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[PMID]:29231937
[Au] Autor:Ugrinic M; Zambrano A; Berger S; Mann S; Tang TD; deMello A
[Ad] Endereço:Department of Chemistry & Applied Biosciences, ETH Zurich, Vladimir Prelog Weg 1, 8093 Zurich, Switzerland. andrew.demello@chem.ethz.ch.
[Ti] Título:Microfluidic formation of proteinosomes.
[So] Source:Chem Commun (Camb);54(3):287-290, 2018 Jan 02.
[Is] ISSN:1364-548X
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Herein we describe a novel microfluidic method for the generation of proteinosome micro-droplets, based on bovine serum albumin and glucose oxidase conjugated to PNIPAAm chains. The size of such water-in-oil droplets is regulated via control of the input reagent flow rate, with generated proteinosome populations exhibiting narrower size distributions than those observed when using standard bulk methodologies. Importantly, proteinosomes transferred from an oil to an aqueous-environment remain intact, become fully hydrated and exhibit an increase in average size. Moreover, functional proteinosomes prepared via microfluidics exhibit lower K values and higher enzymatic activities than proteinosomes produced by bulk methodologies.
[Mh] Termos MeSH primário: Células Artificiais/química
Glucose Oxidase/química
Soroalbumina Bovina/química
[Mh] Termos MeSH secundário: Resinas Acrílicas/química
Animais
Bovinos
Fluoresceína-5-Isotiocianato/química
Peroxidase do Rábano Silvestre/química
Microfluídica
Tamanho da Partícula
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acrylic Resins); 25189-55-3 (poly-N-isopropylacrylamide); 27432CM55Q (Serum Albumin, Bovine); EC 1.1.3.4 (Glucose Oxidase); EC 1.11.1.- (Horseradish Peroxidase); I223NX31W9 (Fluorescein-5-isothiocyanate)
[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:171213
[St] Status:MEDLINE
[do] DOI:10.1039/c7cc08466h


  2 / 4338 MEDLINE  
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[PMID]:27775510
[Au] Autor:Lucisano JY; Routh TL; Lin JT; Gough DA
[Ti] Título:Glucose Monitoring in Individuals With Diabetes Using a Long-Term Implanted Sensor/Telemetry System and Model.
[So] Source:IEEE Trans Biomed Eng;64(9):1982-1993, 2017 09.
[Is] ISSN:1558-2531
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:OBJECTIVE: The use of a fully implanted first-generation prototype sensor/telemetry system is described for long-term monitoring of subcutaneous tissue glucose in a small cohort of people with diabetes. METHODS: Sensors are based on a membrane containing immobilized glucose oxidase and catalase coupled to oxygen electrodes and a telemetry system, integrated as an implant. The devices remained implanted for up to 180 days, with signals transmitted every 2 min to external receivers. RESULTS: The data include signal recordings from glucose clamps and spontaneous glucose excursions, matched, respectively, to reference blood glucose and finger-stick values. The sensor signals indicate dynamic tissue glucose, for which there is no independent standard, and a model describing the relationship between blood glucose and the signal is, therefore, included. The values of all model parameters have been estimated, including the permeability of adjacent tissues to glucose, and equated to conventional mass transfer parameters. As a group, the sensor calibration varied randomly at an average rate of -2.6%/week. Statistical correlation indicated strong association between the sensor signals and reference glucose values. CONCLUSION: Continuous long-term glucose monitoring in individuals with diabetes is feasible with this system. SIGNIFICANCE: All therapies for diabetes are based on glucose control, and therefore, require glucose monitoring. This fully implanted long-term sensor/telemetry system may facilitate a new era of management of the disease.
[Mh] Termos MeSH primário: Técnicas Biossensoriais/instrumentação
Glicemia/análise
Diabetes Mellitus/sangue
Monitorização Ambulatorial/instrumentação
Monitorização Ambulatorial/métodos
Próteses e Implantes
Telemetria/instrumentação
[Mh] Termos MeSH secundário: Glicemia/química
Condutometria/instrumentação
Diabetes Mellitus/diagnóstico
Fontes de Energia Elétrica
Desenho de Equipamento
Análise de Falha de Equipamento
Estudos de Viabilidade
Glucose Oxidase/química
Seres Humanos
Reprodutibilidade dos Testes
Sensibilidade e Especificidade
Integração de Sistemas
Transdutores
Tecnologia sem Fio/instrumentação
[Pt] Tipo de publicação:EVALUATION STUDIES; JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Blood Glucose); EC 1.1.3.4 (Glucose Oxidase)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:180226
[Lr] Data última revisão:
180226
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161025
[St] Status:MEDLINE
[do] DOI:10.1109/TBME.2016.2619333


