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1.
Nat Commun ; 12(1): 4455, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34294705

RESUMO

Plant sulfate transporters (SULTR) mediate absorption and distribution of sulfate (SO42-) and are essential for plant growth; however, our understanding of their structures and functions remains inadequate. Here we present the structure of a SULTR from Arabidopsis thaliana, AtSULTR4;1, in complex with SO42- at an overall resolution of 2.8 Å. AtSULTR4;1 forms a homodimer and has a structural fold typical of the SLC26 family of anion transporters. The bound SO42- is coordinated by side-chain hydroxyls and backbone amides, and further stabilized electrostatically by the conserved Arg393 and two helix dipoles. Proton and SO42- are co-transported by AtSULTR4;1 and a proton gradient significantly enhances SO42- transport. Glu347, which is ~7 Å from the bound SO42-, is required for H+-driven transport. The cytosolic STAS domain interacts with transmembrane domains, and deletion of the STAS domain or mutations to the interface compromises dimer formation and reduces SO42- transport, suggesting a regulatory function of the STAS domain.


Assuntos
Proteínas de Transporte de Ânions/química , Proteínas de Transporte de Ânions/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Transportadores de Sulfato/química , Transportadores de Sulfato/metabolismo , Proteínas de Transporte de Ânions/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Sítios de Ligação/genética , Microscopia Crioeletrônica , Ácido Glutâmico/química , Modelos Moleculares , Domínios e Motivos de Interação entre Proteínas , Multimerização Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Eletricidade Estática , Transportadores de Sulfato/genética , Sulfatos/metabolismo
2.
Int J Mol Sci ; 22(13)2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34281213

RESUMO

3'-Phosphoadenosine 5'-monophosphate (pAp) is a byproduct of sulfate assimilation and coenzyme A metabolism. pAp can inhibit the activity of 3'-phosphoadenosine 5'-phosphosulfate (PAPS) reductase and sulfotransferase and regulate gene expression under stress conditions by inhibiting XRN family of exoribonucleases. In metazoans, plants, yeast, and some bacteria, pAp can be converted into 5'-adenosine monophosphate (AMP) and inorganic phosphate by CysQ. In some bacteria and archaea, nanoRNases (Nrn) from the Asp-His-His (DHH) phosphoesterase superfamily are responsible for recycling pAp. In addition, histidinol phosphatase from the amidohydrolase superfamily can hydrolyze pAp. The bacterial enzymes for pAp turnover and their catalysis mechanism have been well studied, but these processes remain unclear in archaea. Pyrococcus yayanosii, an obligate piezophilic hyperthermophilic archaea, encodes a DHH family pApase homolog (PyapApase). Biochemical characterization showed that PyapApase can efficiently convert pAp into AMP and phosphate. The resolved crystal structure of apo-PyapApase is similar to that of bacterial nanoRNaseA (NrnA), but they are slightly different in the α-helix linker connecting the DHH and Asp-His-His associated 1 (DHHA1) domains. The longer α-helix of PyapApase leads to a narrower substrate-binding cleft between the DHH and DHHA1 domains than what is observed in bacterial NrnA. Through mutation analysis of conserved amino acid residues involved in coordinating metal ion and binding substrate pAp, it was confirmed that PyapApase has an ion coordination pattern similar to that of NrnA and slightly different substrate binding patterns. The results provide combined structural and functional insight into the enzymatic turnover of pAp, implying the potential function of sulfate assimilation in hyperthermophilic cells.


Assuntos
Pyrococcus/enzimologia , Família Multigênica , Pyrococcus/genética , Especificidade por Substrato , Sulfatos/metabolismo
3.
Artigo em Inglês | MEDLINE | ID: mdl-34255623

RESUMO

A novel, spore-forming, acidophilic and metal-resistant sulfate-reducing bacterium, strain OLT, was isolated from a microbial mat in a tailing dam at a gold ore mining site. Cells were slightly curved immotile rods, 0.5 µm in diameter and 2.0-3.0 µm long. Cells were stained Gram-negative, despite the Gram-positive cell structure revealed by electron microscopy of ultrathin layers. OLT grew at pH 4.0-7.0 with an optimum at 5.5. OLT utilised H2, lactate, pyruvate, malate, formate, propionate, ethanol, glycerol, glucose, fructose, sucrose, peptone and tryptone as electron donors for sulfate reduction. Sulfate, sulfite, thiosulfate, nitrate and fumarate were used as electron acceptors in the presence of lactate. Elemental sulfur, iron (III), and arsenate did not serve as electron acceptors. The major cellular fatty acids were C16:1ω7c (39.0 %) and C16 : 0 (12.1 %). The draft genome of OLT was 5.29 Mb in size and contained 4909 protein-coding genes. The 16S rRNA gene sequence placed OLT within the phylum Firmicutes, class Clostridia, family Peptococcaceae, genus Desulfosporosinus. Desulfosporosinus nitroreducens 59.4BT was the closest relative with 97.6 % sequence similarity. On the basis of phenotypic and phylogenetic characteristics, strain OLT represents a novel species within the genus Desulfosporosinus, for which we propose the name Desulfosporosinus metallidurans sp. nov. with the type strain OLT (=DSM 104464T=VKM В-3021T).


