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Pesquisa : D03.633.100.733.315.650.249 [Categoria DeCS]
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  1 / 4014 MEDLINE  
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[PMID]:29264594
[Au] Autor:Hernández-Sánchez D; Villabona-Leal G; Saucedo-Orozco I; Bracamonte V; Pérez E; Bittencourt C; Quintana M
[Ad] Endereço:Instituto de Física, Universidad Autónoma de San Luis Potosí, Manuel Nava 6, Zona Universitaria, San Luis Potosí SLP 78290, Mexico. mildred@ifisica.uaslp.mx.
[Ti] Título:Stable graphene oxide-gold nanoparticle platforms for biosensing applications.
[So] Source:Phys Chem Chem Phys;20(3):1685-1692, 2018 Jan 17.
[Is] ISSN:1463-9084
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Graphene oxide-gold nanoparticle (AuNPs@GO) hybrids were fabricated in water dispersions of graphene oxide (GO) and Au precursor completely free of stabilizing agents by UV-light irradiation. Gold nanoparticle (AuNP) nucleation, growth, and stabilization mechanisms at the surface of GO are discussed on the basis of UV-Vis, Raman, IR, and X-Ray photo-spectroscopy studies. The analyses of AuNPs@GO hybrids by transmission electron microscopy (TEM), thermogravimetric (TGA) and electrochemical tests show that they exhibit outstanding chemical, thermal and electrochemical stabilities. Thus, AuNPs@GO biosensing platforms were fabricated for surface enhanced Raman spectroscopy (SERS) detection of crystal violet (CV), a SERS standard molecule, and in a different set of experiments, for flavin adenine dinucleotide (FAD), a flavoprotein coenzyme that plays an important role in many oxidoreductase and reversible redox conversions in biochemical reactions. AuNPs@GO hybrids synthesized by using UV light irradiation show exceptional stability and high intensification of the Raman signals showing that they have high potential for use as biomedical probes for the detection, monitoring, and diagnosis of medical diseases.
[Mh] Termos MeSH primário: Técnicas Biossensoriais/métodos
Ouro/química
Grafite/química
Nanopartículas Metálicas/química
[Mh] Termos MeSH secundário: Técnicas Eletroquímicas
Flavina-Adenina Dinucleotídeo/química
Microscopia Eletrônica de Transmissão
Oxirredução
Óxidos/química
Oxirredutases/química
Oxirredutases/metabolismo
Espectroscopia Fotoeletrônica
Espectrofotometria
Termogravimetria
Raios Ultravioleta
Água/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Oxides); 059QF0KO0R (Water); 146-14-5 (Flavin-Adenine Dinucleotide); 7440-57-5 (Gold); 7782-42-5 (Graphite); EC 1.- (Oxidoreductases)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180220
[Lr] Data última revisão:
180220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171222
[St] Status:MEDLINE
[do] DOI:10.1039/c7cp04817c


  2 / 4014 MEDLINE  
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[PMID]:29198706
[Au] Autor:Kim S; Kim KJ
[Ad] Endereço:School of Life Sciences, KNU Creative BioResearch Group, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu, 41566, Republic of Korea; KNU Institute for Microorganisms, Kyungpook National University, Daehak-ro 80, Buk-ku, Daegu, 41566, Republic of Korea.
[Ti] Título:Structural insight into the substrate specificity of acyl-CoA oxidase1 from Yarrowia lipolytica for short-chain dicarboxylyl-CoAs.
[So] Source:Biochem Biophys Res Commun;495(2):1628-1634, 2018 01 08.
