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Pesquisa : D02.886.030.498.050 [Categoria DeCS]
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[PMID]:29307522
[Au] Autor:Riberio DF; Cella PS; da Silva LECM; Jordao AA; Deminice R
[Ad] Endereço:Department of Physical Education, State University of Londrina, Londrina, PR, Brazil.
[Ti] Título:Acute exercise alters homocysteine plasma concentration in an intensity-dependent manner due increased methyl flux in liver of rats.
[So] Source:Life Sci;196:63-68, 2018 Mar 01.
[Is] ISSN:1879-0631
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:PURPOSE: We aimed to determine the effects of different intensities of acute exercise on Hcy plasma levels, and the exercise-induced changes in Hcy liver metabolism. METHOD: First, thirty-two Wistar rats were randomly submitted to an acute bout of swimming exercise carrying a load of 2% (n=8), 4% (n=8) and 6% (n=8) of their total body weight attached in their tail. Control rats remained rested (n=8). Blood samples were taken from tail vein for plasma S-containing amino acids determination before (Rest) and post, 1, 2, 3, 4, 6, and 10h after acute swimming exercise. Second, 56 exercised rats (4% loads) were euthanized before (Rest) and1, 2, 3, 4, 6, and 10h after acute swimming exercise. Blood and liver samples were collected for amino acids and keys genes involved in the Hcy metabolism assay. RESULTS: Acute exercise increases (P<0.05) plasma Hcy concentration in an intensity-dependent manner (rest 7.7±0.8; 6% load 13.8±3.6; 4% load 12.2±2.9±and 2% load 10.1±2.6, µmol/L); this increase is transient and does not promote hyperhomocysteinemia (<15µmol/L).Exercise-induced increased plasma Hcywas accompanied by the decreased liver S-adenosylmethionine/S-adenosylhomocysteine ratio and elevated MAT1a mRNA content. Acute exercise also caused elevated mRNA of key enzymes of transsulfuration (CBS) and remethylation (BHMT and the MTRR). CONCLUSION: Our data provided evidence that acute exercise increases plasma Hcy concentration due to the augmented requirement for methylated compounds that increases liver SAM consumption. Also, Hcy remethylation and transsulfuration are coordinately regulated to maintain methyl balance.
[Mh] Termos MeSH primário: Homocisteína/sangue
Fígado/metabolismo
Condicionamento Físico Animal/fisiologia
[Mh] Termos MeSH secundário: Animais
Peso Corporal/efeitos dos fármacos
Hiper-Homocisteinemia/metabolismo
Masculino
Metionina Adenosiltransferase/metabolismo
Metilação
Ratos
Ratos Wistar
S-Adenosil-Homocisteína/metabolismo
S-Adenosilmetionina/metabolismo
Natação/fisiologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0LVT1QZ0BA (Homocysteine); 7LP2MPO46S (S-Adenosylmethionine); 979-92-0 (S-Adenosylhomocysteine); EC 2.5.1.6 (Mat1a protein, rat); EC 2.5.1.6 (Methionine Adenosyltransferase)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180226
[Lr] Data última revisão:
180226
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180109
[St] Status:MEDLINE


  2 / 1251 MEDLINE  
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[PMID]:28911116
[Au] Autor:Krishnamohan A; Jackman JE
[Ad] Endereço:The Ohio State Biochemistry Program, Center for RNA Biology, and Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA.
[Ti] Título:Mechanistic features of the atypical tRNA m1G9 SPOUT methyltransferase, Trm10.
[So] Source:Nucleic Acids Res;45(15):9019-9029, 2017 Sep 06.
