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2.
Vaccine ; 37(24): 3151-3153, 2019 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-31060953

RESUMO

Vaccination against measles has reduced disease, although measles virus antibody (MVAb) levels are lower after vaccination than natural infection. Immunoglobulin (IG) preparations thus contain decreasing MVAb titers. US IG lot release requires a minimum titer of MVAb, yet equivalent information is not available for other geographies. Using a measles virus neutralization assay, IG fractionated from US or EU plasma is shown to contain similar levels of MVAb always above US regulatory requirements, supportive of equivalent protection against MV infection. Thus, the dosage for post-exposure prophylaxis in the EU could be aligned with the US FDA's treatment recommendations.


Assuntos
Anticorpos Neutralizantes/isolamento & purificação , Anticorpos Antivirais/isolamento & purificação , Imunoglobulinas Intravenosas/análise , Sarampo/prevenção & controle , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Europa (Continente) , Humanos , Vacina contra Sarampo , Vírus do Sarampo/imunologia , Testes de Neutralização , Plasma , Profilaxia Pós-Exposição , Estados Unidos
3.
Transfusion ; 58 Suppl 3: 3084-3089, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30536436

RESUMO

BACKGROUND: Wild-type poliovirus may be eradicated soon and under WHO GAPIII guidance, laboratory use will be discontinued or subject to strict containment. Per US Code of Federal Regulations, however, immunoglobulin lot release testing will still require use of replicating poliovirus. The suitability of S19 hyper-attenuated and apathogenic poliovirus strains as alternatives to the currently used wild-type virus in such a release assay was investigated. STUDY DESIGN AND METHODS: S19 poliovirus strains were propagated in a commercial setting using good virological practices and maintenance of the S19 hyper-attenuated genotype was confirmed by massively parallel sequencing. RESULTS: The attenuated phenotype of the produced S19 stocks was confirmed in a highly sensitive mouse-model. Equivalency in performance was seen in the lot release assay for the S19 and wild-type polioviruses. CONCLUSION: The deployment of such hyper-attenuated and thoroughly characterized S19 stocks in these and other essential activities might reconcile final containment measures with continued safe use of poliovirus.


Assuntos
Erradicação de Doenças , Imunoglobulinas/análise , Poliomielite/prevenção & controle , Poliovirus/fisiologia , Virologia/métodos , Animais , Erradicação de Doenças/métodos , Feminino , Variação Genética , Humanos , Masculino , Camundongos , Camundongos Transgênicos , Poliovirus/genética , Poliovirus/imunologia , Vacinas Atenuadas/efeitos adversos , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia , Vacinas Atenuadas/uso terapêutico
4.
Health Phys ; 111(2): 106-11, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27356053

RESUMO

As a compound of high refractive optical glasses, thorium still is present in some professionally used systems-especially in optical equipment with military use. The possible exposure concerns the head and especially the eye lens, whose radiation sensitivity has been reevaluated. The dose rate measurements of the contribution of beta- and gamma-emission by the nuclei of the decay chain of Th are presented for isolated lenses and for the entire optical system, and the dose quantities H'(0.07) and H*(10) are identified. Exposure scenarios for optical technicians and users are evaluated separately. The levels of dose rates for the inspected optical systems are below those requiring radiation protection measures even for extended working time or unintentional use.


Assuntos
Vidro/química , Cristalino/efeitos da radiação , Lentes , Exposição Ocupacional/análise , Exposição à Radiação/análise , Tório/análise , Alemanha , Vidro/análise , Humanos , Doses de Radiação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
5.
Eur Heart J Acute Cardiovasc Care ; 3(4): 363-72, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24818952