[Is] ISSN:1090-2104
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Acyl-CoA oxidase (ACOX) plays an important role in fatty acid degradation. The enzyme catalyzes the first reaction in peroxisomal fatty acid ß-oxidation by reducing acyl-CoA to 2-trans-enoyl-CoA. The yeast Yarrowia lipolytica is able to utilize fatty acids, fats, and oil as carbon sources to produce valuable bioproducts. We determined the crystal structure of ACOX1 from Y. lipolytica (YlACOX1) at a resolution of 2.5 Å. YlACOX1 forms a homodimer, and the monomeric structure is composed of four domains, the Nα, Nß, Cα1, and Cα2. The FAD cofactor is bound at the dimerization interface between the Nß- and Cα1-domains. The substrate-binding tunnel formed by the interface between the Nα-, Nß-, and Cα1-domains is located proximal to FAD. Amino acid and structural comparisons of YlACOX1 with other ACOXs show that the substrate-binding pocket of YlACOX1 is much smaller than that of the medium- or long-chain ACOXs but is rather similar to that of the short-chain ACOXs. Moreover, the hydrophilicity of residues constituting the end region of the substrate-binding pocket in YlACOX1 is quite similar to those in the short-chain ACOXs but different from those of the medium- or long-chain ACOXs. These observations provide structural insights how YlACOX1 prefers short-chain dicarboxylyl-CoAs as a substrate.
[Mh] Termos MeSH primário: Acil-CoA Oxidase/química
Acil-CoA Oxidase/metabolismo
Proteínas Fúngicas/química
Proteínas Fúngicas/metabolismo
Yarrowia/enzimologia
[Mh] Termos MeSH secundário: Acil Coenzima A/química
Acil Coenzima A/metabolismo
Acil-CoA Oxidase/genética
Sequência de Aminoácidos
Domínio Catalítico
Cristalografia por Raios X
Flavina-Adenina Dinucleotídeo/metabolismo
Proteínas Fúngicas/genética
Interações Hidrofóbicas e Hidrofílicas
Isoenzimas/química
Isoenzimas/genética
Isoenzimas/metabolismo
Modelos Moleculares
Estrutura Quaternária de Proteína
Homologia de Sequência de Aminoácidos
Especificidade por Substrato
Yarrowia/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Acyl Coenzyme A); 0 (Fungal Proteins); 0 (Isoenzymes); 146-14-5 (Flavin-Adenine Dinucleotide); EC 1.3.3.6 (Acyl-CoA Oxidase)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180220
[Lr] Data última revisão:
180220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171205
[St] Status:MEDLINE


  3 / 4014 MEDLINE  
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[PMID]:28463500
[Au] Autor:Kobylarz MJ; Heieis GA; Loutet SA; Murphy MEP
[Ad] Endereço:The Department of Microbiology and Immunology, Life Sciences Institute, University of British Columbia , Vancouver, British Columbia V6T 1Z3; Canada.
[Ti] Título:Iron Uptake Oxidoreductase (IruO) Uses a Flavin Adenine Dinucleotide Semiquinone Intermediate for Iron-Siderophore Reduction.
[So] Source:ACS Chem Biol;12(7):1778-1786, 2017 Jul 21.
[Is] ISSN:1554-8937
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Many pathogenic bacteria including Staphylococcus aureus use iron-chelating siderophores to acquire iron. Iron uptake oxidoreductase (IruO), a flavin adenine dinucleotide (FAD)-containing nicotinamide adenine dinucleotide phosphate (NADPH)-dependent reductase from S. aureus, functions as a reductase for IsdG and IsdI, two paralogous heme degrading enzymes. Also, the gene encoding for IruO was shown to be required for growth of S. aureus on hydroxamate siderophores as a sole iron source. Here, we show that IruO binds the hydroxamate-type siderophores desferrioxamine B and ferrichrome A with low micromolar affinity and in the presence of NADPH, Fe(II) was released. Steady-state kinetics of Fe(II) release provides k /K values in the range of 600 to 7000 M s for these siderophores supporting a role for IruO as a siderophore reductase in iron utilization. Crystal structures of IruO were solved in two distinct conformational states mediated by the formation of an intramolecular disulfide bond. A putative siderophore binding site was identified adjacent to the FAD cofactor. This site is partly occluded in the oxidized IruO structure consistent with this form being less active than reduced IruO. This reduction in activity could have a physiological role to limit iron release under oxidative stress conditions. Visible spectroscopy of anaerobically reduced IruO showed that the reaction proceeds by a single electron transfer mechanism through an FAD semiquinone intermediate. From the data, a model for single electron siderophore reduction by IruO using NADPH is described.
