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Pesquisa : D08.811.277.087.902 [Categoria DeCS]
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[PMID]:29324337
[Au] Autor:Ullah A; Iftikhar F; Arfan M; Batool Kazmi ST; Anjum MN; Haq IU; Ayaz M; Farooq S; Rashid U
[Ad] Endereço:Department of Chemistry, Hazara University, Mansehra 21120, Pakistan.
[Ti] Título:Amino acid conjugated antimicrobial drugs: Synthesis, lipophilicity- activity relationship, antibacterial and urease inhibition activity.
[So] Source:Eur J Med Chem;145:140-153, 2018 Feb 10.
[Is] ISSN:1768-3254
[Cp] País de publicação:France
[La] Idioma:eng
[Ab] Resumo:Present work describes the in vitro antibacterial evaluation of some new amino acid conjugated antimicrobial drugs. Structural modification was attempted on the three existing antimicrobial pharmaceuticals namely trimethoprim, metronidazole, isoniazid. Twenty one compounds from seven series of conjugates of these drugs were synthesized by coupling with some selected Boc-protected amino acids. The effect of structural features and lipophilicity on the antibacterial activity was investigated. The synthesized compounds were evaluated against five standard American type culture collection (ATCC) i.e. Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi strains of bacteria. Our results identified a close relationship between the lipophilicity and the activity. Triazine skeleton proved beneficial for the increase in hydrophobicity and potency. Compounds with greater hydrophobicity have shown excellent activities against Gram-negative strains of bacteria than Gram-positive. 4-amino unsubstituted trimethoprim-triazine derivative 7b have shown superior activity with MIC = 3.4 µM (2 µg/mL) for S. aureus and 1.1 µM (0.66 µg/mL) for E. coli. The synthesized compounds were also evaluated for their urease inhibition study. Microbial urease from Bacillus pasteurii was chosen for this study. Triazine derivative 7a showed excellent inhibition with IC = 6.23 ±â€¯0.09 µM. Docking studies on the crystal structure of B. pasteurii urease (PDB ID 4UBP) were carried out.
[Mh] Termos MeSH primário: Aminoácidos/farmacologia
Antibacterianos/farmacologia
Inibidores Enzimáticos/farmacologia
Isoniazida/farmacologia
Metronidazol/farmacologia
Trimetoprima/farmacologia
[Mh] Termos MeSH secundário: Aminoácidos/química
Antibacterianos/síntese química
Antibacterianos/química
Bacillus/efeitos dos fármacos
Bacillus/enzimologia
Relação Dose-Resposta a Droga
Inibidores Enzimáticos/síntese química
Inibidores Enzimáticos/química
Escherichia coli/efeitos dos fármacos
Interações Hidrofóbicas e Hidrofílicas
Isoniazida/síntese química
Isoniazida/química
Metronidazol/síntese química
Metronidazol/química
Testes de Sensibilidade Microbiana
Estrutura Molecular
Pseudomonas aeruginosa/efeitos dos fármacos
Salmonella typhi/efeitos dos fármacos
Staphylococcus aureus/efeitos dos fármacos
Relação Estrutura-Atividade
Trimetoprima/síntese química
Trimetoprima/química
Urease/antagonistas & inibidores
Urease/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amino Acids); 0 (Anti-Bacterial Agents); 0 (Enzyme Inhibitors); 140QMO216E (Metronidazole); AN164J8Y0X (Trimethoprim); EC 3.5.1.5 (Urease); V83O1VOZ8L (Isoniazid)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180227
[Lr] Data última revisão:
180227
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180112
[St] Status:MEDLINE


  2 / 4806 MEDLINE  
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[PMID]:29183662
[Au] Autor:Taha M; Ullah H; Al Muqarrabun LMR; Khan MN; Rahim F; Ahmat N; Javid MT; Ali M; Khan KM
[Ad] Endereço:Department of Clinical Pharmacy, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, P.O. Box 31441, Dammam, Saudi Arabia. Electronic address: taha_hej@yahoo.com.
