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[PMID]: 28358337 [Au] Autor: Hu C; Zhou SW; Chen F; Zheng XH; Shen HF; Lin BR; Zhou GX [Ad] Endereço: College of Pharmacy, Jinan University, Guangzhou 510632, China. kitten_hc@163.com. [Ti] Título: Neoantimycins A and B, Two Unusual Benzamido Nine-Membered Dilactones from Marine-Derived Streptomyces antibioticus H12-15. [So] Source: Molecules;22(4), 2017 Mar 30. [Is] ISSN: 1420-3049 [Cp] País de publicação: Switzerland [La] Idioma: eng [Ab] Resumo: An actinomycete strain (H12-15) isolated from a sea sediment in a mangrove district was identified as on the basis of 16S rDNA gene sequence analysis as well as the investigation of its morphological, physiological, and biochemical characteristics. Two novel benzamido nonacyclic dilactones, namely neoantimycins A ( ) and B ( ), together with the known antimycins A ( , ), A ( ), and A9 ( ), were isolated from the culture broth of this strain. Compounds and are the first natural modified ATNs with an unusual benzamide unit. The structures of these new compounds, including their absolute configuration, were established on the basis of HRMS, NMR spectroscopic data, and quantum chemical ECD calculations. Their cytotoxicities against human breast adenocarcinoma cell line MCF-7, the human glioblastoma cell line SF-268, and the human lung cancer cell line NCI-H460 were also tested. All compounds exhibited mild cytotoxic activity. However, Compounds and showed no activity against at the test concentration of 1 mg/mL via paper disc diffusion, while the known antimycins showed obvious antifungal activity. [Mh] Termos MeSH primário: Benzamidas/química Compostos Orgânicos/química Streptomyces antibioticus/isolamento & purificação [Mh] Termos MeSH secundário: Benzamidas/farmacologia Linhagem Celular Tumoral Ensaios de Seleção de Medicamentos Antitumorais Sedimentos Geológicos/microbiologia Seres Humanos Células MCF-7 Estrutura Molecular Compostos Orgânicos/farmacologia Teoria Quântica Streptomyces antibioticus/química Streptomyces antibioticus/crescimento & desenvolvimento [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Benzamides); 0 (Organic Chemicals); 6X80438640 (benzamide) [Em] Mês de entrada: 1705 [Cu] Atualização por classe: 170518 [Lr] Data última revisão: 170518 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170331 [St] Status: MEDLINE

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[PMID]: 28334892 [Au] Autor: Stone CM; Butt LE; Bufton JC; Lourenco DC; Gowers DM; Pickford AR; Cox PA; Vincent HA; Callaghan AJ [Ad] Endereço: School of Biological Sciences and Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth, PO1 2DY, UK. [Ti] Título: Inhibition of homologous phosphorolytic ribonucleases by citrate may represent an evolutionarily conserved communicative link between RNA degradation and central metabolism. [So] Source: Nucleic Acids Res;45(8):4655-4666, 2017 May 05. [Is] ISSN: 1362-4962 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: Ribonucleases play essential roles in all aspects of RNA metabolism, including the coordination of post-transcriptional gene regulation that allows organisms to respond to internal changes and environmental stimuli. However, as inherently destructive enzymes, their activity must be carefully controlled. Recent research exemplifies the repertoire of regulatory strategies employed by ribonucleases. The activity of the phosphorolytic exoribonuclease, polynucleotide phosphorylase (PNPase), has previously been shown to be modulated by the Krebs cycle metabolite citrate in Escherichia coli. Here, we provide evidence for the existence of citrate-mediated inhibition of ribonucleases in all three domains of life. In silico molecular docking studies predict that citrate will bind not only to bacterial PNPases from E. coli and Streptomyces antibioticus, but also PNPase from human mitochondria and the structurally and functionally related archaeal exosome complex from Sulfolobus