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[PMID]:28429420
[Au] Autor:Harada A; Kamimura N; Takeuchi K; Yu HY; Masai E; Senda T
[Ad] Endereço:Structural Biology Research Center, Photon Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki, Japan.
[Ti] Título:The crystal structure of a new O-demethylase from Sphingobium sp. strain SYK-6.
[So] Source:FEBS J;284(12):1855-1867, 2017 Jun.
[Is] ISSN:1742-4658
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:In the cell, tetrahydrofolate (H folate) derivatives with a C1 unit are utilized in various ways, such as for the synthesis of amino acids and nucleic acids. While H folate derivatives with the C1 unit are typically produced in the glycine cleavage system, Sphingobium sp. strain SYK-6, which can utilize lignin-derived aromatic compounds as a sole source of carbon and energy, lacks this pathway, probably due to its unique nutrient requirements. In this bacterium, H folate-dependent O-demethylases in catabolic pathways for lignin-derived aromatic compounds seem to be involved in the C1 metabolism. LigM is one of the O-demethylases and catalyzes a C1-unit transfer from vanillate (VNL) to H folate. As the primary structure of LigM shows a similarity to T-protein in the glycine cleavage system, we hypothesized that LigM has evolved from T-protein, acquiring its unique biochemical and biological functions. To prove this hypothesis, structure-based understanding of its catalytic reaction is essential. Here, we determined the crystal structure of LigM in apo form and in complex with substrates and H folate. These crystal structures showed that the overall structure of LigM is similar to T-protein, but LigM has a few distinct characteristics, particularly in the active site. Structure-based mutational analysis revealed that His60 and Tyr247, which are not conserved in T-protein, are essential to the catalytic activity of LigM and their interactions with the oxygen atom in the methoxy group of VNL seem to facilitate a methyl moiety (C1-unit) transfer to H folate. Taken together, our structural data suggest that LigM has evolved divergently from T-protein. DATABASES: All atomic coordinates of the crystal structures determined in this study have been deposited to PDB. LigM: 5X1I, LigM-VNL complex: 5X1J, LigM-3-O-methylgallate complex: 5X1K, LigM-H folate complex: 5X1IL, LigM-H folate-protocatechuate (PCA) complex (P2 2 2): 5X1M, LigM-H folate-PCA complex (P3 21): 5X1N.
[Mh] Termos MeSH primário: Oxirredutases O-Desmetilantes/química
Sphingomonadaceae/enzimologia
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Aminometiltransferase/química
Cristalografia por Raios X
Modelos Moleculares
Oxirredutases O-Desmetilantes/metabolismo
Conformação Proteica
Homologia de Sequência de Aminoácidos
Tetra-Hidrofolatos/metabolismo
Ácido Vanílico/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Tetrahydrofolates); EC 1.- (Oxidoreductases, O-Demethylating); EC 2.1.2.10 (Aminomethyltransferase); GM8Q3JM2Y8 (Vanillic Acid)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170911
[Lr] Data última revisão:
170911
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170422
[St] Status:MEDLINE
[do] DOI:10.1111/febs.14085


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[PMID]:28290676
[Au] Autor:Müller TA; Tobar MA; Perian MN; Hausinger RP
[Ad] Endereço:Department of Microbiology and Molecular Genetics, Michigan State University , East Lansing, Michigan 48824, United States.
[Ti] Título:Biochemical Characterization of AP Lyase and m A Demethylase Activities of Human AlkB Homologue 1 (ALKBH1).