[Ti] Título:Bisindolylmethane thiosemicarbazides as potential inhibitors of urease: Synthesis and molecular modeling studies.
[So] Source:Bioorg Med Chem;26(1):152-160, 2018 01 01.
[Is] ISSN:1464-3391
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Bisindolylmethane thiosemicarbazides 1-18 were synthesized, characterized by H NMR and ESI MS and evaluated for urease inhibitory potential. All analogs showed outstanding urease inhibitory potentials with IC values ranging between 0.14 ±â€¯0.01 to 18.50 ±â€¯0.90 µM when compared with the standard inhibitor thiourea having IC value 21.25 ±â€¯0.90 µM. Among the series, analog 9 (0.14 ±â€¯0.01 µM) with di-chloro substitution on phenyl ring was identified as the most potent inhibitor of urease. The structure activity relationship has been also established on the basis of binding interactions of the active analogs. These binding interactions were identified by molecular docking studies.
[Mh] Termos MeSH primário: Inibidores Enzimáticos/farmacologia
Indóis/farmacologia
Semicarbazidas/farmacologia
Urease/antagonistas & inibidores
[Mh] Termos MeSH secundário: Canavalia/enzimologia
Relação Dose-Resposta a Droga
Inibidores Enzimáticos/síntese química
Inibidores Enzimáticos/química
Indóis/química
Modelos Moleculares
Estrutura Molecular
Semicarbazidas/química
Relação Estrutura-Atividade
Urease/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Enzyme Inhibitors); 0 (Indoles); 0 (Semicarbazides); 6056O8W6ET (thiosemicarbazide); EC 3.5.1.5 (Urease); SSZ9HQT61Z (3,3'-diindolylmethane)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180106
[Lr] Data última revisão:
180106
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171130
[St] Status:MEDLINE


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[PMID]:29284254
[Au] Autor:Shi W; Ma X
[Ad] Endereço:University of Science and Technology, Kerui Road 1, Gaoxin, Section, Suzhou 215011, Jiangsu, China. 196131182@qq.com.
[Ti] Título:Effects of heavy metal Cd pollution on microbial activities in soil.
[So] Source:Ann Agric Environ Med;24(4):722-725, 2017 Dec 23.
[Is] ISSN:1898-2263
[Cp] País de publicação:Poland
[La] Idioma:eng
[Ab] Resumo:Heavy metal contamination of soil occurs when heavy metals are introduced to soil through human activities, leading to the gradual deterioration of the ecology and environment. Microorganism activity reflects the intensity of various biochemical reactions in soil, and changes in it reflect the level of heavy metal pollution affecting the soil. The effects were studied of heavy metal Cd on the microbial activity of soil at different concentrations by investigating the respiratory intensity, urease activity, and catalase activity in forest soil and garden soil. The results showed that the respiratory intensity, urease and catalase activities in the garden soil were all higher than in the forest soil. Cd has obvious inhibitory effects on microbial activities. The three parameters exhibited a downward trend with increasing concentrations of Cd. Catalase activity increased when the mass concentration of Cd reached 1.0 mg/kg, indicating that low concentrations of Cd can promote the activity of some microorganisms. Respiratory intensity and urease activity also increased when the concentration reached 10.0 mg/kg, showing that respiratory intensity and urease activity have strong response mechanisms to adverse conditions. The effective state of Cd in soil, as well as inhibition of microbial activity, decreased with incubation time.
