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1.
Physiol Plant ; 175(6): e14064, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38148243

RESUMO

Green tea made from albino buds and leaves has a strong umami taste and aroma. The cultivar 'Zhonghuang 2' (ZH2, Camellia sinensis) is a natural mutant with young shoots that are yellow in spring and green or yellow-green in summer. However, the mechanism of leaf color change remains unclear. Here, we found that young shoots of ZH2 were yellow at low temperature (LT) and green at high temperature (HT), indicating that ZH2 is a temperature-sensitive cultivar. Transmission electron microscopy analysis showed that the grana in the chloroplasts of young shoots grown at LT were poorly stacked, which caused a lack of photoreactions and chlorophyll. RNA-seq results showed 1279 genes differentially expressed in the young shoots grown at LT compared with those at HT, including genes related to cytochrome synthesis, chloroplast development, photosynthesis, and DNA methylation. A whole-genome bisulfite sequencing assay revealed that the dynamics of DNA methylation levels in the CG, CHG, and CHH contexts decreased under LT, and the change was most obvious in the CHH context. Furthermore, 72 genes showed significant changes in both expression and DNA methylation levels, and most of them were related to cytochrome synthesis, chloroplast development, photosynthesis, transcription factors, and signaling pathways. These results demonstrate that DNA methylation is involved in the LT-regulated albino processes of ZH2. Changes in DNA methylation levels were associated with changes in gene expression levels, affecting the structure and function of chloroplasts, which may have a phenotypic impact on shoot and leaf color.


Assuntos
Camellia sinensis , Camellia sinensis/genética , Camellia sinensis/metabolismo , Transcriptoma/genética , Temperatura , Clorofila/metabolismo , Citocromos/análise , Citocromos/genética , Citocromos/metabolismo , Folhas de Planta/metabolismo , Regulação da Expressão Gênica de Plantas/genética , Proteínas de Plantas/metabolismo
2.
Drug Chem Toxicol ; 45(6): 2535-2544, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34380357

RESUMO

The leguminosae of Sophora moorcroftiana (Benth.) Benth.ex Baker is a drought-resistant endemic Sophora shrub species from the Qinghai-Tibet Plateau, and its seeds have hepatoprotective effects. To study the effect of S. moorcroftiana seeds on liver injury and the molecular mechanism underlying the beneficial effects, liquid chromatography-mass spectrometry was used to detect the main active components in the ethanol extract of S. moorcroftiana seeds (SM). Male mice were divided into six groups (n = 8): normal control (NC), CCl4, SM (50, 100, 200 mg/kg), and dimethyl diphenyl bicarboxylate (150 mg/kg) groups. Mice were treated as indicated (once/day, orally) for 14 days, and CCl4 (2 mL/kg) was administered intraperitoneally. The serum and liver of mice were used for biochemical assays. To explore the underlying mechanism, HepG2 cells were treated with SM, stimulated with tert-butyl hydroperoxide (t-BHP, 50 µM), and analyzed by Western blotting. The major active compounds of SM were alkaloids including 22 compounds. Serum alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (ALP) decreased in the SM (200 mg/kg) group. SM can activate the expression of pregnane X receptor (PXR) and downstream molecules cytochrome P4503A11 enzyme (CYP3A11), UDP glucuronosyltransferase 1 family polypeptide A 1 (UGT1A1), and inhibit the multidrug resistance protein 2 (MRP2). In addition, SM improved cell viability in t-BHP-induced HepG2 cells (64% to 83%) and decreased the activation of the mitogen-activated protein kinase (MAPK) pathway. The main compounds in SM were alkaloids. SM showed hepatoprotective effects possibly mediated by the suppression of oxidative stress through the MAPK pathway.


