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1.
Environ Sci Technol ; 48(14): 7747-55, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24922451

RESUMO

Monitoring organism exposure to heavy metals has acquired increased importance in the last decades. The mouse Mus spretus has been used to assess the biological response to contaminants in the relevant ecological area of Doñana National Park (DNP) and surrounding areas (SW Spain), where many migrating birds land for breeding and feeding every year. A metallomics approach, based on the characterization of metal biomolecules using size exclusion chromatography coupled with inductively coupled plasma-mass spectrometry (SEC-ICP-MS) and a metabolomics approach based on direct infusion to a mass spectrometer (DI-ESI-QTOF-MS) followed by a partial linear square-discriminant analysis (PLS-DA), were used to compare the biological responses of M. spretus living in three areas of DNP (the reference) and surrounding areas (El Partido and El Matochal). The activities of key antioxidant enzymes, such as Cu/Zn-SOD, Mn-SOD, CAT, GR, and guaiacol peroxidase, were also determined in connection with environmental contamination issues. The results show differences caused by the presence of metals in the ecosystem that affected to the levels of metals and metalloproteins, such as MT, Cu/Zn-SOD, or Mn-CA, the breakdown of membrane phospholipids, perturbations in metabolic pathways, related to energy metabolism, and oxidative stress.


Assuntos
Monitoramento Ambiental , Poluição Ambiental/análise , Metabolômica , Metais/análise , Animais , Antioxidantes/metabolismo , Sistema Livre de Células , Cromatografia em Gel , Análise Discriminante , Rim/enzimologia , Análise dos Mínimos Quadrados , Fígado/metabolismo , Camundongos , Oxirredução , Espanha , Espectrometria de Massas por Ionização por Electrospray , Espectrofotometria Atômica , Extratos de Tecidos
2.
J Invertebr Pathol ; 118: 47-58, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24607654

RESUMO

The genus Perkinsus includes protozoan parasites of a wide range of marine molluscs worldwide, some of which have been responsible for heavy mollusc mortalities and dramatic economic losses. This study was performed with the aim of increasing the knowledge of Perkinsus spp. proteome. Proteins extracted from in vitro cultured cells of three species of this genus, P. marinus, P. olseni and P. chesapeaki, were analysed using 2D electrophoresis. Four gels from each species were produced. Qualitative and quantitative comparisons among gels were performed with Proteamweaver software. Cluster analysis grouped the four gels of each Perkinsus sp.; furthermore, P. marinus and P. olseni gels were grouped in a cluster different from P. chesapeaki. Around 2000 spots of each species were considered, from which 213 spots were common to the 3 species; P. chesapeaki and P. marinus shared 310 spots, P. chesapeaki and P. olseni shared 315 spots and P. marinus and P. olseni shared 242 spots. A number of spots were exclusive of each Perkinsus species: 1161 spots were exclusive of P. chesapeaki, 1124 of P. olseni and 895 of P. marinus. A total of 84 spots, including common and species-specific ones, were excised from the gels and analysed using MALDI-TOF and nESI-IT (MS/MS) techniques. Forty-two spots were successfully sequenced, from which 28 were annotated, most of them clustered into electron transport, oxidative stress and detoxification, protein synthesis, carbohydrate metabolism, signal transduction, metabolic process and proteolysis.


Assuntos
Dinoflagellida/metabolismo , Moluscos/parasitologia , Proteoma/análise , Sequência de Aminoácidos , Animais , Análise por Conglomerados , Dinoflagellida/genética , Eletroforese em Gel Bidimensional , Espectrometria de Massas , Dados de Sequência Molecular , Proteômica/métodos
3.
Phys Rev Lett ; 111(17): 172501, 2013 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-24206482

RESUMO

The nucleus (154)Gd is located in a region of the nuclear chart where rapid changes of nuclear deformation occur as a function of particle number. It was investigated using a combination of γ-ray scattering experiments and a γγ-coincidence study following electron capture decay of (154)Tb(m). A novel decay channel from the scissors mode to the first excited 0(+) state was observed. Its transition strength was determined to B(M1;1(sc)(+)→0(2)(+))=0.031(4)µ(N)(2). The properties of the scissors mode of (154)Gd imply a much larger matrix element than previously thought for the neutrinoless double-ß decay to the 0(2)(+) state in such a shape-transitional region. Theory indicates an even larger effect for (150)Nd.