solfataricus. Critically, we show experimentally that citrate also inhibits the exoribonuclease activity of bacterial, eukaryotic and archaeal PNPase homologues in vitro. Furthermore, bioinformatics data, showing key citrate-binding motifs conserved across a broad range of PNPase homologues, suggests that this regulatory mechanism may be widespread. Overall, our data highlight a communicative link between ribonuclease activity and central metabolism that may have been conserved through the course of evolution. [Mh] Termos MeSH primário: Ácido Cítrico/química Escherichia coli/enzimologia Polirribonucleotídeo Nucleotidiltransferase/química RNA/química Streptomyces antibioticus/enzimologia Sulfolobus solfataricus/enzimologia [Mh] Termos MeSH secundário: Sequência de Aminoácidos Sítios de Ligação Evolução Biológica Ácido Cítrico/metabolismo Clonagem Molecular Biologia Computacional Sequência Conservada Escherichia coli/genética Exossomos/química Exossomos/enzimologia Expressão Gênica Seres Humanos Cinética Mitocôndrias/química Mitocôndrias/enzimologia Simulação de Acoplamento Molecular Polirribonucleotídeo Nucleotidiltransferase/genética Polirribonucleotídeo Nucleotidiltransferase/metabolismo Ligação Proteica Domínios e Motivos de Interação entre Proteínas Estrutura Secundária de Proteína RNA/metabolismo Estabilidade de RNA/genética Proteínas Recombinantes/química Proteínas Recombinantes/genética Proteínas Recombinantes/metabolismo Alinhamento de Sequência Streptomyces antibioticus/genética Homologia Estrutural de Proteína Especificidade por Substrato Sulfolobus solfataricus/genética Termodinâmica [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Recombinant Proteins); 2968PHW8QP (Citric Acid); 63231-63-0 (RNA); EC 2.7.7.8 (Polyribonucleotide Nucleotidyltransferase) [Em] Mês de entrada: 1709 [Cu] Atualização por classe: 170906 [Lr] Data última revisão: 170906 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 170324 [St] Status: MEDLINE [do] DOI: 10.1093/nar/gkx114

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[PMID]: 26750095 [Au] Autor: Li Y; Li J; Tian Z; Xu Y; Zhang J; Liu W; Tan H [Ad] Endereço: From the State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China, the University of Chinese Academy of Sciences, Beijing 100101, China, and. [Ti] Título: Coordinative Modulation of Chlorothricin Biosynthesis by Binding of the Glycosylated Intermediates and End Product to a Responsive Regulator ChlF1. [So] Source: J Biol Chem;291(10):5406-17, 2016 Mar 04. [Is] ISSN: 1083-351X [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Chlorothricin, isolated from Streptomyces antibioticus, is a parent member of spirotetronate family of antibiotics that have long been appreciated for their remarkable biological activities. ChlF1 plays bifunctional roles in chlorothricin biosynthesis by binding to its target genes (chlJ, chlF1, chlG, and chlK). The dissociation constants of ChlF1 to these genes are ∼ 102-140 nm. A consensus sequence, 5'-GTAANNATTTAC-3', was found in these binding sites. ChlF1 represses the transcription of chlF1, chlG, and chlK but activates chlJ, which encodes a key enzyme acyl-CoA carboxyl transferase involved in the chlorothricin biosynthesis. We demonstrate that the end product chlorothricin and likewise its biosynthetic intermediates (demethylsalicycloyl chlorothricin and deschloro-chlorothricin) can act as signaling molecules to modulate the binding of ChlF1 to its target genes. Intriguingly, a correlation between the antibacterial activity and binding ability of signaling molecules to the regulator ChlF1 is clearly observed. These features of the signaling molecules are associated with the glycosylation of spirotetronate macrolide aglycone. The findings provide new insights into the TetR family regulators responding to special structure of signaling molecules, and we reveal the regulatory mini-network mediated by ChlF1 in chlorothricin biosynthesis for the first time. [Mh] Termos