Assuntos
Mineração , Peptococcaceae/classificação , Filogenia , Ácidos , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Oxirredução , Peptococcaceae/isolamento & purificação , RNA Ribossômico 16S/genética , Federação Russa , Análise de Sequência de DNA , Sulfatos/metabolismo
4.
Appl Environ Microbiol ; 87(17): e0084221, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34160245

RESUMO

Reservoir souring, which is the production of H2S mainly by sulfate-reducing microorganisms (SRM) in oil reservoirs, has been a long-standing issue for the oil industry. While biocides have been frequently applied to control biogenic souring, the effects of biocide treatment are usually temporary, and biocides eventually fail. The reasons for biocide failure and the long-term response of the microbial community remain poorly understood. In this study, one-time biocide treatments with glutaraldehyde (GA) and an aldehyde-releasing biocide (ARB) at low (100 ppm) and high (750 ppm) doses were individually applied to a complex SRM community, followed by 1 year of monitoring of the chemical responses and the microbial community succession. The chemical results showed that souring control failed after 7 days at a dose of 100 ppm regardless of the biocide type and lasting souring control for the entire 1-year period was achieved only with ARB at 750 ppm. Microbial community analyses suggested that the high-dose biocide treatments resulted in 1 order of magnitude lower average total microbial abundance and average SRM abundance, compared to the low-dose treatments. The recurrence of souring was associated with reduction of alpha diversity and with long-term microbial community structure changes; therefore, monitoring changes in microbial community metrics may provide early warnings of the failure of a biocide-based souring control program in the field. Furthermore, spore-forming sulfate reducers (Desulfotomaculum and Desulfurispora) were enriched and became dominant in both GA-treated groups, which could cause challenges for the design of long-lasting remedial souring control strategies. IMPORTANCE Reservoir souring is a problem for the oil and gas industry, because H2S corrodes the steel infrastructure, downgrades oil quality, and poses substantial risks to field personnel and the environment. Biocides have been widely applied to remedy souring, but the long-term performance of biocide treatments is hard to predict or to optimize due to limited understanding of the microbial ecology affected by biocide treatment. This study investigates the long-term biocide performance and associated changes in the abundance, diversity, and structure of the souring microbial community, thus advancing the knowledge toward a deeper understanding of the microbial ecology of biocide-treated systems and contributing to the improvement of current biocide-based souring control practices. The study showcases the potential application of incorporating microbial community analyses to forecast souring, and it highlights the long-term consequences of biocide treatment in the microbial communities, with relevance to both operators and regulators.


Assuntos
Bactérias/efeitos dos fármacos , Desinfetantes/farmacologia , Microbiota/efeitos dos fármacos , Ácidos/análise , Ácidos/metabolismo , Bactérias/classificação , Bactérias/isolamento & purificação , Bactérias/metabolismo , Campos de Petróleo e Gás/química , Campos de Petróleo e Gás/microbiologia , Oxirredução , Sulfatos/análise , Sulfatos/metabolismo , Fatores de Tempo
5.
Commun Biol ; 4(1): 674, 2021 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-34083726

RESUMO

The terminal galactose residues of N- and O-glycans in animal glycoproteins are often sialylated and/or fucosylated, but sulfation, such as 3-O-sulfated galactose (3-O-SGal), represents an additional, but poorly understood modification. To this end, we have developed a novel sea lamprey variable lymphocyte receptor (VLR) termed O6 to explore 3-O-SGal expression. O6 was engineered as a recombinant murine IgG chimera and its specificity and affinity to the 3-O-SGal epitope was defined using a variety of approaches, including glycan and glycoprotein microarray analyses, isothermal calorimetry, ligand-bound crystal structure, FACS, and immunohistochemistry of human tissue macroarrays. 3-O-SGal is expressed on N-glycans of many plasma and tissue glycoproteins, but recognition by O6 is often masked by sialic acid and thus exposed by treatment with neuraminidase. O6 recognizes many human tissues, consistent with expression of the cognate sulfotransferases (GAL3ST-2 and GAL3ST-3). The availability of O6 for exploring 3-O-SGal expression could lead to new biomarkers for disease and aid in understanding the functional roles of terminal modifications of glycans and relationships between terminal sulfation, sialylation and fucosylation.