4.
Biometals ; 26(4): 639-50, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23793301

RESUMO

Characterization of Cd-binding proteins has great analytical interest due to the high toxicity of Cd to living organisms. Metallothioneins (MTs), as Cd(II)-binding proteins are of increasing interest, since they form very stable Cd chelates and are involved in many detoxification processes. In this work, inductively coupled plasma octopole reaction cell mass spectrometry and nanospray ionization time-of-flight mass spectrometry were used in parallel and combined with two-dimensional chromatography: size exclusion followed by reversed-phase high performance liquid chromatography, to study metal complexes of MT isoforms produced in hepatic cytosols of Mus musculus during exposure experiments to Cd. Exposure experiments were carried out by subcutaneous injection of a growing dose of the toxic element ranging from 0.1 to 1.0 mg of Cd per kg of body weight per day during 10 days. A control group and three exposure groups at days 2, 6 and 10 of exposure were studied, and different cadmium, copper and zinc complexes with MTs isoforms were isolated and characterized from the two most exposed groups. The results allow gaining insight into the mechanisms involved in metal detoxification by MTs, showing the changes in the stoichiometry of metal complexes-MTs along cadmium exposure.


Assuntos
Cádmio/toxicidade , Hepatócitos/metabolismo , Metalotioneína/metabolismo , Isoformas de Proteínas/metabolismo , Animais , Cádmio/metabolismo , Hepatócitos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C
5.
Phys Rev Lett ; 109(4): 042501, 2012 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-23006080

RESUMO

Neutrinoless double-ß decay is of fundamental importance for the determining neutrino mass. By combining a calculation of nuclear matrix elements within the framework of the microscopic interacting boson model with an improved calculation of phase space factors, we set limits on the average light neutrino mass and on the average inverse heavy neutrino mass (flavor-violating parameter).

6.
Phys Rev Lett ; 108(6): 062502, 2012 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-22401059

RESUMO

The 110Pd double-ß decay Q value was measured with the Penning-trap mass spectrometer ISOLTRAP to be Q=2017.85(64) keV. This value shifted by 14 keV compared with the literature value and is 17 times more precise, resulting in new phase-space factors for the two-neutrino and neutrinoless decay modes. In addition a new set of the relevant matrix elements has been calculated. The expected half-life of the two-neutrino mode was reevaluated as 1.5(6)×10(20) yr. With its high natural abundance, the new results reveal 110Pd to be an excellent candidate for double-ß decay studies.

7.
Anal Bioanal Chem ; 404(6-7): 1967-81, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23053170

RESUMO

A metallomic approach based on the use of size-exclusion chromatography (Superdex-75) with inductively coupled plasma mass spectrometry (ICP-MS) detection is combined with anion or cation exchange chromatography to characterize the biological response of the free-living mouse Mus spretus. The approach has been applied to contaminated and non-contaminated areas from Doñana National Park (southwest Spain) and the surroundings. Several areas affected by differential contamination from mining, industrial, and agricultural activities have been considered. The high presence of Mn, Cu, and Zn in liver and As and Cd in kidney is remarkable, especially in contaminated areas. The size exclusion chromatograms traced by Mn in liver cytosolic extracts are more intense than in kidney; a Mn-peak matching with the standard of 32 kDa (superoxide dismutase) is present in these organs, and its intensity is correlated with the concentration of Mn in the extracts. High-intensity peaks traced by Cu, Zn, and Cd at 7 kDa (matching with metallothionein I standard) in liver extract are triggered by the presence of contaminants. Other peaks related with molecules of 32 and 67 kDa traced by Cu and Zn can also be observed, although their intensity is higher in sites with low contamination. In kidney extracts, the presence of a Cd-peak with Mr of 7 kDa (tentatively Cd-metallothionein) with high intensity under the action of contaminants was observed, but high biological responses are also proven in the protected area of the Park, which denotes a progressive increase of diffuse contamination.