[Is] ISSN:1362-4962
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The tRNA m1G9 methyltransferase (Trm10) is a member of the SpoU-TrmD (SPOUT) superfamily of methyltransferases, and Trm10 homologs are widely conserved throughout Eukarya and Archaea. Despite possessing the trefoil knot characteristic of SPOUT enzymes, Trm10 does not share the same quaternary structure or key sequences with other members of the SPOUT family, suggesting a novel mechanism of catalysis. To investigate the mechanism of m1G9 methylation by Trm10, we performed a biochemical and kinetic analysis of Trm10 and variants with alterations in highly conserved residues, using crystal structures solved in the absence of tRNA as a guide. Here we demonstrate that a previously proposed general base residue (D210 in Saccharomyces cerevisiae Trm10) is not likely to play this suggested role in the chemistry of methylation. Instead, pH-rate analysis suggests that D210 and other conserved carboxylate-containing residues at the active site collaborate to establish an active site environment that promotes a single ionization that is required for catalysis. Moreover, Trm10 does not depend on a catalytic metal ion, further distinguishing it from the other known SPOUT m1G methyltransferase, TrmD. These results provide evidence for a non-canonical tRNA methyltransferase mechanism that characterizes the Trm10 enzyme family.
[Mh] Termos MeSH primário: Ácido Aspártico/química
RNA de Transferência/química
S-Adenosilmetionina/química
Proteínas de Saccharomyces cerevisiae/química
Saccharomyces cerevisiae/enzimologia
tRNA Metiltransferases/química
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Ácido Aspártico/metabolismo
Sítios de Ligação
Biocatálise
Domínio Catalítico
Clonagem Molecular
Cristalografia por Raios X
Escherichia coli/genética
Escherichia coli/metabolismo
Expressão Gênica
Concentração de Íons de Hidrogênio
Isoenzimas/química
Isoenzimas/genética
Isoenzimas/metabolismo
Cinética
Metilação
Modelos Moleculares
Ligação Proteica
Conformação Proteica em alfa-Hélice
Domínios e Motivos de Interação entre Proteínas
RNA de Transferência/metabolismo
Proteínas Recombinantes/química
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
S-Adenosil-Homocisteína/química
S-Adenosil-Homocisteína/metabolismo
S-Adenosilmetionina/metabolismo
Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/metabolismo
Alinhamento de Sequência
Homologia de Sequência de Aminoácidos
Especificidade por Substrato
tRNA Metiltransferases/genética
tRNA Metiltransferases/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Isoenzymes); 0 (Recombinant Proteins); 0 (Saccharomyces cerevisiae Proteins); 30KYC7MIAI (Aspartic Acid); 7LP2MPO46S (S-Adenosylmethionine); 9014-25-9 (RNA, Transfer); 979-92-0 (S-Adenosylhomocysteine); EC 2.1.1.- (TRM10 protein, S cerevisiae); EC 2.1.1.- (tRNA Methyltransferases)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171114
[Lr] Data última revisão:
171114
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170916
[St] Status:MEDLINE
[do] DOI:10.1093/nar/gkx620


  3 / 1251 MEDLINE  
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[PMID]:28887308
[Au] Autor:Malecki J; Jakobsson ME; Ho AYY; Moen A; Rustan AC; Falnes PØ
[Ad] Endereço:From the Department of Biosciences and.
[Ti] Título:Uncovering human METTL12 as a mitochondrial methyltransferase that modulates citrate synthase activity through metabolite-sensitive lysine methylation.
[So] Source:J Biol Chem;292(43):17950-17962, 2017 Oct 27.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Lysine methylation is an important and much-studied posttranslational modification of nuclear and cytosolic proteins but is present also in mitochondria. However, the responsible mitochondrial lysine-specific methyltransferases (KMTs) remain largely elusive. Here, we investigated METTL12, a mitochondrial human -adenosylmethionine (AdoMet)-dependent methyltransferase and found it to methylate a single protein in mitochondrial extracts, identified as citrate synthase (CS). Using several and approaches, we demonstrated that METTL12 methylates CS on Lys-395, which is localized in the CS active site. Interestingly, the METTL12-mediated methylation inhibited CS activity and was blocked by the CS substrate oxaloacetate. Moreover, METTL12 was strongly inhibited by the reaction product -adenosylhomocysteine (AdoHcy). In summary, we have uncovered a novel human mitochondrial KMT that introduces a methyl modification into a metabolic enzyme and whose activity can be modulated by metabolic cues. Based on the established naming nomenclature for similar enzymes, we suggest that METTL12 be renamed CS-KMT (gene name ).