MeSH primário: Aminoglicosídeos/biossíntese Antibacterianos/biossíntese Produtos Finais de Glicação Avançada/metabolismo Streptomyces antibioticus/metabolismo [Mh] Termos MeSH secundário: Aminoglicosídeos/metabolismo Antibacterianos/metabolismo Proteínas de Bactérias/genética Proteínas de Bactérias/metabolismo Transdução de Sinais Streptomyces antibioticus/genética [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Aminoglycosides); 0 (Anti-Bacterial Agents); 0 (Bacterial Proteins); 0 (Glycation End Products, Advanced); I4O4K2RAQR (chlorothricin) [Em] Mês de entrada: 1608 [Cu] Atualização por classe: 171116 [Lr] Data última revisão: 171116 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 160112 [St] Status: MEDLINE [do] DOI: 10.1074/jbc.M115.695874

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[PMID]: 26475642 [Au] Autor: Montemiglio LC; Parisi G; Scaglione A; Sciara G; Savino C; Vallone B [Ad] Endereço: Istituto Pasteur-Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche "A. Rossi Fanelli", Sapienza Università di Roma, P.le A. Moro 5, 00185 Rome, Italy; Department of Biochemical Sciences, "Sapienza" University of Rome, P.le A. Moro 5, 00185 Rome, Italy. [Ti] Título: Functional analysis and crystallographic structure of clotrimazole bound OleP, a cytochrome P450 epoxidase from Streptomyces antibioticus involved in oleandomycin biosynthesis. [So] Source: Biochim Biophys Acta;1860(3):465-75, 2016 Mar. [Is] ISSN: 0006-3002 [Cp] País de publicação: Netherlands [La] Idioma: eng [Ab] Resumo: BACKGROUND: OleP is a cyt P450 from Streptomyces antibioticus carrying out epoxigenation of the antibiotic oleandomycin during its biosynthesis. The timing of its reaction has not been fully clarified, doubts remain regarding its substrate and catalytic mechanism. METHODS: The crystal structure of OleP in complex with clotrimazole, an inhibitor of P450s used in therapy, was solved and the complex formation dynamics was characterized by equilibrium and kinetic binding studies and compared to ketoconazole, another azole differing for the N1-substituent. RESULTS: Clotrimazole coordinates the heme and occupies the active site. Most of the residues interacting with clotrimazole are conserved and involved in substrate binding in MycG, the P450 epoxigenase with the highest homology with OleP. Kinetic characterization of inhibitor binding revealed OleP to follow a simple bimolecular reaction, without detectable intermediates. CONCLUSIONS: Clotrimazole-bound OleP adopts an open form, held by a π-π stacking chain that fastens helices F and G and the FG loop. Affinity is affected by the interactions of the N1 substituent within the active site, given the one order of magnitude difference of the off-rate constants between clotrimazole and ketoconazole. Based on structural similarities with MycG, we propose a binding mode for both oleandomycin intermediates, that are the candidate substrates of OleP. GENERAL SIGNIFICANCE: Among P450 epoxigenases OleP is the only one that introduces an epoxide on a non-activated C­C bond. The data here presented are necessary to understand the rare chemistry carried out by OleP, to engineer it and to design more selective and potent P450-targeted drugs. [Mh] Termos MeSH primário: Antibacterianos/biossíntese Clotrimazol/química Sistema Enzimático do Citocromo P-450/química Oleandomicina/biossíntese Oxirredutases/química Streptomyces antibioticus/enzimologia [Mh] Termos MeSH secundário: Domínio Catalítico Cristalografia Sistema Enzimático do Citocromo P-450/fisiologia Oxirredutases/fisiologia Estrutura Secundária de Proteína Relação Estrutura-Atividade [Pt] Tipo de publicação: JOURNAL ARTICLE [Nm] Nome de substância: 0 (Anti-Bacterial Agents); 9035-51-2 (Cytochrome P-450 Enzyme System); EC 1.- (Oxidoreductases); EC 1.- (epoxidase); G07GZ97H65 (Clotrimazole); P8ZQ646136 (Oleandomycin) [Em] Mês de entrada: 1605 [Cu] Atualização por classe: 161126 [Lr] Data última revisão: 161126 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 151018 [St] Status: MEDLINE