Assuntos
Alcaloides , Doença Hepática Induzida por Substâncias e Drogas , Sophora , Animais , Camundongos , Sophora/química , Receptor de Pregnano X , terc-Butil Hidroperóxido/análise , terc-Butil Hidroperóxido/farmacologia , Alanina Transaminase/análise , Fosfatase Alcalina , Sementes/química , Aspartato Aminotransferases/análise , Extratos Vegetais/química , Alcaloides/farmacologia , Fígado , Glucuronosiltransferase , Proteínas Quinases Ativadas por Mitógeno/análise , Proteínas Quinases Ativadas por Mitógeno/farmacologia , Etanol , Citocromos/análise , Citocromos/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle
3.
Adv Exp Med Biol ; 977: 67-72, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28685429

RESUMO

We demonstrate the ability of a 16-wavelength time domain near-infrared spectroscopy system to monitor changes in oxy- and deoxy haemoglobin ([HbO2] [HHb]) and the oxidation of cytochrome-c-oxidase ([oxCCO]), during forearm ischaemia. We tested two methods to retrieve the concentration changes. The first uses the measured changes in light attenuation and the modified Beer-Lambert law, and the second uses the absorption and scattering estimated by the measured time-point spread function. The system is able to retrieve the concentration changes with both methods, giving similar results. At the end of forearm ischaemia (t = 5 min), we measured an increase in [HHb] of 16.77 ± 2.52 and 16.37 ± 2.33 µMol, and a decrease in [HbO2] of -6.12 ± 1.62 and -5.57 ± 2.02 µMol for method 1 and 2, respectively. At that same time, the changes in [oxCCO] were -0.36 ± 0.33 and -1.40 ± 1.20 µMol, for method 1 and 2, respectively. These small changes in [oxCCO], despite a huge change in haemoglobin, demonstrate the absence of crosstalk and are comparable to previous measurements using broadband NIRS.


Assuntos
Citocromos/metabolismo , Antebraço/irrigação sanguínea , Hemoglobinas/metabolismo , Isquemia/metabolismo , Músculo Esquelético/irrigação sanguínea , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Adulto , Citocromos/análise , Estudos de Viabilidade , Feminino , Hemoglobinas/análise , Humanos , Masculino , Monitorização Fisiológica , Adulto Jovem
4.
Mitochondrion ; 36: 29-35, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-27890822

RESUMO

Light of different wave-lengths have the potential to interact with four major mitochondrial protein complexes that are involved in the generation of ATP. Neurones of the central nervous system have an absolute dependence on mitochondrial generated ATP. Laboratory studies show that short-wave or blue light (400-480nm) that impinges on the retina affect flavin and cytochrome constituents associated with mitochondria to decrease the rate of ATP formation, stimulate ROS and results in cell death. This suggests that blue light could potentially have a negative influence on retinal ganglion cell (RGC) mitochondria that are abundant and not shielded by macular pigments as occurs for photoreceptor mitochondria. This might be of significance in glaucoma where it is likely that RGC mitochondria are already affected and therefore be more susceptible to blue light. Thus simply filtering out some natural blue light from entering the eye might be beneficial for the treatment of glaucoma. Long-wave or red light (650-800nm) affects mitochondrial complex IV or cytochrome oxidase to increase the rate of formation of ATP and ROS causing the generation of a number of beneficial factors. Significantly, laboratory studies show that increasing the normal amount of natural red light reaching rat RGC mitochondria in situ, subjected to ischemia, proved to be beneficial. A challenge now is to test whether extra red light delivered to the human retina can slow-down RGC loss in glaucoma. Such a methodology has also the advantage of being non-invasive. One very exciting possibility might be in the production of a lens where solar UV light is convertes to add to the amount of natural red light entering the eye.


Assuntos
Trifosfato de Adenosina/biossíntese , Glaucoma/fisiopatologia , Luz , Mitocôndrias/efeitos da radiação , Células Ganglionares da Retina/patologia , Células Ganglionares da Retina/efeitos da radiação , Animais , Morte Celular , Citocromos/análise , Dinitrocresóis/análise , Humanos , Espécies Reativas de Oxigênio/metabolismo
5.
Neuromolecular Med ; 16(1): 175-90, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24203394