RESUMO

AIMS: In the TRial to assess Improvement in Therapeutic Outcomes by optimizing platelet inhibitioN with prasugrel Thrombolysis In Myocardial Infarction 38 (TRITON-TIMI 38), prasugrel reduced the primary ischaemic endpoint as compared with clopidogrel in acute coronary syndrome (ACS) patients planned to undergo percutaneous coronary interventions, but increased the risk of bleeding. The present analysis shows the efficacy and safety data for the 10,074 non-ST segment elevation (NSTE)-ACS patients included in that trial. METHODS AND RESULTS: The primary endpoint was significantly reduced by prasugrel in the overall NSTE-ACS population (hazard ratio (HR) 0.82, 95% confidence interval (CI) 0.73-0.93, p=0.002) as well as in unstable angina (UA) and in non-ST elevation myocardial infarction (NSTEMI) patient subgroups (interaction p value=0.39). Although non-coronary artery bypass graft (CABG) TIMI major bleeding was increased with prasugrel as compared with clopidogrel (HR 1.40, 95% CI 1.05-1.88, p=0.02), there was a net clinical benefit in patients assigned to prasugrel (HR 0.89, 95% CI 0.80-1.00, p=0.043), which was consistent for UA and NSTEMI subgroups (interaction p value=0.84 and 0.72). In patients who met the criteria for prasugrel use recommended by the European Medicines Agency, thus excluding from the analysis patients with prior transient ischemic attack (TIA)/stroke, with weight <60 kg or age ≥75 years, and censoring follow-up at 365 days, (European Union (EU)-label cohort) prasugrel showed superiority over clopidogrel with regard to the primary endpoint (HR 0.73, 95% CI 0.63-0.85, p<0.0001) for the entire NSTE-ACS population, as well as for UA patients and NSTEMI patients without significant differences in non-CABG TIMI major bleeding. CONCLUSION: Prasugrel, as compared with clopidogrel, significantly reduced the primary endpoint of the TRITON-TIMI 38 trial in NSTE-ACS patients, as well as in the UA and NSTEMI groups. A significant reduction in the primary endpoint without increased bleeding was observed in the EU-label cohort.


Assuntos
Angina Instável/tratamento farmacológico , Infarto do Miocárdio/tratamento farmacológico , Piperazinas/uso terapêutico , Inibidores da Agregação Plaquetária/uso terapêutico , Tiofenos/uso terapêutico , Ticlopidina/análogos & derivados , Clopidogrel , Método Duplo-Cego , Feminino , Hemorragia/induzido quimicamente , Humanos , Masculino , Pessoa de Meia-Idade , Cloridrato de Prasugrel , Fatores de Risco , Ticlopidina/uso terapêutico , Resultado do Tratamento
6.
Appl Environ Microbiol ; 77(5): 1718-27, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21216900

RESUMO

Terminal olefins (1-alkenes) are natural products that have important industrial applications as both fuels and chemicals. However, their biosynthesis has been largely unexplored. We describe a group of bacteria, Jeotgalicoccus spp., which synthesize terminal olefins, in particular 18-methyl-1-nonadecene and 17-methyl-1-nonadecene. These olefins are derived from intermediates of fatty acid biosynthesis, and the key enzyme in Jeotgalicoccus sp. ATCC 8456 is a terminal olefin-forming fatty acid decarboxylase. This enzyme, Jeotgalicoccus sp. OleT (OleT(JE)), was identified by purification from cell lysates, and its encoding gene was identified from a draft genome sequence of Jeotgalicoccus sp. ATCC 8456 using reverse genetics. Heterologous expression of the identified gene conferred olefin biosynthesis to Escherichia coli. OleT(JE) is a P450 from the cyp152 family, which includes bacterial fatty acid hydroxylases. Some cyp152 P450 enzymes have the ability to decarboxylate and to hydroxylate fatty acids (in α- and/or ß-position), suggesting a common reaction intermediate in their catalytic mechanism and specific structural determinants that favor one reaction over the other. The discovery of these terminal olefin-forming P450 enzymes represents a third biosynthetic pathway (in addition to alkane and long-chain olefin biosynthesis) to convert fatty acid intermediates into hydrocarbons. Olefin-forming fatty acid decarboxylation is a novel reaction that can now be added to the catalytic repertoire of the versatile cytochrome P450 enzyme family.


Assuntos
Alcenos/metabolismo , Carboxiliases/isolamento & purificação , Carboxiliases/metabolismo , Ácidos Graxos/metabolismo , Staphylococcaceae/enzimologia , Carboxiliases/genética , Clonagem Molecular , DNA Bacteriano/química , DNA Bacteriano/genética , Escherichia coli/genética , Expressão Gênica , Modelos Moleculares , Dados de Sequência Molecular , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Análise de Sequência de DNA
7.
Science ; 329(5991): 559-62, 2010 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-20671186

RESUMO

Alkanes, the major constituents of gasoline, diesel, and jet fuel, are naturally produced by diverse species; however, the genetics and biochemistry behind this biology have remained elusive. Here we describe the discovery of an alkane biosynthesis pathway from cyanobacteria. The pathway consists of an acyl-acyl carrier protein reductase and an aldehyde decarbonylase, which together convert intermediates of fatty acid metabolism to alkanes and alkenes. The aldehyde decarbonylase is related to the broadly functional nonheme diiron enzymes. Heterologous expression of the alkane operon in Escherichia coli leads to the production and secretion of C13 to C17 mixtures of alkanes and alkenes. These genes and enzymes can now be leveraged for the simple and direct conversion of renewable raw materials to fungible hydrocarbon fuels.