[So] Source:Biochemistry;56(13):1899-1910, 2017 Apr 04.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Alkbh1 is one of nine mammalian homologues of Escherichia coli AlkB, a 2-oxoglutarate-dependent dioxygenase that catalyzes direct DNA repair by removing alkyl lesions from DNA. Six distinct enzymatic activities have been reported for Alkbh1, including hydroxylation of variously methylated DNA, mRNA, tRNA, or histone substrates along with the cleavage of DNA at apurinic/apyrimidinic (AP) sites followed by covalent attachment to the 5'-product. The studies described here extend the biochemical characterization of two of these enzymatic activities using human ALKBH1: the AP lyase and 6-methyl adenine DNA demethylase activities. The steady-state and single-turnover kinetic parameters for ALKBH1 cleavage of AP sites in DNA were determined and shown to be comparable to those of other AP lyases. The α,ß-unsaturated aldehyde of the 5'-product arising from DNA cleavage reacts predominantly with C129 of ALKBH1, but secondary sites also generate covalent adducts. The 6-methyl adenine demethylase activity was examined with a newly developed assay using a methylation-sensitive restriction endonuclease, and the enzymatic rate was found to be very low. Indeed, the demethylase activity was less than half that of the AP lyase activity when ALKBH1 samples were assayed using identical buffer conditions. The two enzymatic activities were examined using a series of site-directed variant proteins, revealing the presence of distinct but partially overlapping active sites for the two reactions. We postulate that the very low 6-methyl adenine oxygenase activity associated with ALKBH1 is unlikely to represent the major function of the enzyme in the cell, while the cellular role of the lyase activity (including its subsequent covalent attachment to DNA) remains uncertain.
[Mh] Termos MeSH primário: Adenina/química
Homólogo AlkB 1 da Histona H2a Dioxigenase/química
DNA/química
Proteínas de Escherichia coli/química
Oxigenases de Função Mista/química
Oxirredutases O-Desmetilantes/química
[Mh] Termos MeSH secundário: Adenina/metabolismo
Homólogo AlkB 1 da Histona H2a Dioxigenase/genética
Homólogo AlkB 1 da Histona H2a Dioxigenase/metabolismo
Domínio Catalítico
DNA/genética
DNA/metabolismo
Adutos de DNA
Ensaios Enzimáticos
Escherichia coli/enzimologia
Escherichia coli/genética
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Expressão Gênica
Seres Humanos
Oxigenases de Função Mista/genética
Oxigenases de Função Mista/metabolismo
Modelos Moleculares
Oligonucleotídeos/química
Oligonucleotídeos/metabolismo
Oxirredutases O-Desmetilantes/genética
Oxirredutases O-Desmetilantes/metabolismo
Estrutura Secundária de Proteína
Proteínas Recombinantes de Fusão/química
Proteínas Recombinantes de Fusão/genética
Proteínas Recombinantes de Fusão/metabolismo
Homologia de Sequência de Aminoácidos
Especificidade da Espécie
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA Adducts); 0 (Escherichia coli Proteins); 0 (Oligonucleotides); 0 (Recombinant Fusion Proteins); 9007-49-2 (DNA); EC 1.- (Mixed Function Oxygenases); EC 1.- (Oxidoreductases, O-Demethylating); EC 1.14.11.- (AlkB protein, E coli); EC 1.14.11.33 (ALKBH1 protein, human); EC 1.14.11.33 (AlkB Homolog 1, Histone H2a Dioxygenase); JAC85A2161 (Adenine)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170527
[Lr] Data última revisão:
170527
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170315
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.7b00060


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[PMID]:27575686
[Au] Autor:Wang C; Glenn KC; Kessenich C; Bell E; Burzio LA; Koch MS; Li B; Silvanovich A
[Ad] Endereço:Monsanto Company, 800 North Lindbergh Blvd, St. Louis, MO 63167, USA. Electronic address: cunxi.wang@monsanto.com.
[Ti] Título:Safety assessment of dicamba mono-oxygenases that confer dicamba tolerance to various crops.
[So] Source:Regul Toxicol Pharmacol;81:171-182, 2016 Nov.
[Is] ISSN:1096-0295
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Dicamba tolerant (DT) soybean, cotton and maize were developed through constitutive expression of dicamba mono-oxygenase (DMO) in chloroplasts. DMO expressed in three DT crops exhibit 91.6-97.1% amino acid sequence identity to wild type DMO. All DMO forms maintain the characteristics of Rieske oxygenases that have a history of safe use. Additionally, they are all functionally similar in vivo since the three DT crops are all tolerant to dicamba treatment. None of these DMO sequences were found to have similarity to any known allergens or toxins. Herein, to further understand the safety of these DMO variants, a weight of evidence approach was employed. Each purified DMO protein was found to be completely deactivated in vitro by heating at temperatures 55 °C and above, and all were completely digested within 30 s or 5 min by pepsin and pancreatin, respectively. Mice orally dosed with each of these DMO proteins showed no adverse effects as evidenced by analysis of body weight gain, food consumption and clinical observations. Therefore, the weight of evidence from all these protein safety studies support the conclusion that the various forms of DMO proteins introduced into DT soybean, cotton and maize are safe for food and feed consumption, and the small amino acid sequence differences outside the active site of DMO do not raise any additional safety concerns.