[Mh] Termos MeSH primário: Bactérias/efeitos dos fármacos
Cádmio/farmacologia
Microbiologia do Solo
Poluentes do Solo/farmacologia
[Mh] Termos MeSH secundário: Bactérias/enzimologia
Bactérias/genética
Bactérias/isolamento & purificação
Proteínas de Bactérias/metabolismo
Cádmio/análise
Catalase/metabolismo
Solo/química
Poluentes do Solo/análise
Urease/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Soil); 0 (Soil Pollutants); 00BH33GNGH (Cadmium); EC 1.11.1.6 (Catalase); EC 3.5.1.5 (Urease)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180105
[Lr] Data última revisão:
180105
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171230
[St] Status:MEDLINE


  4 / 4806 MEDLINE  
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[PMID]:28857549
[Au] Autor:Mazzei L; Cianci M; Contaldo U; Musiani F; Ciurli S
[Ad] Endereço:Laboratory of Bioinorganic Chemistry, Department of Pharmacy and Biotechnology, University of Bologna , Bologna, Italy.
[Ti] Título:Urease Inhibition in the Presence of N-(n-Butyl)thiophosphoric Triamide, a Suicide Substrate: Structure and Kinetics.
[So] Source:Biochemistry;56(40):5391-5404, 2017 Oct 10.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The nickel-dependent enzyme urease is a virulence factor for a large number of pathogenic and antibiotic-resistant bacteria, as well as a negative factor for the efficiency of soil nitrogen fertilization for crop production. The use of urease inhibitors to offset these effects requires knowledge, at a molecular level, of their mode of action. The 1.28 Å resolution structure of the enzyme-inhibitor complex obtained upon incubation of Sporosarcina pasteurii urease with N-(n-butyl)thiophosphoric triamide (NBPT), a molecule largely utilized in agriculture, reveals the presence of the monoamidothiophosphoric acid (MATP) moiety, obtained upon enzymatic hydrolysis of the diamide derivative of NBPT (NBPD) to yield n-butyl amine. MATP is bound to the two Ni(II) ions in the active site of urease using a µ -bridging O atom and terminally bound O and NH groups, with the S atom of the thiophosphoric amide pointing away from the metal center. The mobile flap modulating the size of the active site cavity is found in the closed conformation. Docking calculations suggest that the interaction between urease in the open flap conformation and NBPD involves a role for the conserved αArg339 in capturing and orienting the inhibitor prior to flap closure. Calorimetric and spectrophotometric determinations of the kinetic parameters of this inhibition indicate the occurrence of a reversible slow inhibition mode of action, characterized, for both bacterial and plant ureases, by a very small value of the dissociation constant of the urease-MATP complex. No need to convert NBPT to its oxo derivative NBPTO, as previously proposed, is necessary for urease inhibition.
[Mh] Termos MeSH primário: Inibidores Enzimáticos/metabolismo
Inibidores Enzimáticos/farmacologia
Compostos Organofosforados/metabolismo
Compostos Organofosforados/farmacologia
Urease/antagonistas & inibidores
Urease/metabolismo
[Mh] Termos MeSH secundário: Domínio Catalítico
Hidrólise
Cinética
Simulação de Acoplamento Molecular
Sporosarcina/enzimologia
Ureia/metabolismo
Urease/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzyme Inhibitors); 0 (N-(n-butyl) thiophosphoric triamide); 0 (Organophosphorus Compounds); 8W8T17847W (Urea); EC 3.5.1.5 (Urease)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171019
[Lr] Data última revisão:
171019
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170901
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.7b00750


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[PMID]:28809946
[Au] Autor:Blum FC; Hu HQ; Servetas SL; Benoit SL; Maier RJ; Maroney MJ; Merrell DS
[Ad] Endereço:Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, United States of America.
[Ti] Título:Structure-function analyses of metal-binding sites of HypA reveal residues important for hydrogenase maturation in Helicobacter pylori.