[Mh] Termos MeSH primário: Citrato (si)-Sintase/metabolismo
Metiltransferases/metabolismo
Proteínas Mitocondriais/metabolismo
Ácido Oxaloacético/metabolismo
S-Adenosil-Homocisteína/metabolismo
[Mh] Termos MeSH secundário: Citrato (si)-Sintase/genética
Células HeLa
Seres Humanos
Metilação
Metiltransferases/classificação
Metiltransferases/genética
Proteínas Mitocondriais/classificação
Proteínas Mitocondriais/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (METTL12 protein, human); 0 (Mitochondrial Proteins); 2F399MM81J (Oxaloacetic Acid); 979-92-0 (S-Adenosylhomocysteine); EC 2.1.1.- (Methyltransferases); EC 2.3.3.1 (Citrate (si)-Synthase)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171103
[Lr] Data última revisão:
171103
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170910
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M117.808451


  4 / 1251 MEDLINE  
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[PMID]:28665591
[Au] Autor:Fenwick MK; Almabruk KH; Ealick SE; Begley TP; Philmus B
[Ad] Endereço:Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States.
[Ti] Título:Biochemical Characterization and Structural Basis of Reactivity and Regioselectivity Differences between Burkholderia thailandensis and Burkholderia glumae 1,6-Didesmethyltoxoflavin N-Methyltransferase.
[So] Source:Biochemistry;56(30):3934-3944, 2017 Aug 01.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Burkholderia glumae converts the guanine base of guanosine triphosphate into an azapteridine and methylates both the pyrimidine and triazine rings to make toxoflavin. Strains of Burkholderia thailandensis and Burkholderia pseudomallei have a gene cluster encoding seven putative biosynthetic enzymes that resembles the toxoflavin gene cluster. Four of the enzymes are similar in sequence to BgToxBCDE, which have been proposed to make 1,6-didesmethyltoxoflavin (1,6-DDMT). One of the remaining enzymes, BthII1283 in B. thailandensis E264, is a predicted S-adenosylmethionine (SAM)-dependent N-methyltransferase that shows a low level of sequence identity to BgToxA, which sequentially methylates N6 and N1 of 1,6-DDMT to form toxoflavin. Here we show that, unlike BgToxA, BthII1283 catalyzes a single methyl transfer to N1 of 1,6-DDMT in vitro. In addition, we investigated the differences in reactivity and regioselectivity by determining crystal structures of BthII1283 with bound S-adenosylhomocysteine (SAH) or 1,6-DDMT and SAH. BthII1283 contains a class I methyltransferase fold and three unique extensions used for 1,6-DDMT recognition. The active site structure suggests that 1,6-DDMT is bound in a reduced form. The plane of the azapteridine ring system is orthogonal to its orientation in BgToxA. In BthII1283, the modeled SAM methyl group is directed toward the p orbital of N1, whereas in BgToxA, it is first directed toward an sp orbital of N6 and then toward an sp orbital of N1 after planar rotation of the azapteridine ring system. Furthermore, in BthII1283, N1 is hydrogen bonded to a histidine residue whereas BgToxA does not supply an obvious basic residue for either N6 or N1 methylation.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Burkholderia/enzimologia
Metiltransferases/metabolismo
Modelos Moleculares
Pirimidinonas/metabolismo
S-Adenosilmetionina/metabolismo
Triazinas/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/química
Proteínas de Bactérias/genética
Sítios de Ligação
Domínio Catalítico
Cristalografia por Raios X
Histidina/química
Ligações de Hidrogênio
Metilação
Metiltransferases/química
Metiltransferases/genética
Família Multigênica
Oxirredução
Filogenia
Conformação Proteica
Pirimidinonas/síntese química
Pirimidinonas/química
Proteínas Recombinantes/química
Proteínas Recombinantes/metabolismo
S-Adenosil-Homocisteína/química
S-Adenosil-Homocisteína/metabolismo
S-Adenosilmetionina/química
Especificidade da Espécie
Estereoisomerismo
Triazinas/química
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Pyrimidinones); 0 (Recombinant Proteins); 0 (Triazines); 4QD397987E (Histidine); 5N5YI4IP1P (toxoflavin); 7LP2MPO46S (S-Adenosylmethionine); 979-92-0 (S-Adenosylhomocysteine); EC 2.1.1.- (Methyltransferases)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170811
[Lr] Data última revisão:
170811
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170701
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.7b00476


  5 / 1251 MEDLINE  
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[PMID]:28420001
[Au] Autor:Li Q; He MD; Mao L; Wang X; Jiang YL; Li M; Lu YH; Yu ZP; Zhou Z
[Ad] Endereço:Department of Occupational Health, Nanning, China.