Assuntos
Aldeído Liases/metabolismo , Alcanos/metabolismo , Cianobactérias/genética , Escherichia coli/genética , Genes Bacterianos , Oxirredutases/metabolismo , Synechococcus/genética , Synechococcus/metabolismo , Proteína de Transporte de Acila/metabolismo , Aldeído Liases/química , Aldeído Liases/genética , Aldeídos/metabolismo , Alcenos/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Vias Biossintéticas , Cianobactérias/enzimologia , Cianobactérias/metabolismo , Escherichia coli/metabolismo , Ácidos Graxos/metabolismo , Álcoois Graxos/metabolismo , Óperon , Oxirredutases/genética , Conformação Proteica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , Synechococcus/enzimologia
8.
Nature ; 463(7280): 559-62, 2010 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-20111002

RESUMO

Increasing energy costs and environmental concerns have emphasized the need to produce sustainable renewable fuels and chemicals. Major efforts to this end are focused on the microbial production of high-energy fuels by cost-effective 'consolidated bioprocesses'. Fatty acids are composed of long alkyl chains and represent nature's 'petroleum', being a primary metabolite used by cells for both chemical and energy storage functions. These energy-rich molecules are today isolated from plant and animal oils for a diverse set of products ranging from fuels to oleochemicals. A more scalable, controllable and economic route to this important class of chemicals would be through the microbial conversion of renewable feedstocks, such as biomass-derived carbohydrates. Here we demonstrate the engineering of Escherichia coli to produce structurally tailored fatty esters (biodiesel), fatty alcohols, and waxes directly from simple sugars. Furthermore, we show engineering of the biodiesel-producing cells to express hemicellulases, a step towards producing these compounds directly from hemicellulose, a major component of plant-derived biomass.


Assuntos
Biocombustíveis/microbiologia , Biomassa , Escherichia coli/genética , Escherichia coli/metabolismo , Ácidos Graxos/biossíntese , Plantas/metabolismo , Álcoois Graxos/metabolismo , Engenharia Genética , Óperon/genética , Polissacarídeos/metabolismo , Xilanos/metabolismo
9.
Curr Opin Microbiol ; 12(3): 274-81, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19447673

RESUMO

Bioethanol and plant oil-derived biodiesel are generally considered first generation biofuels. Recognizing their apparent disadvantages, scientists and engineers are developing more sustainable and economically feasible second generation biofuels. The new microbial fuels summarized here have great potential to become viable replacements or at least supplements of petroleum-derived liquid transportation fuels. Yields and efficiencies of the four metabolic pathways leading to these microbial fuels-mostly designed and optimized in Escherichia coli and Saccharomyces cerevisiae using modern tools of metabolic engineering and synthetic biology-and the robustness of the biocatalysts that convert the metabolic intermediates to, in some cases, finished and engine-ready fuels, will determine if they can be commercially successful and contribute to alleviating our dependence on fossil fuels.


Assuntos
Álcoois/metabolismo , Escherichia coli/metabolismo , Engenharia Genética , Hidrocarbonetos/metabolismo , Redes e Vias Metabólicas/genética , Saccharomyces cerevisiae/metabolismo , Escherichia coli/genética , Saccharomyces cerevisiae/genética
10.
Clin Drug Investig ; 27(11): 783-96, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17914897