RESUMO

In the present study, we tried to answer the following questions: which kind of defense pathways are activated after Aß insult? How defense systems react against noxious effects of Aß and whether they are able to deal against apoptosis or not? So, we traced some molecular pathways including autophagy, mitophagy, and mitochondrial biogenesis before reaching to the endpoint of apoptosis. Besides, we measured the function of mitochondria after injection of Aß (1-42) in CA1 area of hippocampus as a model of Alzheimer's disease (AD). Based on our data, autophagy markers reached to their maximum level and returned to the control level as apoptotic markers started to increase. As a specialized form of autophagy, mitophagy markers followed the trend of autophagy markers. Whereas mitochondrial dynamic processes shifted toward fission, mitochondrial biogenesis was severely affected by Aß and significantly decreased. Alongside suppression of mitochondrial biogenesis, activity of specific enzymes involved in antioxidant defense system, electron transport chain, and tricarboxylic acid cycle (TCA) decreased in response to the Aß. Activity of antioxidant enzymes increased at first and then decreased significantly compared to the control. TCA enzymes aconitase and malate dehydrogenase activities reduced immediately while citrate synthase and fumarase activities did not change. Based on our finding, monitoring of the master molecules of intracellular cascades and determining their trends before the destructive function of Aß could be the target of therapeutic issues for AD.


Assuntos
Peptídeos beta-Amiloides/toxicidade , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Região CA1 Hipocampal/efeitos dos fármacos , Ciclo do Ácido Cítrico/efeitos dos fármacos , Mitofagia/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Fragmentos de Peptídeos/toxicidade , Aconitato Hidratase/análise , Animais , Região CA1 Hipocampal/patologia , Catalase/análise , Citrato (si)-Sintase/análise , Citocromos/análise , Transporte de Elétrons , Indução Enzimática , Fumarato Hidratase/análise , Glutationa/análise , Malato Desidrogenase/análise , Masculino , Microinjeções , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Proteínas do Tecido Nervoso/análise , Proteínas do Tecido Nervoso/fisiologia , Neurônios/patologia , Proteínas Quinases/análise , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/análise , Fatores de Tempo
6.
Analyst ; 138(21): 6309-15, 2013 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-23722160

RESUMO

The paper presents a new multi-parametric protein microarray embracing the multi-analyte capabilities of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The combination of high throughput reverse phase protein microarrays with element tagged antibodies and LA-ICP-MS makes it possible to detect and quantify many proteins or biomarkers in multiple samples simultaneously. A proof of concept experiment is performed for the analysis of cytochromes particularly of cytochrome P450 enzymes, which play an important role in the metabolism of xenobiotics such as toxicants and drugs. With the aid of the LA-ICP-MS based multi-parametric reverse phase protein microarray it was possible to analyse 8 cytochromes in 14 different proteomes in one run. The methodology shows excellent detection limits in the lower amol range and a very good linearity of R(2) ≥ 0.9996 which is a prerequisite for the development of further quantification strategies.


Assuntos
Anticorpos/química , Citocromos/análise , Terapia a Laser/métodos , Análise Serial de Proteínas/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Espectrofotometria Atômica/métodos , Animais , Feminino , Masculino , Microssomos Hepáticos/química , Ratos , Ratos Sprague-Dawley
7.
Biosci Rep ; 33(3)2013 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-23683062

RESUMO

The periplasmic cytochrome cd1 nitrite reductase NirS occurring in denitrifying bacteria such as the human pathogen Pseudomonas aeruginosa contains the essential tetrapyrrole cofactors haem c and haem d1. Whereas the haem c is incorporated into NirS by the cytochrome c maturation system I, nothing is known about the insertion of the haem d1 into NirS. Here, we show by co-immunoprecipitation that NirS interacts with the potential haem d1 insertion protein NirN in vivo. This NirS-NirN interaction is dependent on the presence of the putative haem d1 biosynthesis enzyme NirF. Further, we show by affinity co-purification that NirS also directly interacts with NirF. Additionally, NirF is shown to be a membrane anchored lipoprotein in P. aeruginosa. Finally, the analysis by UV-visible absorption spectroscopy of the periplasmic protein fractions prepared from the P. aeruginosa WT (wild-type) and a P. aeruginosa ΔnirN mutant shows that the cofactor content of NirS is altered in the absence of NirN. Based on our results, we propose a potential model for the maturation of NirS in which the three proteins NirS, NirN and NirF form a transient, membrane-associated complex in order to achieve the last step of haem d1 biosynthesis and insertion of the cofactor into NirS.