[Mh] Termos MeSH primário: Benzoquinonas/química
Flavina-Adenina Dinucleotídeo/química
Ferro/metabolismo
Oxirredutases/metabolismo
Sideróforos/metabolismo
[Mh] Termos MeSH secundário: Anaerobiose
Sítios de Ligação
Clonagem Molecular
Cristalografia por Raios X
Cinética
Modelos Moleculares
NADP/química
Oxirredução
Oxirredutases/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Benzoquinones); 0 (Siderophores); 146-14-5 (Flavin-Adenine Dinucleotide); 3225-29-4 (semiquinone radicals); 53-59-8 (NADP); E1UOL152H7 (Iron); EC 1.- (Oxidoreductases)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180207
[Lr] Data última revisão:
180207
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170503
[St] Status:MEDLINE
[do] DOI:10.1021/acschembio.7b00203


  4 / 4014 MEDLINE  
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[PMID]:29227076
[Au] Autor:Danylovych HV
[Ti] Título:Evaluation of functioning of mitochondrial electron transport chain with NADH and FAD autofluorescence
[So] Source:Ukr Biochem J;88(1):31-43, 2016 Jan-Feb.
[Is] ISSN:2409-4943
[Cp] País de publicação:Ukraine
[La] Idioma:eng
[Ab] Resumo:We prove the feasibility of evaluation of mitochondrial electron transport chain function in isolated mitochondria of smooth muscle cells of rats from uterus using fluorescence of NADH and FAD coenzymes. We found the inversely directed changes in FAD and NADH fluorescence intensity under normal functioning of mitochondrial electron transport chain. The targeted effect of inhibitors of complex I, III and IV changed fluorescence of adenine nucleotides. Rotenone (5 µM) induced rapid increase in NADH fluorescence due to inhibition of complex I, without changing in dynamics of FAD fluorescence increase. Antimycin A, a complex III inhibitor, in concentration of 1 µg/ml caused sharp increase in NADH fluorescence and moderate increase in FAD fluorescence in comparison to control. NaN3 (5 mM), a complex IV inhibitor, and CCCP (10 µM), a protonophore, caused decrease in NADH and FAD fluorescence. Moreover, all the inhibitors caused mitochondria swelling. NO donors, e.g. 0.1 mM sodium nitroprusside and sodium nitrite similarly to the effects of sodium azide. Energy-dependent Ca2+ accumulation in mitochondrial matrix (in presence of oxidation substrates and Mg-ATP2- complex) is associated with pronounced drop in NADH and FAD fluorescence followed by increased fluorescence of adenine nucleotides, which may be primarily due to Ca2+- dependent activation of dehydrogenases of citric acid cycle. Therefore, the fluorescent signal of FAD and NADH indicates changes in oxidation state of these nucleotides in isolated mitochondria, which may be used to assay the potential of effectors of electron transport chain.