  3 / 4338 MEDLINE  
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[PMID]:28467664
[Au] Autor:Gamella M; Privman M; Bakshi S; Melman A; Katz E
[Ad] Endereço:Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, NY, 13699-5810, USA.
[Ti] Título:DNA Release from Fe -Cross-Linked Alginate Films Triggered by Logically Processed Biomolecular Signals: Integration of Biomolecular Computing and Actuation.
[So] Source:Chemphyschem;18(13):1811-1821, 2017 Jul 05.
[Is] ISSN:1439-7641
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Signal-controlled release of DNA from Fe -cross-linked alginate hydrogel electrochemically deposited on an electrode surface was studied. The multiple input signals were logically processed with the help of the enzyme-biocatalyzed reactions. Boolean logic gates, OR, AND, INH, were realized with the biocatalytic reactions performed by the enzymes entrapped in the alginate film. Hydrogen peroxide produced by the enzymatic reactions resulted in the degradation of the alginate hydrogel and DNA release. The alginate degradation was facilitated by the formation of free radicals in the Fenton-type reaction catalyzed by iron cations cross-linking the alginate hydrogel. The studied approach is versatile and can be adapted to various chemical signals processed by various enzymes with differently implemented Boolean logic. This work illustrates a novel concept of functional integration of biomolecular computing and actuation.
[Mh] Termos MeSH primário: Alginatos/química
Computadores Moleculares
Reagentes para Ligações Cruzadas/química
DNA/metabolismo
Compostos Férricos/química
Lógica
[Mh] Termos MeSH secundário: Animais
Biocatálise
DNA/química
Esterases/química
Esterases/metabolismo
Glucose Oxidase/química
Glucose Oxidase/metabolismo
Ácido Glucurônico/química
Ácidos Hexurônicos/química
Peroxidase do Rábano Silvestre/química
Peroxidase do Rábano Silvestre/metabolismo
Lactato Desidrogenases/química
Lactato Desidrogenases/metabolismo
Oxigenases de Função Mista/química
Oxigenases de Função Mista/metabolismo
Nanopartículas/química
Nanopartículas/metabolismo
Dióxido de Silício/química
Dióxido de Silício/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Alginates); 0 (Cross-Linking Reagents); 0 (Ferric Compounds); 0 (Hexuronic Acids); 7631-86-9 (Silicon Dioxide); 8A5D83Q4RW (Glucuronic Acid); 8C3Z4148WZ (alginic acid); 9007-49-2 (DNA); EC 1.- (Mixed Function Oxygenases); EC 1.1.- (Lactate Dehydrogenases); EC 1.1.3.4 (Glucose Oxidase); EC 1.11.1.- (Horseradish Peroxidase); EC 1.13.12.4 (lactate 2-monooxygenase); EC 3.1.- (Esterases)
[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:170504
[St] Status:MEDLINE
[do] DOI:10.1002/cphc.201700301