RESUMO

BACKGROUND AND OBJECTIVE: Despite the fact that high BP is a leading risk factor for cardiovascular morbidity and mortality, BP goals are achieved in less than 10-30% of hypertensive patients. Irbesartan alone or in combination with hydrochlorothiazide has been shown to control BP in >70% of hypertensive patients in clinical trials. We set out to investigate the role in clinical practice of irbesartan in improving BP in uncontrolled hypertensive patients with a particular focus on patients with the metabolic syndrome through analysis of data from a post-marketing surveillance study. METHODS: A multicentre, prospective, post-marketing surveillance study was conducted over 9 months in 14 200 patients aged > or =18 years with previously uncontrolled hypertension (either receiving therapy or newly diagnosed), paying particular attention to a subgroup of patients receiving irbesartan/hydrochlorothiazide as first-line combination therapy. BP was measured by a sphygmomanometer. The main outcome measures were systolic BP (SBP) and diastolic BP (DBP) reduction, response rate (DBP reduction of > or =10mm Hg or to <90 mm Hg), and BP normalisation (SBP <140 and DBP <90 mm Hg) in patients treated with irbesartan alone or in combination with hydrochlorothiazide. Analyses per patient subgroup, previous medication and whether treatment was initiated by the treating physician as first-line combination therapy were conducted. The number and nature of adverse events were documented. RESULTS: Use of irbesartan 300 mg/day as monotherapy in previously uncontrolled patients resulted in a significant reduction in SBP/DBP (-26.8/-13.3mm Hg, p < 0.0001), which was comparable to the subgroup of patients with the metabolic syndrome (-26.3/-13.0mm Hg, p < 0.0001 vs baseline). Combination therapy (irbesartan 300 mg/hydrochlorothiazide 12.5mg once daily) lowered BP by -27.9/-14.2mm Hg (p < 0.0001) in previously uncontrolled patients; again the subgroup of patients with the metabolic syndrome achieved a comparable BP reduction (-27.5/-14.1mm Hg, p < 0.0001 vs baseline). Overall, no linear dose-response relationship was observed. Use of irbesartan/hydrochlorothiazide as first-line combination therapy was effective (BP normalisation rates between 65.7% and 78.6%) and safe. The mean number of antihypertensive tablets taken was reduced and after a mean period of 9 months, 92% of patients were still taking irbesartan therapy. CONCLUSION: The study demonstrates that treatment with an irbesartan-based regimen for 9 months results in a strong BP reduction and is feasible as first-line combination therapy. Similar BP reductions were observed in the subgroup of patients with the metabolic syndrome. Compliance with treatment is particularly good, with >90% of patients continuing with treatment after 9 months.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Compostos de Bifenilo/uso terapêutico , Hipertensão/tratamento farmacológico , Vigilância de Produtos Comercializados , Tetrazóis/uso terapêutico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Compostos de Bifenilo/administração & dosagem , Compostos de Bifenilo/efeitos adversos , Quimioterapia Combinada , Feminino , Humanos , Hidroclorotiazida/administração & dosagem , Irbesartana , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Estudos Prospectivos , Tetrazóis/administração & dosagem , Tetrazóis/efeitos adversos
11.
Appl Environ Microbiol ; 73(7): 2144-55, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17293531

RESUMO

Numerous marine sponges harbor enormous amounts of as-yet-uncultivated bacteria in their tissues. There is increasing evidence that these symbionts play an important role in the synthesis of protective metabolites, many of which are of great pharmacological interest. In this study, genes for the biosynthesis of polyketides, one of the most important classes of bioactive natural products, were systematically investigated in 20 demosponge species from different oceans. Unexpectedly, the sponge metagenomes were dominated by a ubiquitously present, evolutionarily distinct, and highly sponge-specific group of polyketide synthases (PKSs). Open reading frames resembling animal fatty acid genes were found on three corresponding DNA regions isolated from the metagenomes of Theonella swinhoei and Aplysina aerophoba. Their architecture suggests that methyl-branched fatty acids are the metabolic product. According to a phylogenetic analysis of housekeeping genes, at least one of the PKSs belongs to a bacterium of the Deinococcus-Thermus phylum. The results provide new insights into the chemistry of sponge symbionts and allow inference of a detailed phylogeny of the diverse functional PKS types present in sponge metagenomes. Based on these qualitative and quantitative data, we propose a significantly simplified strategy for the targeted isolation of biomedically relevant PKS genes from complex sponge-symbiont associations.