[Mh] Termos MeSH primário: Complexo III da Cadeia de Transporte de Elétrons/metabolismo
Complexo IV da Cadeia de Transporte de Elétrons/metabolismo
Complexo I de Transporte de Elétrons/metabolismo
Flavina-Adenina Dinucleotídeo/química
Mitocôndrias/metabolismo
NAD/química
[Mh] Termos MeSH secundário: Animais
Antimicina A/farmacologia
Cálcio/metabolismo
Carbonil Cianeto m-Clorofenil Hidrazona/farmacologia
Fracionamento Celular
Transporte de Elétrons/efeitos dos fármacos
Complexo I de Transporte de Elétrons/antagonistas & inibidores
Complexo III da Cadeia de Transporte de Elétrons/antagonistas & inibidores
Complexo IV da Cadeia de Transporte de Elétrons/antagonistas & inibidores
Inibidores Enzimáticos/farmacologia
Feminino
Flavina-Adenina Dinucleotídeo/metabolismo
Mitocôndrias/efeitos dos fármacos
Miócitos de Músculo Liso/efeitos dos fármacos
Miócitos de Músculo Liso/metabolismo
Miométrio/efeitos dos fármacos
Miométrio/metabolismo
NAD/metabolismo
Nitroprussiato/farmacologia
Imagem Óptica
Ratos
Rotenona/farmacologia
Azida Sódica/farmacologia
Nitrito de Sódio/farmacologia
Desacopladores/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzyme Inhibitors); 0 (Uncoupling Agents); 03L9OT429T (Rotenone); 0U46U6E8UK (NAD); 146-14-5 (Flavin-Adenine Dinucleotide); 169D1260KM (Nitroprusside); 555-60-2 (Carbonyl Cyanide m-Chlorophenyl Hydrazone); 642-15-9 (Antimycin A); 968JJ8C9DV (Sodium Azide); EC 1.10.2.2 (Electron Transport Complex III); EC 1.6.5.3 (Electron Transport Complex I); EC 1.9.3.1 (Electron Transport Complex IV); M0KG633D4F (Sodium Nitrite); SY7Q814VUP (Calcium)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180116
[Lr] Data última revisão:
180116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171212
[St] Status:MEDLINE
[do] DOI:10.15407/ubj88.01.031


  5 / 4014 MEDLINE  
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[PMID]:27770423
[Au] Autor:Milton RD
[Ad] Endereço:Department of Chemistry, University of Utah, 315 S 1400 E, Rm 2020, Salt Lake City, UT, 84112, USA. rm7745@hotmail.co.uk.
[Ti] Título:FAD-Dependent Glucose Dehydrogenase Immobilization and Mediation Within a Naphthoquinone Redox Polymer.
[So] Source:Methods Mol Biol;1504:193-202, 2017.
[Is] ISSN:1940-6029
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Electrochemically-active polymers (redox polymers) are useful tools for simultaneous immobilization and electron transfer of enzymes at electrode surfaces, which also serve to increase the localized concentration of the biocatalyst. The properties of the employed redox couple must be compatible with the target biocatalyst from both an electrochemical (potential) and biochemical standpoint. This chapter details the synthesis of a naphthoquinone-functionalized redox polymer (NQ-LPEI) that is used to immobilize and electronically communicate with flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH), yielding an enzymatic bioanode that is able to deliver large catalytic current densities for glucose oxidation at a relatively low associated potential.
[Mh] Termos MeSH primário: Aspergillus/enzimologia
Enzimas Imobilizadas/química
Glucose 1-Desidrogenase/química
Naftoquinonas/química
Polímeros/química
[Mh] Termos MeSH secundário: Aspergillus/química
Aspergillus/metabolismo
Técnicas Biossensoriais
Técnicas Eletroquímicas
Transporte de Elétrons
Enzimas Imobilizadas/metabolismo
Flavina-Adenina Dinucleotídeo/metabolismo
Glucose/metabolismo
Glucose 1-Desidrogenase/metabolismo
Modelos Moleculares
Oxirredução
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzymes, Immobilized); 0 (Naphthoquinones); 0 (Polymers); 146-14-5 (Flavin-Adenine Dinucleotide); EC 1.1.1.47 (Glucose 1-Dehydrogenase); IY9XDZ35W2 (Glucose)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180115
[Lr] Data última revisão:
180115
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161023
[St] Status:MEDLINE


  6 / 4014 MEDLINE  
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[PMID]:29177972
[Au] Autor:Hanukoglu I
[Ad] Endereço:Laboratory of Cell Biology, Ariel University, 40700, Ariel, Israel. mbiochem@gmail.com.
[Ti] Título:Conservation of the Enzyme-Coenzyme Interfaces in FAD and NADP Binding Adrenodoxin Reductase-A Ubiquitous Enzyme.
[So] Source:J Mol Evol;85(5-6):205-218, 2017 Dec.