[Mh] Termos MeSH primário: Produtos Agrícolas/toxicidade
Dicamba/farmacologia
Resistência a Medicamentos
Alimentos Geneticamente Modificados/toxicidade
Gossypium/toxicidade
Herbicidas/farmacologia
Oxigenases de Função Mista/toxicidade
Oxirredutases O-Desmetilantes/toxicidade
Plantas Geneticamente Modificadas/toxicidade
Feijão de Soja/toxicidade
Zea mays/toxicidade
[Mh] Termos MeSH secundário: Administração Oral
Sequência de Aminoácidos
Animais
Biologia Computacional
Segurança de Produtos ao Consumidor
Produtos Agrícolas/enzimologia
Produtos Agrícolas/genética
Bases de Dados de Proteínas
Resistência a Medicamentos/genética
Estabilidade Enzimática
Feminino
Inocuidade dos Alimentos
Alimentos Geneticamente Modificados/parasitologia
Regulação da Expressão Gênica de Plantas
Gossypium/enzimologia
Gossypium/genética
Seres Humanos
Masculino
Camundongos
Oxigenases de Função Mista/administração & dosagem
Oxigenases de Função Mista/genética
Oxigenases de Função Mista/metabolismo
Pancreatina/metabolismo
Pepsina A/metabolismo
Plantas Geneticamente Modificadas/enzimologia
Plantas Geneticamente Modificadas/genética
Desnaturação Proteica
Proteólise
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
Proteínas Recombinantes/toxicidade
Medição de Risco
Feijão de Soja/enzimologia
Feijão de Soja/genética
Stenotrophomonas maltophilia/enzimologia
Stenotrophomonas maltophilia/genética
Temperatura Ambiente
Testes de Toxicidade Aguda
Zea mays/enzimologia
Zea mays/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Herbicides); 0 (Recombinant Proteins); 8049-47-6 (Pancreatin); EC 1.- (Mixed Function Oxygenases); EC 1.- (Oxidoreductases, O-Demethylating); EC 1.- (dicamba O-demethylase); EC 3.4.23.1 (Pepsin A); SJG3M6RY6H (Dicamba)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170324
[Lr] Data última revisão:
170324
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160831
[St] Status:MEDLINE


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[PMID]:27236811
[Au] Autor:Chen JX; Deng CY; Zhang YT; Liu ZM; Wang PZ; Liu SL; Qian W; Yang DH
[Ad] Endereço:Department of Natural Medicines, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China.
[Ti] Título:Cloning, expression, and characterization of a four-component O-demethylase from human intestinal bacterium Eubacterium limosum ZL-II.
[So] Source:Appl Microbiol Biotechnol;100(21):9111-9124, 2016 Nov.
[Is] ISSN:1432-0614
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Eubacterium limosum ZL-II was described to convert secoisolariciresinol (SECO) to its demethylating product 4,4'-dihydroxyenterodiol (DHEND) under anoxic conditions. However, the reaction cascade remains unclear. Here, the O-demethylase being responsible for the conversion was identified and characterized. Nine genes encoding two methyltransferase-Is (MT-I), two corrinoid proteins (CP), two methyltransferase-IIs (MT-II), and three activating enzymes (AE) were screened, cloned, and expressed in Escherichia coli. Four of the nine predicted enzymes, including ELI_2003 (MT-I), ELI_2004 (CP), ELI_2005 (MT-II), and ELI_0370 (AE), were confirmed to constitute the O-demethylase in E. limosum ZL-II. The complete O-demethylase (combining the four components) reaction system was reconstructed in vitro. As expected, the demethylating products 3-demethyl-SECO and DHEND were both produced. During the reaction process, ELI_2003 (MT-I) initially catalyzed the transfer of methyl group from SECO to the corrinoid of ELI_2004 ([Co ]-CP), yielding demethylating products and [CH -Co ]-CP; then ELI_2005 (MT-II) mediated the transfer of methyl group from [CH -Co ]-CP to tetrahydrofolate, forming methyltetrahydrofolate and [Co ]-CP. Due to the low redox potential of [Co ]/[Co ], [Co ]-CP was oxidized to [Co ]-CP immediately in vitro, and ELI_0370 (AE) was responsible for catalyzing the reduction of [Co ]-CP to its active form [Co ]-CP. The active-site residues in ELI_2003, ELI_2005, and ELI_0370 were subsequently determined using molecular modeling combined with site-directed mutagenesis. To our knowledge, this is the first study on the identification and characterization of a four-component O-demethylase from E. limosum ZL-II, which will facilitate the development of method to artificial synthesis of related bioactive chemicals.