Assuntos
Proteínas de Bactérias/metabolismo , Citocromos/metabolismo , Heme/análogos & derivados , Nitrito Redutases/metabolismo , Pseudomonas aeruginosa/metabolismo , Proteínas de Bactérias/análise , Citocromos/análise , Desnitrificação , Heme/metabolismo , Humanos , Imunoprecipitação , Nitrito Redutases/análise , Mapas de Interação de Proteínas , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/enzimologia , Pseudomonas aeruginosa/crescimento & desenvolvimento , Tetrapirróis/metabolismo
8.
Int J Syst Evol Microbiol ; 63(Pt 4): 1499-1504, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22863988

RESUMO

A Gram-stain-negative, non-motile, facultatively anaerobic, acid-tolerant rod, designated strain DKE6(T), was isolated from an acidic biofilm (pH 2.5) harvested in the pyrite mine Drei Kronen und Ehrt in Germany. The isolate grew optimally at pH 5.5, between 25 and 30 °C and only with casein as the carbon and energy source; although a variety of sugars were tested as growth substrates, none supported growth of the isolate. During casein consumption, strain DKE6(T) produced ammonium, which led to an alkalinization of the medium. This is a possible strategy to raise the pH in the direct vicinity of the cell and hence modulate the pH towards the growth optimum. The predominant fatty acids (>5 %) were iso-C11 : 0 3-OH, iso-C15 : 0, iso-C17 : 0 and iso-C17 : 1ω9c. The DNA G+C content was 66.6 %. Strain DKE6(T) was not able to oxidize iron or thiosulfate. Iron reduction was detected. The isolate showed 93.3 % 16S rRNA gene sequence similarity to the most closely related cultivable strain, Dokdonella koreensis DS-123(T), but <93.2 % sequence similarity with other type strains of closely related type species of the Gammaproteobacteria. On the basis of physiological and biochemical data, the isolate is considered to represent a novel species of a new genus in the class Gammaproteobacteria, for which we propose the name Metallibacterium scheffleri gen. nov., sp. nov. The type strain of the type species is DKE6(T) ( = DSM 24874(T) = JCM 17596(T)).


Assuntos
Mineração , Filogenia , Xanthomonadaceae/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Biofilmes , Citocromos/análise , DNA Bacteriano/genética , Ácidos Graxos/análise , Alemanha , Ferro , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Sulfetos , Ubiquinona/análise , Xanthomonadaceae/genética , Xanthomonadaceae/isolamento & purificação
9.
J Biosci Bioeng ; 110(1): 42-7, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20541114

RESUMO

Rhodococcus rhodochrous is an active soil bacterium belonging to the Nocardia group of high GC gram-positive bacteria. It is rich in various enzymes and thus important in the industrial production of chemicals and bioremediation. In this work, the respiratory chain of this aerobic organism was investigated and characterized. Grown under highly aerobic conditions, the membrane fraction of R. rhodochrous cells only contained a-, b- and c-type cytochromes, suggesting that it is the cytochrome bcc-aa(3)-type pathway that mainly operates under these conditions. In contrast, the d-type cytochrome was also present under microaerobic conditions, indicating that the alternative pathway of the bd-type oxidase works in these circumstances. In addition, the results of H(+)/O ratio measurements indicate that these two pathways have different energy efficiencies.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Rhodococcus/enzimologia , Aerobiose/fisiologia , Membrana Celular/química , Grupo dos Citocromos c/metabolismo , Grupo dos Citocromos d/metabolismo , Citocromos/análise , Citocromos/metabolismo , Transporte de Elétrons/fisiologia , Complexo IV da Cadeia de Transporte de Elétrons/química , Metabolismo Energético/fisiologia , Inibidores Enzimáticos/farmacologia , Concentração de Íons de Hidrogênio , Oxirredução , Oxirredutases/metabolismo , Oxigênio/metabolismo , Rhodococcus/crescimento & desenvolvimento
10.
Cancer Prev Res (Phila) ; 3(6): 745-52, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20484175

