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  1 / 108 MEDLINE  
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[PMID]:28665588
[Au] Autor:Dunsirn MM; Thoden JB; Gilbert M; Holden HM
[Ad] Endereço:Department of Biochemistry, University of Wisconsin , Madison, Wisconsin 53706, United States.
[Ti] Título:Biochemical Investigation of Rv3404c from Mycobacterium tuberculosis.
[So] Source:Biochemistry;56(29):3818-3825, 2017 Jul 25.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The causative agent of tuberculosis, Mycobacterium tuberculosis, is a bacterium with a complex cell wall and a complicated life cycle. The genome of M. tuberculosis contains well over 4000 genes thought to encode proteins. One of these codes for a putative enzyme referred to as Rv3404c, which has attracted research attention as a potential virulence factor for over 12 years. Here we demonstrate that Rv3404c functions as a sugar N-formyltransferase that converts dTDP-4-amino-4,6-dideoxyglucose into dTDP-4-formamido-4,6-dideoxyglucose using N -formyltetrahydrofolate as the carbon source. Kinetic analyses demonstrate that Rv3404c displays a significant catalytic efficiency of 1.1 × 10 M s . In addition, we report the X-ray structure of a ternary complex of Rv3404c solved in the presence of N -formyltetrahydrofolate and dTDP-4-amino-4,6-dideoxyglucose. The final model of Rv3404c was refined to an overall R-factor of 16.8% at 1.6 Å resolution. The results described herein are especially intriguing given that there have been no published reports of N-formylated sugars associated with M. tuberculosis. The data thus provide a new avenue of research into this fascinating, yet deadly, organism that apparently has been associated with human infection since ancient times.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Hidroximetil e Formil Transferases/química
Modelos Moleculares
Mycobacterium tuberculosis/enzimologia
Fatores de Virulência/química
[Mh] Termos MeSH secundário: Proteínas de Bactérias/metabolismo
Catálise
Cristalografia por Raios X
Desoxiaçúcares/química
Desoxiaçúcares/metabolismo
Formiltetra-Hidrofolatos/química
Formiltetra-Hidrofolatos/metabolismo
Hidroximetil e Formil Transferases/metabolismo
Cinética
Mycobacterium tuberculosis/patogenicidade
Nucleotídeos de Timina/química
Nucleotídeos de Timina/metabolismo
Fatores de Virulência/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Deoxy Sugars); 0 (Formyltetrahydrofolates); 0 (Thymine Nucleotides); 0 (Virulence Factors); 0 (dTDP-4-amino-4,6-dideoxy-glucose); EC 2.1.2.- (Hydroxymethyl and Formyl Transferases)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:171018
[Lr] Data última revisão:
171018
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170701
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.7b00506


  2 / 108 MEDLINE  
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[PMID]:27171345
[Au] Autor:Genthe NA; Thoden JB; Holden HM
[Ad] Endereço:Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706.
[Ti] Título:Structure of the Escherichia coli ArnA N-formyltransferase domain in complex with N(5) -formyltetrahydrofolate and UDP-Ara4N.
[So] Source:Protein Sci;25(8):1555-62, 2016 08.
[Is] ISSN:1469-896X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:ArnA from Escherichia coli is a key enzyme involved in the formation of 4-amino-4-deoxy-l-arabinose. The addition of this sugar to the lipid A moiety of the lipopolysaccharide of pathogenic Gram-negative bacteria allows these organisms to evade the cationic antimicrobial peptides of the host immune system. Indeed, it is thought that such modifications may be responsible for the repeated infections of cystic fibrosis patients with Pseudomonas aeruginosa. ArnA is a bifunctional enzyme with the N- and C-terminal domains catalyzing formylation and oxidative decarboxylation reactions, respectively. The catalytically competent cofactor for the formylation reaction is N(10) -formyltetrahydrofolate. Here we describe the structure of the isolated N-terminal domain of ArnA in complex with its UDP-sugar substrate and N(5) -formyltetrahydrofolate. The model presented herein may prove valuable in the development of new antimicrobial therapeutics.