[Ti] Título:Nicotinamide N-Methyltransferase Suppression Participates in Nickel-Induced Histone H3 Lysine9 Dimethylation in BEAS-2B Cells.
[So] Source:Cell Physiol Biochem;41(5):2016-2026, 2017.
[Is] ISSN:1421-9778
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Nickel compounds are well-established human carcinogens with weak mutagenic activity. Histone methylation has been proposed to play an important role in nickel-induced carcinogenesis. Nicotinamide N-methyltransferase (NNMT) decreases histone methylation in several cancer cells by altering the cellular ratio of S-adenosylmethionine (SAM) to S-adenosylhomocysteine (SAH). However, the role of NNMT in nickel-induced histone methylation remains unclear. METHODS: BEAS-2B cells were exposed to different concentrations of nickel chloride (NiCl2) for 72 h or 200 µM NiCl2 for different time periods. Histone H3 on lysine 9 (H3K9) mono-, di-, and trimethylation and NNMT protein levels were measured by western blot analysis. Expressions of NNMT mRNA and the H3k9me2-associated genes, mitogen-activated protein kinase 3 (MAP2K3) and dickkopf1 (DKK1), were determined by qPCR analysis. The cellular ratio of nicotinamide adenine dinucleotide (NAD+) to reduced NAD (NADH) and SAM/SAH ratio were determined. RESULTS: Exposure of BEAS-2B cells to nickel increased H3K9 dimethylation (H3K9me2), suppressed the expressions of H3K9me2-associated genes (MAP2K3 and DKK1), and induced NNMT repression at both the protein and mRNA levels. Furthermore, over-expression of NNMT inhibited nickel-induced H3K9me2 and altered the cellular SAM/SAH ratio. Additionally, the NADH oxidant phenazine methosulfate (PMS) not only reversed the nickel-induced reduction in NAD+/NADH but also inhibited the increase in H3K9me2. CONCLUSIONS: These findings indicate that the repression of NNMT may underlie nickel-induced H3K9 dimethylation by altering the cellular SAM/SAH ratio.
[Mh] Termos MeSH primário: Histonas/metabolismo
Níquel/farmacologia
Nicotinamida N-Metiltransferase/metabolismo
S-Adenosil-Homocisteína/metabolismo
S-Adenosilmetionina/metabolismo
[Mh] Termos MeSH secundário: Linhagem Celular
Histonas/genética
Seres Humanos
Peptídeos e Proteínas de Sinalização Intercelular/genética
Peptídeos e Proteínas de Sinalização Intercelular/metabolismo
MAP Quinase Quinase 3/genética
MAP Quinase Quinase 3/metabolismo
Metilação/efeitos dos fármacos
Nicotinamida N-Metiltransferase/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DKK1 protein, human); 0 (Histones); 0 (Intercellular Signaling Peptides and Proteins); 696BNE976J (nickel chloride); 7LP2MPO46S (S-Adenosylmethionine); 7OV03QG267 (Nickel); 979-92-0 (S-Adenosylhomocysteine); EC 2.1.1.1 (NNMT protein, human); EC 2.1.1.1 (Nicotinamide N-Methyltransferase); EC 2.7.12.2 (MAP Kinase Kinase 3); EC 2.7.12.2 (MAP2K3 protein, human)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170623
[Lr] Data última revisão:
170623
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170419
[St] Status:MEDLINE
[do] DOI:10.1159/000475432


  6 / 1251 MEDLINE  
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[PMID]:28366644
[Au] Autor:Ye C; Sutter BM; Wang Y; Kuang Z; Tu BP
[Ad] Endereço:Department of Biochemistry, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390-9038, USA.
[Ti] Título:A Metabolic Function for Phospholipid and Histone Methylation.