Assuntos
Epitopos/metabolismo , Galactose/análogos & derivados , Glicoproteínas/metabolismo , Lampreias/metabolismo , Polissacarídeos/metabolismo , Sequência de Aminoácidos , Animais , Células CHO , Cricetinae , Cricetulus , Fucose/metabolismo , Galactose/metabolismo , Glicoproteínas/química , Glicosilação , Células HEK293 , Humanos , Lampreias/imunologia , Ligantes , Espectrometria de Massas/métodos , Ácido N-Acetilneuramínico/metabolismo , Sulfatos/metabolismo , Sulfotransferases/química , Sulfotransferases/genética , Sulfotransferases/metabolismo
6.
Expert Opin Drug Metab Toxicol ; 17(7): 767-784, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34107842

RESUMO

INTRODUCTION: Cytosolic sulfotransferases (SULTs)-mediated sulfation is critically involved in the metabolism of key endogenous compounds, such as catecholamines and thyroid/steroid hormones, as well as a variety of drugs and other xenobiotics. Studies performed in the past three decades have yielded a good understanding about the enzymology of the SULTs and their structural biology, phylogenetic relationships, tissue/organ-specific/developmental expression, as well as the regulation of the SULT gene expression. An emerging area is related to the functional impact of the SULT genetic polymorphisms. AREAS COVERED: The current review aims to summarize our current knowledge about the above-mentioned aspects of the SULT research. An emphasis is on the information concerning the effects of the polymorphisms of the SULT genes on the functional activity of the SULT allozymes and the associated physiological, pharmacological, and clinical implications. EXPERT OPINION: Elucidation of how SULT SNPs may influence the drug-sulfating activity of SULT allozymes will help understand the differential drug metabolism and eventually aid in formulating personalized drug regimens. Moreover, the information concerning the differential sulfating activities of SULT allozymes toward endogenous compounds may allow for the development of strategies for mitigating anomalies in the metabolism of these endogenous compounds in individuals with certain SULT genotypes.


Assuntos
Preparações Farmacêuticas/metabolismo , Sulfotransferases/genética , Animais , Citosol/metabolismo , Regulação Enzimológica da Expressão Gênica , Genótipo , Humanos , Polimorfismo de Nucleotídeo Único , Sulfatos/metabolismo , Sulfotransferases/metabolismo
7.
J Gen Virol ; 102(6)2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34106826

RESUMO

White spot syndrome virus (WSSV) is the most virulent pathogen causing high mortality and economic loss in shrimp aquaculture and various crustaceans. Therefore, the understanding of molecular mechanisms of WSSV infection is important to develop effective therapeutics to control the spread of this viral disease. In a previous study, we found that VP37 could bind with shrimp haemocytes through the interaction between its C-terminal domain and heparin-like molecules on the shrimp cells, and this interaction can also be inhibited by sulphated galactan. In this study, we present the crystal structure of C-terminal domain of VP37 from WSSV at a resolution of 2.51 Å. The crystal structure contains an eight-stranded ß-barrel fold with an antiparallel arrangement and reveals a trimeric assembly. Moreover, there are two sulphate binding sites found in the position corresponding to R213 and K257. In order to determine whether these sulphate binding sites are involved in binding of VP37 to heparin, mutagenesis was performed to replace these residues with alanine (R213A and K257A), and the Surface Plasmon Resonance (SPR) system was used to study the interaction of each mutated VP37 with heparin. The results showed that mutants R213A and K257A exhibited a significant loss in heparin binding activity. These findings indicated that the sites of R213 and K257 on the C-terminal domain of envelope protein VP37 are essential for binding to sulphate molecules of heparin. This study provides further insight into the structure of C-terminal domain of VP37 and it is anticipated that the structure of VP37 might be used as a guideline for development of antivirus agent targeting on the VP37 protein.


Assuntos
Heparina/metabolismo , Sulfatos/metabolismo , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/metabolismo , Vírus da Síndrome da Mancha Branca 1/química , Substituição de Aminoácidos , Animais , Sítios de Ligação , Cristalização , Cristalografia por Raios X , Modelos Moleculares , Penaeidae/virologia , Ligação Proteica , Conformação Proteica , Conformação Proteica em Folha beta , Domínios Proteicos , Estrutura Quaternária de Proteína , Ressonância de Plasmônio de Superfície , Proteínas do Envelope Viral/genética , Vírus da Síndrome da Mancha Branca 1/genética
8.
Microbes Environ ; 36(2)2021.
Artigo em Inglês | MEDLINE | ID: mdl-34039816

RESUMO

We investigated variations in cell growth and ATP Sulfurylase (ATPS) activity when two cyanobacterial strains-Synechocystis sp. PCC6803 and Synechococcus sp. WH7803-were grown in conventional media, and media with low ammonium, low sulfate and a high CO2/low O2 atmosphere. In both organisms, a transition and adaptation to the reconstructed environmental media resulted in a decrease in ATPS activity. This variation appears to be decoupled from growth rate, suggesting the enzyme is not rate-limiting in S assimilation and raising questions about the role of ATPS redox regulation in cell physiology and throughout Earth history.