[Mh] Termos MeSH primário: Amino Açúcares/química
Carboxiliases/química
Coenzimas/química
Escherichia coli/química
Formiltetra-Hidrofolatos/química
Açúcares de Uridina Difosfato/química
[Mh] Termos MeSH secundário: Amino Açúcares/metabolismo
Carboxiliases/genética
Carboxiliases/metabolismo
Clonagem Molecular
Coenzimas/metabolismo
Escherichia coli/enzimologia
Escherichia coli/genética
Formiltetra-Hidrofolatos/metabolismo
Expressão Gênica
Modelos Moleculares
Domínios Proteicos
Estrutura Secundária de Proteína
Proteínas Recombinantes/química
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
Açúcares de Uridina Difosfato/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Amino Sugars); 0 (Coenzymes); 0 (Formyltetrahydrofolates); 0 (Recombinant Proteins); 0 (Uridine Diphosphate Sugars); 14697-41-7 (uridine diphosphate arabinose); 33406-49-4 (4-amino-4-deoxyarabinose); EC 4.1.1.- (Carboxy-Lyases); EC 4.1.1.35 (UDPglucuronate decarboxylase)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170801
[Lr] Data última revisão:
170801
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160513
[St] Status:MEDLINE
[do] DOI:10.1002/pro.2938


  3 / 108 MEDLINE  
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[PMID]:25752909
[Au] Autor:Genthe NA; Thoden JB; Benning MM; Holden HM
[Ad] Endereço:Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706.
[Ti] Título:Molecular structure of an N-formyltransferase from Providencia alcalifaciens O30.
[So] Source:Protein Sci;24(6):976-86, 2015 Jun.
[Is] ISSN:1469-896X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The existence of N-formylated sugars in the O-antigens of Gram-negative bacteria has been known since the middle 1980s, but only recently have the biosynthetic pathways for their production been reported. In these pathways, glucose-1-phosphate is first activated by attachment to a dTMP moiety. This step is followed by a dehydration reaction and an amination. The last step in these pathways is catalyzed by N-formyltransferases that utilize N(10) -formyltetrahydrofolate as the carbon source. Here we describe the three-dimensional structure of one of these N-formyltransferases, namely VioF from Providencia alcalifaciens O30. Specifically, this enzyme catalyzes the conversion of dTDP-4-amino-4,6-dideoxyglucose (dTDP-Qui4N) to dTDP-4,6-dideoxy-4-formamido-d-glucose (dTDP-Qui4NFo). For this analysis, the structure of VioF was solved to 1.9 Å resolution in both its apoform and in complex with tetrahydrofolate and dTDP-Qui4N. The crystals used in the investigation belonged to the space group R32 and demonstrated reticular merohedral twinning. The overall catalytic core of the VioF subunit is characterized by a six stranded mixed ß-sheet flanked on one side by three α-helices and on the other side by mostly random coil. This N-terminal domain is followed by an α-helix and a ß-hairpin that form the subunit:subunit interface. The active site of the enzyme is shallow and solvent-exposed. Notably, the pyranosyl moiety of dTDP-Qui4N is positioned into the active site by only one hydrogen bond provided by Lys 77. Comparison of the VioF model to that of a previously determined N-formyltransferase suggests that substrate specificity is determined by interactions between the protein and the pyrophosphoryl group of the dTDP-sugar substrate.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Hidroximetil e Formil Transferases/química
Providencia/enzimologia
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Domínio Catalítico
Cristalografia por Raios X
Formiltetra-Hidrofolatos/metabolismo
Hidroximetil e Formil Transferases/genética
Hidroximetil e Formil Transferases/metabolismo
Modelos Moleculares
Conformação Proteica
Providencia/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Formyltetrahydrofolates); EC 2.1.2.- (Hydroxymethyl and Formyl Transferases)
[Em] Mês de entrada:1602
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150311
[St] Status:MEDLINE
[do] DOI:10.1002/pro.2675


  4 / 108 MEDLINE  
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[PMID]:25448816
[Au] Autor:Sah S; Aluri S; Rex K; Varshney U
[Ad] Endereço:Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.
[Ti] Título:One-carbon metabolic pathway rewiring in Escherichia coli reveals an evolutionary advantage of 10-formyltetrahydrofolate synthetase (Fhs) in survival under hypoxia.
