Base de dados : MEDLINE
Pesquisa : D03.383.129.578.840.437.777.270 [Categoria DeCS]
Referências encontradas : 966 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 97 ir para página                         

  1 / 966 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29239480
[Au] Autor:Anantharam P; Whitley EM; Mahama B; Kim DS; Sarkar S; Santana C; Chan A; Kanthasamy AG; Kanthasamy A; Boss GR; Rumbeiha WK
[Ad] Endereço:Department of Veterinary Diagnostic and Production Animal Medicine, Iowa State University, Ames, Iowa.
[Ti] Título:Cobinamide is effective for treatment of hydrogen sulfide-induced neurological sequelae in a mouse model.
[So] Source:Ann N Y Acad Sci;1408(1):61-78, 2017 Nov.
[Is] ISSN:1749-6632
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Hydrogen sulfide (H S) is a highly neurotoxic gas. Acute exposure can lead to neurological sequelae among survivors. A drug for treating neurological sequelae in survivors of acute H S intoxication is needed. Using a novel mouse model we evaluated the efficacy of cobinamide (Cob) for increasing survival of, and reducing neurological sequalae in, mice exposed to sublethal doses of H S. There were two objectives: (1) to determine the dose-response efficacy of Cob and (2) to determine the effective therapeutic time window of Cob. To explore objective 1, mice were injected intramuscularly with Cob at 0, 50, or 100 mg/kg at 2 min after H S exposure. For objective 2, mice were injected intramuscularly with 100 mg/kg Cob at 2, 15, and 30 min after H S exposure. For both objectives, mice were exposed to 765 ppm of H S gas. Cob significantly reduced H S-induced lethality in a dose-dependent manner (P < 0.05). Cob-treated mice exhibited significantly fewer seizures and knockdowns compared with the H S-exposed group. Cob also reversed H S-induced weight loss, behavioral deficits, neurochemical changes, cytochrome c oxidase enzyme inhibition, and neurodegeneration in a dose- and time-dependent manner (P < 0.01). Overall, these findings show that Cob increases survival and is neuroprotective in a mouse model of H S-induced neurological sequelae.
[Mh] Termos MeSH primário: Cobamidas/farmacologia
Transtornos Mentais/prevenção & controle
Convulsões/prevenção & controle
Perda de Peso/efeitos dos fármacos
[Mh] Termos MeSH secundário: Animais
Relação Dose-Resposta a Droga
Sulfeto de Hidrogênio/toxicidade
Masculino
Transtornos Mentais/induzido quimicamente
Camundongos Endogâmicos C57BL
Modelos Neurológicos
Convulsões/induzido quimicamente
Análise de Sobrevida
Fatores de Tempo
Resultado do Tratamento
Complexo Vitamínico B/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cobamides); 12001-76-2 (Vitamin B Complex); 13497-85-3 (cobinamide); YY9FVM7NSN (Hydrogen Sulfide)
[Em] Mês de entrada:1712
[Cu] Atualização por classe:171227
[Lr] Data última revisão:
171227
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171215
[St] Status:MEDLINE
[do] DOI:10.1111/nyas.13559