[Mh] Termos MeSH primário: Eubacterium/enzimologia
Oxirredutases O-Desmetilantes/genética
Oxirredutases O-Desmetilantes/metabolismo
[Mh] Termos MeSH secundário: Clonagem Molecular
Escherichia coli
Eubacterium/genética
Eubacterium/isolamento & purificação
Trato Gastrointestinal/microbiologia
Seres Humanos
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Recombinant Proteins); EC 1.- (Oxidoreductases, O-Demethylating)
[Em] Mês de entrada:1701
[Cu] Atualização por classe:170118
[Lr] Data última revisão:
170118
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160530
[St] Status:MEDLINE


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[PMID]:26264169
[Au] Autor:Farrow SC; Facchini PJ
[Ad] Endereço:Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
[Ti] Título:Papaverine 7-O-demethylase, a novel 2-oxoglutarate/Fe(2+)-dependent dioxygenase from opium poppy.
[So] Source:FEBS Lett;589(19 Pt B):2701-6, 2015 Sep 14.
[Is] ISSN:1873-3468
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Opium poppy (Papaver somniferum) produces several pharmacologically important benzylisoquinoline alkaloids including the vasodilator papaverine. Pacodine and palaudine are tri-O-methylated analogs of papaverine, which contains four O-linked methyl groups. However, the biosynthetic origin of pacodine and palaudine has not been established. Three members of the 2-oxoglutarate/Fe(2+)-dependent dioxygenases (2ODDs) family in opium poppy display widespread O-dealkylation activity on several benzylisoquinoline alkaloids with diverse structural scaffolds, and two are responsible for the antepenultimate and ultimate steps in morphine biosynthesis. We report a novel 2ODD from opium poppy catalyzing the efficient substrate- and regio-specific 7-O-demethylation of papaverine yielding pacodine. The occurrence of papaverine 7-O-demethylase (P7ODM) expands the enzymatic scope of the 2ODD family in opium poppy and suggests an unexpected biosynthetic route to pacodine.
[Mh] Termos MeSH primário: Ferro/metabolismo
Ácidos Cetoglutáricos/metabolismo
Oxirredutases O-Desmetilantes/metabolismo
Papaver/enzimologia
Papaverina/metabolismo
[Mh] Termos MeSH secundário: Regulação da Expressão Gênica de Plantas
Metilação
Oxirredutases O-Desmetilantes/genética
Oxirredutases O-Desmetilantes/isolamento & purificação
Papaverina/química
RNA Mensageiro/genética
RNA Mensageiro/metabolismo
Estereoisomerismo
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Ketoglutaric Acids); 0 (RNA, Messenger); 8ID597Z82X (alpha-ketoglutaric acid); DAA13NKG2Q (Papaverine); E1UOL152H7 (Iron); EC 1.- (Oxidoreductases, O-Demethylating)
[Em] Mês de entrada:1512
[Cu] Atualização por classe:161125
[Lr] Data última revisão:
161125
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150813
[St] Status:MEDLINE


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[PMID]:26118119
[Au] Autor:Qi LJ; Yuan Y; Wu C; Huang LQ; Chen P
[Ti] Título:[Bioinformatics analysis of DNA demethylase genes in Lonicera japonica Thunb].
[So] Source:Yao Xue Xue Bao;50(3):367-71, 2015 Mar.