Assuntos
Proteínas de Bactérias/metabolismo , Sulfato Adenililtransferase/metabolismo , Synechococcus/enzimologia , Synechococcus/crescimento & desenvolvimento , Synechocystis/enzimologia , Synechocystis/crescimento & desenvolvimento , Compostos de Amônio/metabolismo , Proteínas de Bactérias/genética , Sulfato Adenililtransferase/genética , Sulfatos/metabolismo , Synechococcus/genética , Synechocystis/genética
9.
World J Microbiol Biotechnol ; 37(6): 103, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34013421

RESUMO

Microbiocides are used to control problematic microorganisms. High doses of microbiocides cause environmental and operational problems. Therefore, using microbiocide enhancers to make microbiocides more efficacious is highly desirable. 2,2-dibromo-3-nitrilopropionamide (DBNPA) is a popular biodegradable microbiocide. D-Amino acids have been used in lab tests to enhance microbiocides to treat microbial biofilms. In this investigation, D-tyrosine was used to enhance DBNPA against Desulfovibrio vulgaris biofilm on C1018 carbon steel. After 7 days of incubation, the mass loss of coupons without treatment chemicals in the ATCC 1249 culture medium was found to be 3.1 ± 0.1 mg/cm2. With 150 ppm (w/w) DBNPA in the culture medium, the mass loss was reduced to 1.9 ± 0.1 mg/cm2 accompanied by a 1-log reduction in the sessile cell count. The 150 ppm DBNPA + 1 ppm D-tyrosine combination attained an extra 3-log reduction in sessile cell count and an additional 30% reduction in mass loss compared with 150 ppm DBNPA only treatment. The combination also led to a smaller maximum pit depth. Linear polarization resistance (LPR), electrochemical impedance spectrometry (EIS), and potentiodynamic polarization (PDP) tests corroborated the enhancement effects.


Assuntos
Biofilmes/efeitos dos fármacos , Carbono/química , Desulfovibrio vulgaris/fisiologia , Nitrilas/farmacologia , Tirosina/química , Corrosão , Meios de Cultura/química , Desulfovibrio vulgaris/efeitos dos fármacos , Espectroscopia Dielétrica , Testes de Sensibilidade Microbiana , Nitrilas/química , Oxirredução , Aço/química , Sulfatos/metabolismo
10.
Biochem Biophys Res Commun ; 562: 15-20, 2021 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-34030040

RESUMO

Bile acids play essential roles in facilitating the intestinal absorption of lipophilic nutrients as well as regulation of glucose, lipid, and energy homeostasis via activation of some receptors. Bile acids are cytotoxic, and consequently their concentrations are tightly controlled. A critical pathway for bile acid elimination and detoxification is sulfation. The pattern of bile acid sulfation differs by species. Sulfation preferentially occurs at the 3α-OH of bile acids in humans, but at the 7α-OH in mice. A recent study identified mouse cytosolic sulfotransferase 2A8 (mSULT2A8) as the major hepatic 7α-hydroxyl bile acid-sulfating enzyme. To elucidate the 7α-OH specific sulfation mechanism of mSULT2A8, instead of 3α-OH specific sulfation in humans, we determined a crystal structure of mSULT2A8 in complex with cholic acid, a major bile acid, and 3'-phosphoadenosine-5'-phosphate, the sulfate donor product. Our study shows that bile acid-binding mode of mSULT2A8 and how the enzyme holds the 7α-OH group of bile acids at the catalytic center, revealing that the mechanism underlying 7α-OH specific sulfation. The structure shows the substrate binds to mSULT2A8 in an orientation perpendicular to that of human 3α-hydroxyl bile acid-sulfotransferase (hSULT2A1). The structure of the complex provides new insight into species different bile acid metabolism.