  2 / 966 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28956602
[Au] Autor:Plegaria JS; Sutter M; Ferlez B; Aussignargues C; Niklas J; Poluektov OG; Fromwiller C; TerAvest M; Utschig LM; Tiede DM; Kerfeld CA
[Ad] Endereço:MSU-DOE Plant Research Laboratory, Michigan State University , East Lansing, Michigan 48824, United States.
[Ti] Título:Structural and Functional Characterization of a Short-Chain Flavodoxin Associated with a Noncanonical 1,2-Propanediol Utilization Bacterial Microcompartment.
[So] Source:Biochemistry;56(42):5679-5690, 2017 Oct 24.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Bacterial microcompartments (BMCs) are proteinaceous organelles that encapsulate enzymes involved in CO fixation (carboxysomes) or carbon catabolism (metabolosomes). Metabolosomes share a common core of enzymes and a distinct signature enzyme for substrate degradation that defines the function of the BMC (e.g., propanediol or ethanolamine utilization BMCs, or glycyl-radical enzyme microcompartments). Loci encoding metabolosomes also typically contain genes for proteins that support organelle function, such as regulation, transport of substrate, and cofactor (e.g., vitamin B ) synthesis and recycling. Flavoproteins are frequently among these ancillary gene products, suggesting that these redox active proteins play an undetermined function in many metabolosomes. Here, we report the first characterization of a BMC-associated flavodoxin (Fld1C), a small flavoprotein, derived from the noncanonical 1,2-propanediol utilization BMC locus (PDU1C) of Lactobacillus reuteri. The 2.0 Å X-ray structure of Fld1C displays the α/ß flavodoxin fold, which noncovalently binds a single flavin mononucleotide molecule. Fld1C is a short-chain flavodoxin with redox potentials of -240 ± 3 mV oxidized/semiquinone and -344 ± 1 mV semiquinone/hydroquinone versus the standard hydrogen electrode at pH 7.5. It can participate in an electron transfer reaction with a photoreductant to form a stable semiquinone species. Collectively, our structural and functional results suggest that PDU1C BMCs encapsulate Fld1C to store and transfer electrons for the reactivation and/or recycling of the B cofactor utilized by the signature enzyme.
[Mh] Termos MeSH primário: Cobamidas/química
Mononucleotídeo de Flavina/química
Flavodoxina/química
Lactobacillus reuteri/química
[Mh] Termos MeSH secundário: Dióxido de Carbono/química
Dióxido de Carbono/metabolismo
Cobamidas/metabolismo
Mononucleotídeo de Flavina/metabolismo
Flavodoxina/metabolismo
Lactobacillus reuteri/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cobamides); 0 (Flavodoxin); 142M471B3J (Carbon Dioxide); 7N464URE7E (Flavin Mononucleotide)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171027
[Lr] Data última revisão:
171027
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170929
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.7b00682


  3 / 966 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28910388
[Au] Autor:Bloch JS; Ruetz M; Kräutler B; Locher KP
[Ad] Endereço:Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland.
[Ti] Título:Structure of the human transcobalamin beta domain in four distinct states.
[So] Source:PLoS One;12(9):e0184932, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Vitamin B12 (cyanocobalamin, CNCbl) is an essential cofactor-precursor for two biochemical reactions in humans. When ingested, cobalamins (Cbl) are transported via a multistep transport system into the bloodstream, where the soluble protein transcobalamin (TC) binds Cbl and the complex is taken up into the cells via receptor mediated endocytosis. Crystal structures of TC in complex with CNCbl have been solved previously. However, the initial steps of holo-TC assembly have remained elusive. Here, we present four crystal structures of the beta domain of human TC (TC-beta) in different substrate-bound states. These include the apo and CNCbl-bound states, providing insight into the early steps of holo-TC assembly. We found that in vitro assembly of TC-alpha and TC-beta to a complex was Cbl-dependent. We also determined the structure of TC-beta in complex with cobinamide (Cbi), an alternative substrate, shedding light on the specificity of TC. We finally determined the structure of TC-beta in complex with an inhibitory antivitamin B12 (anti-B12). We used this structure to model the binding of anti-B12 into full-length holo-TC and could rule out that the inhibitory function of anti-B12 was based on an inability to form a functional complex with TC.
[Mh] Termos MeSH primário: Transcobalaminas/química
Transcobalaminas/metabolismo
Vitamina B 12/metabolismo
[Mh] Termos MeSH secundário: Cobamidas/metabolismo
Cristalografia por Raios X
Seres Humanos
Modelos Moleculares
Ligação Proteica
Multimerização Proteica
Estrutura Secundária de Proteína
Estrutura Terciária de Proteína
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cobamides); 0 (Transcobalamins); 13497-85-3 (cobinamide); P6YC3EG204 (Vitamin B 12)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171012
[Lr] Data última revisão:
171012
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170915
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0184932