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[PMID]: 26154602 [Au] Autor: Damnjanovic J; Kuroiwa C; Tanaka H; Ishida K; Nakano H; Iwasaki Y [Ad] Endereço: Laboratory of Molecular Biotechnology, Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan. [Ti] Título: Directing positional specificity in enzymatic synthesis of bioactive 1-phosphatidylinositol by protein engineering of a phospholipase D. [So] Source: Biotechnol Bioeng;113(1):62-71, 2016 Jan. [Is] ISSN: 1097-0290 [Cp] País de publicação: United States [La] Idioma: eng [Ab] Resumo: Phosphatidylinositol (PI) holds a potential of becoming an important dietary supplement due to its effects on lipid metabolism in animals and humans manifested as a decrease of the blood cholesterol and lipids, and relief of the metabolic syndrome. To establish an efficient, enzymatic system for PI production from phosphatidylcholine and myo-inositol as an alcohol acceptor, our previous study started with the wild-type Streptomyces antibioticus phospholipase D (SaPLD) as a template for generation of PI-synthesizing variants by saturation mutagenesis targeting positions involved in acceptor accommodation, W187, Y191, and Y385. The isolated variants generated PI as a mixture of positional isomers, among which only 1-PI exists in nature. Thus, the current study has focused to improve positional specificity of W187N/Y191Y/Y385R SaPLD (NYR) which generates PI as a mixture of 1-PI and 3-PI in the ratio of 76/24, by subjecting four residues of its acceptor-binding site to saturation mutagenesis. Subsequent screening pointed at NYR-186T and NYR-186L as the most improved variants producing PI with a ratio of 1-/3-PI = 93/7 and 87/13, respectively, at 37°C. Lowering the reaction temperature further improved the specificity of both variants to 1-/3-PI > 97/3 at 20°C with no change in total PI yield. Structure model analyses imply that G186T and G186L mutations increased rigidity of the acceptor-binding site, thus limiting the possible orientations of myo-inositol. The two newly isolated PLDs are promising for future application in large-scale 1-PI production. [Mh] Termos MeSH primário: Fosfatidilinositóis/metabolismo Fosfolipase D/genética Fosfolipase D/metabolismo Engenharia de Proteínas/métodos Streptomyces antibioticus/enzimologia [Mh] Termos MeSH secundário: Substituição de Aminoácidos Inositol/metabolismo Modelos Moleculares Mutagênese Sítio-Dirigida Proteínas Mutantes/genética Proteínas Mutantes/metabolismo Fosfatidilcolinas/metabolismo Conformação Proteica Streptomyces antibioticus/genética Especificidade por Substrato Temperatura Ambiente [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Mutant Proteins); 0 (Phosphatidylcholines); 0 (Phosphatidylinositols); 4L6452S749 (Inositol); EC 3.1.4.4 (Phospholipase D) [Em] Mês de entrada: 1609 [Cu] Atualização por classe: 151128 [Lr] Data última revisão: 151128 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 150709 [St] Status: MEDLINE [do] DOI: 10.1002/bit.25697

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[PMID]: 26347302 [Au] Autor: Gohain A; Gogoi A; Debnath R; Yadav A; Singh BP; Gupta VK; Sharma R; Saikia R [Ad] Endereço: Biotechnology Division, CSIR-North East Institute of Science and Technology, Jorhat 785006, Assam, India. [Ti] Título: Antimicrobial biosynthetic potential and genetic diversity of endophytic actinomycetes associated with medicinal plants. [So] Source: FEMS Microbiol Lett;362(19), 2015 Oct. [Is] ISSN: 1574-6968 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: Endophytic actinomycetes are one of the primary groups that share symbiotic relationships with medicinal plants and are key reservoir of biologically active compounds. In this study, six selective medicinal plants were targeted for the first time for endophytic actinomycetes isolation from Gibbon Wild Life Sanctuary, Assam, India, during winter and summer and 76 isolates were obtained. The isolates were found to be prevalent in roots followed by stem and leaves. 