Assuntos
Ácidos e Sais Biliares/metabolismo , Sulfatos/metabolismo , Sulfotransferases/química , Sequência de Aminoácidos , Animais , Sítios de Ligação , Biocatálise , Cristalografia por Raios X , Humanos , Cinética , Camundongos , Modelos Moleculares , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Especificidade por Substrato , Sulfotransferases/metabolismo
11.
Infect Immun ; 89(6)2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-33820814

RESUMO

During enteric salmonellosis, neutrophil-generated reactive oxygen species alter the gut microenvironment, favoring survival of Salmonella Typhimurium. While type 3 secretion system 1 (T3SS-1) and flagellar motility are potent Salmonella Typhimurium agonists of the neutrophil respiratory burst in vitro, neither of these pathways alone is responsible for stimulation of a maximal respiratory burst. To identify Salmonella Typhimurium genes that impact the magnitude of the neutrophil respiratory burst, we performed a two-step screen of defined mutant libraries in coculture with human neutrophils. We first screened Salmonella Typhimurium mutants lacking defined genomic regions and then tested single-gene deletion mutants representing particular regions under selection. A subset of single-gene deletion mutants was selected for further investigation. Mutants in four genes, STM1696 (sapF), STM2201 (yeiE), STM2112 (wcaD), and STM2441 (cysA), induced an attenuated respiratory burst. We linked the altered respiratory burst to reduced T3SS-1 expression and/or altered flagellar motility for two mutants (ΔSTM1696 and ΔSTM2201). The ΔSTM2441 mutant, defective for sulfate transport, formed aggregates in minimal medium and adhered to surfaces in rich medium, suggesting a role for sulfur homeostasis in the regulation of aggregation/adherence. We linked the aggregation/adherence phenotype of the ΔSTM2441 mutant to biofilm-associated protein A and flagellins and hypothesize that aggregation caused the observed reduction in the magnitude of the neutrophil respiratory burst. Our data demonstrate that Salmonella Typhimurium has numerous mechanisms to limit the magnitude of the neutrophil respiratory burst. These data further inform our understanding of how Salmonella may alter human neutrophil antimicrobial defenses.


Assuntos
Interações Hospedeiro-Patógeno/imunologia , Neutrófilos/imunologia , Explosão Respiratória/imunologia , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Salmonella typhimurium/fisiologia , Sulfatos/metabolismo , Cisteína/metabolismo , Flagelos/fisiologia , Genes Bacterianos , Humanos , Mutação , Neutrófilos/metabolismo , Sistemas de Secreção Tipo III/genética , Sistemas de Secreção Tipo III/metabolismo
12.
Arch Microbiol ; 203(6): 3443-3456, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33893827

RESUMO

Seagrass meadows are vital ecosystems with high productivity and biodiversity and often in the oligotrophic area. Nitrogen usually limits productivity in this ecosystem as the main nutrient factor. Biological nitrogen fixation by diazotrophs in the rhizosphere sediment can introduce "new" nitrogen into the ecosystem. Previous studies revealed that most sulfate-reducing bacteria (SRB) can also fix nitrogen like the nitrogen-fixing bacteria (NFB). Moreover, both sulfate reduction and nitrogen fixation were affected by the organic pollutant. However, rare information is available regarding the NFB and SRB community composition and their temporal response to the pollutant. The quantitative real-time polymerase chain reaction and polymerase chain reaction denaturing gradient gel electrophoresis have been used to analyze NFB and SRB communities' shifts under different PAHs concentrations. They both experienced a dramatic shift under PAHs stress but exhibited different patterns. SRB could use the low and high concentration PAHs at the early stage of the incubation, while only the low concentration of PAHs could stimulate the growth of NFB through the whole incubation period. The predominant species of NFB communities were Alphaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria; while for SRB communities were class Epsilonproteobacteria. Redundancy analysis indicated the significant environmental factors for the two communities were both ammonium and pH (P < 0.05). There existed nifH sequences related to known nitrogen fixing SRB Desulfatibacillum alkenivorans, which confirmed that microbial N2 fixation and sulfate reduction were coupled in the seagrass ecosystem by molecular technique. Our investigation provides new insight into the NFB and SRB community in the seagrass meadow.


Assuntos
Bactérias , Sedimentos Geológicos , Microbiota , Hidrocarbonetos Policíclicos Aromáticos , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Deltaproteobacteria/genética , Sedimentos Geológicos/microbiologia , Hydrocharitaceae/microbiologia , Microbiota/efeitos dos fármacos , Microbiota/genética , Fixação de Nitrogênio , Oxirredutases/genética , Hidrocarbonetos Policíclicos Aromáticos/farmacologia , Sulfatos/metabolismo , Poluentes Químicos da Água/farmacologia
13.
Plant Cell ; 33(4): 1268-1285, 2021 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-33793849