[Is] ISSN:0513-4870
[Cp] País de publicação:China
[La] Idioma:chi
[Ab] Resumo:The DNA demethylase genes are widespread in plants. Four DNA demethylase genes (LJDME1, LJDME2, LJDME3 and LJDME4) were obtained from transcriptome dataset of Lonicera japonica Thunb by using bioinformatics methods and the proteins' physicochemical properties they encoded were predicted. The phylogenetic tree showed that the four DNA demethylase genes and Arabidopsis thaliana DME had a close relationship. The result of gene expression model showed that four DNA demethylase genes were different between species. The expression levels of LJDME1 and LJDME2 were even more higher in Lonicera japonica var. chinensis than those in L. japonica. LJDME] and LJDME2 maybe regulate the active compounds of L. japonica. This study aims to lay a foundation for further understanding of the function of DNA demethylase genes in L. japonica.
[Mh] Termos MeSH primário: Biologia Computacional
Lonicera/genética
Oxirredutases O-Desmetilantes/genética
[Mh] Termos MeSH secundário: DNA de Plantas/química
Genes de Plantas
Lonicera/enzimologia
Filogenia
Proteínas de Plantas/genética
Transcriptoma
[Pt] Tipo de publicação:ENGLISH ABSTRACT; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA, Plant); 0 (Plant Proteins); EC 1.- (Oxidoreductases, O-Demethylating)
[Em] Mês de entrada:1509
[Cu] Atualização por classe:150629
[Lr] Data última revisão:
150629
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150630
[St] Status:MEDLINE


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[PMID]:25968601
[Au] Autor:Rong Tan L; Chen Lu Y; Jing Zhang J; Luo F; Yang H
[Ad] Endereço:Jiangsu Key Laboratory of Pesticide Science, College of Sciences, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, China.
[Ti] Título:A collection of cytochrome P450 monooxygenase genes involved in modification and detoxification of herbicide atrazine in rice (Oryza sativa) plants.
[So] Source:Ecotoxicol Environ Saf;119:25-34, 2015 Sep.
[Is] ISSN:1090-2414
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Plant cytochrome P450 monooxygenases constitute one of the largest families of protein genes involved in plant growth, development and acclimation to biotic and abiotic stresses. However, whether these genes respond to organic toxic compounds and their biological functions for detoxifying toxic compounds such as herbicides in rice are poorly understood. The present study identified 201 genes encoding cytochrome P450s from an atrazine-exposed rice transcriptome through high-throughput sequencing. Of these, 69 cytochrome P450 genes were validated by microarray and some of them were confirmed by real time PCR. Activities of NADPH-cytochrome P450 reductase (CPR) and p-nitroanisole O-demethylase (PNOD) related to toxicity were determined and significantly induced by atrazine exposure. To dissect the mechanism underlying atrazine modification and detoxification by P450, metabolites (or derivatives) of atrazine in plants were analyzed by ultra performance liquid chromatography mass spectrometry (UPLC/MS). Major metabolites comprised desmethylatrazine (DMA), desethylatrazine (DEA), desisopropylatrazine (DIA), hydroxyatrazine (HA), hydroxyethylatrazine (HEA) and hydroxyisopropylatrazine (HIA). All of them were chemically modified by P450s. Furthermore, two specific inhibitors of piperonyl butoxide (PBO) and malathion (MAL) were used to assess the correlation between the P450s activity and rice responses including accumulation of atrazine in tissues, shoot and root growth and detoxification.
[Mh] Termos MeSH primário: Atrazina/toxicidade
Sistema Enzimático do Citocromo P-450/genética
Herbicidas/toxicidade
Oryza/enzimologia
[Mh] Termos MeSH secundário: Sistema Enzimático do Citocromo P-450/metabolismo
Exposição Ambiental
Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos
Regulação da Expressão Gênica de Plantas/efeitos dos fármacos
Inativação Metabólica
Análise em Microsséries
NADPH-Ferri-Hemoproteína Redutase/metabolismo
Oryza/efeitos dos fármacos
Oxirredutases O-Desmetilantes/metabolismo
Butóxido de Piperonila
Raízes de Plantas/efeitos dos fármacos
Raízes de Plantas/metabolismo
Transcriptoma/efeitos dos fármacos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Herbicides); 9035-51-2 (Cytochrome P-450 Enzyme System); EC 1.- (4-nitroanisole O-demethylase); EC 1.- (Oxidoreductases, O-Demethylating); EC 1.6.2.4 (NADPH-Ferrihemoprotein Reductase); LWK91TU9AH (Piperonyl Butoxide); QJA9M5H4IM (Atrazine)
[Em] Mês de entrada:1602
[Cu] Atualização por classe:150615
[Lr] Data última revisão:
150615
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150514
[St] Status:MEDLINE


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[PMID]:25898947
[Au] Autor:Lopez-Sanchez P; Schuster E; Wang D; Gidley MJ; Strom A
[Ad] Endereço:ARC Centre of Excellence in Plant Cell Walls, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, The University of Queensland, Brisbane, 4072, Australia. p.lopezsanhcez@uq.edu au.