Assuntos
Bactérias/enzimologia , Genoma Bacteriano , Policetídeo Sintases/genética , Poríferos/microbiologia , Simbiose , Microbiologia da Água , Animais , Bactérias/classificação , Bactérias/genética , Variação Genética , Filogenia , Policetídeo Sintases/química
12.
Proc Natl Acad Sci U S A ; 103(11): 4234-9, 2006 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-16537514

RESUMO

Resorcylic acid lactones containing a cis-enone are susceptible to Michael addition reactions and are potent inhibitors of several protein kinases. A structural-bioinformatics analysis identified a conserved Cys residue in the ATP-binding site of the kinases reported to be inhibited by cis-enone resorcylic acid lactones but absent in those that are not. Mining of the kinome database revealed that a subset of some 46 kinases contained this Cys residue. Screening a panel of 124 kinases with the resorcylic acid lactone hypothemycin showed that 18 of 19 targets containing the conserved Cys were inhibited. Kinetic analyses showed time-dependent inhibition, a hallmark of covalent inactivation, and biochemical studies of the interaction of extracellular signal-regulated kinase (ERK)2 with hypothemycin confirmed covalent adduct formation. Resorcylic acid lactones are unique among kinase inhibitors in that they target mitogen-activated protein (MAP) kinase pathways at four levels: mitogen receptors, MAP kinase kinase (MEK)1/2 and ERK1/2, and certain downstream ERK substrates. Cell lines dependent on the activation of Tyr kinase mitogen receptor targets of the resorcylic acid lactones were unusually sensitive toward hypothemycin and showed the expected inhibition of kinase phosphorylation due to inhibition of the mitogen receptors and/or MEK1/2 and ERK1/2. Among cells without mitogen receptor targets, those harboring an ERK pathway-activating B-RAF V600E mutation were selectively and potently inhibited by hypothemycin. Hypothemycin also prevented stimulated activation of the p38 cascade through inhibition of the Cys-containing targets MEK3/6 and TGF-beta-activated kinase 1 and of the JNK/SAPK (c-Jun N-terminal kinase/stress-activated protein kinase) cascade through inhibition of MEK4/7.


Assuntos
Lactonas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Resorcinóis/farmacologia , Trifosfato de Adenosina/metabolismo , Sítios de Ligação/genética , Linhagem Celular , Sequência Conservada , Humanos , Técnicas In Vitro , Cinética , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Filogenia , Proteínas Quinases/química , Proteínas Quinases/classificação , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Compostos de Sulfidrila/metabolismo , Zearalenona/análogos & derivados , Zearalenona/farmacologia
13.
Appl Environ Microbiol ; 71(8): 4840-9, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16085882

RESUMO

Sponge-associated bacteria are thought to produce many novel bioactive compounds, including polyketides. PCR amplification of ketosynthase domains of type I modular polyketide synthases (PKS) from the microbial community of the marine sponge Discodermia dissoluta revealed great diversity and a novel group of sponge-specific PKS ketosynthase domains. Metagenomic libraries totaling more than four gigabases of bacterial genomes associated with this sponge were screened for type I modular PKS gene clusters. More than 90% of the clones in total sponge DNA libraries represented bacterial DNA inserts, and 0.7% harbored PKS genes. The majority of the PKS hybridizing clones carried small PKS clusters of one to three modules, although some clones encoded large multimodular PKSs (more than five modules). The most abundant large modular PKS appeared to be encoded by a bacterial symbiont that made up < 1% of the sponge community. Sequencing of this PKS revealed 14 modules that, if expressed and active, is predicted to produce a multimethyl-branched fatty acid reminiscent of mycobacterial lipid components. Metagenomic libraries made from fractions enriched for unicellular or filamentous bacteria differed significantly, with the latter containing numerous nonribosomal peptide synthetase (NRPS) and mixed NRPS-PKS gene clusters. The filamentous bacterial community of D. dissoluta consists mainly of Entotheonella spp., an unculturable sponge-specific taxon previously implicated in the biosynthesis of bioactive peptides.


Assuntos
Deltaproteobacteria/enzimologia , Biblioteca Genômica , Família Multigênica , Policetídeo Sintases/genética , Poríferos/microbiologia , Animais , DNA Bacteriano/análise , DNA Ribossômico/análise , Deltaproteobacteria/genética , Deltaproteobacteria/crescimento & desenvolvimento , Dados de Sequência Molecular , Peptídeo Sintases/genética , Peptídeo Sintases/metabolismo , Filogenia , Policetídeo Sintases/metabolismo , RNA Ribossômico 16S/genética , Água do Mar , Análise de Sequência de DNA
14.
Antimicrob Agents Chemother ; 48(12): 4703-12, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15561847