16S rRNA gene sequence analysis revealed 16 genera, including rare genera, Verrucosispora, Isoptericola and Kytococcus, which have never been previously reported as endophytic. The genus Streptomyces (66%) was dominant in both seasons. Shannon's diversity index showed that Azadirachta indica (1.49), Rauwolfia serpentina (1.43) and Emblica officinalis (1.24) were relatively good habitat for endophytic actinomycetes. Antimicrobial strains showed prevalence of polyketide synthase (PKS) type-II (85%) followed by PKS type-I (14%) encoded in the genomes. Expression studies showed 12-fold upregulation of PKSII gene in seventh day of incubation for Streptomyces antibioticus (EAAG90). Our results emphasize that the actinomycetes assemblages within plant tissue exhibited biosynthetic systems encoding for important biologically active compounds. [Mh] Termos MeSH primário: Actinobacteria/genética Actinobacteria/metabolismo Variação Genética Plantas Medicinais/microbiologia Policetídeo Sintases/genética [Mh] Termos MeSH secundário: Actinobacteria/classificação Actinobacteria/isolamento & purificação Anti-Infecciosos/isolamento & purificação Antibiose Azadirachta/microbiologia Biodiversidade Endófitos/genética Endófitos/metabolismo Genoma Bacteriano Índia Micromonosporaceae Phyllanthus emblica/microbiologia Filogenia Folhas de Planta/microbiologia Raízes de Plantas/microbiologia Caules de Planta/microbiologia Policetídeo Sintases/biossíntese RNA Ribossômico 16S Rauwolfia/microbiologia Análise de Sequência de DNA Streptomyces/genética Streptomyces antibioticus/genética Simbiose [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Anti-Infective Agents); 0 (RNA, Ribosomal, 16S); 79956-01-7 (Polyketide Synthases) [Em] Mês de entrada: 1607 [Cu] Atualização por classe: 151002 [Lr] Data última revisão: 151002 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 150909 [St] Status: MEDLINE

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[PMID]: 25861759 [Au] Autor: Schäfer M; Le TB; Hearnshaw SJ; Maxwell A; Challis GL; Wilkinson B; Buttner MJ [Ad] Endereço: Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, United Kingdom. [Ti] Título: SimC7 Is a Novel NAD(P)H-Dependent Ketoreductase Essential for the Antibiotic Activity of the DNA Gyrase Inhibitor Simocyclinone. [So] Source: J Mol Biol;427(12):2192-204, 2015 Jun 19. [Is] ISSN: 1089-8638 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: Simocyclinone D8 (SD8) is a potent DNA gyrase inhibitor produced by Streptomyces antibioticus Tü6040. The simocyclinone (sim) biosynthetic gene cluster has been sequenced and a hypothetical biosynthetic pathway has been proposed. The tetraene linker in SD8 was suggested to be the product of a modular type I polyketide synthase working in trans with two monofunctional enzymes. One of these monofunctional enzymes, SimC7, was proposed to supply a dehydratase activity missing from two modules of the polyketide synthase. In this study, we report the function of SimC7. We isolated the entire ~72-kb sim cluster on a single phage artificial chromosome clone and produced simocyclinone heterologously in a Streptomyces coelicolor strain engineered for improved antibiotic production. Deletion of simC7 resulted in the production of a novel simocyclinone, 7-oxo-SD8, which unexpectedly carried a normal tetraene linker but was altered in the angucyclinone moiety. We demonstrate that SimC7 is an NAD(P)H-dependent ketoreductase that catalyzes the conversion of 7-oxo-SD8 into SD8. 