  4 / 966 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28882898
[Au] Autor:Campanello GC; Lofgren M; Yokom AL; Southworth DR; Banerjee R
[Ad] Endereço:From the Departments of Biological Chemistry, University of Michigan Medical Center, and.
[Ti] Título:Switch I-dependent allosteric signaling in a G-protein chaperone-B enzyme complex.
[So] Source:J Biol Chem;292(43):17617-17625, 2017 Oct 27.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:G-proteins regulate various processes ranging from DNA replication and protein synthesis to cytoskeletal dynamics and cofactor assimilation and serve as models for uncovering strategies deployed for allosteric signal transduction. MeaB is a multifunctional G-protein chaperone, which gates loading of the active 5'-deoxyadenosylcobalamin cofactor onto methylmalonyl-CoA mutase (MCM) and precludes loading of inactive cofactor forms. MeaB also safeguards MCM, which uses radical chemistry, against inactivation and rescues MCM inactivated during catalytic turnover by using the GTP-binding energy to offload inactive cofactor. The conserved switch I and II signaling motifs used by G-proteins are predicted to mediate allosteric regulation in response to nucleotide binding and hydrolysis in MeaB. Herein, we targeted conserved residues in the MeaB switch I motif to interrogate the function of this loop. Unexpectedly, the switch I mutations had only modest effects on GTP binding and on GTPase activity and did not perturb stability of the MCM-MeaB complex. However, these mutations disrupted multiple MeaB chaperone functions, including cofactor editing, loading, and offloading. Hence, although residues in the switch I motif are not essential for catalysis, they are important for allosteric regulation. Furthermore, single-particle EM analysis revealed, for the first time, the overall architecture of the MCM-MeaB complex, which exhibits a 2:1 stoichiometry. These EM studies also demonstrate that the complex exhibits considerable conformational flexibility. In conclusion, the switch I element does not significantly stabilize the MCM-MeaB complex or influence the affinity of MeaB for GTP but is required for transducing signals between MeaB and MCM.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Cobamidas/química
Metilmalonil-CoA Mutase/química
Methylobacterium extorquens/química
Chaperonas Moleculares/química
Complexos Multiproteicos/química
Transdução de Sinais/fisiologia
Fatores de Transcrição/química
[Mh] Termos MeSH secundário: Motivos de Aminoácidos
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Cobamidas/genética
Cobamidas/metabolismo
Metilmalonil-CoA Mutase/genética
Metilmalonil-CoA Mutase/metabolismo
Methylobacterium extorquens/genética
Methylobacterium extorquens/metabolismo
Chaperonas Moleculares/genética
Chaperonas Moleculares/metabolismo
Complexos Multiproteicos/genética
Complexos Multiproteicos/metabolismo
Estabilidade Proteica
Fatores de Transcrição/genética
Fatores de Transcrição/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Cobamides); 0 (Molecular Chaperones); 0 (Multiprotein Complexes); 0 (Transcription Factors); EC 5.4.99.2 (Methylmalonyl-CoA Mutase)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171104
[Lr] Data última revisão:
171104
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170909
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M117.786095


  5 / 966 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28654327
[Au] Autor:Padmanabhan S; Jost M; Drennan CL; Elías-Arnanz M
[Ad] Endereço:Instituto de Química Física Rocasolano, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain; email: padhu@iqfr.csic.es.
[Ti] Título:A New Facet of Vitamin B : Gene Regulation by Cobalamin-Based Photoreceptors.
[So] Source:Annu Rev Biochem;86:485-514, 2017 Jun 20.
[Is] ISSN:1545-4509
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Living organisms sense and respond to light, a crucial environmental factor, using photoreceptors, which rely on bound chromophores such as retinal, flavins, or linear tetrapyrroles for light sensing. The discovery of photoreceptors that sense light using 5'-deoxyadenosylcobalamin, a form of vitamin B that is best known as an enzyme cofactor, has expanded the number of known photoreceptor families and unveiled a new biological role of this vitamin. The prototype of these B -dependent photoreceptors, the transcriptional repressor CarH, is widespread in bacteria and mediates light-dependent gene regulation in a photoprotective cellular response. CarH activity as a transcription factor relies on the modulation of its oligomeric state by 5'-deoxyadenosylcobalamin and light. This review surveys current knowledge about these B -dependent photoreceptors, their distribution and mode of action, and the structural and photochemical basis of how they orchestrate signal transduction and control gene expression.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Cobamidas/metabolismo
Regulação Bacteriana da Expressão Gênica
Fotorreceptores Microbianos/química
Proteínas Repressoras/química
Fatores de Transcrição/química
[Mh] Termos MeSH secundário: Bacillus megaterium/genética
Bacillus megaterium/metabolismo
Bacillus megaterium/efeitos da radiação
Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Cobamidas/química
Luz
Modelos Moleculares
Myxococcus xanthus/genética
Myxococcus xanthus/metabolismo
Myxococcus xanthus/efeitos da radiação
Fotoquímica
Fotorreceptores Microbianos/genética
Fotorreceptores Microbianos/metabolismo
Conformação Proteica
Proteínas Repressoras/genética
Proteínas Repressoras/metabolismo
Transdução de Sinais
Thermus thermophilus/genética
Thermus thermophilus/metabolismo
Thermus thermophilus/efeitos da radiação
Fatores de Transcrição/genética
Fatores de Transcrição/metabolismo
Transcrição Genética
Vitamina B 12/química
Vitamina B 12/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Cobamides); 0 (Photoreceptors, Microbial); 0 (Repressor Proteins); 0 (Transcription Factors); F0R1QK73KB (cobamamide); P6YC3EG204 (Vitamin B 12)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170704
[Lr] Data última revisão:
170704
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170628
[St] Status:MEDLINE
[do] DOI:10.1146/annurev-biochem-061516-044500