RESUMO

A deficiency of the essential macronutrient sulfur leads to stunted plant growth and yield loss; however, an association with a symbiotic fungus can greatly improve nutrient uptake by the host plant. Here, we identified and functionally characterized a high-affinity sulfate transporter from the endophytic fungus Serendipita indica. SiSulT fulfills all the criteria expected of a functional sulfate transporter responding to sulfur limitation: SiSulT expression was induced when S. indica was grown under low-sulfate conditions, and heterologous expression of SiSulT complemented a yeast mutant lacking sulfate transport. We generated a knockdown strain of SiSulT by RNA interference to investigate the consequences of the partial loss of this transporter for the fungus and the host plant (maize, Zea mays) during colonization. Wild-type (WT) S. indica, but not the knockdown strain (kd-SiSulT), largely compensated for low-sulfate availability and supported plant growth. Colonization by WT S. indica also allowed maize roots to allocate precious resources away from sulfate assimilation under low-sulfur conditions, as evidenced by the reduction in expression of most sulfate assimilation genes. Our study illustrates the utility of the endophyte S. indica in sulfur nutrition research and offers potential avenues for agronomically sound amelioration of plant growth in low-sulfate environments.


Assuntos
Basidiomycota/fisiologia , Transportadores de Sulfato/metabolismo , Enxofre/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/microbiologia , Cultura Axênica , Basidiomycota/metabolismo , Transporte Biológico , Cromatos/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Mutação , Micologia/métodos , Filogenia , Interferência de RNA , Transportadores de Sulfato/genética , Sulfatos/metabolismo , Leveduras/genética , Zea mays/metabolismo
14.
Int J Mol Sci ; 22(8)2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33924516

RESUMO

This paper is devoted to microscopic methods for the identification of sulfate-reducing bacteria (SRB). In this context, it describes various habitats, morphology and techniques used for the detection and identification of this very heterogeneous group of anaerobic microorganisms. SRB are present in almost every habitat on Earth, including freshwater and marine water, soils, sediments or animals. In the oil, water and gas industries, they can cause considerable economic losses due to their hydrogen sulfide production; in periodontal lesions and the colon of humans, they can cause health complications. Although the role of these bacteria in inflammatory bowel diseases is not entirely known yet, their presence is increased in patients and produced hydrogen sulfide has a cytotoxic effect. For these reasons, methods for the detection of these microorganisms were described. Apart from selected molecular techniques, including metagenomics, fluorescence microscopy was one of the applied methods. Especially fluorescence in situ hybridization (FISH) in various modifications was described. This method enables visual identification of SRB, determining their abundance and spatial distribution in environmental biofilms and gut samples.


Assuntos
Bactérias/metabolismo , Ecossistema , Microscopia/métodos , Sulfatos/metabolismo , Animais , Humanos , Metagenômica , Oxirredução
15.
PLoS One ; 16(3): e0241960, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33760840

RESUMO

Diatoms are unicellular photosynthetic algae known to secrete organic matter that fuels secondary production in the ocean, though our knowledge of how their physiology impacts the composition of dissolved organic matter remains limited. Like all photosynthetic organisms, their use of light for energy and reducing power creates the challenge of avoiding cellular damage. To better understand the interplay between redox balance and organic matter secretion, we reconstructed a genome-scale metabolic model of Thalassiosira pseudonana strain CCMP 1335, a model for diatom molecular biology and physiology, with a 60-year history of studies. The model simulates the metabolic activities of 1,432 genes via a network of 2,792 metabolites produced through 6,079 reactions distributed across six subcellular compartments. Growth was simulated under different steady-state light conditions (5-200 µmol photons m-2 s-1) and in a batch culture progressing from exponential growth to nitrate-limitation and nitrogen-starvation. We used the model to examine the dissipation of reductants generated through light-dependent processes and found that when available, nitrate assimilation is an important means of dissipating reductants in the plastid; under nitrate-limiting conditions, sulfate assimilation plays a similar role. The use of either nitrate or sulfate uptake to balance redox reactions leads to the secretion of distinct organic nitrogen and sulfur compounds. Such compounds can be accessed by bacteria in the surface ocean. The model of the diatom Thalassiosira pseudonana provides a mechanistic explanation for the production of ecologically and climatologically relevant compounds that may serve as the basis for intricate, cross-kingdom microbial networks. Diatom metabolism has an important influence on global biogeochemistry; metabolic models of marine microorganisms link genes to ecosystems and may be key to integrating molecular data with models of ocean biogeochemistry.