[So] Source:J Bacteriol;197(4):717-26, 2015 Feb 15.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In cells, N(10)-formyltetrahydrofolate (N(10)-fTHF) is required for formylation of eubacterial/organellar initiator tRNA and purine nucleotide biosynthesis. Biosynthesis of N(10)-fTHF is catalyzed by 5,10-methylene-tetrahydrofolate dehydrogenase/cyclohydrolase (FolD) and/or 10-formyltetrahydrofolate synthetase (Fhs). All eubacteria possess FolD, but some possess both FolD and Fhs. However, the reasons for possessing Fhs in addition to FolD have remained unclear. We used Escherichia coli, which naturally lacks fhs, as our model. We show that in E. coli, the essential function of folD could be replaced by Clostridium perfringens fhs when it was provided on a medium-copy-number plasmid or integrated as a single-copy gene in the chromosome. The fhs-supported folD deletion (ΔfolD) strains grow well in a complex medium. However, these strains require purines and glycine as supplements for growth in M9 minimal medium. The in vivo levels of N(10)-fTHF in the ΔfolD strain (supported by plasmid-borne fhs) were limiting despite the high capacity of the available Fhs to synthesize N(10)-fTHF in vitro. Auxotrophy for purines could be alleviated by supplementing formate to the medium, and that for glycine was alleviated by engineering THF import into the cells. The ΔfolD strain (harboring fhs on the chromosome) showed a high NADP(+)-to-NADPH ratio and hypersensitivity to trimethoprim. The presence of fhs in E. coli was disadvantageous for its aerobic growth. However, under hypoxia, E. coli strains harboring fhs outcompeted those lacking it. The computational analysis revealed a predominant natural occurrence of fhs in anaerobic and facultative anaerobic bacteria.
[Mh] Termos MeSH primário: Proteínas de Bactérias/metabolismo
Evolução Biológica
Clostridium perfringens/enzimologia
Escherichia coli/metabolismo
Formiato-Tetra-Hidrofolato Ligase/metabolismo
Redes e Vias Metabólicas
Viabilidade Microbiana
Oxigênio/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Carbono/metabolismo
Clonagem Molecular
Clostridium perfringens/genética
Escherichia coli/genética
Escherichia coli/crescimento & desenvolvimento
Proteínas de Escherichia coli/genética
Proteínas de Escherichia coli/metabolismo
Formiato-Tetra-Hidrofolato Ligase/genética
Formiltetra-Hidrofolatos/metabolismo
Metilenotetra-Hidrofolato Desidrogenase (NADP)/genética
Metilenotetra-Hidrofolato Desidrogenase (NADP)/metabolismo
Oxigênio/análise
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Escherichia coli Proteins); 0 (Formyltetrahydrofolates); 7440-44-0 (Carbon); EC 1.5.1.5 (Methylenetetrahydrofolate Dehydrogenase (NADP)); EC 6.3.4.3 (Formate-Tetrahydrofolate Ligase); S88TT14065 (Oxygen)
[Em] Mês de entrada:1503
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:141203
[St] Status:MEDLINE
[do] DOI:10.1128/JB.02365-14


  5 / 108 MEDLINE  
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[PMID]:24347283
[Au] Autor:Zimmer AL; Thoden JB; Holden HM
[Ad] Endereço:Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706.
[Ti] Título:Three-dimensional structure of a sugar N-formyltransferase from Francisella tularensis.
[So] Source:Protein Sci;23(3):273-83, 2014 Mar.
[Is] ISSN:1469-896X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:N-formylated sugars have been observed on the O-antigens of such pathogenic Gram-negative bacteria as Campylobacter jejuni and Francisella tularensis. Until recently, however, little was known regarding the overall molecular architectures of the N-formyltransferases that are required for the biosynthesis of these unusual sugars. Here we demonstrate that the protein encoded by the wbtj gene from F. tularensis is an N-formyltransferase that functions on dTDP-4-amino-4,6-dideoxy-d-glucose as its substrate. The enzyme, hereafter referred to as WbtJ, demonstrates a strict requirement for N(10) -formyltetrahydrofolate as its carbon source. In addition to the kinetic analysis, the three-dimensional structure of the enzyme was solved in the presence of dTDP-sugar ligands to a nominal resolution of 2.1 Å. Each subunit of the dimeric enzyme is dominated by a "core" domain defined by Met 1 to Ser 185. This core motif harbors the active site residues. Following the core domain, the last 56 residues fold into two α-helices and a ß-hairpin motif. The hairpin motif is responsible primarily for the subunit:subunit interface, which is characterized by a rather hydrophobic pocket. From the study presented here, it is now known that WbtJ functions on C-4' amino sugars. Another enzyme recently investigated in the laboratory, WlaRD, formylates only C-3' amino sugars. Strikingly, the quaternary structures of WbtJ and WlaRD are remarkably different. In addition, there are several significant variations in the side chains that line their active site pockets, which may be important for substrate specificity. Details concerning the kinetic and structural properties of WbtJ are presented.