[So] Source:PLoS One;12(8):e0183260, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The nickel-containing enzymes of Helicobacter pylori, urease and hydrogenase, are essential for efficient colonization in the human stomach. The insertion of nickel into urease and hydrogenase is mediated by the accessory protein HypA. HypA contains an N-terminal nickel-binding site and a dynamic structural zinc-binding site. The coordination of nickel and zinc within HypA is known to be critical for urease maturation and activity. Herein, we test the hydrogenase activity of a panel of H. pylori mutant strains containing point mutations within the nickel- and zinc-binding sites. We found that the residues that are important for hydrogenase activity are those that were similarly vital for urease activity. Thus, the zinc and metal coordination sites of HypA play similar roles in urease and hydrogenase maturation. In other pathogenic bacteria, deletion of hydrogenase leads to a loss in acid resistance. Thus, the acid resistance of two strains of H. pylori containing a hydrogenase deletion was also tested. These mutant strains demonstrated wild-type levels of acid resistance, suggesting that in H. pylori, hydrogenase does not play a role in acid resistance.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Proteínas de Bactérias/metabolismo
Helicobacter pylori/enzimologia
Hidrogenase/química
Hidrogenase/metabolismo
[Mh] Termos MeSH secundário: Sítios de Ligação
Helicobacter pylori/metabolismo
Concentração de Íons de Hidrogênio
Níquel/metabolismo
Ligação Proteica
Urease/química
Urease/metabolismo
Zinco/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 7OV03QG267 (Nickel); EC 1.12.7.2 (Hydrogenase); EC 3.5.1.5 (Urease); J41CSQ7QDS (Zinc)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171011
[Lr] Data última revisão:
171011
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170816
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0183260


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[PMID]:28792967
[Au] Autor:Macegoniuk K; Grela E; Biernat M; Psurski M; Gosciniak G; Dzielak A; Mucha A; Wietrzyk J; Berlicki L; Grabowiecka A
[Ad] Endereço:Wroclaw University of Technology, Faculty of Chemistry, Department of Bioorganic Chemistry, Wroclaw, Poland.
[Ti] Título:Aminophosphinates against Helicobacter pylori ureolysis-Biochemical and whole-cell inhibition characteristics.
[So] Source:PLoS One;12(8):e0182437, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Urease is an important virulence factor from Helicobacter pylori that enables bacterial colonization of human gastric mucosa. Specific inhibition of urease activity can be regarded as a promising adjuvant strategy for eradication of this pathogen. A group of organophosphorus inhibitors of urease, namely, aminophosphinic acid and aminophosphonic acid derivatives, were evaluated in vitro against H. pylori urease. The kinetic characteristics of recombinant enzyme activity demonstrated a competitive reversible mode of inhibition with Ki values ranging from 0.294 to 878 µM. N-n-Hexylaminomethyl-P-aminomethylphosphinic acid and N-methylaminomethyl-P-hydroxymethylphosphinic acid were the most effective inhibitors (Ki = 0.294 µM and 1.032 µM, respectively, compared to Ki = 23 µM for the established urease inhibitor acetohydroxamic acid). The biological relevance of the inhibitors was verified in vitro against a ureolytically active Escherichia coli Rosetta host that expressed H. pylori urease and against a reference strain, H. pylori J99 (CagA+/VacA+). The majority of the studied compounds exhibited urease-inhibiting activity in these whole-cell systems. Bis(N-methylaminomethyl)phosphinic acid was found to be the most effective inhibitor in the susceptibility profile studies of H. pylori J99. The cytotoxicity of nine structurally varied inhibitors was evaluated against four normal human cell lines and was found to be negligible.
[Mh] Termos MeSH primário: Antibacterianos/uso terapêutico
Helicobacter pylori/efeitos dos fármacos
Ácidos Fosfínicos/uso terapêutico
Ácidos Fosforosos/uso terapêutico
Urease/antagonistas & inibidores
[Mh] Termos MeSH secundário: Animais
Células 3T3 BALB
Linhagem Celular
Escherichia coli/efeitos dos fármacos
Escherichia coli/enzimologia
Infecções por Helicobacter/tratamento farmacológico
Helicobacter pylori/enzimologia
Seres Humanos
Camundongos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Phosphinic Acids); 0 (Phosphorous Acids); EC 3.5.1.5 (Urease)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171010
[Lr] Data última revisão:
171010
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170810
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0182437


  7 / 4806 MEDLINE  
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[PMID]:28753459
[Au] Autor:Iftikhar F; Ali Y; Ahmad Kiani F; Fahad Hassan S; Fatima T; Khan A; Niaz B; Hassan A; Latif Ansari F; Rashid U
[Ad] Endereço:Department of Chemistry, Hazara University, Mansehra 21120, Pakistan.