  6 / 966 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28620693
[Au] Autor:Dereven'kov IA; Ivlev PA; Bischin C; Salnikov DS; Silaghi-Dumitrescu R; Makarov SV; Koifman OI
[Ad] Endereço:Institute of Macroheterocyclic Compounds, Ivanovo State University of Chemistry and Technology, Sheremetevskiy str. 7, 153000, Ivanovo, Russia.
[Ti] Título:Comparative studies of reaction of cobalamin (II) and cobinamide (II) with sulfur dioxide.
[So] Source:J Biol Inorg Chem;22(6):969-975, 2017 Aug.
[Is] ISSN:1432-1327
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:The kinetics of reactions of cobalamin (II) and cobinamide (II) with sulfur dioxide was studied by UV-visible (UV-vis) spectroscopy. Reaction results in oxidation of Co(II) center and involves two aquated SO moieties. The final product is suggested to be complex Co(III)-S O . The absence of corrin ring modifications during the reactions was proved.
[Mh] Termos MeSH primário: Cobamidas/química
Dióxido de Enxofre/química
Vitamina B 12/química
[Mh] Termos MeSH secundário: Cinética
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cobamides); 0UZA3422Q4 (Sulfur Dioxide); 13497-85-3 (cobinamide); P6YC3EG204 (Vitamin B 12)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170918
[Lr] Data última revisão:
170918
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170617
[St] Status:MEDLINE
[do] DOI:10.1007/s00775-017-1474-z


  7 / 966 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28548844
[Au] Autor:Kohne M; Zhu C; Warncke K
[Ad] Endereço:Department of Physics, Emory University , Atlanta, Georgia 30322, United States.
[Ti] Título:Two Dynamical Regimes of the Substrate Radical Rearrangement Reaction in B -Dependent Ethanolamine Ammonia-Lyase Resolve Contributions of Native Protein Configurations and Collective Configurational Fluctuations to Catalysis.
[So] Source:Biochemistry;56(25):3257-3264, 2017 Jun 27.
[Is] ISSN:1520-4995
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The kinetics of the substrate radical rearrangement reaction step in B -dependent ethanolamine ammonia-lyase (EAL) from Salmonella typhimurium are measured over a 92 K temperature range. The observed first-order rate constants display a piecewise-continuous Arrhenius dependence, with linear regions over 295 → 220 K (monoexponential) and 214 → 203 K (biexponential) that are delineated by a kinetic bifurcation and kinks at 219 and 217 K, respectively. The results are interpreted by using a free energy landscape model and derived microscopic kinetic mechanism. The bifurcation and kink transitions correspond to the effective quenching of two distinct sets of native collective protein configurational fluctuations that (1) reconfigure the protein within the substrate radical free energy minimum, in a reaction-enabling step, and (2) create the protein configurations associated with the chemical step. Below 217 K, the substrate radical decay reaction persists. Increases in activation enthalpy and entropy of both the microscopic enabling and reaction steps indicate that this non-native reaction coordinate is conducted by local, incremental fluctuations. Continuity in the Arrhenius relations indicates that the same sets of protein groups and interactions mediate the rearrangement over the 295 to 203 K range, but with a repertoire of configurations below 217 K that is restricted, relative to the native configurations accessible above 219 K. The experimental features of a culled reaction step, first-order kinetic measurements, and wide room-to-cryogenic temperature range, allow the direct demonstration and kinetic characterization of protein dynamical contributions to the core adiabatic, bond-making/bond-breaking reaction in EAL.
[Mh] Termos MeSH primário: Cobalto/química
Cobamidas/química
Etanolamina Amônia-Liase/química
Salmonella typhimurium/enzimologia
[Mh] Termos MeSH secundário: Catálise
Cobalto/metabolismo
Cobamidas/metabolismo
Espectroscopia de Ressonância de Spin Eletrônica
Etanolamina Amônia-Liase/metabolismo
Radicais Livres
Cinética
Termodinâmica
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cobamides); 0 (Free Radicals); 3G0H8C9362 (Cobalt); EC 4.3.1.7 (Ethanolamine Ammonia-Lyase)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170907
[Lr] Data última revisão:
170907
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170527
[St] Status:MEDLINE
[do] DOI:10.1021/acs.biochem.7b00294