[Mh] Termos MeSH primário: Desoxiaçúcares/metabolismo
Formiltetra-Hidrofolatos/metabolismo
Francisella tularensis/enzimologia
Hidroximetil e Formil Transferases/química
Hidroximetil e Formil Transferases/metabolismo
Nucleotídeos de Timina/metabolismo
[Mh] Termos MeSH secundário: Motivos de Aminoácidos
Proteínas de Bactérias/química
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Domínio Catalítico
Cristalografia por Raios X
Francisella tularensis/química
Hidroximetil e Formil Transferases/genética
Modelos Moleculares
Estrutura Quaternária de Proteína
Estrutura Secundária de Proteína
Estrutura Terciária de Proteína
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Deoxy Sugars); 0 (Formyltetrahydrofolates); 0 (Thymine Nucleotides); 0 (dTDP-4-amino-4,6-dideoxy-glucose); EC 2.1.2.- (Hydroxymethyl and Formyl Transferases)
[Em] Mês de entrada:1411
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:131219
[St] Status:MEDLINE
[do] DOI:10.1002/pro.2409


  6 / 108 MEDLINE  
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[PMID]:24033320
[Au] Autor:Jägerstad M; Jastrebova J
[Ad] Endereço:Department of Food Science, Uppsala BioCenter, Swedish University of Agricultural Sciences (SLU) , P.O. Box 7051, SE-750 07 Uppsala, Sweden.
[Ti] Título:Occurrence, stability, and determination of formyl folates in foods.
[So] Source:J Agric Food Chem;61(41):9758-68, 2013 Oct 16.
[Is] ISSN:1520-5118
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The B-vitamin folate has specific tasks as a one-carbon (C1) group supplier in the building and repair of DNA and RNA as well as in the methylation of homocysteine to methionine. Folate occurs in all living cells as a dynamic pool of several interconvertible forms carrying different C1 groups. Along the food chain, this dynamic pool of folates constantly changes due to either enzymatic or chemical interconversions during food processing and storage. These interconversions make it difficult to determine individual folate forms in foods. The formyl folates, the second most predominant forms of food folates, after 5-methyltetrahydrofolate, are particularly prone to interconvert at low pH. Today, this knowledge is often neglected, leading to risks for analytical underestimation of formyl folates. The purpose of the review is to explore the stability and interconversions of formyl folates in foods as well as to analyze the pitfalls in the determination of formyl folates.
[Mh] Termos MeSH primário: Análise de Alimentos
Formiltetra-Hidrofolatos/química
Complexo Vitamínico B/química
[Mh] Termos MeSH secundário: Manipulação de Alimentos
Oxirredução
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Formyltetrahydrofolates); 12001-76-2 (Vitamin B Complex)
[Em] Mês de entrada:1404
[Cu] Atualização por classe:131016
[Lr] Data última revisão:
131016
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:130917
[St] Status:MEDLINE
[do] DOI:10.1021/jf4028427


  7 / 108 MEDLINE  
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[PMID]:20844072
[Au] Autor:Obeid R; Kasoha M; Kirsch SH; Munz W; Herrmann W
[Ad] Endereço:Department of Clinical Chemistry and Laboratory Medicine and Gynecology, University Hospital of Saarland, Homburg, Germany. rima.obeid@uniklinikum-saarland.de
[Ti] Título:Concentrations of unmetabolized folic acid and primary folate forms in pregnant women at delivery and in umbilical cord blood.
[So] Source:Am J Clin Nutr;92(6):1416-22, 2010 Dec.