Assuntos
Diatomáceas/metabolismo , Genoma , Nitrogênio/metabolismo , Enxofre/metabolismo , Trifosfato de Adenosina/metabolismo , Biomassa , Diatomáceas/genética , Diatomáceas/crescimento & desenvolvimento , Diatomáceas/efeitos da radiação , Luz , Análise do Fluxo Metabólico , Mitocôndrias/metabolismo , Nitratos/química , Nitratos/metabolismo , Nitrogênio/química , Oxirredução , Sulfatos/química , Sulfatos/metabolismo , Enxofre/química
16.
J Steroid Biochem Mol Biol ; 211: 105880, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33757894

RESUMO

Steroids play an important role in cell regulation and homeostasis. Many diseases like Alzheimer's disease or Smith-Lemli-Opitz syndrome are known to be associated with deviations in the steroid profile. Most published methods only allow the analysis of small subgroups of steroids and cannot give an overview of the total steroid profile. We developed and validated a method that allows the analysis of free neutral steroids, including intermediates of cholesterol biosynthesis, free oxysterols, C19 and C21 steroids, free steroid acids, including bile acids, and sterol sulfates using gas chromatography-mass spectrometry. Samples were analyzed in scan mode for screening purposes and in dynamic multiple reaction monitoring mode for highly sensitive quantitative analysis. The method was validated for mouse brain and liver tissue and consists of sample homogenization, lipid extraction, steroid group separation, deconjugation, derivatization and gas chromatography-mass spectrometry analysis. We applied the method on brain and liver samples of mice (10 months and 3 weeks old) and cultured N2a cells and report the endogenous concentrations of 29 physiological steroids.


Assuntos
Encéfalo/metabolismo , Cromatografia Gasosa-Espectrometria de Massas/métodos , Fígado/metabolismo , Esteroides/análise , Sulfatos/análise , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Esteroides/metabolismo , Sulfatos/metabolismo
17.
Int J Biol Macromol ; 180: 684-691, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33766590

RESUMO

The anti-glycation effects of polysaccharides from Ecklonia cava were examined according to extraction method-hot buffer (HP), ultrasound (UP), enzyme (EP), or a combination of ultrasound and enzyme (UEP). The physicochemical properties, monosaccharide compositions, and structural characteristics of the polysaccharides were determined. UP, EP, and UEP had higher fucose and galactose compositions than HP. The FT-IR spectra of samples showed the presence of sulfate esters and 4-sulfate galactose. 1H NMR indicated that alginate was removed by purification. UP, EP, and UEP possessed higher sulfate contents than HP. UEP presented with the highest extraction yield and lowest protein and uronic acid contents. The levels of AGE formation, as well as fructosamine, α-dicarbonyl, and protein carbonyl contents were determined during a 3-week incubation in a BSA/fructose system. UEP and UP effectively inhibited AGE, although the inhibition effect was lower than that of aminoguanidine. However, UP and UEP showed higher inhibition of fructosamine, α-dicarbonyl, and protein carbonyl than aminoguanidine. AGE formation was negatively correlated with sulfate content and some monosaccharide compositions (fucose, galactose, and glucose), but positively correlated with molecular weight. Overall, the present study suggests that UEP is a suitable extraction method for obtaining anti-glycation agents from E. cava.


Assuntos
Glucana 1,4-alfa-Glucosidase/metabolismo , Feófitas/química , Polissacarídeos/isolamento & purificação , Ultrassom/métodos , Glicosilação/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Peso Molecular , Monossacarídeos/análise , Polissacarídeos/química , Polissacarídeos/farmacologia , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Sulfatos/metabolismo , Ácidos Urônicos/metabolismo
18.
Biomed Pharmacother ; 138: 111459, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33706132

RESUMO

Silymarin is a mixture of flavonolignans isolated from the fruit of milk thistle (Silybum marianum (L.) Gaertner). Milk thistle extract is the active ingredient of several medications and dietary supplements to treat liver injury/diseases. After the oral administration, flavonolignans are extensively biotransformed, resulting in the formation of sulfate and/or glucuronide metabolites. Previous studies demonstrated that silymarin components form stable complexes with serum albumin and can inhibit certain cytochrome P450 (CYP) enzymes. Nevertheless, in most of these investigations, silybin was tested; while no or only limited information is available regarding other silymarin components and metabolites. In this study, the interactions of five silymarin components (silybin A, silybin B, isosilybin A, silychristin, and 2,3-dehydrosilychristin) and their sulfate metabolites were examined with human serum albumin and CYP (2C9, 2C19, 2D6, and 3A4) enzymes. Our results demonstrate that each compound tested forms stable complexes with albumin, and certain silymarin components/metabolites can inhibit CYP enzymes. Most of the sulfate conjugates were less potent inhibitors of CYP enzymes, but 2,3-dehydrosilychristin-19-O-sulfate showed the strongest inhibitory effect on CYP3A4. Based on these observations, the simultaneous administration of high dose silymarin with medications should be carefully considered, because milk thistle flavonolignans and/or their sulfate metabolites may interfere with drug therapy.


