data última revisão:
180131
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170505
[St] Status:MEDLINE


  9 / 39313 MEDLINE  
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[PMID]:28745631
[Au] Autor:Li XS; Li S; Ahrens M; Kellermann G
[Ad] Endereço:Pharmasan Labs, Inc.; xiaoguang.li@pharmasan.com.
[Ti] Título:Integration of Miniaturized Solid Phase Extraction and LC-MS/MS Detection of 3-Nitrotyrosine in Human Urine for Clinical Applications.
[So] Source:J Vis Exp;(125), 2017 Jul 14.
[Is] ISSN:1940-087X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Free 3-nitrotyrosine (3-NT) has been extensively used as a possible biomarker for oxidative stress. Increased levels of 3-NT have been reported in a wide variety of pathological conditions. However, existing methods lack the sufficient sensitivity and/or specificity necessary to measure the low endogenous level of 3-NT reliably and are too cumbersome for clinical applications. Hence, analytical improvement is urgently needed to accurately quantify the levels of 3-NT and verify the role of 3-NT in pathological conditions. This protocol presents the development of a novel liquid chromatography tandem mass spectrometry (LC-MS/MS) detection combined with a miniaturized solid phase extraction (SPE) for the rapid and accurate measurement of 3-NT in human urine as a non-invasive biomarker for oxidative stress. SPE using a 96-well plate markedly simplified the process by combining sample cleanup and analyte enrichment without tedious derivatization and evaporation steps, reducing solvent consumption, waste disposal, risk of contamination and overall processing time. The employment of 25 mM ammonium acetate (NH4OAc) at pH 9 as the SPE elution solution substantially enhanced the selectivity. Mass spectrometry signal response was improved through adjustment of the multiple reaction monitoring (MRM) transitions. Use of 0.01% HCOOH as additive on a pentafluorophenyl (PFP) column (150 mm x 2.1 mm, 3 µm) improved signal response another 2.5-fold and shortened the overall run time to 7 min. A lower limit of quantitation (LLOQ) of 10 pg/mL (0.044 nM) was achieved, representing a significant sensitivity improvement over the reported assays. This simplified, rapid, selective and sensitive method allows two plates of urine samples (n = 192) to be processed in a 24 h time-period. Considering the markedly improved analytical performance, and non-invasive and inexpensive urine sampling, the proposed assay is beneficial for pre-clinical and clinical studies.
[Mh] Termos MeSH primário: Cromatografia Líquida de Alta Pressão/métodos
Espectrometria de Massas em Tandem
Tirosina/análogos & derivados
[Mh] Termos MeSH secundário: Biomarcadores/urina
Cromatografia Líquida de Alta Pressão/normas
Seres Humanos
Concentração de Íons de Hidrogênio
Limite de Detecção
Miniaturização
Estresse Oxidativo
Reprodutibilidade dos Testes
Extração em Fase Sólida
Espectrometria de Massas em Tandem/normas
Tirosina/isolamento & purificação
Tirosina/normas
Tirosina/urina
Gravação em Vídeo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Biomarkers); 3604-79-3 (3-nitrotyrosine); 42HK56048U (Tyrosine)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180130
[Lr] Data última revisão:
180130
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170727
[St] Status:MEDLINE
[do] DOI:10.3791/55778


  10 / 39313 MEDLINE  
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[PMID]:28745873
[Au] Autor:Nauser T; Gebicki JM
[Ad] Endereço:Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology , Zurich CH8093, Switzerland.
[Ti] Título:Physiological Concentrations of Ascorbate Cannot Prevent the Potentially Damaging Reactions of Protein Radicals in Humans.
[So] Source:Chem Res Toxicol;30(9):1702-1710, 2017 09 18.
[Is] ISSN:1520-5010
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The principal initial biological targets of free radicals formed under conditions of oxidative stress are the proteins. The most common products of the interaction are carbon-centered alkyl radicals which react rapidly with oxygen to form peroxyl radicals and hydroperoxides. All these species are reactive, capable of propagating the free radical damage to enzymes, nucleic acids, lipids, and endogenous antioxidants, leading finally to the pathologies associated with oxidative stress. The best chance of preventing this chain of damage is in early repair of the protein radicals by antioxidants. Estimate of the effectiveness of the physiologically significant antioxidants requires knowledge of the antioxidant tissue concentrations and rate constants of their reaction with protein radicals. Previous studies by pulse radiolysis have shown that only ascorbate can repair the Trp and Tyr protein radicals before they form peroxyl radicals under physiological concentrations of oxygen. We have now extended this work to other protein C-centered radicals generated by hydroxyl radicals because these and many other free radicals formed under oxidative stress can produce secondary radicals on virtually any amino acid residue. Pulse radiolysis identified two classes of rate constants for reactions of protein radicals with ascorbate, a faster one in the range (9-60) × 10 M s and a slow one with a range of (0.5-2) × 10 M s . These results show that ascorbate can prevent further reactions of protein radicals only in the few human tissues where its concentration exceeds about 2.5 mM.
[Mh] Termos MeSH primário: Ácido Ascórbico/química
Radicais Livres/química
Proteínas/química
[Mh] Termos MeSH secundário: Raios gama
Seres Humanos
Insulina/química
Muramidase/química
Óxidos de Nitrogênio/química
Radiólise de Impulso
Albumina Sérica/química
Espectrofotometria Ultravioleta
Triptofano/química
Tirosina/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Free Radicals); 0 (Insulin); 0 (Nitrogen Oxides); 0 (Proteins); 0 (Serum Albumin); 42HK56048U (Tyrosine); 8DUH1N11BX (Tryptophan); EC 3.2.1.17 (Muramidase); PQ6CK8PD0R (Ascorbic Acid)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:180127
[Lr] Data última revisão:
180127
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170727
[St] Status:MEDLINE
[do] DOI:10.1021/acs.chemrestox.7b00160



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