[Is] ISSN:1938-3207
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: The importance of unmetabolized folic acid in maternal and fetal blood is not known. OBJECTIVE: We investigated total folate, tetrahydrofolate (THF), 5-methyltetrahydrofolate (5-MTHF), formyl-THF, 5,10-methenylTHF, and folic acid concentrations in women and in umbilical cord blood at delivery. DESIGN: The study included 87 pregnant women and 29 cord blood samples, including 24 mother-infant pairs. We measured serum concentrations of folate forms by using ultraperformance liquid chromatography-tandem mass spectrometry. RESULTS: Pregnant women who received 400 µg folic acid daily (n = 25) had higher total folate (P = 0.041), 5-MTHF (P = 0.049), and formyl-THF (P < 0.001) concentrations and slightly higher THF (P = 0.093) concentrations than did nonsupplemented pregnant women (n = 61). We measured folic acid concentrations >0.20 nmol/L in 38 (44%) pregnant women and in 55% of the cord serum samples, but these measurements were not explained by maternal supplement use. Concentrations of folic acid were nonsignificantly higher in cord blood from supplemented women than in cord blood from nonsupplemented women (P = 0.154). Proportions of folic acid to total folate in cord serum did not differ according to maternal supplement usage (0.54% compared with 0.43% in supplemented and nonsupplemented women, respectively). Concentrations of folic acid did not differ between maternal and cord serum. However, folic acid constituted a significantly lower proportion of total folate in cord serum than in maternal serum. CONCLUSIONS: We detected unmetabolized folic acid in more than one-half of cord blood samples. Folic acid (400 µg/d) supplied during pregnancy is not likely to accumulate in the fetus, in contrast to 5-MTHF and THF, which accumulate in the fetus.
[Mh] Termos MeSH primário: Sangue Fetal/química
Ácido Fólico/administração & dosagem
Ácido Fólico/sangue
Formiltetra-Hidrofolatos/sangue
Recém-Nascido/sangue
Gravidez/sangue
Tetra-Hidrofolatos/sangue
[Mh] Termos MeSH secundário: Adulto
Suplementos Nutricionais
Feminino
Seres Humanos
Adulto Jovem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Formyltetrahydrofolates); 0 (Tetrahydrofolates); 935E97BOY8 (Folic Acid)
[Em] Mês de entrada:1012
[Cu] Atualização por classe:131121
[Lr] Data última revisão:
131121
[Sb] Subgrupo de revista:AIM; IM
[Da] Data de entrada para processamento:100917
[St] Status:MEDLINE
[do] DOI:10.3945/ajcn.2010.29361


  8 / 108 MEDLINE  
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[PMID]:19439459
[Au] Autor:Aufreiter S; Gregory JF; Pfeiffer CM; Fazili Z; Kim YI; Marcon N; Kamalaporn P; Pencharz PB; O'Connor DL
[Ad] Endereço:Department of Nutritional Sciences, University of Toronto, Toronto, Canada.
[Ti] Título:Folate is absorbed across the colon of adults: evidence from cecal infusion of (13)C-labeled [6S]-5-formyltetrahydrofolic acid.
[So] Source:Am J Clin Nutr;90(1):116-23, 2009 Jul.
[Is] ISSN:1938-3207
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Folate deficiency increases the risk of several human diseases. Likewise, high intakes of folate, particularly synthetic folic acid intake, may be associated with adverse health outcomes in humans. A more comprehensive understanding of the "input side" of folate nutrition may help to set dietary recommendations that strike the right balance between health benefits and risks. It is well known that the microflora in the colon produce large quantities of folate that approach or exceed recommended dietary intakes; however, there is no direct evidence of the bioavailability of this pool in humans. OBJECTIVE: The objective was to determine whether, and to what extent, the natural folate vitamer 5-formyltetrahydrofolic acid is absorbed across the intact colon of humans. DESIGN: During screening colonoscopy, 684 nmol (320 microg) [(13)C]glutamyl-5-formyltetrahydrofolic acid was infused directly into the cecum of 6 healthy adults. Three or more weeks later, each subject received an intravenous injection of the same compound (172 nmol). Blood samples were collected before and after each treatment. The ratio of labeled to unlabeled folates was determined in plasma by tandem mass spectrometry. RESULTS: The apparent rate of folate absorption across the colon of a bolus dose of [(13)C]5-formyltetrahydrofolic acid infused into the cecum was 0.6 +/- 0.2 nmol/h, as determined by the appearance of [(13)C(5)]5-methyltetrahydrofolic acid in plasma. In comparison, the rate of appearance of [(13)C(5)]5-methyltetrahydrofolic acid after an intravenous injection of [(13)C(5)]5-formyltetrahydrofolate was 7 +/- 1.2 nmol/h. CONCLUSION: Physiologic doses of natural folate are absorbed across the intact colon in humans.