Assuntos
Animais Selvagens/metabolismo , Cromatografia em Gel/métodos , Exposição Ambiental , Espectrometria de Massas/métodos , Metais/análise , Camundongos/metabolismo , Animais , Encéfalo/metabolismo , Química Encefálica , Monitoramento Ambiental , Rim/química , Rim/metabolismo , Fígado/química , Fígado/metabolismo , Masculino , Metais/metabolismo , Espanha
8.
Eur Respir J ; 37(4): 873-9, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20650989

RESUMO

The aim of the present study was to evaluate ischaemic reactive hyperaemia (IRH) in obstructive sleep apnoea (OSA) and its relationship with oxidative stress. We studied 69 consecutive patients referred to our Sleep Unit (Reina Sofia University Hospital, Cordoba, Spain). Patients with chronic diseases or those taking medication were excluded. IRH was assessed before and after polysomnography. Morning IRH and oxidative stress markers were compared between patients with (apnoea-hypopnoea index (AHI) ≥ 5) and without (AHI < 5) OSA. Measurements were repeated in 25 severe OSA patients after continuous positive airway pressure (CPAP) therapy. We included 46 OSA patients (mean ± sd AHI 49 ± 32.1) and 23 non-OSA subjects (AHI 3 ± 0.9). The OSA patients showed a significant worsening of morning IRH, and a significant increase in malondialdehyde and 8-hydroxydeoxyguanosine levels. Only the oxygen desaturation index independently explained morning IRH, while malondialdehyde levels showed a weak effect on IRH. In severe OSA patients, IRH improved significantly after CPAP treatment, as did malondialdehyde, 8-hydroxydeoxyguanosine and protein carbonyl levels. In OSA patients, endothelial dysfunction and oxidative stress were observed, and IRH worsened after sleep. The increase in oxidative stress was not associated with IRH, while intermittent hypoxia was strongly associated with IRH. In severe OSA patients, CPAP treatment improved oxidative stress and endothelial function.


Assuntos
Endotélio/metabolismo , Regulação da Expressão Gênica , Estresse Oxidativo , Apneia Obstrutiva do Sono/metabolismo , 8-Hidroxi-2'-Desoxiguanosina , Adulto , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Endotélio Vascular/metabolismo , Feminino , Humanos , Hipóxia/metabolismo , Masculino , Malondialdeído/metabolismo , Pessoa de Meia-Idade , Oxigênio/química , Polissonografia/métodos , Estudos Prospectivos
9.
Ecology ; 91(10): 3027-36, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21058562

RESUMO

Soils are extremely rich in biodiversity, and soil organisms play pivotal roles in supporting terrestrial life, but the role that individual plants and plant communities play in influencing the diversity and functioning of soil food webs remains highly debated. Plants, as primary producers and providers of resources to the soil food web, are of vital importance for the composition, structure, and functioning of soil communities. However, whether natural soil food webs that are completely open to immigration and emigration differ underneath individual plants remains unknown. In a biodiversity restoration experiment we first compared the soil nematode communities of 228 individual plants belonging to eight herbaceous species. We included grass, leguminous, and non-leguminous species. Each individual plant grew intermingled with other species, but all plant species had a different nematode community. Moreover, nematode communities were more similar when plant individuals were growing in the same as compared to different plant communities, and these effects were most apparent for the groups of bacterivorous, carnivorous, and omnivorous nematodes. Subsequently, we analyzed the composition, structure, and functioning of the complete soil food webs of 58 individual plants, belonging to two of the plant species, Lotus corniculatus (Fabaceae) and Plantago lanceolata (Plantaginaceae). We isolated and identified more than 150 taxa/groups of soil organisms. The soil community composition and structure of the entire food webs were influenced both by the species identity of the plant individual and the surrounding plant community. Unexpectedly, plant identity had the strongest effects on decomposing soil organisms, widely believed to be generalist feeders. In contrast, quantitative food web modeling showed that the composition of the plant community influenced nitrogen mineralization under individual plants, but that plant species identity did not affect nitrogen or carbon mineralization or food web stability. Hence, the composition and structure of entire soil food webs vary at the scale of individual plants and are strongly influenced by the species identity of the plant. However, the ecosystem functions these food webs provide are determined by the identity of the entire plant community.