  8 / 966 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28483920
[Au] Autor:Polaski JT; Webster SM; Johnson JE; Batey RT
[Ad] Endereço:From the Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309.
[Ti] Título:Cobalamin riboswitches exhibit a broad range of ability to discriminate between methylcobalamin and adenosylcobalamin.
[So] Source:J Biol Chem;292(28):11650-11658, 2017 Jul 14.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Riboswitches are a widely distributed class of regulatory RNAs in bacteria that modulate gene expression via small-molecule-induced conformational changes. Generally, these RNA elements are grouped into classes based upon conserved primary and secondary structure and their cognate effector molecule. Although this approach has been very successful in identifying new riboswitch families and defining their distributions, small sequence differences between structurally related RNAs can alter their ligand selectivity and regulatory behavior. Herein, we use a structure-based mutagenic approach to demonstrate that cobalamin riboswitches have a broad spectrum of preference for the two biological forms of cobalamin using isothermal titration calorimetry. This selectivity is primarily mediated by the interaction between a peripheral element of the RNA that forms a T-loop module and a subset of nucleotides in the cobalamin-binding pocket. Cell-based fluorescence reporter assays in revealed that mutations that switch effector preference lead to differential regulatory responses in a biological context. These data demonstrate that a more comprehensive analysis of representative sequences of both previously and newly discovered classes of riboswitches might reveal subgroups of RNAs that respond to different effectors. Furthermore, this study demonstrates a second distinct means by which tertiary structural interactions in cobalamin riboswitches dictate ligand selectivity.
[Mh] Termos MeSH primário: Cobamidas/metabolismo
Cianobactérias/metabolismo
Modelos Moleculares
RNA Bacteriano/metabolismo
Riboswitch
Vitamina B 12/análogos & derivados
Vitamina B 12/metabolismo
[Mh] Termos MeSH secundário: Organismos Aquáticos/metabolismo
Sequência de Bases
Sítios de Ligação
Sequência Conservada
Escherichia coli/metabolismo
Genes Reporter
Cinética
Ligantes
Mutação
RNA/química
RNA/metabolismo
Dobramento de RNA
RNA Bacteriano/agonistas
RNA Bacteriano/química
Proteínas Recombinantes/metabolismo
Especificidade da Espécie
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cobamides); 0 (Ligands); 0 (RNA, Bacterial); 0 (RNA, recombinant); 0 (Recombinant Proteins); 0 (Riboswitch); 63231-63-0 (RNA); BR1SN1JS2W (mecobalamin); F0R1QK73KB (cobamamide); P6YC3EG204 (Vitamin B 12)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170803
[Lr] Data última revisão:
170803
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170510
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M117.787176