[Ti] Título:Design, synthesis, in vitro Evaluation and docking studies on dihydropyrimidine-based urease inhibitors.
[So] Source:Bioorg Chem;74:53-65, 2017 Oct.
[Is] ISSN:1090-2120
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In our previous report, we have identified 3,4-dihydropyrimidine scaffold as promising class of urease inhibitor in a structure based virtual screen (SBVS) experiment. In present study, we attempted to optimize the scaffold by varying C-5 substituent. The elongation of the C-5 chain was achieved by the reaction of C-5 ester with hydrazine leading to C-5 carbohydrazides which were further used as building blocks for the synthesis of fifteen new compounds having diverse moieties. A significantly higher in vitro urease inhibitory activity with IC values in submicromolar range was observed for semithiocarbazide derivatives (4a-c, 0.58-0.79µM) and isatin Schiff base derivative 5a (0.23µM). Docking analysis suggests that the synthesized compounds were anchored well in the catalytic site and extending to the entrance of binding pocket and thus restrict the mobility of the flap by interacting with its key amino acid residues. The overall results of urease inhibition have shown that these compounds can be further optimized and developed as lead urease inhibitors.
[Mh] Termos MeSH primário: Canavalia/enzimologia
Desenho de Drogas
Inibidores Enzimáticos/farmacologia
Simulação de Acoplamento Molecular
Pirimidinas/farmacologia
Urease/antagonistas & inibidores
[Mh] Termos MeSH secundário: Relação Dose-Resposta a Droga
Inibidores Enzimáticos/síntese química
Inibidores Enzimáticos/química
Estrutura Molecular
Pirimidinas/síntese química
Pirimidinas/química
Teoria Quântica
Relação Estrutura-Atividade
Urease/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzyme Inhibitors); 0 (Pyrimidines); EC 3.5.1.5 (Urease)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171010
[Lr] Data última revisão:
171010
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170729
[St] Status:MEDLINE


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[PMID]:28710280
[Au] Autor:Myrach T; Zhu A; Witte CP
[Ad] Endereço:From the Freie Universität Berlin, Dahlem Centre of Plant Sciences, Department of Plant Biochemistry, Königin-Luise-Strasse 12-16, 14195 Berlin, Germany and.
[Ti] Título:The assembly of the plant urease activation complex and the essential role of the urease accessory protein G (UreG) in delivery of nickel to urease.
[So] Source:J Biol Chem;292(35):14556-14565, 2017 Sep 01.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Urease is a ubiquitous nickel metalloenzyme. In plants, its activation requires three urease accessory proteins (UAPs), UreD, UreF, and UreG. In bacteria, the UAPs interact with urease and facilitate activation, which involves the channeling of two nickel ions into the active site. So far this process has not been investigated in eukaryotes. Using affinity pulldowns of Strep-tagged UAPs from and rice transiently expressed , we demonstrate that a urease-UreD-UreF-UreG complex exists in plants and show its stepwise assembly. UreG is crucial for nickel delivery because UreG-dependent urease activation was observed only with UreG obtained from nickel-sufficient plants. This activation competence could not be generated by incubation of UreG with nickel, bicarbonate, and GTP. Compared with their bacterial orthologs, plant UreGs possess an N-terminal extension containing a His- and Asp/Glu-rich hypervariable region followed by a highly conserved sequence comprising two potential H H metal-binding sites. Complementing the mutant of with N-terminal deletion variants of UreG demonstrated that the hypervariable region has a minor impact on activation efficiency, whereas the conserved region up to the first H H motif is highly beneficial and up to the second H H motif strictly required for activation. We also show that urease reaches its full activity several days after nickel becomes available in the leaves, indicating that urease activation is limited by nickel accessibility Our data uncover the crucial role of UreG for nickel delivery during eukaryotic urease activation, inciting further investigations of the details of this process.