[Mh] Termos MeSH primário: Isótopos de Carbono/farmacocinética
Ceco/fisiologia
Colo/metabolismo
Ácido Fólico/análogos & derivados
Ácido Fólico/metabolismo
Formiltetra-Hidrofolatos/farmacocinética
Leucovorina/metabolismo
[Mh] Termos MeSH secundário: Adulto
Colonoscopia
Feminino
Genótipo
Seres Humanos
Absorção Intestinal
Masculino
Metilenotetra-Hidrofolato Redutase (NADPH2)/genética
Meia-Idade
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Carbon Isotopes); 0 (Formyltetrahydrofolates); 52196-22-2 (5-methyltetrahydrohomofolic acid); 935E97BOY8 (Folic Acid); EC 1.5.1.20 (Methylenetetrahydrofolate Reductase (NADPH2)); Q573I9DVLP (Leucovorin)
[Em] Mês de entrada:0907
[Cu] Atualização por classe:161025
[Lr] Data última revisão:
161025
[Sb] Subgrupo de revista:AIM; IM
[Da] Data de entrada para processamento:090515
[St] Status:MEDLINE
[do] DOI:10.3945/ajcn.2008.27345


  9 / 108 MEDLINE  
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[PMID]:18628352
[Au] Autor:Collakova E; Goyer A; Naponelli V; Krassovskaya I; Gregory JF; Hanson AD; Shachar-Hill Y
[Ad] Endereço:Plant Biology Department, Michigan State University, East Lansing, Michigan 48824, USA. collakov@msu.edu
[Ti] Título:Arabidopsis 10-formyl tetrahydrofolate deformylases are essential for photorespiration.
[So] Source:Plant Cell;20(7):1818-32, 2008 Jul.
[Is] ISSN:1040-4651
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In prokaryotes, PurU (10-formyl tetrahydrofolate [THF] deformylase) metabolizes 10-formyl THF to formate and THF for purine and Gly biosyntheses. The Arabidopsis thaliana genome contains two putative purU genes, At4g17360 and At5g47435. Knocking out these genes simultaneously results in plants that are smaller and paler than the wild type. These double knockout (dKO) mutant plants show a 70-fold increase in Gly levels and accumulate elevated levels of 5- and 10-formyl THF. Embryo development in dKO mutants arrests between heart and early bent cotyledon stages. Mature seeds are shriveled, accumulate low amounts of lipids, and fail to germinate. However, the dKO mutant is only conditionally lethal and is rescued by growth under nonphotorespiratory conditions. In addition, culturing dKO siliques in the presence of sucrose restores normal embryo development and seed viability, suggesting that the seed and embryo development phenotypes are a result of a maternal effect. Our findings are consistent with the involvement of At4g17360 and At5g47435 proteins in photorespiration, which is to prevent excessive accumulation of 5-formyl THF, a potent inhibitor of the Gly decarboxylase/Ser hydroxymethyltransferase complex. Supporting this role, deletion of the At2g38660 gene that encodes the bifunctional 5,10-methylene THF dehydrogenase/5,10-methenyl THF cyclohydrolase that acts upstream of 5-formyl THF formation restored the wild-type phenotype in dKO plants.