Assuntos
Cadeia Alimentar , Invertebrados/fisiologia , Plantas/classificação , Microbiologia do Solo , Solo , Animais , Especificidade da Espécie
10.
J Environ Radioact ; 100(2): 198-202, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19101061

RESUMO

The bulk gross alpha, gross beta and (7)Be depositional fluxes were measured in Málaga (36.7 degrees N, 4.5 degrees W), a coastal Mediterranean station in the south of Spain for one whole year. In order to quantify the local variation of deposition rates, we have analysed the monthly results from two deposition collectors: a "pot "collector with a continuous water-covered surface and a "funnel" collector. In general, the alpha and beta depositional fluxes from the funnel collector were approximately two times lower than the pot collector. Whereas for the cosmogenic (7)Be, the depositional flux of (7)Be from funnel collector was also approximately two times lower than the pot collector. A good correlation of the depositional flux of (7)Be has been obtained from both collectors.


Assuntos
Poluentes Radioativos do Ar/análise , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Berílio/análise , Radioisótopos/análise , Estações do Ano
11.
Anal Bioanal Chem ; 390(1): 17-28, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17994227

RESUMO

Mus musculus mice have been investigated for the total elements content in different organs (lung, liver, spleen, kidney, brain, testicle, heart and muscle) and molecular mass distribution patterns of Mn, Ni, Cu, Zn, As, Pb, Cr, Fe, Co, Se and Cd. Some differences have been found in the organs studied, with especially relevant being the Cu-containing fraction present only in the brain and the As-containing one in the liver. Other differences related to the abundance of the metallospecies have also been found. The present paper is the first step in the study of the "metallome" of this inbred laboratory species from which the genome is completely known. This organism could be used as a model in future studies focused on wild mice and the analytical approach developed could be applied to wild mice to find markers of environmental pollution. [figure: see text] The present paper is the first step in the study of the "metallome" of the inbred laboratory specie Mus musculus from which the genome is completely known. Some interesting differences have been found in the extracts from the organs that are discussed along the text.


Assuntos
Cromatografia em Gel/métodos , Espectrometria de Massas/métodos , Metais Pesados/análise , Metais Pesados/química , Análise Espectral/métodos , Raios Ultravioleta , Animais , Metais Pesados/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Peso Molecular , Especificidade de Órgãos
12.
Toxicol Lett ; 168(3): 260-8, 2007 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-17157454

RESUMO

Utility of carboxylesterase and acetylcholinesterase inhibition as pesticide exposure biomarker was studied at Doñana National Park (SW Spain) in crayfish (Procambarus clarkii). Activities were measured in animals from reference sites or potentially exposed to pesticides, and their reactivation studied after dilution or 2-PAM treatment. Crayfish from affected sites had significantly less carboxylesterase and acetylcholinesterase activity than reference ones. No significant differences were found after dilution or 2-PAM treatment, showing that inhibition was irreversible. High pesticide levels were found in water and/or soil at rice growing sites, and lower levels at other affected places. High metal levels existed at rice growing sites and lower at other affected and at both reference sites. A combined effect on esterase inhibition of pesticides and metals is proposed. This field study suggest that the rice growing areas near Guadiamar stream are most polluted, followed by strawberry and citrics growing zones near Partido and Rocina streams. However, no correlation exist between the pesticide concentration at different sites and the extent of esterase inhibition, indicating that other factors could affect esterase response of animals from polluted sites.