RESUMO

Two primary prevention trials unexpectedly showed adverse effects of supplemental beta-carotene on lung cancer incidence in cigarette smokers. To elucidate the molecular mechanisms that might underlie these effects, we studied the immunohistochemical expression of cytochrome P450 1A1, 1A2, and 2E1, retinoic acid receptor beta, activated protein-1 elements, cyclin D1, and Ki67 in lung tumors and, when available, adjacent normal tissues obtained from incident cases in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. Archival lung tissue was available from 52 men randomized to receive 20 mg of beta-carotene per day and 30 men randomized to the placebo arm, all of whom were diagnosed with incident non-small-cell lung carcinoma during the course of the trial and subsequently underwent radical pulmonary resection. In normal-appearing bronchial epithelium, positive staining for cyclin D1 was observed in 23% of cases in the beta-carotene group and 0% of cases in the placebo group (based on only 3 of 13 versus 0 of 11 cases staining positively, however; P = 0.04), with no differences in expression noted in lung tumor tissue (P = 0.48). There were no statistically significant differences in Ki67 expression in normal or cancerous lung tissue between intervention groups, although a small increase in staining in tumors was noted among cases in the beta-carotene versus placebo group (88% versus 71% of cases stained positive, respectively; P = 0.13). Contrary to expectation, beta-carotene supplementation had no apparent effect on retinoic acid receptor-beta expression. These findings suggest that male smokers supplemented with beta-carotene may have had an increased risk of lung cancer due to aberrant cell growth, although our results are based on a relatively small number of cases and require confirmation in other completed trials of beta-carotene supplementation.


Assuntos
Biomarcadores Tumorais/análise , Carcinoma Pulmonar de Células não Pequenas/etiologia , Suplementos Nutricionais/efeitos adversos , Neoplasias Pulmonares/etiologia , Proteínas de Neoplasias/análise , Fumar/efeitos adversos , beta Caroteno/efeitos adversos , Idoso , Carcinoma Pulmonar de Células não Pequenas/química , Carcinoma Pulmonar de Células não Pequenas/prevenção & controle , Cocarcinogênese , Ciclina D1/análise , Citocromos/análise , Método Duplo-Cego , Humanos , Antígeno Ki-67/análise , Pulmão/química , Neoplasias Pulmonares/química , Neoplasias Pulmonares/prevenção & controle , Masculino , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto/estatística & dados numéricos , Ensaios Clínicos Controlados Aleatórios como Assunto/estatística & dados numéricos , Receptores do Ácido Retinoico/análise , Estudos Retrospectivos , alfa-Tocoferol/uso terapêutico , beta Caroteno/uso terapêutico
11.
Analyst ; 135(5): 908-17, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20419238

RESUMO

The cytochrome distribution in hyphal tip cells of Schizophyllum commune was visualized using resonance Raman mapping and CARS microscopy. For comparison, resonance Raman mapping and CARS imaging of cytochrome was also performed during branch formation and in completely developed central hyphae. Cytochrome, as an essential component of the electron transport chain in mitochondria, plays an important role in providing energy to actively growing mycelia. It could be shown that mitochondria at the growing hyphal tips and at branching regions are more active, i.e. contain more cytochrome, as compared to those in older parts of the hyphae. This finding is compatible with the idea of high energy consumption for biosynthesis and intracellular transport at the growing tip, while older hyphae have lower needs for ATP generated via the respiratory chain in mitochondria. To the best of our knowledge this is the first study reporting about the localization and distribution of cytochrome, as an indirect mitochondria localization within S. commune or other basidiomycetous fungi, by means of resonance Raman microspectroscopy and CARS microscopy. These Raman methods bear the potential of label-free in vivo mitochondria localization and investigation.


Assuntos
Citocromos/análise , Análise Espectral Raman/métodos , Hifas/metabolismo , Microscopia de Fluorescência , Mitocôndrias/metabolismo , Schizophyllum/metabolismo
12.
Appl Environ Microbiol ; 75(9): 2931-5, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19286784

RESUMO

Antibody recognition force microscopy showed that OmcA and MtrC are expressed on the exterior surface of living Shewanella oneidensis MR-1 cells when Fe(III), including solid-phase hematite (Fe(2)O(3)), was the terminal electron acceptor. OmcA was localized to the interface between the cell and mineral. MtrC displayed a more uniform distribution across the cell surface. Both cytochromes were associated with an extracellular polymeric substance.