[Mh] Termos MeSH primário: Proteínas de Arabidopsis/metabolismo
Arabidopsis/enzimologia
Modelos Moleculares
Níquel/metabolismo
Plantas Geneticamente Modificadas/metabolismo
Tabaco/metabolismo
Urease/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Apoenzimas/química
Apoenzimas/genética
Apoenzimas/isolamento & purificação
Apoenzimas/metabolismo
Arabidopsis/metabolismo
Proteínas de Arabidopsis/química
Proteínas de Arabidopsis/genética
Proteínas de Arabidopsis/isolamento & purificação
Células Cultivadas
Células Clonais
Sequência Conservada
Ativação Enzimática
Deleção de Genes
Hidroponia
Mutação
Oryza/enzimologia
Oryza/metabolismo
Folhas de Planta/citologia
Folhas de Planta/genética
Folhas de Planta/crescimento & desenvolvimento
Folhas de Planta/metabolismo
Proteínas de Plantas/química
Proteínas de Plantas/genética
Proteínas de Plantas/metabolismo
Plantas Geneticamente Modificadas/citologia
Plantas Geneticamente Modificadas/genética
Plantas Geneticamente Modificadas/crescimento & desenvolvimento
Multimerização Proteica
Proteínas Recombinantes de Fusão/química
Proteínas Recombinantes de Fusão/isolamento & purificação
Proteínas Recombinantes de Fusão/metabolismo
Proteínas Recombinantes/química
Proteínas Recombinantes/isolamento & purificação
Proteínas Recombinantes/metabolismo
Tabaco/citologia
Tabaco/genética
Tabaco/crescimento & desenvolvimento
Urease/química
Urease/genética
Urease/isolamento & purificação
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Apoenzymes); 0 (Arabidopsis Proteins); 0 (Plant Proteins); 0 (Recombinant Fusion Proteins); 0 (Recombinant Proteins); 0 (UreD protein, Arabidopsis); 0 (UreF protein, Arabidopsis); 0 (UreG protein, Arabidopsis); 7OV03QG267 (Nickel); EC 3.5.1.5 (Urease)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170926
[Lr] Data última revisão:
170926
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170716
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M117.780403


  9 / 4806 MEDLINE  
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[PMID]:28644872
[Au] Autor:Debowski AW; Walton SM; Chua EG; Tay AC; Liao T; Lamichhane B; Himbeck R; Stubbs KA; Marshall BJ; Fulurija A; Benghezal M
[Ad] Endereço:Helicobacter pylori Research Laboratory, Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Nedlands, Western Australia, Australia.
[Ti] Título:Helicobacter pylori gene silencing in vivo demonstrates urease is essential for chronic infection.
[So] Source:PLoS Pathog;13(6):e1006464, 2017 Jun.
[Is] ISSN:1553-7374
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Helicobacter pylori infection causes chronic active gastritis that after many years of infection can develop into peptic ulceration or gastric adenocarcinoma. The bacterium is highly adapted to surviving in the gastric environment and a key adaptation is the virulence factor urease. Although widely postulated, the requirement of urease expression for persistent infection has not been elucidated experimentally as conventional urease knockout mutants are incapable of colonization. To overcome this constraint, conditional H. pylori urease mutants were constructed by adapting the tetracycline inducible expression system that enabled changing the urease phenotype of the bacteria during established infection. Through tight regulation we demonstrate that urease expression is not only required for establishing initial colonization but also for maintaining chronic infection. Furthermore, successful isolation of tet-escape mutants from a late infection time point revealed the strong selective pressure on this gastric pathogen to continuously express urease in order to maintain chronic infection. In addition to mutations in the conditional gene expression system, escape mutants were found to harbor changes in other genes including the alternative RNA polymerase sigma factor, fliA, highlighting the genetic plasticity of H. pylori to adapt to a changing niche. The tet-system described here opens up opportunities to studying genes involved in the chronic stage of H. pylori infection to gain insight into bacterial mechanisms promoting immune escape and life-long infection. Furthermore, this genetic tool also allows for a new avenue of inquiry into understanding the importance of various virulence determinants in a changing biological environment when the bacterium is put under duress.