Assuntos
Acetilcolinesterase/metabolismo , Astacoidea/enzimologia , Carboxilesterase/antagonistas & inibidores , Inibidores da Colinesterase/análise , Poluentes Químicos da Água/análise , Animais , Astacoidea/efeitos dos fármacos , Biomarcadores/análise , Carboxilesterase/metabolismo , Inibidores da Colinesterase/toxicidade , Reativadores da Colinesterase/farmacologia , Sistema Digestório/enzimologia , Monitoramento Ambiental , Metais Pesados/análise , Metais Pesados/toxicidade , Tecido Nervoso/enzimologia , Praguicidas/análise , Praguicidas/toxicidade , Compostos de Pralidoxima/farmacologia , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Espanha , Poluentes Químicos da Água/toxicidade
14.
Environ Pollut ; 139(2): 214-23, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16054738

RESUMO

Metal accumulation and some of their biochemical effects have been studied in oysters (Crassostrea angulata) and mussels (Mytilus galloprovincialis) of the South Atlantic Spanish littoral. Especial attention has been paid to antioxidant defences and oxidative damage to biomolecules. Deep differences in the response of oysters and mussels to metal pollution were found. Oysters, with the higher metal loads of both species, showed increased antioxidant defences, and less extensive oxidative damage. In contrast, mussels, which accumulated much lower metal concentrations, showed clear increases in oxidized biomolecules, in agreement with their low increases in the antioxidant defence mechanisms. Our results suggest that mussels are more sensitive and less well adapted to metal pollution, probably explaining their absence in the most contaminated studied site, Mazagón. We conclude that oysters can be used as more sensitive bioindicator of pollution in the South Spanish littoral, and as a suitable model to study the adaptation to metal pollution.


Assuntos
Ecossistema , Contaminação de Alimentos/análise , Metais Pesados/toxicidade , Frutos do Mar , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/análise , Biodegradação Ambiental , Bivalves/metabolismo , Cromatografia Líquida de Alta Pressão , Colorimetria , Cobre/análise , Cobre/toxicidade , DNA/análise , Monitoramento Ambiental/métodos , Metalotioneína/análise , Metais Pesados/análise , Ostreidae/metabolismo , Estresse Oxidativo , Espanha , Taurina/análise , Poluentes Químicos da Água/análise , Zinco/análise , Zinco/toxicidade
15.
Chemosphere ; 62(9): 1523-33, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16098559

RESUMO

In this study we investigated the interactions among plant, rhizosphere microorganisms and Zn pollution. We tested the influence of two bacterial strains isolated from a Zn-polluted soil on plant growth and on the symbiotic efficiency of native arbuscular mycorrhizal fungi (AMF) under Zn toxicity. The two bacterial strains exhibited Zn tolerance when cultivated under increasing Zn levels in the medium. However, strain B-I showed a higher Zn tolerance than strain B-II at the two highest Zn levels in the medium (75 and 100 mg l(-1) Zn). Molecular identification placed the strain B-I within the genus Brevibacillus. Our results showed that bacterial strain B-I consistently enhanced plant growth, N and P accumulation, as well as nodule number and mycorrhizal infection which demonstrated its plant-growth promoting (PGP) activity. This strain B-I has been shown to produce IAA (3.95 microg ml) and to accumulate 5.6% of Zn from the growing medium. The enhanced growth and nutrition of plants dually inoculated with the AMF and bacterium B-I was observed at three Zn levels assayed. This effect can be related to the stimulation of symbiotic structures (nodules and AMF colonization) and a decreased Zn concentration in plant tissues. The amount of Zn acquired per root weight unit was reduced by each one of these bacterial strains or AMF and particularly by the mixed bacterium-AMF inocula. These mechanisms explain the alleviation of Zn toxicity by selected microorganisms and indicate that metal-adapted bacteria and AMF play a key role enhancing plant growth under soil Zn contamination.


Assuntos
Micorrizas/crescimento & desenvolvimento , Rhizobium/isolamento & purificação , Microbiologia do Solo , Poluentes do Solo/análise , Trifolium/crescimento & desenvolvimento , Zinco/análise , Biodegradação Ambiental , DNA Bacteriano/análise , Simbiose , Trifolium/microbiologia
16.
J Plant Physiol ; 201: 28-41, 2016 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-27393918