[Ti] Título:Diffusion of macromolecules in self-assembled cellulose/hemicellulose hydrogels.
[So] Source:Soft Matter;11(20):4002-10, 2015 May 28.
[Is] ISSN:1744-6848
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Cellulose hydrogels are extensively applied in many biotechnological fields and are also used as models for plant cell walls. We synthesised model cellulosic hydrogels containing hemicelluloses, as a biomimetic of plant cell walls, in order to study the role of hemicelluloses on their mass transport properties. Microbial cellulose is able to self-assemble into composites when hemicelluloses, such as xyloglucan and arabinoxylan, are present in the incubation media, leading to hydrogels with different nano and microstructures. We investigated the diffusivities of a series of fluorescently labelled dextrans, of different molecular weight, and proteins, including a plant pectin methyl esterase (PME), using fluorescence recovery after photobleaching (FRAP). The presence of xyloglucan, known to be able to crosslink cellulose fibres, confirmed by scanning electron microscopy (SEM) and (13)C NMR, reduced mobility of macromolecules of molecular weight higher than 10 kDa, reflected in lower diffusion coefficients. Furthermore PME diffusion was reduced in composites containing xyloglucan, despite the lack of a particular binding motif in PME for this polysaccharide, suggesting possible non-specific interactions between PME and this hemicellulose. In contrast, hydrogels containing arabinoxylan coating cellulose fibres showed enhanced diffusivity of the molecules studied. The different diffusivities were related to the architectural features found in the composites as a function of polysaccharide composition. Our results show the effect of model hemicelluloses in the mass transport properties of cellulose networks in highly hydrated environments relevant to understanding the role of hemicelluloses in the permeability of plant cell walls and aiding design of plant based materials with tailored properties.
[Mh] Termos MeSH primário: Celulose/química
Hidrogéis/química
Polissacarídeos/química
[Mh] Termos MeSH secundário: Materiais Biomiméticos/química
Materiais Biomiméticos/metabolismo
Parede Celular/metabolismo
Difusão
Corantes Fluorescentes/química
Hidrogéis/metabolismo
Oxirredutases O-Desmetilantes/química
Oxirredutases O-Desmetilantes/metabolismo
Permeabilidade
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Fluorescent Dyes); 0 (Hydrogels); 0 (Polysaccharides); 8024-50-8 (hemicellulose); 9004-34-6 (Cellulose); EC 1.- (Oxidoreductases, O-Demethylating); EC 1.- (methyl etherase)
[Em] Mês de entrada:1602
[Cu] Atualização por classe:150514
[Lr] Data última revisão:
150514
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150423
[St] Status:MEDLINE
[do] DOI:10.1039/c5sm00103j


  9 / 286 MEDLINE  
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[PMID]:25826329
[Au] Autor:Horsburgh S; Robson-Ansley P; Adams R; Smith C
[Ad] Endereço:Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle upon Tyne, United Kingdom.
[Ti] Título:Exercise and inflammation-related epigenetic modifications: focus on DNA methylation.
[So] Source:Exerc Immunol Rev;21:26-41, 2015.
[Is] ISSN:1077-5552
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Epigenetics is the study of mitotically or meiotically heritable phenotypes that occur as a result of modifications to DNA, thereby regulating gene expression independently of changes in base sequence due to manipulation of the chromatin structure. These modifications occur through a variety of mechanisms, such as DNA methylation, post-translational histone modifications, and non-coding RNAs, and can cause transcriptional suppression or activation depending on the location within the gene. Environmental stimuli, such as diet and exercise, are thought to be able to regulate these mechanisms, with inflammation as a probable contributory factor. Research into these areas is still in its infancy however. This review will focus on DNA methylation in the context of inflammation (both pro- and anti-inflammatory processes) and exercise. The complexity and relative shortcomings of some existing techniques for studying epigenetics will be highlighted, and recommendations for future study approaches made.