Assuntos
Proteínas de Bactérias/análise , Grupo dos Citocromos c/análise , Citocromos/análise , Proteínas de Membrana/análise , Shewanella/química , Anticorpos/metabolismo , Compostos Férricos/metabolismo , Microscopia de Força Atômica
13.
ISME J ; 3(2): 266-70, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18843299

RESUMO

Pellicle biofilms colonize the air-solution interface of underground acid mine drainage (AMD) streams and pools within the Richmond Mine (Iron Mountain, Redding, CA, USA). They exhibit relatively low species richness and, consequently, represent good model systems to study natural microbial community structure. Fluorescence in situ hybridization combined with epifluorescent microscopy and transmission electron microscopy revealed spatially and temporally defined microbial assemblages. Leptospirillum group II dominates the earliest developmental stages of stream pellicles. With increasing biofilm maturity, the proportion of archaea increases in conjunction with the appearance of eukaryotes. In contrast, mature pool pellicles are stratified with a densely packed bottom layer of Leptospirillum group II, a less dense top layer composed mainly of archaea and no eukarya. Immunohistochemical detection of Leptospirillum group II cytochrome 579 indicates a high abundance of this protein at the interface of the biofilm with the AMD solution. Consequently, community architecture, which most likely develops in response to chemical gradients across the biofilm, is reflected at the functional gene expression level.


Assuntos
Archaea/isolamento & purificação , Archaea/fisiologia , Bactérias/isolamento & purificação , Fenômenos Fisiológicos Bacterianos , Biodiversidade , Biofilmes , Microbiologia Ambiental , Archaea/classificação , Bactérias/classificação , Proteínas de Bactérias/análise , California , Citocromos/análise , Células Eucarióticas , Hibridização in Situ Fluorescente , Microscopia de Fluorescência
14.
Mikrobiologiia ; 77(3): 386-95, 2008.
Artigo em Russo | MEDLINE | ID: mdl-18683657

RESUMO

We investigated the formation of the B800-850 complex in cells of the bacterium Rhodopseudomonas palustris AB illuminated by red and blue light under anaerobic growth conditions. Under red illumination, the B800-850 complex was assembled with a reduced absorption band at 850 nm. The results of re-electrophoresis of the B800-850 complex and oxidation in the presence of potassium iridate suggest its heterogeneity. It may be a mixture of two complexes (B800 and B800-850). The B800-850 complex lacks the capacity for conformational transitions if assembled under blue illumination. Accordingly, the light-harvesting complex assembled in the blue light contains polypeptides that are not synthesized under normal conditions or at increased or decreased light intensities. The mechanism of regulation of the synthesis of the polypeptides of light-harvesting B800-850 complex and its dependence on the spectral composition of the light is discussed.


Assuntos
Proteínas de Bactérias/biossíntese , Complexos de Proteínas Captadores de Luz/biossíntese , Luz , Rodopseudomonas/metabolismo , Proteínas de Bactérias/análise , Cromatografia Líquida de Alta Pressão , Citocromos/análise , Citocromos/biossíntese , Complexos de Proteínas Captadores de Luz/análise , Rodopseudomonas/crescimento & desenvolvimento , Espectrofotometria
15.
J Bacteriol ; 190(14): 5127-31, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18487320

RESUMO

We have functionally produced the outer membrane cytochrome OmcA from Shewanella oneidensis in Escherichia coli. Substrate accessibility experiments indicate that OmcA is surface exposed in an E. coli B strain but not in a K-12 strain. We show that a functional type II secretion system is required for surface localization.


Assuntos
Proteínas da Membrana Bacteriana Externa/análise , Proteínas de Bactérias/genética , Citocromos/análise , Citocromos/genética , Shewanella/genética , Clonagem Molecular , Escherichia coli/genética , Transporte Proteico , Proteínas Recombinantes/análise , Proteínas Recombinantes/genética
16.
Rapid Commun Mass Spectrom ; 22(1): 52-8, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18050240

RESUMO

The in vitro metabolism of deoxypodophyllotoxin (DPT), a medicinal herbal product isolated from Anthriscus sylvestris (Apiaceae), was investigated in rats and human microsomes and human recombinant cDNA-expressed CYPs. The incubation of DPT with pooled human microsomes in the presence of NADPH generated five metabolites while its incubation with dexamethasone (Dex)-induced rat liver resulted in seven metabolites (M1-M7) with major metabolic reactions including mono-hydroxylation, O-demethylation and demethylenation. Reasonable structures of the seven metabolites of DPT could be proposed, based on the electrospray tandem mass spectra. Chemical inhibition by ketoconazole and metabolism studies with human recombinant cDNA-expressed CYPs indicated that CYP 3A4 and 2C19 are the major CYP isozymes in the metabolism of DPT in human liver microsomes.