RESUMO

Chalcomycin, a 16-membered macrolide antibiotic made by the bacterium Streptomyces bikiniensis, contains a 2,3-trans double bond and the neutral sugar D-chalcose in place of the amino sugar mycaminose found in most other 16-membered macrolides. Degenerate polyketide synthase (PKS)-specific primers were used to amplify DNA fragments from S. bikiniensis with very high identity to a unique ketosynthase domain of the tylosin PKS. The resulting amplimers were used to identify two overlapping cosmids encompassing the chm PKS. Sequencing revealed a contiguous segment of >60 kb carrying 25 putative genes for biosynthesis of the polyketide backbone, the two deoxysugars, and enzymes involved in modification of precursors of chalcomycin or resistance to it. The chm PKS lacks the ketoreductase and dehydratase domains in the seventh module expected to produce the 2,3-double bond in chalcomycin. Expression of PKS in the heterologous host Streptomyces fradiae, from which the tyl genes encoding the PKS had been removed, resulted in production of at least one novel compound, characterized as a 3-keto 16-membered macrolactone in equilibrium with its 3-trans enol tautomer and containing the sugar mycaminose at the C-5 position, in agreement with the structure predicted on the basis of the domain organization of the chm PKS. The production of a 3-keto macrolide from the chm PKS indicates that a discrete set of enzymes is responsible for the introduction of the 2,3-trans double bond in chalcomycin. From comparisons of the open reading frames to sequences in databases, a pathway for the synthesis of nucleoside diphosphate-D-chalcose was proposed.


Assuntos
Antibacterianos/biossíntese , Macrolídeos/metabolismo , Policetídeo Sintases/metabolismo , Streptomyces/genética , Streptomyces/metabolismo , Meios de Cultura , DNA Bacteriano/genética , Farmacorresistência Bacteriana , Fermentação , Dados de Sequência Molecular , Família Multigênica , Plasmídeos/genética
15.
Anal Biochem ; 317(1): 40-6, 2003 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-12729599

RESUMO

A filter binding assay to measure affinity of [3H-allyl]17-allylamino geldanamycin ([3H]AAG) for the ATP binding site of the N-terminal domain of human Hsp90alpha (hHsp90alpha9-236) was developed. Diethylaminoethyl cellulose or glass fiber filters impregnated with polyethyleneimine were used to capture the [3H]AAG-Hsp90 complex, and conditions which washed >98% of free [3H]AAG from the filters were developed. The complex formed at a rapid rate (k(on)=2.5 x 10(7)Lmol(-1) x s(-1)) and dissociated with a half-life of 2.3 min (k(off)=5 x 10(-3) x s(-1)). hHsp90alpha9-236 bound to [3H]AAG with a K(d) value of 0.4+/-0.1 microM. [3H]AAG had similar affinities for full-length hHsp90alpha and for hHsp90alpha9-236 variants containing biotinylated N-terminal biotinylation signal sequences and N- or C-terminal His(6) tags. Geldanamycin, ADP, ATP, and radicicol-all known to bind to the ATP domain of Hsp90-competed with [3H]AAG for binding to hHsp90alpha9-236, showing K(d) values in good agreement with reported values.


Assuntos
Proteínas de Choque Térmico HSP90/metabolismo , Quinonas/metabolismo , Ensaio Radioligante/métodos , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Benzoquinonas , Sítios de Ligação , Ligação Competitiva , Biotinilação , Filtração/instrumentação , Proteínas de Choque Térmico HSP90/química , Proteínas de Choque Térmico HSP90/genética , Humanos , Cinética , Lactamas Macrocíclicas , Ligação Proteica , Quinonas/química , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Sensibilidade e Especificidade , Streptomyces/química , Streptomyces/genética , Trítio
16.
FEMS Microbiol Lett ; 218(2): 223-30, 2003 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-12586396

RESUMO

We illustrate the use of a PCR-based method by which the genomic DNA of a microorganism can be rapidly queried for the presence of type I modular polyketide synthase genes to clone and characterize, by sequence analysis and gene disruption, a major portion of the geldanamycin production gene cluster from Streptomyces hygroscopicus var. geldanus NRRL 3602.


Assuntos
Genes Bacterianos , Família Multigênica , Quinonas/metabolismo , Streptomyces/genética , Sequência de Bases , Benzoquinonas , Clonagem Molecular , DNA Bacteriano/química , DNA Bacteriano/classificação , DNA Bacteriano/genética , Regulação Bacteriana da Expressão Gênica , Lactamas Macrocíclicas , Modelos Moleculares , Dados de Sequência Molecular , Quinonas/isolamento & purificação , Quinonas/farmacologia , Streptomyces/metabolismo
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