[Mh] Termos MeSH primário: Metilação de DNA
Exercício/fisiologia
Inflamação/genética
[Mh] Termos MeSH secundário: Animais
Animais Recém-Nascidos
Atletas
Proteínas de Transporte/fisiologia
Ilhas de CpG
Citocinas/genética
Citocinas/fisiologia
Proteínas de Ligação a DNA/fisiologia
DNA-Citosina Metilases/fisiologia
Diabetes Mellitus Tipo 2/genética
Diabetes Mellitus Tipo 2/fisiopatologia
Diabetes Mellitus Tipo 2/terapia
Modelos Animais de Doenças
Suscetibilidade a Doenças
Epigênese Genética
Terapia por Exercício
Previsões
Glucocorticoides/farmacologia
Glucocorticoides/fisiologia
Seres Humanos
Inflamassomos/fisiologia
Inflamação/etiologia
Inflamação/metabolismo
Lipopolissacarídeos/toxicidade
Comportamento Materno
Terapia de Alvo Molecular
Proteína 3 que Contém Domínio de Pirina da Família NLR
Neoplasias/imunologia
Neoplasias/fisiopatologia
Neoplasias/prevenção & controle
Neoplasias/terapia
Obesidade/complicações
Obesidade/genética
Obesidade/fisiopatologia
Oxirredutases O-Desmetilantes/fisiologia
Roedores
Estresse Psicológico/genética
Estresse Psicológico/fisiopatologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Carrier Proteins); 0 (Cytokines); 0 (DNA-Binding Proteins); 0 (Glucocorticoids); 0 (Inflammasomes); 0 (Lipopolysaccharides); 0 (NLR Family, Pyrin Domain-Containing 3 Protein); 0 (NLRP3 protein, human); 0 (Nlrp3 protein, mouse); EC 1.- (Oxidoreductases, O-Demethylating); EC 1.- (methyl-CpG DNA demethylase); EC 2.1.1.- (DNA-Cytosine Methylases)
[Em] Mês de entrada:1504
[Cu] Atualização por classe:161125
[Lr] Data última revisão:
161125
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150401
[St] Status:MEDLINE


  10 / 286 MEDLINE  
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Texto completo
[PMID]:25437362
[Au] Autor:Yin H; Yang Z; Li B; Zhou Y; Ai S
[Ad] Endereço:College of Chemistry and Material Science, Shandong Agricultural University, 271018 Taian, Shandong, PR China.
[Ti] Título:Electrochemical biosensor for DNA demethylase detection based on demethylation triggered endonuclease BstUI and Exonuclease III digestion.
[So] Source:Biosens Bioelectron;66:266-70, 2015 Apr 15.
[Is] ISSN:1873-4235
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Herein, an electrochemical biosensor was fabricated for DNA demethylase detection based on DNA demethylation triggered endonuclease BstUI and Exonuclease III digestion. After the double-strand DNA was demethylated, it can be further digested by BstUI and formed a blunt end at the electrode surface. Then, the remained fragment of DNA-DNA duplex was further cleaved by exonuclease III and led to increased electrochemical signal. Based on this detection strategy, the biosensor showed high sensitivity with low detection limit of 0.15ng/mL. Moreover, the developed method also presented high selectivity and acceptable reproducibility. This work provides a novel detection platform for DNA demethylase detection.
[Mh] Termos MeSH primário: Técnicas Biossensoriais/métodos
Técnicas Eletroquímicas/métodos
Oxirredutases O-Desmetilantes/isolamento & purificação
[Mh] Termos MeSH secundário: DNA/química
Metilação de DNA
Endonucleases/química
Exodesoxirribonucleases/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
9007-49-2 (DNA); EC 1.- (Oxidoreductases, O-Demethylating); EC 1.- (methyl-CpG DNA demethylase); EC 3.1.- (Endonucleases); EC 3.1.- (Exodeoxyribonucleases); EC 3.1.11.2 (exodeoxyribonuclease III)
[Em] Mês de entrada:1508
[Cu] Atualização por classe:141223
[Lr] Data última revisão:
141223
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:141202
[St] Status:MEDLINE



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