[So] Source:Mol Cell;66(2):180-193.e8, 2017 Apr 20.
[Is] ISSN:1097-4164
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:S-adenosylmethionine (SAM) is the methyl donor for biological methylation modifications that regulate protein and nucleic acid functions. Here, we show that methylation of a phospholipid, phosphatidylethanolamine (PE), is a major consumer of SAM. The induction of phospholipid biosynthetic genes is accompanied by induction of the enzyme that hydrolyzes S-adenosylhomocysteine (SAH), a product and inhibitor of methyltransferases. Beyond its function for the synthesis of phosphatidylcholine (PC), the methylation of PE facilitates the turnover of SAM for the synthesis of cysteine and glutathione through transsulfuration. Strikingly, cells that lack PE methylation accumulate SAM, which leads to hypermethylation of histones and the major phosphatase PP2A, dependency on cysteine, and sensitivity to oxidative stress. Without PE methylation, particular sites on histones then become methyl sinks to enable the conversion of SAM to SAH. These findings reveal an unforeseen metabolic function for phospholipid and histone methylation intrinsic to the life of a cell.
[Mh] Termos MeSH primário: Histonas/metabolismo
Fosfatidiletanolaminas/metabolismo
Processamento de Proteína Pós-Traducional
S-Adenosilmetionina/metabolismo
Saccharomyces cerevisiae/metabolismo
[Mh] Termos MeSH secundário: Cisteína/metabolismo
Metabolismo Energético
Perfilação da Expressão Gênica/métodos
Regulação Enzimológica da Expressão Gênica
Regulação Fúngica da Expressão Gênica
Lisina/metabolismo
Metilação
Mutação
Estresse Oxidativo
Fosfatidilcolinas/metabolismo
Fosfatidiletanolamina N-Metiltransferase/genética
Fosfatidiletanolamina N-Metiltransferase/metabolismo
Proteína Fosfatase 2/genética
Proteína Fosfatase 2/metabolismo
S-Adenosil-Homocisteína/metabolismo
Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/metabolismo
Fatores de Tempo
Transcrição Genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Histones); 0 (Phosphatidylcholines); 0 (Phosphatidylethanolamines); 0 (Saccharomyces cerevisiae Proteins); 39382-08-6 (phosphatidylethanolamine); 7LP2MPO46S (S-Adenosylmethionine); 979-92-0 (S-Adenosylhomocysteine); EC 2.1.1.17 (CHO2 protein, S cerevisiae); EC 2.1.1.17 (Phosphatidylethanolamine N-Methyltransferase); EC 3.1.3.16 (Protein Phosphatase 2); K3Z4F929H6 (Lysine); K848JZ4886 (Cysteine)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170908
[Lr] Data última revisão:
170908
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170404
[St] Status:MEDLINE


  7 / 1251 MEDLINE  
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[PMID]:28337758
[Au] Autor:Hao X; Zhou M; Li H; Angres IA
[Ad] Endereço:Arthus Biosystems, Richmond, CA, USA.
[Ti] Título:Novel immunoassays to detect methionine adenosyltransferase activity and quantify S-adenosylmethionine.
[So] Source:FEBS Lett;591(8):1114-1125, 2017 Apr.
[Is] ISSN:1873-3468
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:We present a novel real-time immunoassay to measure methionine adenosyltransferase (MAT) activity that integrates the MAT-catalyzed reaction of Met and adenosine triphosphate to produce S-adenosylmethionine (SAM) and a highly sensitive immunoassay to specifically quantify SAM simultaneously. The cellular localization of SAM and S-adenosylhomocysteine varies with cell proliferation status: in normal cells, they are found mostly in the cytoplasm, but localize to the nucleus in proliferating cells. MAT-I/III activity is stimulated by Met, but inhibited by S-nitrosoglutathione, and the methylation index (MI) increases after Met stimulation of L02 cells. Met and S-nitrosoglutathione inhibit MAT-II activity, and the MI decreases after Met stimulation of HepG2 cells. The method described provides a significant advancement in the field for the measurement of MAT activity under various conditions.