[Is] ISSN:1432-1432
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:FAD and NAD(P) together represent an ideal pair for coupled redox reactions in their capacity to accept two electrons and their redox potentials. Enzymes that bind both NAD(P) and FAD represent large superfamilies that fulfill essential roles in numerous metabolic pathways. Adrenodoxin reductase (AdxR) shares Rossmann fold features with some of these superfamilies but remains in a group of its own in the absence of sequence homology. This article documents the phylogenetic distribution of AdxR by examining whole genome databases for Metazoa, Plantae, Fungi, and Protista, and determines the conserved structural features of AdxR. Scanning these databases showed that most organisms have a single gene coding for an AdxR ortholog. The sequence identity between AdxR orthologs is correlated with the phylogenetic distance among metazoan species. The NADP binding site of all AdxR orthologs showed a modified Rossmann fold motif with a GxGxxA consensus instead of the classical GxGxxG at the edge of the first ßα-fold. To examine the hypothesis that enzyme-coenzyme interfaces represent the conserved regions of AdxR, the residues interfacing FAD and NADP were identified and compared with multiple-sequence alignment results. Most conserved residues were indeed found at sites that surround the interfacing residues between the enzyme and the two coenzymes. In contrast to protein-protein interaction hot-spots that may appear in isolated patches, in AdxR the conserved regions show strict preservation of the overall structure. This structure maintains the precise positioning of the two coenzymes for optimal electron transfer between NADP and FAD without electron leakage to other acceptors.
[Mh] Termos MeSH primário: Ferredoxina-NADP Redutase/química
Ferredoxina-NADP Redutase/genética
Ferredoxina-NADP Redutase/metabolismo
[Mh] Termos MeSH secundário: Sequência de Aminoácidos
Sítios de Ligação
Coenzimas/metabolismo
Sequência Conservada/genética
Transporte de Elétrons
Flavina-Adenina Dinucleotídeo/química
Flavina-Adenina Dinucleotídeo/genética
Flavina-Adenina Dinucleotídeo/metabolismo
Proteínas Mitocondriais/metabolismo
Modelos Moleculares
NADP/química
NADP/genética
NADP/metabolismo
Filogenia
Alinhamento de Sequência
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Coenzymes); 0 (Mitochondrial Proteins); 146-14-5 (Flavin-Adenine Dinucleotide); 53-59-8 (NADP); EC 1.18.1.2 (Ferredoxin-NADP Reductase)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180102
[Lr] Data última revisão:
180102
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171128
[St] Status:MEDLINE
[do] DOI:10.1007/s00239-017-9821-9


  7 / 4014 MEDLINE  
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[PMID]:28985219
[Au] Autor:Gygli G; Lucas MF; Guallar V; van Berkel WJH
[Ad] Endereço:Laboratory of Biochemistry, Wageningen University & Research, Stippeneng 4, WE Wageningen, The Netherlands.
[Ti] Título:The ins and outs of vanillyl alcohol oxidase: Identification of ligand migration paths.
[So] Source:PLoS Comput Biol;13(10):e1005787, 2017 Oct.
[Is] ISSN:1553-7358
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Vanillyl alcohol oxidase (VAO) is a homo-octameric flavoenzyme belonging to the VAO/PCMH family. Each VAO subunit consists of two domains, the FAD-binding and the cap domain. VAO catalyses, among other reactions, the two-step conversion of p-creosol (2-methoxy-4-methylphenol) to vanillin (4-hydroxy-3-methoxybenzaldehyde). To elucidate how different ligands enter and exit the secluded active site, Monte Carlo based simulations have been performed. One entry/exit path via the subunit interface and two additional exit paths have been identified for phenolic ligands, all leading to the si side of FAD. We argue that the entry/exit path is the most probable route for these ligands. A fourth path leading to the re side of FAD has been found for the co-ligands dioxygen and hydrogen peroxide. Based on binding energies and on the behaviour of ligands in these four paths, we propose a sequence of events for ligand and co-ligand migration during catalysis. We have also identified two residues, His466 and Tyr503, which could act as concierges of the active site for phenolic ligands, as well as two other residues, Tyr51 and Tyr408, which could act as a gateway to the re side of FAD for dioxygen. Most of the residues in the four paths are also present in VAO's closest relatives, eugenol oxidase and p-cresol methylhydroxylase. Key path residues show movements in our simulations that correspond well to conformations observed in crystal structures of these enzymes. Preservation of other path residues can be linked to the electron acceptor specificity and oligomerisation state of the three enzymes. This study is the first comprehensive overview of ligand and co-ligand migration in a member of the VAO/PCMH family, and provides a proof of concept for the use of an unbiased method to sample this process.