RESUMO

Bacteria (Pseudomonas sp. and Bacillus sp.) and/or the arbuscular mycorrhizal (AM) fungus Rhizophagus intraradices were able to improve growth, physiological and biochemical characteristics of four Sulla carnosa Desf. provenances (Sidi khlif, Thelja, Kalbia and Kerker) from Tunisia under both saline and non-saline conditions. S. carnosa is a salt-tolerant legume plant, native from North Africa. The intrinsic bacterial characteristics evidenced the fitness of these bacteria to support salt stress and to stimulate plant growth. Bacillus sp. produced more indol acetic acid (IAA) than Pseudomonas sp. and showed a great surviving capacity under salt conditions supporting its capacity to improve plant growth under stress conditions. The microorganisms applied also have a different potential to increase the nutritional and related plant growth parameters. It is noticeable that some provenances reached the highest level of growth when inoculated with Bacillus sp. in Sidi khlif or by Bacillus plus AMF in Kalbia, which increased shoot by 318% and root by 774%. In contrast, in Thelja and Kerker the impact of the test microorganisms was mainly evidenced at increasing nutritional and physiological functions. Salinity reduced some growth and physiological variables as stomatal conductance, photosynthetic pigments and photosynthetic efficiency and increased electrolyte leakage. However, the microbial inoculants compensated these detrimental effects in a degree depending on the S. carnosa provenance. These microorganisms also orchestrate antioxidant activities involved in adaptative responses in S. carnosa provenances. The intrinsic ability of inoculants allow us to select the provenance/microorganism combination which maximizes S. carnosa growth, nutrition and physiological/biochemical responses under salt and non-salt conditions. The results obtained support that the target microbial inocula are beneficial for the ecological stability if this Mediterranean legume.


Assuntos
Antioxidantes/metabolismo , Bactérias/metabolismo , Biomassa , Fabaceae/microbiologia , Fabaceae/fisiologia , Fungos/metabolismo , Salinidade , Cloreto de Sódio/farmacologia , Bactérias/efeitos dos fármacos , Eletrólitos/metabolismo , Fabaceae/efeitos dos fármacos , Fabaceae/crescimento & desenvolvimento , Fotossíntese/efeitos dos fármacos , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/fisiologia , Análise de Componente Principal , Simbiose/efeitos dos fármacos
17.
Data Brief ; 9: 438-447, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27699198

RESUMO

The data are related to the proteomic analysis of 43 newborns with intrauterine growth retardation (IUGR) and 45 newborns with appropriate weight for gestational age (AGA) carried out by separation via 2DE and analyzed by MS-TOF/TOF. All newborns were separated into three gestational age groups, "Very Preterm" 29-32 weeks, "Moderate Preterm" 33-36 weeks, and, "Term" ≥37weeks. From each newborn, blood was drawn three times from birth to 1 month life. High-abundant serum proteins were depleted, and the minority ones were separated by 2DE and analyzed for significant expression differences. The data reflect analytic and clinic variables analyzed globally and categorized by gestational age in relation to IUGR and the optimization of conditions for 2-DE separation. The data from this study are related to the research article entitled "Alterations of Protein Expression in Serum of Infants with Intrauterine Growth Restriction and Different Gestational Ages" (M.D. Ruis-González, M.D. Cañete, J.L. Gómez-Chaparro, N. Abril, R. Cañete, J. López-Barea, 2015) [1]. The present dataset of serum IUGR newborn proteome can be used as a reference for any study involving intrauterine growth restriction during the first month of life.

18.
Biochim Biophys Acta ; 524(1): 1-14, 1978 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-148913

RESUMO

The bifunctional enzyme quinate (shikimate) dehydrogenase (quinate: NAD+ oxidoreductase, EC 1.1.1.24), which catalyzes the first reaction in the inducible quinic acid catabolic pathway of Neurospora crassa, has been purified to homogeneity. The enzyme is a monomer of 41000 daltons with an s20,w = 2.94 S. However, electrophoresis under non-denaturing conditions revealed three protein species, which have both quinate and shikimate dehydrogenase activities. The enzyme, with a single binding site for both substrates, has a Km of 0.37 mM for quinate and of 1.18 mM for shikimate, although the V is about 3-fold higher with shikimate. Essential sulphydryl groups which were not localized in the active site were detected. Thermal stability of the enzyme was greatly enhanced by low concentrations of quinate, shikimate, NADH, or by high ionic strength.