[Mh] Termos MeSH primário: Hepatócitos/metabolismo
Metionina Adenosiltransferase/metabolismo
S-Adenosil-Homocisteína/metabolismo
S-Adenosilmetionina/metabolismo
[Mh] Termos MeSH secundário: Transporte Ativo do Núcleo Celular/efeitos dos fármacos
Animais
Especificidade de Anticorpos
Linhagem Celular
Núcleo Celular/efeitos dos fármacos
Núcleo Celular/enzimologia
Núcleo Celular/metabolismo
Proliferação Celular/efeitos dos fármacos
Células Cultivadas
Citoplasma/efeitos dos fármacos
Citoplasma/enzimologia
Citoplasma/metabolismo
Inibidores Enzimáticos/farmacologia
Ensaio de Imunoadsorção Enzimática
Citometria de Fluxo
Células Hep G2
Hepatócitos/citologia
Hepatócitos/efeitos dos fármacos
Seres Humanos
Metionina Adenosiltransferase/antagonistas & inibidores
Metilação/efeitos dos fármacos
Camundongos
Microscopia de Fluorescência
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzyme Inhibitors); 7LP2MPO46S (S-Adenosylmethionine); 979-92-0 (S-Adenosylhomocysteine); EC 2.5.1.6 (Methionine Adenosyltransferase)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170808
[Lr] Data última revisão:
170808
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170325
[St] Status:MEDLINE
[do] DOI:10.1002/1873-3468.12631


  8 / 1251 MEDLINE  
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[PMID]:28152088
[Au] Autor:Pavkov-Keller T; Steiner K; Faber M; Tengg M; Schwab H; Gruber-Khadjawi M; Gruber K
[Ad] Endereço:Institute of Molecular Biosciences, University of Graz, Graz, Austria.
[Ti] Título:Crystal Structure and Catalytic Mechanism of CouO, a Versatile C-Methyltransferase from Streptomyces rishiriensis.
[So] Source:PLoS One;12(2):e0171056, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Friedel-Crafts alkylation of aromatic systems is a classic reaction in organic chemistry, for which regiospecific mono-alkylation, however, is generally difficult to achieve. In nature, methyltransferases catalyze the addition of methyl groups to a wide range of biomolecules thereby modulating the physico-chemical properties of these compounds. Specifically, S-adenosyl-L-methionine dependent C-methyltransferases possess a high potential to serve as biocatalysts in environmentally benign organic syntheses. Here, we report on the high resolution crystal structure of CouO, a C-methyltransferase from Streptomyces rishiriensis involved in the biosynthesis of the antibiotic coumermycin A1. Through molecular docking calculations, site-directed mutagenesis and the comparison with homologous enzymes we identified His120 and Arg121 as key functional residues for the enzymatic activity of this group of C-methyltransferases. The elucidation of the atomic structure and the insight into the catalytic mechanism provide the basis for the (semi)-rational engineering of the enzyme in order to increase the substrate scope as well as to facilitate the acceptance of SAM-analogues as alternative cofactors.
[Mh] Termos MeSH primário: Metiltransferases/química
Metiltransferases/metabolismo
Streptomyces/enzimologia
[Mh] Termos MeSH secundário: Proteínas de Bactérias/química
Proteínas de Bactérias/metabolismo
Domínio Catalítico
Cristalografia por Raios X
Metiltransferases/genética
Modelos Moleculares
Simulação de Acoplamento Molecular
Conformação Proteica
S-Adenosil-Homocisteína/química
S-Adenosil-Homocisteína/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 979-92-0 (S-Adenosylhomocysteine); EC 2.1.1.- (Methyltransferases)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170814
[Lr] Data última revisão:
170814
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170203
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0171056


  9 / 1251 MEDLINE  
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[PMID]:28140508
[Au] Autor:Catcott KC; Yan J; Qu W; Wysocki VH; Zhou ZS
[Ad] Endereço:Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston, MA, 02115, USA.
[Ti] Título:Identifying Unknown Enzyme-Substrate Pairs from the Cellular Milieu with Native Mass Spectrometry.
[So] Source:Chembiochem;18(7):613-617, 2017 Apr 04.