[Mh] Termos MeSH primário: Oxirredutases do Álcool/metabolismo
Flavina-Adenina Dinucleotídeo/metabolismo
Peróxido de Hidrogênio/metabolismo
Modelos Moleculares
Oxigênio/metabolismo
Fenóis/metabolismo
[Mh] Termos MeSH secundário: Oxirredutases do Álcool/química
Sequência de Aminoácidos
Proteínas de Bactérias/química
Sítios de Ligação
Cristalografia por Raios X
Flavina-Adenina Dinucleotídeo/química
Peróxido de Hidrogênio/química
Cinética
Ligantes
Oxigenases de Função Mista/química
Simulação de Acoplamento Molecular
Método de Monte Carlo
Oxigênio/química
Fenóis/química
Conformação Proteica
Subunidades Proteicas
Alinhamento de Sequência
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Ligands); 0 (Phenols); 0 (Protein Subunits); 146-14-5 (Flavin-Adenine Dinucleotide); BBX060AN9V (Hydrogen Peroxide); EC 1.- (Mixed Function Oxygenases); EC 1.1.- (Alcohol Oxidoreductases); EC 1.1.3.38 (vanillyl-alcohol oxidase); EC 1.14.15.- (eugenol hydroxylase); EC 1.17.99.1 (4-cresol dehydrogenase (hydroxylating)); S88TT14065 (Oxygen)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171007
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pcbi.1005787


  8 / 4014 MEDLINE  
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[PMID]:28887045
[Au] Autor:Garajová K; Zimmermann M; Petrencáková M; Dzurová L; Nemergut M; Skultéty L; Zoldák G; Sedlák E
[Ad] Endereço:Department of Biochemistry, Faculty of Science, P. J. Safárik University in Kosice, Moyzesova 11, 04154 Kosice, Slovakia.
[Ti] Título:The molten-globule residual structure is critical for reflavination of glucose oxidase.
[So] Source:Biophys Chem;230:74-83, 2017 Nov.
[Is] ISSN:1873-4200
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Glucose oxidase (GOX) is a homodimeric glycoprotein with tightly bound one molecule of FAD cofactor per monomer of the protein. GOX has numerous applications, but the preparation of biotechnologically interesting GOX sensors requires a removal of the native FAD cofactor. This process often leads to unwanted irreversible deflavination and, as a consequence, to the low enzyme recovery. Molecular mechanisms of reversible reflavination are poorly understood; our current knowledge is based only on empiric rules, which is clearly insufficient for further development. To develop conceptual understanding of flavin-binding competent states, we studied the effect of deflavination protocols on conformational properties of GOX. After deflavination, the apoform assembles into soluble oligomers with nearly native-like holoform secondary structure but largely destabilized tertiary structure presumambly due to the packing density defects around the vacant flavin binding site. The reflavination is cooperative but not fully efficient; after the binding the flavin cofactor, the protein directly disassembles into native homodimers while the fraction of oligomers remains irreversibly inactivated. Importantly, the effect of Hofmeister salts on the conformational properties of GOX and reflavination efficiency indicates that the native-like residual tertiary structure in the molten-globule states favorably supports the reflavination and minimizes the inactivated oligomers. We interpret our results by combining the ligand-induced changes in quaternary structure with salt-sensitive, non-equilibrated conformational selection model. In summary, our work provides the very first steps toward molecular understanding the complexity of the GOX reflavination mechanism.