[Mh] Termos MeSH primário: Amidoidrolases/metabolismo
Proteínas de Arabidopsis/metabolismo
Arabidopsis/enzimologia
Fotossíntese/fisiologia
[Mh] Termos MeSH secundário: Amidoidrolases/genética
Sequência de Aminoácidos
Arabidopsis/genética
Arabidopsis/fisiologia
Proteínas de Arabidopsis/genética
Ácido Fólico/metabolismo
Formiatos/metabolismo
Formiltetra-Hidrofolatos/metabolismo
Regulação da Expressão Gênica de Plantas/efeitos dos fármacos
Glicina Hidroximetiltransferase/genética
Glicina Hidroximetiltransferase/metabolismo
Dados de Sequência Molecular
Mutação
Oxigênio/metabolismo
Reação em Cadeia da Polimerase Via Transcriptase Reversa
Sementes/enzimologia
Sementes/genética
Sementes/fisiologia
Homologia de Sequência de Aminoácidos
Sacarose/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Arabidopsis Proteins); 0 (Formates); 0 (Formyltetrahydrofolates); 0YIW783RG1 (formic acid); 57-50-1 (Sucrose); 935E97BOY8 (Folic Acid); EC 2.1.2.1 (Glycine Hydroxymethyltransferase); EC 3.5.- (Amidohydrolases); EC 3.5.1.88 (peptide deformylase); S88TT14065 (Oxygen)
[Em] Mês de entrada:0901
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:080717
[St] Status:MEDLINE
[do] DOI:10.1105/tpc.108.058701


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[PMID]:18344075
[Au] Autor:Wang JP; Ding WX; Deng YH; Lan P; Pan K; Dong GH; Deng JZ; Wang L; Wu XJ; Guo XF; Zheng J
[Ad] Endereço:Department of Colorectal Surgery, The Sixth Affiliated Hospital, Sun Yat-sen University, Guangzhou 510655, China. wangjianp@mail.sysu.edu.cn
[Ti] Título:[Preoperative chemoradiotherapy with FOLFOX in low rectal cancer: a multicenter study].
[So] Source:Zhonghua Wei Chang Wai Ke Za Zhi;11(2):116-9, 2008 Mar.
[Is] ISSN:1671-0274
[Cp] País de publicação:China
[La] Idioma:chi
[Ab] Resumo:OBJECTIVE: To investigate the toxicity and safety of FOLFOX regimen concurrent with radiotherapy in neoadjuvant setting in patients with low rectal cancer. METHODS: Fifty-six patients with stage T(3-4)N(0)M(0) and T(1-4)N(1-2)M(0) were eligible from Aug. 2004 to Jul. 2007. Upon entry the study, they received 4 cycles of chemotherapy with FOLFOX regimen. Radiotherapy was added from the second cycle of chemotherapy (CT). The total dose of radiotherapy (RT) was 46 Gy (2 Gy x 23). Total mesorectal excision (TME) was performed 4-8 weeks after RT. RESULTS: Among them, 54 cases received 4 cycles of CT, 1 patient stopped CT after the second cycle of CT because of unrecovery from neutropenia. One patient stopped chemoradiotherapy(CRT) because of complicating with active pulmonary tuberculosis after 2 cycles of CT and 10 times of RT. Two occurred liver, lung and bone metastases after CT. Totally 220 cycles of CT were administrated. Fifty-two patients received operation after CRT, 50 with anal interior sphincter reservation, 19 with prophylactic ileac stoma. Anastomotic leakage occurred in 2 patients after operation, and rectal vaginal fistula in 2 patients 1 month after operation. According to the pathologic results, 7 patients achieved complete response, 41 partial response, 4 stable disease, and the objective response rate was 85.7%. CONCLUSION: Concomitant treatment of FOLFOX regimen and RT in neoadjuvant setting of rectal cancer was safe and tolerable, and it suggests that protective ileostomy for anastomotic leakage following anus-preserving operation should be performed.
[Mh] Termos MeSH primário: Terapia Neoadjuvante/métodos
Neoplasias Retais/terapia
[Mh] Termos MeSH secundário: Adulto
Idoso
Quimioterapia Adjuvante
Feminino
Fluoruracila/administração & dosagem
Formiltetra-Hidrofolatos/administração & dosagem
Seres Humanos
Masculino
Meia-Idade
Estadiamento de Neoplasias
Compostos Organoplatínicos/administração & dosagem
Radioterapia Adjuvante
Neoplasias Retais/patologia
Reto/patologia
Adulto Jovem
[Pt] Tipo de publicação:CLINICAL TRIAL; ENGLISH ABSTRACT; JOURNAL ARTICLE; MULTICENTER STUDY
[Nm] Nome de substância:
0 (Formyltetrahydrofolates); 0 (Organoplatinum Compounds); 04ZR38536J (oxaliplatin); U3P01618RT (Fluorouracil)
[Em] Mês de entrada:1003
[Cu] Atualização por classe:141120
[Lr] Data última revisão:
141120
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:080318
[St] Status:MEDLINE



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