[Mh] Termos MeSH primário: Gastrite/genética
Inativação Gênica/fisiologia
Infecções por Helicobacter/imunologia
Helicobacter pylori/genética
Urease/metabolismo
[Mh] Termos MeSH secundário: Animais
Proteínas de Bactérias/metabolismo
Doença Crônica
Mucosa Gástrica/microbiologia
Gastrite/microbiologia
Expressão Gênica/genética
Camundongos
Neoplasias Gástricas/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); EC 3.5.1.5 (Urease)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170929
[Lr] Data última revisão:
170929
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170624
[St] Status:MEDLINE
[do] DOI:10.1371/journal.ppat.1006464


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[PMID]:28623137
[Au] Autor:Ahmed M; Qadir MA; Hameed A; Arshad MN; Asiri AM; Muddassar M
[Ad] Endereço:Institute of Chemistry, University of the Punjab, Lahore, 54590, Pakistan. Electronic address: mahmoodresearchscholar@gmail.com.
[Ti] Título:Azomethines, isoxazole, N-substituted pyrazoles and pyrimidine containing curcumin derivatives: Urease inhibition and molecular modeling studies.
[So] Source:Biochem Biophys Res Commun;490(2):434-440, 2017 Aug 19.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Curcumin has shown large number of pharmacological properties against different phenotypes of various disease models. Different synthetic routes have been employed to develop its various derivatives for diverse biological functions. In this study, curcumin derived azomethine, isoxazole, pyrimidines and N-substituted pyrazoles were synthesized to investigate their urease enzyme inhibition. The structures of newly synthesized compounds were described by IR, MS, H NMR and C NMR spectral data. Urease enzyme inhibition was evaluated through in vitro assays in which compound 8b was found to be the most potent (IC = 2.44 ± 0.07 µM) among the tested compounds. The compounds with diazine ring system except the 4d showed better urease inhibition (IC = 11.43 ± 0.21-19.63 ± 0.28 µM) than the standard urease inhibitor thiourea (IC = 22.61 ± 0.23 µM). Similarly enzyme kinetics data revealed that compounds 3c-3e and 8b were competitive inhibitors with Ki values of 20.0, 19.87, 20.23 and 19.11 µM respectively while the compounds 4b, 4c and 4e were mixed type of inhibitors with Ki values 6.72, 19.69 and 6.72 µM respectively. Molecular docking studies were also performed to identify the plausible binding modes of the most active compounds.
[Mh] Termos MeSH primário: Canavalia/enzimologia
Curcumina/análogos & derivados
Curcumina/farmacologia
Inibidores Enzimáticos/química
Inibidores Enzimáticos/farmacologia
Urease/antagonistas & inibidores
[Mh] Termos MeSH secundário: Compostos Azo/química
Compostos Azo/farmacologia
Concentração Inibidora 50
Isoxazóis/química
Isoxazóis/farmacologia
Pirazóis/química
Pirazóis/farmacologia
Pirimidinas/química
Pirimidinas/farmacologia
Relação Estrutura-Atividade
Tiossemicarbazonas/química
Tiossemicarbazonas/farmacologia
Tioureia/análogos & derivados
Tioureia/farmacologia
Urease/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Azo Compounds); 0 (Enzyme Inhibitors); 0 (Isoxazoles); 0 (Pyrazoles); 0 (Pyrimidines); 0 (Thiosemicarbazones); 0 (azomethine); EC 3.5.1.5 (Urease); GYV9AM2QAG (Thiourea); IT942ZTH98 (Curcumin)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170731
[Lr] Data última revisão:
170731
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170618
[St] Status:MEDLINE



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