[Mh] Termos MeSH primário: Flavina-Adenina Dinucleotídeo/química
Glucose Oxidase/química
[Mh] Termos MeSH secundário: Aspergillus niger/enzimologia
Biocatálise
Varredura Diferencial de Calorimetria
Dicroísmo Circular
Flavina-Adenina Dinucleotídeo/metabolismo
Glucose Oxidase/metabolismo
Isoformas de Proteínas/química
Isoformas de Proteínas/metabolismo
Multimerização Proteica
Estabilidade Proteica
Estrutura Secundária de Proteína
Estrutura Terciária de Proteína
Espectrofotometria Ultravioleta
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Protein Isoforms); 146-14-5 (Flavin-Adenine Dinucleotide); EC 1.1.3.4 (Glucose Oxidase)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171030
[Lr] Data última revisão:
171030
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170910
[St] Status:MEDLINE


  9 / 4014 MEDLINE  
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[PMID]:28847921
[Au] Autor:Jiang T; Guo X; Yan J; Zhang Y; Wang Y; Zhang M; Sheng B; Ma C; Xu P; Gao C
[Ad] Endereço:State Key Laboratory of Microbial Technology, Shandong University, Jinan, People's Republic of China.
[Ti] Título:A Bacterial Multidomain NAD-Independent d-Lactate Dehydrogenase Utilizes Flavin Adenine Dinucleotide and Fe-S Clusters as Cofactors and Quinone as an Electron Acceptor for d-Lactate Oxidization.
[So] Source:J Bacteriol;199(22), 2017 Nov 15.
[Is] ISSN:1098-5530
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Bacterial membrane-associated NAD-independent d-lactate dehydrogenase (Fe-S d-iLDH) oxidizes d-lactate into pyruvate. A sequence analysis of the enzyme reveals that it contains an Fe-S oxidoreductase domain in addition to a flavin adenine dinucleotide (FAD)-containing dehydrogenase domain, which differs from other typical d-iLDHs. Fe-S d-iLDH from KT2440 was purified as a His-tagged protein and characterized in detail. This monomeric enzyme exhibited activities with l-lactate and several d-2-hydroxyacids. Quinone was shown to be the preferred electron acceptor of the enzyme. The two domains of the enzyme were then heterologously expressed and purified separately. The Fe-S cluster-binding motifs predicted by sequence alignment were preliminarily verified by site-directed mutagenesis of the Fe-S oxidoreductase domain. The FAD-containing dehydrogenase domain retained 2-hydroxyacid-oxidizing activity, although it decreased compared to the full Fe-S d-iLDH. Compared to the intact enzyme, the FAD-containing dehydrogenase domain showed increased catalytic efficiency with cytochrome as the electron acceptor, but it completely lost the ability to use coenzyme Q Additionally, the FAD-containing dehydrogenase domain was no longer associated with the cell membrane, and it could not support the utilization of d-lactate as a carbon source. Based on the results obtained, we conclude that the Fe-S oxidoreductase domain functions as an electron transfer component to facilitate the utilization of quinone as an electron acceptor by Fe-S d-iLDH, and it helps the enzyme associate with the cell membrane. These functions make the Fe-S oxidoreductase domain crucial for the d-lactate utilization function of Fe-S d-iLDH. Lactate metabolism plays versatile roles in most domains of life. Lactate utilization processes depend on certain enzymes to oxidize lactate to pyruvate. In recent years, novel bacterial lactate-oxidizing enzymes have been continually reported, including the unique NAD-independent d-lactate dehydrogenase that contains an Fe-S oxidoreductase domain besides the typical flavin-containing domain (Fe-S d-iLDH). Although Fe-S d-iLDH is widely distributed among bacterial species, the investigation of it is insufficient. Fe-S d-iLDH from KT2440, which is the major d-lactate-oxidizing enzyme for the strain, might be a representative of this type of enzyme. A study of it will be helpful in understanding the detailed mechanisms underlying the lactate utilization processes.