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[PMID]:28745425
[Au] Autor:Filipov Y; Domanskyi S; Wood ML; Gamella M; Privman V; Katz E
[Ad] Endereço:Department of Chemistry and Biomolecular Science, Clarkson University, Potsdam, NY, 13699, USA.
[Ti] Título:Experimental Realization of a High-Quality Biochemical XOR Gate.
[So] Source:Chemphyschem;18(20):2908-2915, 2017 Oct 19.
[Is] ISSN:1439-7641
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:We report an experimental realization of a biochemical XOR gate function that avoids many of the pitfalls of earlier realizations based on biocatalytic cascades. Inputs-represented by pairs of chemicals-cross-react to largely cancel out when both are nearly equal. The cross-reaction can be designed to also optimize gate functioning for noise handling. When not equal, the residual inputs are further processed to result in the output of the XOR type, by biocatalytic steps that allow for further gate-function optimization. The quality of the realized XOR gate is theoretically analyzed.
[Mh] Termos MeSH primário: Álcool Desidrogenase/metabolismo
Oxirredutases do Álcool/metabolismo
Biocatálise
Glucose Oxidase/metabolismo
Hexoquinase/metabolismo
NAD/metabolismo
Peroxidase/metabolismo
[Mh] Termos MeSH secundário: Armoracia/enzimologia
Aspergillus niger/enzimologia
Modelos Moleculares
Pichia/enzimologia
Saccharomyces cerevisiae/enzimologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0U46U6E8UK (NAD); EC 1.1.- (Alcohol Oxidoreductases); EC 1.1.1.1 (Alcohol Dehydrogenase); EC 1.1.3.13 (alcohol oxidase); EC 1.1.3.4 (Glucose Oxidase); EC 1.11.1.7 (Peroxidase); EC 2.7.1.1 (Hexokinase)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180215
[Lr] Data última revisão:
180215
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170727
[St] Status:MEDLINE
[do] DOI:10.1002/cphc.201700705


  5 / 4338 MEDLINE  
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[PMID]:28745633
[Au] Autor:De Porcellinis A; Frigaard NU; Sakuragi Y
[Ad] Endereço:Carlsberg Research Laboratory.
[Ti] Título:Determination of the Glycogen Content in Cyanobacteria.
[So] Source:J Vis Exp;(125), 2017 Jul 17.
[Is] ISSN:1940-087X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Cyanobacteria accumulate glycogen as a major intracellular carbon and energy storage during photosynthesis. Recent developments in research have highlighted complex mechanisms of glycogen metabolism, including the diel cycle of biosynthesis and catabolism, redox regulation, and the involvement of non-coding RNA. At the same time, efforts are being made to redirect carbon from glycogen to desirable products in genetically engineered cyanobacteria to enhance product yields. Several methods are used to determine the glycogen contents in cyanobacteria, with variable accuracies and technical complexities. Here, we provide a detailed protocol for the reliable determination of the glycogen content in cyanobacteria that can be performed in a standard life science laboratory. The protocol entails the selective precipitation of glycogen from the cell lysate and the enzymatic depolymerization of glycogen to generate glucose monomers, which are detected by a glucose oxidase-peroxidase (GOD-POD) enzyme coupled assay. The method has been applied to Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 7002, two model cyanobacterial species that are widely used in metabolic engineering. Moreover, the method successfully showed differences in the glycogen contents between the wildtype and mutants defective in regulatory elements or glycogen biosynthetic genes.
[Mh] Termos MeSH primário: Ensaios Enzimáticos/métodos
Glicogênio/metabolismo
Synechocystis/metabolismo
[Mh] Termos MeSH secundário: Glucose/análise
Glucose/metabolismo
Glucose Oxidase/metabolismo
Manitol/metabolismo
Peroxidase/metabolismo
Synechocystis/genética
Gravação em Vídeo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
3OWL53L36A (Mannitol); 9005-79-2 (Glycogen); EC 1.1.3.4 (Glucose Oxidase); EC 1.11.1.7 (Peroxidase); IY9XDZ35W2 (Glucose)
[Em] Mês de entrada:1801
[Cu] Atualização por classe:180130
[Lr] Data última revisão:
180130
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170727
[St] Status:MEDLINE
[do] DOI:10.3791/56068