7-oxo-SD8 was essentially inactive as a DNA gyrase inhibitor, and the reduction of the keto group by SimC7 was shown to be crucial for high-affinity binding to the enzyme. Thus, SimC7 is an angucyclinone ketoreductase that is essential for the biological activity of simocyclinone. [Mh] Termos MeSH primário: Oxirredutases do Álcool/metabolismo Antibacterianos/farmacologia DNA Girase/metabolismo NAD/metabolismo Streptomyces antibioticus/enzimologia [Mh] Termos MeSH secundário: Oxirredutases do Álcool/genética Vias Biossintéticas/genética Biotransformação Cumarínicos/farmacologia Inibidores Enzimáticos/farmacologia Deleção de Genes Glicosídeos/farmacologia Família Multigênica Oxirredução Proteínas Recombinantes/genética Proteínas Recombinantes/metabolismo Streptomyces antibioticus/genética Streptomyces coelicolor/enzimologia Streptomyces coelicolor/genética Streptomyces coelicolor/metabolismo [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Anti-Bacterial Agents); 0 (Coumarins); 0 (Enzyme Inhibitors); 0 (Glycosides); 0 (Recombinant Proteins); 0 (simocyclinone D8); 0U46U6E8UK (NAD); EC 1.1.- (Alcohol Oxidoreductases); EC 5.99.1.3 (DNA Gyrase) [Em] Mês de entrada: 1507 [Cu] Atualização por classe: 170922 [Lr] Data última revisão: 170922 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 150412 [St] Status: MEDLINE

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[PMID]: 25209510 [Au] Autor: Sasaki Y; Takaya N; Morita A; Nakamura A; Shoun H [Ad] Endereço: a Faculty of Applied Bioscience, Department of Bioscience , Tokyo University of Agriculture , Tokyo , Japan. [Ti] Título: Nitrite formation from organic nitrogen by Streptomyces antibioticus supporting bacterial cell growth and possible involvement of nitric oxide as an intermediate. [So] Source: Biosci Biotechnol Biochem;78(9):1603-10, 2014. [Is] ISSN: 1347-6947 [Cp] País de publicação: England [La] Idioma: eng [Ab] Resumo: The actinomycete Streptomyces antibioticus was shown to produce nitrite (NO-(2)) and ammonium (NH+(4)]) when aerobically incubated in an organic nitrogen-rich medium. The production of NO-(2) was synchronized with rapid cell growth, whereas most NH+(4)] was produced after cell proliferation had ceased. Intracellular formation of nitric oxide (NO) was also observed during the incubation. The production of these inorganic nitrogen compounds along with cell growth was prevented by several enzyme inhibitors (of nitric oxide synthase or nitrate reductase) or glucose. Distinct, membrane-bound nitrate reductase was induced in the NO-(2)-producing cells. Tungstate (a potent inhibitor of this enzyme) prevented the NO-(2) production and cell growth, whereas it did not prevent the NO formation. These results revealed the occurrence of novel nitrogen metabolic pathway in S. antibioticus forming NO-(2) from organic nitrogen by which rapid cell growth is possible. NO synthase, NO dioxygenase (flavohemoglobin), and dissimilatory nitrate reductase are possible enzymes responsible for the NO-(2) formation. [Mh] Termos MeSH primário: Óxido Nítrico/metabolismo Nitritos/metabolismo Streptomyces antibioticus/crescimento & desenvolvimento [Mh] Termos MeSH secundário: Citoplasma/metabolismo Óxido Nítrico Sintase Nitrogênio/metabolismo Streptomyces antibioticus/metabolismo [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Nitrites); 31C4KY9ESH (Nitric Oxide); EC 1.14.13.39 (Nitric Oxide Synthase); N762921K75 (Nitrogen) [Em] Mês de entrada: 1505 [Cu] Atualização por classe: 140911 [Lr] Data última revisão: 140911 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 140912 [St] Status: MEDLINE [do] DOI: 10.1080/09168451.2014.932665

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[PMID]: 24849818 [Au] Autor: Haudecoeur R; Gouron A; Dubois C; Jamet H; Lightbody M; Hardré R; Milet A; Bergantino E; Bubacco L; Belle C; Réglier M; Boumendjel A [Ad] Endereço: Univ. Grenoble Alpes/CNRS, DPM UMR 5063, 38041 Grenoble (France). [Ti] Título: Investigation of binding-site homology between mushroom and bacterial tyrosinases by using aurones as effectors. [So] Source: Chembiochem;15(9):1325-33, 2014 Jun 16. [Is] ISSN: 1439-7633 [Cp] País de publicação: Germany [La] Idioma: eng [Ab] Resumo: Tyrosinase is a copper-containing enzyme found in plants and bacteria, as well as in humans, where it is involved in the biosynthesis of