[Mh] Termos MeSH primário: Flavina-Adenina Dinucleotídeo/metabolismo
Proteínas com Ferro-Enxofre/metabolismo
Lactato Desidrogenases/genética
Lactato Desidrogenases/metabolismo
Ácido Láctico/metabolismo
Quinonas/metabolismo
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Proteínas de Bactérias/metabolismo
Coenzimas
Citocromos c/metabolismo
Elétrons
Lactato Desidrogenases/isolamento & purificação
Mutagênese Sítio-Dirigida
NAD/metabolismo
Oxirredução
Pseudomonas putida/enzimologia
Ubiquinona/análogos & derivados
Ubiquinona/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Coenzymes); 0 (Iron-Sulfur Proteins); 0 (Quinones); 0U46U6E8UK (NAD); 1339-63-5 (Ubiquinone); 146-14-5 (Flavin-Adenine Dinucleotide); 33X04XA5AT (Lactic Acid); 9007-43-6 (Cytochromes c); EC 1.1.- (Lactate Dehydrogenases); EC 1.1.1.28 (D-lactate dehydrogenase); EJ27X76M46 (coenzyme Q10)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171030
[Lr] Data última revisão:
171030
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170830
[St] Status:MEDLINE


  10 / 4014 MEDLINE  
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[PMID]:28802828
[Au] Autor:Zhang M; Wang L; Zhong D
[Ad] Endereço:Department of Physics, Department of Chemistry and Biochemistry, Programs of Biophysics, Chemical Physics, and Biochemistry, The Ohio State University, Columbus, OH 43210, USA.
[Ti] Título:Photolyase: Dynamics and electron-transfer mechanisms of DNA repair.
[So] Source:Arch Biochem Biophys;632:158-174, 2017 Oct 15.
[Is] ISSN:1096-0384
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Photolyase, a flavoenzyme containing flavin adenine dinucleotide (FAD) molecule as a catalytic cofactor, repairs UV-induced DNA damage of cyclobutane pyrimidine dimer (CPD) and pyrimidine-pyrimidone (6-4) photoproduct using blue light. The FAD cofactor, conserved in the whole protein superfamily of photolyase/cryptochromes, adopts a unique folded configuration at the active site that plays a critical functional role in DNA repair. Here, we review our comprehensive characterization of the dynamics of flavin cofactor and its repair photocycles by different classes of photolyases on the most fundamental level. Using femtosecond spectroscopy and molecular biology, significant advances have recently been made to map out the entire dynamical evolution and determine actual timescales of all the catalytic processes in photolyases. The repair of CPD reveals seven electron-transfer (ET) reactions among ten elementary steps by a cyclic ET radical mechanism through bifurcating ET pathways, a direct tunneling route mediated by the intervening adenine and a two-step hopping path bridged by the intermediate adenine from the cofactor to damaged DNA, through the conserved folded flavin at the active site. The unified, bifurcated ET mechanism elucidates the molecular origin of various repair quantum yields of different photolyases from three life kingdoms. For 6-4 photoproduct repair, a similar cyclic ET mechanism operates and a new cyclic proton transfer with a conserved histidine residue at the active site of (6-4) photolyases is revealed.
[Mh] Termos MeSH primário: Dano ao DNA
Reparo do DNA
Desoxirribodipirimidina Fotoliase
Flavoproteínas
Dobramento de Proteína
Dímeros de Pirimidina
[Mh] Termos MeSH secundário: Domínio Catalítico
Desoxirribodipirimidina Fotoliase/química
Desoxirribodipirimidina Fotoliase/metabolismo
Transporte de Elétrons
Flavina-Adenina Dinucleotídeo/química
Flavina-Adenina Dinucleotídeo/metabolismo
Flavoproteínas/química
Flavoproteínas/metabolismo
Dímeros de Pirimidina/química
Dímeros de Pirimidina/metabolismo
Raios Ultravioleta
[Pt] Tipo de publicação:JOURNAL ARTICLE; REVIEW
[Nm] Nome de substância:
0 (Flavoproteins); 0 (Pyrimidine Dimers); 146-14-5 (Flavin-Adenine Dinucleotide); EC 4.1.99.3 (Deoxyribodipyrimidine Photo-Lyase)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171026
[Lr] Data última revisão:
171026
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170814
[St] Status:MEDLINE



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