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[PMID]:27770422
[Au] Autor:Hickey DP
[Ad] Endereço:Department of Chemistry, University of Utah, 315 S 1400 E, Salt Lake City, UT, 84112, USA. dhickeychem@gmail.com.
[Ti] Título:Ferrocene-Modified Linear Poly(ethylenimine) for Enzymatic Immobilization and Electron Mediation.
[So] Source:Methods Mol Biol;1504:181-191, 2017.
[Is] ISSN:1940-6029
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Enzymatic glucose biosensors and biofuel cells make use of the electrochemical transduction between an oxidoreductase enzyme, such as glucose oxidase (GOx), and an electrode to either quantify the amount of glucose in a solution or generate electrical energy. However, many enzymes including GOx are not able to electrochemically interact with an electrode surface directly, but require an external electrochemical relay to shuttle electrons to the electrode. Ferrocene-modified linear poly(ethylenimine) (Fc-LPEI) redox polymers have been designed to simultaneously immobilize glucose oxidase (GOx) at an electrode and mediate electron transfer from their flavin adenine dinucleotide (FAD) active site to the electrode surface. Cross-linked films of Fc-LPEI create hydrogel networks that allow for rapid transport of glucose, while the covalently bound ferrocene moieties are able to facilitate rapid electron transfer due to the ability of ferrocene to exchange electrons between adjacent ferrocene residues. For these reasons, Fc-LPEI films have been widely used in the development of high current density bioanode materials. This chapter describes the synthesis of a commonly used dimethylferrocene-modified linear poly(ethylenimine), as well as the subsequent preparation and electrochemical characterization of a GOx bioanode film utilizing the synthesized polymer.
[Mh] Termos MeSH primário: Aspergillus niger/enzimologia
Técnicas Biossensoriais/métodos
Enzimas Imobilizadas/química
Compostos Ferrosos/química
Glucose Oxidase/química
Glucose/análise
Metalocenos/química
Polietilenoimina/análogos & derivados
[Mh] Termos MeSH secundário: Aspergillus niger/química
Aspergillus niger/metabolismo
Eletrodos
Transporte de Elétrons
Elétrons
Enzimas Imobilizadas/metabolismo
Glucose/metabolismo
Glucose Oxidase/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzymes, Immobilized); 0 (Ferrous Compounds); 0 (Metallocenes); 9002-98-6 (Polyethyleneimine); EC 1.1.3.4 (Glucose Oxidase); IY9XDZ35W2 (Glucose); U96PKG90JQ (ferrocene)
[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


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[PMID]:27770424
[Au] Autor:Suroviec AH
[Ad] Endereço:Department of Chemistry and Biochemistry, Berry College, 2277 Martha Berry Highway, Mt. Berry, GA, 30149-4005, USA. asuroviec@berry.edu.
[Ti] Título:Layer-by-Layer Assembly of Glucose Oxidase on Carbon Nanotube Modified Electrodes.
[So] Source:Methods Mol Biol;1504:203-213, 2017.
[Is] ISSN:1940-6029
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The use of enzymatically modified electrodes for the detection of glucose or other non-electrochemically active analytes is becoming increasingly common. Direct heterogeneous electron transfer to glucose oxidase has been shown to be kinetically difficult, which is why electron transfer mediators or indirect detection is usually used for monitoring glucose with electrochemical sensors. It has been found, however, that electrodes modified with single or multi-walled carbon nanotubes (CNTs) demonstrate fast heterogeneous electron transfer kinetics as compared to that found for traditional electrodes. Incorporating CNTs into the assembly of electrochemical glucose sensors, therefore, affords the possibility of facile electron transfer to glucose oxidase, and a more direct determination of glucose. This chapter describes the methods used to use CNTs in a layer-by-layer structure along with glucose oxidase to produce an enzymatically modified electrode with high turnover rates, increased stability and shelf-life.
[Mh] Termos MeSH primário: Aspergillus niger/enzimologia
Enzimas Imobilizadas/química
Glucose Oxidase/química
Nanotubos de Carbono/química
[Mh] Termos MeSH secundário: Aspergillus niger/química
Aspergillus niger/metabolismo
Técnicas Biossensoriais/métodos
Técnicas Eletroquímicas/métodos
Eletrodos
Transporte de Elétrons
Enzimas Imobilizadas/metabolismo
Glucose/análise
Glucose/metabolismo
Glucose Oxidase/metabolismo
Modelos Moleculares
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzymes, Immobilized); 0 (Nanotubes, Carbon); EC 1.1.3.4 (Glucose Oxidase); 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