melanin-type pigments. Tyrosinase inhibitors have attracted remarkable research interest as whitening agents in cosmetology, antibrowning agents in food chemistry, and as therapeutics. In this context, commercially available tyrosinase from mushroom (TyM) is frequently used for the identification of inhibitors. This and bacterial tyrosinase (TyB) have been the subjects of intense biochemical and structural studies, including X-ray diffraction analysis, and this has led to the identification of structural homology and divergence among enzymes from different sources. To better understand the behavior of potential inhibitors of TyM and TyB, we selected the aurone family-previously identified as potential inhibitors of melanin biosynthesis in human melanocytes. In this study, a series of 24 aurones with different hydroxylation patterns at the A- and B-rings were evaluated on TyM and TyB. The results show that, depending on the hydroxylation pattern of A- and B-rings, aurones can behave as inhibitors, substrates, and activators of both enzymes. Computational analysis was performed to identify residues surrounding the aurones in the active sites of both enzymes and to rationalize the interactions. Our results highlight similarities and divergence in the behavior of TyM and TyB toward the same set of molecules. [Mh] Termos MeSH primário: Agaricus/enzimologia Benzofuranos/farmacologia Inibidores Enzimáticos/farmacologia Monofenol Mono-Oxigenase/antagonistas & inibidores Streptomyces antibioticus/enzimologia [Mh] Termos MeSH secundário: Benzofuranos/química Sítios de Ligação/efeitos dos fármacos Relação Dose-Resposta a Droga Inibidores Enzimáticos/química Modelos Moleculares Estrutura Molecular Monofenol Mono-Oxigenase/metabolismo Relação Estrutura-Atividade [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T [Nm] Nome de substância: 0 (Benzofurans); 0 (Enzyme Inhibitors); 0 (aurone); EC 1.14.18.1 (Monophenol Monooxygenase) [Em] Mês de entrada: 1503 [Cu] Atualização por classe: 140612 [Lr] Data última revisão: 140612 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 140523 [St] Status: MEDLINE [do] DOI: 10.1002/cbic.201402003

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[PMID]: 24677528 [Au] Autor: Zhang J; Singh S; Hughes RR; Zhou M; Sunkara M; Morris AJ; Thorson JS [Ti] Título: A simple strategy for glycosyltransferase-catalyzed aminosugar nucleotide synthesis. [So] Source: Chembiochem;15(5):647-52, 2014 Mar 21. [Is] ISSN: 1439-7633 [Cp] País de publicação: Germany [La] Idioma: eng [Ab] Resumo: A set of 2-chloro-4-nitrophenyl glucosamino-/xylosaminosides were synthesized and assessed as potential substrates in the context of glycosyltransferase-catalyzed formation of the corresponding UDP/TDP-α-D-glucosamino-/xylosaminosugars and in single-vessel model transglycosylation reactions. This study highlights a robust platform for aminosugar nucleotide synthesis and reveals OleD Loki to be a proficient catalyst for U/TDP-aminosugar synthesis and utilization [Mh] Termos MeSH primário: Aminas/metabolismo Metabolismo dos Carboidratos Glicosiltransferases/metabolismo Nucleotídeos/metabolismo Streptomyces antibioticus/enzimologia [Mh] Termos MeSH secundário: Aminas/química Carboidratos/química Catálise Glucosídeos/química Glucosídeos/metabolismo Glicosiltransferases/genética Nitrofenóis/química Nitrofenóis/metabolismo Nucleotídeos/química Engenharia de Proteínas Streptomyces antibioticus/genética Especificidade por Substrato [Pt] Tipo de publicação: JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL [Nm] Nome de substância: 0 (Amines); 0 (Carbohydrates); 0 (Glucosides); 0 (Nitrophenols); 0 (Nucleotides); 2395-99-5 (4-nitrophenyl); EC 2.4.- (Glycosyltransferases) [Em] Mês de entrada: 1412 [Cu] Atualização por classe: 170220 [Lr] Data última revisão: 170220 [Sb] Subgrupo de revista: IM [Da] Data de entrada para processamento: 140329 [St] Status: MEDLINE

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