Assuntos
Inseticidas/análise , Microssomos Hepáticos/química , Podofilotoxina/análogos & derivados , Animais , Biotransformação , Cromatografia Líquida de Alta Pressão , Citocromos/análise , Citocromos/antagonistas & inibidores , Citocromos/metabolismo , DNA Complementar/biossíntese , DNA Complementar/genética , Medicamentos de Ervas Chinesas , Inibidores Enzimáticos/farmacologia , Humanos , Técnicas In Vitro , Inseticidas/farmacocinética , Isoenzimas/análise , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Masculino , Microssomos Hepáticos/metabolismo , Podofilotoxina/análise , Podofilotoxina/farmacocinética , Prótons , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/metabolismo , Espectrometria de Massas em Tandem
17.
FEMS Microbiol Lett ; 278(1): 94-100, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18031533

RESUMO

A hydrogen-oxidizing bacterium strain AH-24 was isolated, which was classified in the genus Hydrogenophaga, based on the 16S rRNA gene sequence. The isolate possessed a typical yellow pigment of Hydrogenophaga species. Its closest relative was Hydrogenophaga pseudoflava, but the assimilation profile of sugar compounds resembled that of no species of Hydrogenophaga. The optimum temperature and pH for autotrophic growth were, respectively, 33-35 degrees C and 7.0. Most hydrogenase activity (benzyl viologen reducing activity) was localized in the membrane fraction (MF), but NAD(P)-reducing hydrogenase activity was detected in neither the membrane nor the soluble fractions. Cytochromes b561 and c551 were present in MF; both were reduced when hydrogen was supplied to the oxidized MF, suggesting involvement in respiratory H2 oxidation as electron carriers. Cytochrome b561 was inferred to function as the redox partner of the membrane-bound hydrogenase.


Assuntos
Comamonadaceae/isolamento & purificação , Hidrogênio/metabolismo , Microbiologia do Solo , Membrana Celular/química , Comamonadaceae/química , Comamonadaceae/classificação , Comamonadaceae/fisiologia , Citocromos/análise , Citocromos/metabolismo , DNA Bacteriano/genética , DNA Ribossômico/genética , Hidrogenase/análise , Hidrogenase/metabolismo , Lotus , Oxirredução , Filogenia , RNA Ribossômico 16S/genética , Análise Espectral
18.
J Appl Microbiol ; 102(6): 1485-98, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17578413

RESUMO

AIM: The aim of the present study was to investigate the phenotypic and genotypic variability of two strains of Acidithiobacillus ferrooxidans genus during growth in sewage sludge. METHODS AND RESULTS: Compared with A. ferrooxidans cells grown in mineral medium, those grown in sewage sludge demonstrated remarkable changes in ultrastructure (transmission electron microscopy) and significantly elongated lag phases. These latter cells also lacked carboxysomes and rusticyanin, showed lower level of cytochromes and exhibited modifications to their outer membrane proteins (SDS-PAGE). Restriction fragment length polymorphism analysis using pulsed-field gel electrophoresis showed that most restriction fragments were highly conserved and shared by strains grown under different conditions. However, in relation to cells grown in mineral medium, sludge-grown A. ferrooxidans lacked a number of restriction fragments, clearly indicating structural changes to the chromosomal DNA of the organism. CONCLUSIONS: In combination, the results of this study provide evidence of adaptive responses by chemolithoautotrophic acidophilic A. ferrooxidans to facilitate growth in sewage sludge. SIGNIFICANCE AND IMPACT OF THE STUDY: The obtained results are important from scientific as well as industrial application point of view, because they confirmed that A. ferrooxidans highly sensitive to organic compounds bacteria is useful in biotechnologies of heavy metal removal from shale ore, polluted soils and sewage sludge containing organic hazardous compounds.