[Is] ISSN:1439-7633
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:The enzyme-substrate complex is inherently transient, rendering its detection difficult. In our framework designed for bisubstrate systems-isotope-labeled, activity-based identification and tracking (IsoLAIT)-the common substrate, such as S-adenosyl-l-methionine (AdoMet) for methyltransferases, is replaced by an analogue (e.g., S-adenosyl-l-vinthionine) that, as a probe, creates a tightly bound [enzymeâ‹…substrateâ‹…probe] complex upon catalysis by thiopurine-S-methyltransferase (TPMT, EC 2.1.1.67). This persistent complex is then identified by native mass spectrometry from the cellular milieu without separation. Furthermore, the probe's isotope pattern flags even unknown substrates and enzymes. IsoLAIT is broadly applicable for other enzyme systems, particularly those catalyzing group transfer and with multiple substrates, such as glycosyltransferases and kinases.
[Mh] Termos MeSH primário: Metiltransferases/química
Sondas Moleculares/análise
S-Adenosil-Homocisteína/análogos & derivados
S-Adenosilmetionina/química
[Mh] Termos MeSH secundário: Radioisótopos de Carbono
Escherichia coli/metabolismo
Marcação por Isótopo
Espectrometria de Massas
Metiltransferases/metabolismo
Sondas Moleculares/química
Radioisótopos de Nitrogênio
S-Adenosil-Homocisteína/química
S-Adenosil-Homocisteína/metabolismo
S-Adenosilmetionina/metabolismo
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Carbon Radioisotopes); 0 (Molecular Probes); 0 (Nitrogen Radioisotopes); 0 (S-adenosylvinthionine); 7LP2MPO46S (S-Adenosylmethionine); 979-92-0 (S-Adenosylhomocysteine); EC 2.1.1.- (Methyltransferases); EC 2.1.1.67 (thiopurine methyltransferase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:171007
[Lr] Data última revisão:
171007
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170201
[St] Status:MEDLINE
[do] DOI:10.1002/cbic.201600634


  10 / 1251 MEDLINE  
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[PMID]:28122329
[Au] Autor:Zhou H; Wang F; Wang H; Chen C; Zhang T; Han X; Wang D; Chen C; Wu C; Xie W; Wang Z; Zhang L; Wang L; Yang H
[Ad] Endereço:School of Life Sciences, Tianjin University, Tianjin 300072, China.
[Ti] Título:The conformational changes of Zika virus methyltransferase upon converting SAM to SAH.
[So] Source:Oncotarget;8(9):14830-14834, 2017 Feb 28.
[Is] ISSN:1949-2553
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:An outbreak of Zika virus (ZIKV) infection has been reported in South and Central America and the Caribbean. Neonatal microcephaly potentially associated with ZIKV infection has already caused a public health emergency of international concern. Currently, there are no clinically effective vaccines or antiviral drugs available to treat ZIKV infection. The methyltransferase domain (MTase) of ZIKV nonstructural protein 5 (NS5) can sequentially methylate guanine N-7 and ribose 2'-O to form m7NGpppA2'Om cap structure in the new RNA transcripts. This methylation step is crucial for ZIKV replication cycle and evading the host immune system, making it a target for drug design. Here, we present the 1.76 Å crystal structure of ZIKV MTase in complex with the byproduct SAH, providing insight into the elegant methylation process, which will benefit the following antiviral drug development.
[Mh] Termos MeSH primário: Metiltransferases/química
Conformação Proteica
S-Adenosil-Homocisteína/metabolismo
S-Adenosilmetionina/metabolismo
Proteínas não Estruturais Virais/química
Zika virus/enzimologia
[Mh] Termos MeSH secundário: Domínio Catalítico
Cristalografia por Raios X
Seres Humanos
Metiltransferases/metabolismo
Modelos Moleculares
Proteínas não Estruturais Virais/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Viral Nonstructural Proteins); 7LP2MPO46S (S-Adenosylmethionine); 979-92-0 (S-Adenosylhomocysteine); EC 2.1.1.- (Methyltransferases)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171004
[Lr] Data última revisão:
171004
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170126
[St] Status:MEDLINE
[do] DOI:10.18632/oncotarget.14780



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