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[PMID]:27770421
[Au] Autor:VandeZande GR; Olvany JM; Rutherford JL; Rasmussen M
[Ad] Endereço:Chemistry Department, Lebanon Valley College, 101 N College Avenue, Annville, PA, 17003-1400, USA.
[Ti] Título:Enzyme Immobilization and Mediation with Osmium Redox Polymers.
[So] Source:Methods Mol Biol;1504:165-179, 2017.
[Is] ISSN:1940-6029
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Enzymatic electrodes are becoming increasingly common for energy production and sensing applications. Research over the past several decades has addressed a major issue that can occur when using these biocatalysts, i.e., slow heterogeneous electron transfer, by incorporation of a redox active species to act as an electron shuttle. There are several advantages to immobilizing both the enzyme and mediator at the enzyme surface, including increased electron transfer rates, decreased enzyme leaching, and minimized diffusion limitations. Redox polymers consisting of a redox active center attached to a polymer backbone are a particularly attractive option because they have high self-exchange rates for electron transfer and tunable redox potential. Osmium (Os) polymers are the most well studied of this type of polymer for bioelectrocatalysis. Here, we describe the methods to synthesize one of the most common Os redox polymers and how it can be used to fabricate glucose oxidase electrodes. Procedures are also outlined for evaluating the enzymatic electrodes.
[Mh] Termos MeSH primário: 2,2´-Dipiridil/análogos & derivados
Aspergillus niger/enzimologia
Enzimas Imobilizadas/química
Glucose Oxidase/química
Osmio/química
Polímeros/química
[Mh] Termos MeSH secundário: Aspergillus niger/química
Aspergillus niger/metabolismo
Técnicas Biossensoriais/métodos
Técnicas Eletroquímicas/métodos
Eletrodos
Transporte de Elétrons
Enzimas Imobilizadas/metabolismo
Glucose/análise
Glucose/metabolismo
Glucose Oxidase/metabolismo
Imidazóis/química
Modelos Moleculares
Oxirredução
Polivinil/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzymes, Immobilized); 0 (Imidazoles); 0 (Polymers); 0 (Polyvinyls); 0 (poly(1-vinylimidazole)); 2E7M255OPY (Osmium); 551W113ZEP (2,2'-Dipyridyl); EC 1.1.3.4 (Glucose Oxidase); 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


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[PMID]:27770413
[Au] Autor:Stine KJ; Jefferson K; Shulga OV
[Ad] Endereço:Department of Chemistry and Biochemistry, Center for Nanoscience, University of Missouri-Saint Louis, One University Boulevard, Saint Louis, MO, 63121-4400, USA. kstine@umsl.edu.
[Ti] Título:Nanoporous Gold for Enzyme Immobilization.
[So] Source:Methods Mol Biol;1504:37-60, 2017.
[Is] ISSN:1940-6029
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Nanoporous gold (NPG) is a material of emerging interest for immobilization of biomolecules, especially enzymes. The material provides a high surface area form of gold that is suitable for physisorption or for covalent modification by self-assembled monolayers. The material can be used as a high surface area electrode and with immobilized enzymes can be used for amperometric detection schemes. NPG can be prepared in a variety of formats from alloys containing between 20 and 50 % atomic composition of gold and less noble element(s) by dealloying procedures. Materials resembling NPG can be prepared by hydrothermal and electrodeposition methods. Related high surface area gold structures have been prepared using templating approaches. Covalent enzyme immobilization can be achieved by first forming a self-assembled monolayer on NPG bearing a terminal reactive functional group followed by conjugation to the enzyme through amide linkages to lysine residues. Enzymes can also be entrapped by physisorption or immobilized by electrostatic interactions.
[Mh] Termos MeSH primário: Enzimas Imobilizadas/química
Ouro/química
Nanoporos/ultraestrutura
[Mh] Termos MeSH secundário: Acetilcolinesterase/química
Animais
Técnicas Biossensoriais
Técnicas Eletroquímicas
Eletrodos
Estabilidade Enzimática
Glucose Oxidase/química
Peroxidase do Rábano Silvestre/química
Seres Humanos
Imunoconjugados/química
Lacase/química
Complexo de Proteína do Fotossistema I/química
Porosidade
Spinacia oleracea/enzimologia
Eletricidade Estática
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzymes, Immobilized); 0 (Immunoconjugates); 0 (Photosystem I Protein Complex); 7440-57-5 (Gold); EC 1.1.3.4 (Glucose Oxidase); EC 1.10.3.2 (Laccase); EC 1.11.1.- (Horseradish Peroxidase); EC 3.1.1.7 (Acetylcholinesterase)
[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


  10 / 4338 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



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