Assuntos
Oxirredutases do Álcool/metabolismo , Neurospora crassa/enzimologia , Neurospora/enzimologia , Oxirredutases do Álcool/isolamento & purificação , Indução Enzimática , Cinética , Peso Molecular , Ácido Quínico , Ácido Chiquímico
19.
Genetics ; 90(1): 69-84, 1978 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-151647

RESUMO

The qa-3 gene, one of the four genes in the qa gene cluster, encodes quinate (shikimate) dehydrogenase (quinate: NAD oxidoreductase, ER 1.1.1.24), the first enzyme in the inducible quinic acid catabolic pathway in Neurospora crassa. Genetic analyses have localized 26 qa-3 mutants at 11 sites on the aq-3 genetic map on the basis of prototroph frequencies. Certain mutants, e.g., 336-3-10 and 336-3-3, are located at opposite ends of the qa-3 gene. Data from four-point crosses (qa-1s mutant 124 X five different qa-3 mutants in triple mutants qa-3, qa-4, qa-2) indicate the following orientation of the qa-3 gene within the qa cluster; qa-1, qa-3 mutant 336-3-10 ("left" end) qa-3 mutant 336-3-3 ("right" end), qa-4, qa-2. Ultraviolet-induced revertants have been obtained from 14 of the qa-3 mutants. The revertable mutants fall into two major classes: those that revert by changes either at the same site or at a second site within the qa-3 gene, and those that revert by unlinked suppressor mutations. The intragenic revertants can be further distinguished by quantative and/or qualitative differences in their quinate dehydrogenase activities. Some revertants with activities either equivalent to or less than wild type produce a thermostable enzyme, and others an enzyme which is thermolabile in vitro at 35 degrees. A concentration of quinic acid or shikimic acid as low as 50 micron protects the enzyme markedly from heat inactivation. The genetic organization and the orientation of the qa-3 gene are discussed with respect to its direction of transcription and to the possible localization of a promoter (initiator) region(s) within the qa gene cluster.


Assuntos
Genes , Mutação , Neurospora crassa/genética , Neurospora/genética , Oxirredutases/genética , Oxirredutases do Álcool , Alelos , Teste de Complementação Genética , Mutação/efeitos da radiação , Ácido Quínico , Recombinação Genética , Raios Ultravioleta
20.
J Biotechnol ; 116(4): 369-78, 2005 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-15748763

RESUMO

The microbial transformation of sugar beet (SB) agrowaste with or without rock-phosphate (RP) has utility for the improvement of plant growth in a Cd (5 microg g-1) artificially contaminated soil, particularly when the soil is co-inoculated with arbuscular mycorrhizal (AM) fungus Glomus mosseae isolated from a Cd-polluted area. Under such Cd-polluted conditions, the limited growth, mineral nutrition, symbiotic developments (nodulation and AM-colonization) and soil enzymatic activities were stimulated using SB or SB+RP as soil amendments and G. mosseae as inoculant. G. mosseae enhanced plant establishment in a higher extent in amended soil; it is probably due to the interactive effect increasing the potential fertility of such compounds and its ability for decreasing Cd transfer from soil to plant. The amount of Cd transferred from soil solution to biomass of AM-colonized plants ranged from 0.09 microg Cd g-1 (in SB+RP-amended soil) to 0.6 microg Cd g-1 (in non-amended soil). Nodule formation was more sensitive to Cd than AM-colonization, and both symbioses were stimulated in amended soils. Not only AM-colonization but also amendments were critical for plant growth and nutrition in Cd-polluted soil. The high effectiveness of AM inoculum increasing nutrients and decreasing Cd in amended soil indicated the positive interaction of these treatments in increasing plant tolerance to Cd contamination.


Assuntos
Aspergillus niger/fisiologia , Cádmio/farmacocinética , Micorrizas/fisiologia , Microbiologia do Solo , Poluentes do Solo/farmacocinética , Trifolium/crescimento & desenvolvimento , Trifolium/microbiologia , Agricultura/métodos , Resíduos Industriais/prevenção & controle , Fosfatos/metabolismo , Simbiose/fisiologia
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