Assuntos
Acidithiobacillus/fisiologia , Esgotos/microbiologia , Acidithiobacillus/genética , Acidithiobacillus/ultraestrutura , Adaptação Biológica , Proteínas de Bactérias/análise , Cromossomos Bacterianos/genética , Meios de Cultura , Citocromos/análise , DNA Bacteriano/genética , Genótipo , Microscopia Eletrônica/métodos , Minerais , Fenótipo , Polimorfismo de Fragmento de Restrição , Esgotos/química
19.
FEMS Yeast Res ; 7(6): 879-86, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17559411

RESUMO

We have previously reported that growth on alcohol vapors confers hemolytic properties on certain yeast species and strains ('microbial alcohol conferred hemolysis'; MACH). Here, a Saccharomyces cerevisiae deletion library consisting of c. 4800 clones was screened for MACH mutants in the presence of n-butanol vapors; 136 mutants were MACH-negative, and 325 exhibited reduced hemolysis and/or growth. Of the MACH-negative mutants, 35.3% were affected in mitochondrial-related genes. The data suggest that intact mitochondrial and respiratory chain functions are critical for the observed MACH phenomenon. We propose that the uncontrolled cellular uptake of alcohol results in yeast 'hyper-respiration', leading to elaboration of hemolytic molecules such as hydrogen peroxide and hemolysis-causing lipids. To support this premise, we showed that: (1) exogenous catalase and glutathione reduce alcohol-conferred hemolysis in S. cerevisiae BY4741 and Candida tropicalis 59445; (2) C. tropicalis produces hydrogen peroxide following growth on ethanol and n-butanol, as shown using xylenol orange; and (3) a lysophospholipid-containing lipid extract from alcohol-grown C. tropicalis specifically causes hemolysis.


Assuntos
Álcoois/farmacologia , Hemólise/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Catalase/metabolismo , Citocromos/análise , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Regulação Fúngica da Expressão Gênica , Glutationa/metabolismo , Peróxido de Hidrogênio/toxicidade , Lisofosfolipídeos/metabolismo , Mutação/genética , Consumo de Oxigênio/efeitos dos fármacos , Fenóis , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/enzimologia , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Sulfóxidos , Xilenos/metabolismo
20.
Med. clín (Ed. impr.) ; 126(18): 697-706, mayo 2006. tab
Artigo em Es | IBECS | ID: ibc-045207

RESUMO

En el genoma humano, hay un gran número de genes polimórficos, y muchos de ellos codifican enzimas que metabolizan fármacos y agentes xenobióticos, incluyendo carcinógenos. Entre las más conocidas figuran varias isoenzimas del sistema oxidativo microsomal P450 (CYP3A4, CYP2C9, CYP2C19 y CYP2D6). En este artículo, se han revisado los aspectos siguientes: a) la frecuencia de presentación del genotipo y/o fenotipo «metabolizador lento» para sustratos del CYP2C19; b) el papel del polimorfismo CYP2C19 en el metabolismo de fármacos (la mefenitoína y otros antiepilépticos, inhibidores de la bomba de protones, diversos antidepresivos, ansiolíticos, el agente antipalúdico proguanil y propranolol, entre otros utilizan esta vía metabólica), y c) el posible papel del polimorfismo CYP2C19 en el riesgo de desarrollo de diversas neoplasias y otras enfermedades (lupus eritematoso sistémico, psoriasis, osteonecrosis de cadera, enfermedad de Alzheimer, esclerosis lateral amiotrófica, temblor esencial)


There are a great number of polymorphic genes in the human genome. Many of them codify enzymes that metabolizes drugs and xenobiotic agents, including carcinogens. Among the better known of them, there are a number of isozymes of the microsomal oxidative system (CYP3A4, CYP2C9, CYP2C19 y CYP2D6). This article reviews the following issues: a) frequency of presentation of the «poor metabolizer» genotype and/or phenotype for substrates of CYP2C19; b) role of CYP2C19 polymorphism on the metabolism of some drugs (mephenytoine and other antiepileptic drugs, proton pump inhibitors, several antidepressants and anxyolitics, the antimalaria aggent proguanyl, and propranolol, among others, use this metabolic pathway), and c) possible role of CYP2C19 polymorphism in the risk for development of neoplasia and other diseases (systemic lupus erythematosus, psoriasis, hip osteonecrosis, Alzheimer's disease, amyotrophic lateral sclerosis, essential tremor)


Assuntos
Humanos , /genética , Polimorfismo Genético , Citocromos/análise , Fenótipo , Genótipo , Fatores de Risco , Predisposição Genética para Doença/genética
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