Assuntos
Citocromo P-450 CYP2C19/metabolismo , Citocromo P-450 CYP2C9/metabolismo , Citocromo P-450 CYP2D6/metabolismo , Citocromo P-450 CYP3A/metabolismo , Albumina Sérica Humana/metabolismo , Silimarina/metabolismo , Relação Dose-Resposta a Droga , Interações Medicamentosas/fisiologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , Ligação Proteica/fisiologia , Silimarina/química , Silimarina/farmacologia , Sulfatos/química , Sulfatos/metabolismo , Sulfatos/farmacologia
19.
Anaerobe ; 68: 102356, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33766774

RESUMO

Fluoxetine (FLX), an antidepressant extensively used worldwide is considered an emerging pollutant. The present work intends to investigate for the first time the capacity of a bacterial community containing sulphate-reducing bacteria (SRB) enriched from an anaerobic sludge to biodegrade and use FLX as sole carbon source, since current literature suggests that this drug is poorly biodegraded being mainly removed by adsorption to sediments, where it persists. FLX was biodegraded under sulphate reducing conditions until reaching its lowest and reliably detectable concentration, when 20 mg/L of the drug was used as sole carbon source, while 66 ± 9% of 50 mg/L FLX was removed, after 31 days. The initial bacterial population was mainly constituted by Desulfomicrobium and Desulfovibrio whereas during the experiments using FLX as unique carbon source a clear shift occurred with the increase of vadinBC27 wastewater-sludge group, Macellibacteroidetes, Dethiosulfovibrio, Bacteroides, Tolumonas, Sulfuricurvum, f_Enterobacteriaceae_OTU_18 that are assumed for the first time as FLX degrading bacteria. Although the main mechanism of FLX removal described in literature is by adsorption, in the results herein presented anaerobic biodegradation appears to play the main role in the removal of the FLX, thus demonstrating the potentialities that the anaerobic processes can play in wastewater treatment aiming the removal of new emerging compounds.


Assuntos
Antidepressivos/metabolismo , Bactérias/metabolismo , Fluoxetina/metabolismo , Anaerobiose , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biodegradação Ambiental , Reatores Biológicos/microbiologia , Esgotos/microbiologia , Sulfatos/metabolismo , Águas Residuárias/microbiologia
20.
Oxid Med Cell Longev ; 2021: 8877691, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33628390

RESUMO

Hydrogen sulfide (H2S) is naturally synthesized in a wide range of mammalian tissues. Whether H2S is involved in the regulation of erythrocyte functions remains unknown. Using mice with a genetic deficiency in a H2S natural synthesis enzyme cystathionine-γ-lyase (CSE) and high-throughput metabolomic profiling, we found that levels of erythrocyte 2,3-bisphosphoglycerate (2,3-BPG), an erythroid-specific metabolite negatively regulating hemoglobin- (Hb-) oxygen (O2) binding affinity, were increased in CSE knockout (Cse -/-) mice under normoxia. Consistently, the 50% oxygen saturation (P50) value was increased in erythrocytes of Cse -/- mice. These effects were reversed by treatment with H2S donor GYY4137. In the models of cultured mouse and human erythrocytes, we found that H2S directly acts on erythrocytes to decrease 2,3-BPG production, thereby enhancing Hb-O2 binding affinity. Mouse genetic studies showed that H2S produced by peripheral tissues has a tonic inhibitory effect on 2,3-BPG production and consequently maintains Hb-O2 binding affinity in erythrocytes. We further revealed that H2S promotes Hb release from the membrane to the cytosol and consequently enhances bisphosphoglycerate mutase (BPGM) anchoring to the membrane. These processes might be associated with S-sulfhydration of Hb. Moreover, hypoxia decreased the circulatory H2S level and increased the erythrocyte 2,3-BPG content in mice, which could be reversed by GYY4137 treatment. Altogether, our study revealed a novel signaling pathway that regulates oxygen-carrying capacity in erythrocytes and highlights a previously unrecognized role of H2S in erythrocyte 2,3-BPG production.


Assuntos
2,3-Difosfoglicerato/metabolismo , Eritrócitos/metabolismo , Hemoglobinas/metabolismo , Sulfeto de Hidrogênio/farmacologia , Oxigênio/metabolismo , Animais , Bisfosfoglicerato Mutase/metabolismo , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Células Cultivadas , Citosol/efeitos dos fármacos , Citosol/metabolismo , Eritrócitos/efeitos dos fármacos , Humanos , Hipóxia/metabolismo , Camundongos Endogâmicos C57BL , Modelos Biológicos , Transporte Proteico/efeitos dos fármacos , Sulfatos/metabolismo
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