  9 / 966 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28442570
[Au] Autor:Li Z; Shanmuganathan A; Ruetz M; Yamada K; Lesniak NA; Kräutler B; Brunold TC; Koutmos M; Banerjee R
[Ad] Endereço:From the Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0600.
[Ti] Título:Coordination chemistry controls the thiol oxidase activity of the B -trafficking protein CblC.
[So] Source:J Biol Chem;292(23):9733-9744, 2017 Jun 09.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The cobalamin or B cofactor supports sulfur and one-carbon metabolism and the catabolism of odd-chain fatty acids, branched-chain amino acids, and cholesterol. CblC is a B -processing enzyme involved in an early cytoplasmic step in the cofactor-trafficking pathway. It catalyzes the glutathione (GSH)-dependent dealkylation of alkylcobalamins and the reductive decyanation of cyanocobalamin. CblC from ( CblC) also exhibits a robust thiol oxidase activity, converting reduced GSH to oxidized GSSG with concomitant scrubbing of ambient dissolved O The mechanism of thiol oxidation catalyzed by CblC is not known. In this study, we demonstrate that novel coordination chemistry accessible to CblC-bound cobalamin supports its thiol oxidase activity via a glutathionyl-cobalamin intermediate. Deglutathionylation of glutathionyl-cobalamin by a second molecule of GSH yields GSSG. The crystal structure of CblC provides insights into how architectural differences at the α- and ß-faces of cobalamin promote the thiol oxidase activity of CblC but mute it in wild-type human CblC. The R161G and R161Q mutations in human CblC unmask its latent thiol oxidase activity and are correlated with increased cellular oxidative stress disease. In summary, we have uncovered key architectural features in the cobalamin-binding pocket that support unusual cob(II)alamin coordination chemistry and enable the thiol oxidase activity of CblC.
[Mh] Termos MeSH primário: Proteínas de Caenorhabditis elegans/química
Caenorhabditis elegans/enzimologia
Proteínas de Transporte/química
Cobamidas/química
Estresse Oxidativo
[Mh] Termos MeSH secundário: Animais
Caenorhabditis elegans/genética
Proteínas de Caenorhabditis elegans/genética
Proteínas de Caenorhabditis elegans/metabolismo
Proteínas de Transporte/genética
Proteínas de Transporte/metabolismo
Cobamidas/genética
Cobamidas/metabolismo
Seres Humanos
Mutação de Sentido Incorreto
Oxirredutases atuantes sobre Doadores de Grupo Enxofre
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Caenorhabditis elegans Proteins); 0 (Carrier Proteins); 0 (Cobamides); 0 (MMACHC protein, human); EC 1.8.- (Oxidoreductases Acting on Sulfur Group Donors)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170616
[Lr] Data última revisão:
170616
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170427
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M117.788554


  10 / 966 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28397170
[Au] Autor:Schubert T
[Ad] Endereço:Department of Applied and Ecological Microbiology, Institute of Microbiology, Friedrich Schiller University, Philosophenweg 12, 07743, Jena, Germany. torsten.schubert@uni-jena.de.
[Ti] Título:The organohalide-respiring bacterium Sulfurospirillum multivorans: a natural source for unusual cobamides.
[So] Source:World J Microbiol Biotechnol;33(5):93, 2017 May.
[Is] ISSN:1573-0972
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Cobamides ('complete' corrinoids) are essential for organohalide-respiring bacteria because they act as cofactors of reductive dehalogenases (RDases). RDases are the key enzymes in organohalide respiration, a process relevant for environmental remediation. More than a decade ago, the unusual norpseudo-B was identified as cofactor of the tetrachloroethene RDase (PceA) purified from the epsilonproteobacterium Sulfurospirillum multivorans. Since then, the question was raised whether or not the production of the uncommon cobamide is a specific adaptation to the requirements of PceA. Recently, efforts were made to unravel variations in the cobamide biosynthetic pathway, which lead to the production of the structurally unique norpseudo-B . The acquisition of genomic and proteomic data together with structural analyses of PceA provided insights into norcobamide formation and utilization. By the use of guided biosynthesis, S. multivorans was shown to be an effective cobamide producer capable of generating unusual norcobamides either functional or non-functional as cofactors of PceA. The organism turned out to be a suitable tool for testing the impact of cobamide structure on enzyme function. The results summarized here highlight S. multivorans in particular and the organohalide-respiring bacteria in general as a resource for new discoveries on cobamide diversity and utilization.
[Mh] Termos MeSH primário: Cobamidas/biossíntese
Epsilonproteobacteria/metabolismo
Oxirredutases/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/química
Proteínas de Bactérias/metabolismo
Vias Biossintéticas
Cobamidas/química
Epsilonproteobacteria/enzimologia
Estrutura Molecular
Oxirredutases/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Cobamides); EC 1.- (Oxidoreductases); EC 1.- (tetrachloroethene dehalogenase)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:171102
[Lr] Data última revisão:
171102
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170412
[St] Status:MEDLINE
[do] DOI:10.1007/s11274-017-2258-x



página 1 de 97 ir para página                         
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde