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Pesquisa : D08.811.913.400.450 [Categoria DeCS]
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[PMID]:28776993
[Au] Autor:Yu S; Zhang Y; Zhu Y; Zhang T; Jiang B; Mu W
[Ad] Endereço:State Key Laboratory of Food Science and Technology, Jiangnan University , Wuxi, Jiangsu 214122, China.
[Ti] Título:Improving the Catalytic Behavior of DFA I-Forming Inulin Fructotransferase from Streptomyces davawensis with Site-Directed Mutagenesis.
[So] Source:J Agric Food Chem;65(34):7579-7587, 2017 Aug 30.
[Is] ISSN:1520-5118
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Previously, a α-d-fructofuranose-ß-d-fructofuranose 1,2':2,1'-dianhydride (DFA I)-forming inulin fructotransferase (IFTase), namely, SdIFTase, was identified. The enzyme does not show high performances. In this work, to improve catalytic behavior including activity and thermostability, the enzyme was modified using site-directed mutagenesis on the basis of structure. The mutated residues were divided into three groups. Those in group I are located at central tunnel including G236, A257, G281, T313, and A314S. The group II contains residues at the inner edge of substrate binding pocket including I80, while group III at the outer edge includes G121 and T122. The thermostability was reflected by the melting temperature (T ) determined by Nano DSC. Finally, the T values of G236S/G281S/A257S/T313S/A314S in group I and G121A/T122L in group III were enhanced by 3.2 and 4.5 °C, and the relative activities were enhanced to 140.5% and 148.7%, respectively. The method in this work may be applicable to other DFA I-forming IFTases.
[Mh] Termos MeSH primário: Proteínas de Bactérias/química
Proteínas de Bactérias/metabolismo
Dissacarídeos/metabolismo
Hexosiltransferases/química
Hexosiltransferases/metabolismo
Inulina/metabolismo
Streptomyces/enzimologia
[Mh] Termos MeSH secundário: Proteínas de Bactérias/genética
Catálise
Clonagem Molecular
Estabilidade Enzimática
Hexosiltransferases/genética
Mutagênese Sítio-Dirigida
Streptomyces/química
Streptomyces/genética
Temperatura Ambiente
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Disaccharides); 9005-80-5 (Inulin); EC 2.4.1.- (Hexosyltransferases); EC 2.4.1.9 (inulosucrase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170915
[Lr] Data última revisão:
170915
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170805
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jafc.7b02897


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[PMID]:28728943
[Au] Autor:Chaudhary B; Mazumder S; Mohanty S
[Ad] Endereço:Department of Chemistry, Oklahoma State University, Stillwater, OK 74078, USA.
[Ti] Título:Production and biophysical characterization of a mini-membrane protein, Ost4V23D: A functionally important mutant of yeast oligosaccharyltransferase subunit Ost4p.
[So] Source:Protein Expr Purif;139:43-48, 2017 Nov.
[Is] ISSN:1096-0279
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:N-linked glycosylation of proteins is an essential and highly conserved co- and post-translational protein modification reaction that occurs in all eukaryotes. Oligosaccharyltransferase (OST), a multi-subunit membrane-associated enzyme complex, carries out this reaction. In the central reaction, a carbohydrate group is transferred to the side chain of a consensus asparagine residue in the newly synthesized protein. Genetic defects in humans cause a series of disorders known as congenital disorders of glycosylation (CDG) that include mental retardation, developmental delay, hypoglycemia etc. Complete loss of N-glycosylation is lethal in all organisms. In Saccharomyces cerevisiae, OST consists of nine non-identical protein subunits. Ost4p is the smallest subunit containing 36 residues. It bridges catalytic subunit Stt3p to Ost3p/Ost6p subunit. Mutation of Valine (V) at position 23 in Ost4p to Aspartate (D) causes defects in the N-glycosylation process. To understand the structure, function and role of Ost4p in N-glycosylation, characterization of Ost4p and its functionally important mutant/s are critical. We report the mutagenesis, heterologous overexpression, purification, reconstitution in DPC micelles and biophysical characterization of Ost4V23D and compare its secondary structure and conformation to that of Ost4p. CD and NMR data suggest that mutation of Val to Asp impacts the secondary structure and conformation of Ost4p.
[Mh] Termos MeSH primário: Hexosiltransferases/química
Hexosiltransferases/metabolismo
Proteínas de Membrana/química
Proteínas de Membrana/metabolismo
[Mh] Termos MeSH secundário: Dicroísmo Circular
Escherichia coli/genética
Glicosilação
Hexosiltransferases/genética
Proteínas de Membrana/genética
Ressonância Magnética Nuclear Biomolecular
Proteínas Recombinantes/química
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Membrane Proteins); 0 (Recombinant Proteins); EC 2.4.1.- (Hexosyltransferases); EC 2.4.99.18 (dolichyl-diphosphooligosaccharide - protein glycotransferase)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170920
[Lr] Data última revisão:
170920
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170722
[St] Status:MEDLINE


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[PMID]:28639160
[Au] Autor:Guan L; Chen L; Chen Y; Zhang N; Han Y
[Ad] Endereço:College of Food and Bioengineering, Zhengzhou University of Light Industry, Number 5, Dongfeng Road, Zhengzhou, 450002, China.
[Ti] Título:Expression and Activity Analysis of Fructosyltransferase from Aspergillus oryzae.
[So] Source:Protein J;36(4):352-360, 2017 Aug.
[Is] ISSN:1875-8355
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:The fructosyltransferase gene was isolated and cloned from Aspergillus oryzae. The gene was 1368 bp, which encoded a protein of 455 amino acids. To analyze the activity of the expressed fructosyltransferase, the pET32a-fructosyltransferase recombined plasmid was transformed into Escherichia coli BL21. The fructosyltransferase gene was successfully expressed by Isopropyl-ß-d-thiogalactoside (IPTG) induction. The molecular weight of the expression protein was about 45 kDa. The optimal conditions of protein expression were 25 °C, 0.1 mM IPTG, and 8 h of inducing time. The optimal concentration of urea dealing with inclusion body was 2.5 M. The expressed protein exhibited a strong fructosyl transfer activity. These results showed that the expressed fructosyltransferas owned transferase activity, and could catalyze the synthesis of sucrose-6-acetate.
[Mh] Termos MeSH primário: Aspergillus oryzae/química
Proteínas Fúngicas/genética
Hexosiltransferases/genética
Plasmídeos/metabolismo
Sacarose/análogos & derivados
[Mh] Termos MeSH secundário: Aspergillus oryzae/enzimologia
Sequência de Bases
Clonagem Molecular
Escherichia coli/genética
Escherichia coli/metabolismo
Proteínas Fúngicas/metabolismo
Expressão Gênica
Hexosiltransferases/metabolismo
Corpos de Inclusão/química
Corpos de Inclusão/efeitos dos fármacos
Peso Molecular
Fases de Leitura Aberta
Plasmídeos/química
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
Alinhamento de Sequência
Sacarose/metabolismo
Transformação Bacteriana
Ureia/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Fungal Proteins); 0 (Recombinant Proteins); 0 (sucrose-6-acetate); 57-50-1 (Sucrose); 8W8T17847W (Urea); EC 2.4.1.- (Hexosyltransferases); EC 2.4.1.9 (inulosucrase)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170728
[Lr] Data última revisão:
170728
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170623
[St] Status:MEDLINE
[do] DOI:10.1007/s10930-017-9725-y


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[PMID]:28512128
[Au] Autor:Lara P; Öjemalm K; Reithinger J; Holgado A; Maojun Y; Hammed A; Mattle D; Kim H; Nilsson I
[Ad] Endereço:From the Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden and.
[Ti] Título:Refined topology model of the STT3/Stt3 protein subunit of the oligosaccharyltransferase complex.
[So] Source:J Biol Chem;292(27):11349-11360, 2017 Jul 07.
[Is] ISSN:1083-351X
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The oligosaccharyltransferase complex, localized in the endoplasmic reticulum (ER) of eukaryotic cells, is responsible for the -linked glycosylation of numerous protein substrates. The membrane protein STT3 is a highly conserved part of the oligosaccharyltransferase and likely contains the active site of the complex. However, understanding the catalytic determinants of this system has been challenging, in part because of a discrepancy in the structural topology of the bacterial eukaryotic proteins and incomplete information about the mechanism of membrane integration. Here, we use a glycosylation mapping approach to investigate these questions. We measured the membrane integration efficiency of the mouse STT3-A and yeast Stt3p transmembrane domains (TMDs) and report a refined topology of the N-terminal half of the mouse STT3-A. Our results show that most of the STT3 TMDs are well inserted into the ER membrane on their own or in the presence of the natural flanking residues. However, for the mouse STT3-A hydrophobic domains 4 and 6 and yeast Stt3p domains 2, 3a, 3c, and 6 we measured reduced insertion efficiency into the ER membrane. Furthermore, we mapped the first half of the STT3-A protein, finding two extra hydrophobic domains between the third and the fourth TMD. This result indicates that the eukaryotic STT3 has 13 transmembrane domains, consistent with the structure of the bacterial homolog of STT3 and setting the stage for future combined efforts to interrogate this fascinating system.
[Mh] Termos MeSH primário: Retículo Endoplasmático
Hexosiltransferases
Membranas Intracelulares
Proteínas de Membrana
Modelos Moleculares
Proteínas de Saccharomyces cerevisiae
Saccharomyces cerevisiae
[Mh] Termos MeSH secundário: Animais
Retículo Endoplasmático/química
Retículo Endoplasmático/genética
Retículo Endoplasmático/metabolismo
Hexosiltransferases/química
Hexosiltransferases/genética
Hexosiltransferases/metabolismo
Membranas Intracelulares/química
Membranas Intracelulares/metabolismo
Proteínas de Membrana/química
Proteínas de Membrana/genética
Proteínas de Membrana/metabolismo
Camundongos
Domínios Proteicos
Estrutura Quaternária de Proteína
Saccharomyces cerevisiae/química
Saccharomyces cerevisiae/genética
Saccharomyces cerevisiae/metabolismo
Proteínas de Saccharomyces cerevisiae/química
Proteínas de Saccharomyces cerevisiae/genética
Proteínas de Saccharomyces cerevisiae/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Membrane Proteins); 0 (STT3-A protein, mouse); 0 (Saccharomyces cerevisiae Proteins); EC 2.4.1.- (Hexosyltransferases); EC 2.4.99.18 (STT3 protein, S cerevisiae)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170714
[Lr] Data última revisão:
170714
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170518
[St] Status:MEDLINE
[do] DOI:10.1074/jbc.M117.779421


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[PMID]:28424003
[Au] Autor:Ghosh A; Urquhart J; Daly S; Ferguson A; Scotcher D; Morris AAM; Clayton-Smith J
[Ad] Endereço:1 Willink Biochemical Genetics Unit, Manchester Centre for Genomic Medicine, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
[Ti] Título:Phenotypic Heterogeneity in a Congenital Disorder of Glycosylation Caused by Mutations in STT3A.
[So] Source:J Child Neurol;32(6):560-565, 2017 May.
[Is] ISSN:1708-8283
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:STT3A encodes the catalytic subunit of the oligosaccharyltransferase complex. A congenital disorder of glycosylation caused by mutations in STT3A has only been reported in one family to date, associated with a Type I congenital disorder of glycosylation pattern of transferrin glycoforms. The authors describe a further 5 related individuals with a likely pathogenic variant in STT3A, 2 of whom also had variants in TUSC3. Common phenotypic features in all symptomatic individuals include developmental delay, intellectual disability, with absent speech and seizures. Two individuals also developed episodic hypothermia and altered consciousness. The family were investigated by autozygosity mapping, which revealed both a homozygous region containing STT3A and, in addition, a homozygous deletion of TUSC3 in one child. A likely pathogenic variant in STT3A was confirmed on Sanger sequencing of all affected individuals: the authors discuss the molecular findings in detail and further delineate the clinical phenotype of this rare disorder.
[Mh] Termos MeSH primário: Defeitos Congênitos da Glicosilação/genética
Hexosiltransferases/genética
Proteínas de Membrana/genética
Polimorfismo de Nucleotídeo Único/genética
[Mh] Termos MeSH secundário: Adolescente
Adulto
Criança
Defeitos Congênitos da Glicosilação/diagnóstico por imagem
Eletroencefalografia
Saúde da Família
Feminino
Homozigoto
Seres Humanos
Imagem por Ressonância Magnética
Masculino
Adulto Jovem
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Membrane Proteins); EC 2.4.1.- (Hexosyltransferases); EC 2.4.99.18 (STT3A protein, human)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170714
[Lr] Data última revisão:
170714
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170421
[St] Status:MEDLINE
[do] DOI:10.1177/0883073817696816


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[PMID]:28334793
[Au] Autor:Johnstone DL; Nguyen TT; Murakami Y; Kernohan KD; Tétreault M; Goldsmith C; Doja A; Wagner JD; Huang L; Hartley T; St-Denis A; le Deist F; Majewski J; Bulman DE; Kinoshita T; Dyment DA; Boycott KM; Campeau PM; Care4Rare Canada Consortium
[Ad] Endereço:Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, Ontario K1H8L1, Canada.
[Ti] Título:Compound heterozygous mutations in the gene PIGP are associated with early infantile epileptic encephalopathy.
[So] Source:Hum Mol Genet;26(9):1706-1715, 2017 May 01.
[Is] ISSN:1460-2083
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:There are over 150 known human proteins which are tethered to the cell surface via glycosylphosphatidylinositol (GPI) anchors. These proteins play a variety of important roles in development, and particularly in neurogenesis. Not surprisingly, mutations in the GPI anchor biosynthesis and remodeling pathway cause a number of developmental disorders. This group of conditions has been termed inherited GPI deficiencies (IGDs), a subgroup of congenital disorders of glycosylation; they present with variable phenotypes, often including seizures, hypotonia and intellectual disability. Here, we report two siblings with compound heterozygous variants in the gene phosphatidylinositol glycan anchor biosynthesis, class P (PIGP) (NM_153681.2: c.74T > C;p.Met25Thr and c.456delA;p.Glu153AsnFs*34). PIGP encodes a subunit of the enzyme that catalyzes the first step of GPI anchor biosynthesis. Both children presented with early-onset refractory seizures, hypotonia, and profound global developmental delay, reminiscent of other IGD phenotypes. Functional studies with patient cells showed reduced PIGP mRNA levels, and an associated reduction of GPI-anchored cell surface proteins, which was rescued by exogenous expression of wild-type PIGP. This work associates mutations in the PIGP gene with a novel autosomal recessive IGD, and expands our knowledge of the role of PIG genes in human development.
[Mh] Termos MeSH primário: Hexosiltransferases/genética
Proteínas de Membrana/genética
Espasmos Infantis/genética
[Mh] Termos MeSH secundário: Anormalidades Múltiplas/genética
Adulto
Linhagem Celular
Criança
Deficiências do Desenvolvimento/genética
Glicosilfosfatidilinositóis/deficiência
Glicosilfosfatidilinositóis/genética
Glicosilfosfatidilinositóis/metabolismo
Hemoglobinúria Paroxística/genética
Hexosiltransferases/metabolismo
Seres Humanos
Deficiência Intelectual/genética
Proteínas de Membrana/metabolismo
Hipotonia Muscular/genética
Mutação
Linhagem
Convulsões/genética
Espasmos Infantis/metabolismo
[Pt] Tipo de publicação:CASE REPORTS; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Glycosylphosphatidylinositols); 0 (Membrane Proteins); EC 2.4.1.- (Hexosyltransferases); EC 2.4.1.198 (PIGP protein, human)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171017
[Lr] Data última revisão:
171017
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170324
[St] Status:MEDLINE
[do] DOI:10.1093/hmg/ddx077


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[PMID]:28274423
[Au] Autor:Miranda-Molina A; Castillo E; Lopez Munguia A
[Ad] Endereço:Departamento Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Col. Chamilpa, C.P. 62209 Cuernavaca-Mor., Mexico.
[Ti] Título:A novel two-step enzymatic synthesis of blastose, a ß-d-fructofuranosyl-(2↔6)-d-glucopyranose sucrose analogue.
[So] Source:Food Chem;227:202-210, 2017 Jul 15.
[Is] ISSN:0308-8146
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Blastose, a natural disaccharide found in honey, is usually found as a byproduct of fructo-oligosaccharide synthesis from sucrose with fructosyltransferases. In this study, we describe a novel two-step biosynthetic route to obtain blastose, designed from a detailed observation of B. subtilis levansucrase (SacB) acceptor structural requirements for fructosylation. The strategy consisted first in the synthesis of the trisaccharide O-ß-d-Fruf-(2↔6)-O-α-d-Glcp-(1↔1)-α-d-Glcp, through a regioselective ß-d-transfructosylation of trehalose (Tre) which acts as acceptor in a reaction catalyzed by SacB using sucrose or levan as fructosyl donor. In this reaction, levansucrase (LS) transfers regioselectively a fructosyl residue to either C -OH group of the glucose residues in Tre. The resulting trisaccharide obtained in 23% molar yield based on trehalose, was purified and fully characterized by extensive NMR studies. In the second step, the trisaccharide is specifically hydrolyzed by trehalase, to obtain blastose in 43.2% molar yield based on the trisaccharide. This is the first report describing the formation of blastose through a sequential transfuctosylation-hydrolysis reaction.
[Mh] Termos MeSH primário: Dissacaridases/metabolismo
Hexosiltransferases/metabolismo
Trealose/metabolismo
Trissacarídeos/metabolismo
[Mh] Termos MeSH secundário: Bacillus subtilis/enzimologia
Proteínas de Bactérias/metabolismo
Frutanos/metabolismo
Hidrólise
Sacarose/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Fructans); 0 (Trisaccharides); 0 (blastose); 57-50-1 (Sucrose); 9013-95-0 (levan); B8WCK70T7I (Trehalose); EC 2.4.1.- (Hexosyltransferases); EC 2.4.1.10 (levansucrase); EC 3.2.1.- (Disaccharidases)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170519
[Lr] Data última revisão:
170519
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170310
[St] Status:MEDLINE


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[PMID]:28271385
[Au] Autor:Hamdy AA; Elattal NA; Amin MA; Ali AE; Mansour NM; Awad GE; Awad HM; Esawy MA
[Ad] Endereço:Pharmaceutical Industries Division, Chemistry of Natural and Microbial Products Department, National Research Centre, 33 El Bohouth St. (Former El Tahrir St.), Dokki, P.O. Box 12622, Giza, Egypt.
[Ti] Título:Possible correlation between levansucrase production and probiotic activity of Bacillus sp. isolated from honey and honey bee.
[So] Source:World J Microbiol Biotechnol;33(4):69, 2017 Apr.
[Is] ISSN:1573-0972
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Five bacterial isolates from honey and bee gut were selected based on their high levansucrase activity and levan yield which were strongly positively correlated. All isolates showed good tolerance to temperature up to 70 °C, to NaCl up to 3 M and to 0.1% H O . They maintained over 59 and 64% survival at pH 9.0 and 2.0 respectively, but showed varying tolerance to 0.1% bile salts and pancreatic enzymes. Most isolates were susceptible to widely used antibiotics, but demonstrated diverse antimicrobial activity. Non hemolytic isolates were identified on the basis of 16S rRNA sequencing as Bacillus subtilis HMNig-2 and B. subtilis MENO2 with 97% homology. They exhibited promising probiotic characteristics and achieved highest levansucrase activity of 94.1 and 81.5 U/mL respectively. Both exhibited highest biofilm formation ability in static microtiter plate assay. Also, they achieved 34 and 26% adhesion respectively to Caco-2cells and had highest free radical scavenging activity of 30.8 and 26.2% respectively. The levans of the two isolates showed good antimicrobial activity against some pathogens and exhibited positive prebiotic effect (prebiotic index >1) with Lactobacillus casei and Lactobacillus reuteri. Results suggest a correlation between levansucrase production, levan yield and pre-probiotic activities of the studied strains.
[Mh] Termos MeSH primário: Bacillus/isolamento & purificação
Abelhas/microbiologia
Hexosiltransferases/metabolismo
Mel/microbiologia
[Mh] Termos MeSH secundário: Animais
Antibacterianos/farmacologia
Bacillus/efeitos dos fármacos
Bacillus/enzimologia
Bacillus/fisiologia
Aderência Bacteriana
Proteínas de Bactérias/metabolismo
Células CACO-2
Seres Humanos
Concentração de Íons de Hidrogênio
Testes de Sensibilidade Microbiana
Viabilidade Microbiana
Probióticos/farmacologia
RNA Bacteriano/análise
RNA Ribossômico 16S/análise
Análise de Sequência de RNA
Termotolerância
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Bacterial Proteins); 0 (RNA, Bacterial); 0 (RNA, Ribosomal, 16S); EC 2.4.1.- (Hexosyltransferases); EC 2.4.1.10 (levansucrase)
[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:170309
[St] Status:MEDLINE
[do] DOI:10.1007/s11274-017-2231-8


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[PMID]:28259735
[Au] Autor:Gabrielczyk J; Jördening HJ
[Ad] Endereço:Institute of Technical Chemistry, Section of Carbohydrate Technology, Technical University Braunschweig, Gaußstraße 17, D-38106 Braunschweig, Germany. Electronic address: j.gabrielczyk@tu-braunschweig.de.
[Ti] Título:Ion exchange resins as additives for efficient protein refolding by dialysis.
[So] Source:Protein Expr Purif;133:35-40, 2017 May.
[Is] ISSN:1096-0279
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The most significant drawback of bacterial protein production involving inclusion bodies is the subsequent refolding into bioactive form. Implementation of refolding operations in large-scale applications often fails due to low yields and/or low product concentrations. This paper presents a simple method of integrated refolding by dialysis and matrix assisted refolding that combines advantages of both methods, high product concentrations and high refolding yields. Ion exchange resins (IER) and size exclusion media served as refolding additives and were added to solubilized protein prior to refolding by continuous exchange of dialysis buffer. Refolding experiments were performed with fructosyltransferase (FTF, EC 2.4.1.162) from Bacillus subtilis NCIMB 11871 produced as inclusion bodies. Conventional anion exchangers with gel matrix structure enhanced refolding performance by about 43% with final protein concentration of 9 mg/mL and yield improvement is strictly linear dependent on the mass ratio of resins to protein. With the applied setup refolded protein was self-eluted from resin due to pH and salt concentration shift during dialysis. Macroporous resins and gel filtration media showed a negative effect on refolding yields.
[Mh] Termos MeSH primário: Bacillus subtilis/enzimologia
Proteínas de Bactérias/química
Hexosiltransferases/química
Resinas de Troca Iônica/química
Redobramento de Proteína
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Ion Exchange Resins); EC 2.4.1.- (Hexosyltransferases); EC 2.4.1.9 (inulosucrase)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170717
[Lr] Data última revisão:
170717
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170306
[St] Status:MEDLINE


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[PMID]:28103254
[Au] Autor:Mardo K; Visnapuu T; Vija H; Aasamets A; Viigand K; Alamäe T
[Ad] Endereço:Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia.
[Ti] Título:A Highly Active Endo-Levanase BT1760 of a Dominant Mammalian Gut Commensal Bacteroides thetaiotaomicron Cleaves Not Only Various Bacterial Levans, but Also Levan of Timothy Grass.
[So] Source:PLoS One;12(1):e0169989, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Bacteroides thetaiotaomicron, an abundant commensal of the human gut, degrades numerous complex carbohydrates. Recently, it was reported to grow on a ß-2,6-linked polyfructan levan produced by Zymomonas mobilis degrading the polymer into fructooligosaccharides (FOS) with a cell surface bound endo-levanase BT1760. The FOS are consumed by B. thetaiotaomicron, but also by other gut bacteria, including health-promoting bifidobacteria and lactobacilli. Here we characterize biochemical properties of BT1760, including the activity of BT1760 on six bacterial levans synthesized by the levansucrase Lsc3 of Pseudomonas syringae pv. tomato, its mutant Asp300Asn, levansucrases of Zymomonas mobilis, Erwinia herbicola, Halomonas smyrnensis as well as on levan isolated from timothy grass. For the first time a plant levan is shown as a perfect substrate for an endo-fructanase of a human gut bacterium. BT1760 degraded levans to FOS with degree of polymerization from 2 to 13. At optimal reaction conditions up to 1 g of FOS were produced per 1 mg of BT1760 protein. Low molecular weight (<60 kDa) levans, including timothy grass levan and levan synthesized from sucrose by the Lsc3Asp300Asn, were degraded most rapidly whilst levan produced by Lsc3 from raffinose least rapidly. BT1760 catalyzed finely at human body temperature (37°C) and in moderately acidic environment (pH 5-6) that is typical for the gut lumen. According to differential scanning fluorimetry, the Tm of the endo-levanase was 51.5°C. All tested levans were sufficiently stable in acidic conditions (pH 2.0) simulating the gastric environment. Therefore, levans of both bacterial and plant origin may serve as a prebiotic fiber for B. thetaiotaomicron and contribute to short-chain fatty acids synthesis by gut microbiota. In the genome of Bacteroides xylanisolvens of human origin a putative levan degradation locus was disclosed.
[Mh] Termos MeSH primário: Bacteroides thetaiotaomicron/enzimologia
Frutanos/metabolismo
Glicosídeo Hidrolases/metabolismo
Phleum/metabolismo
[Mh] Termos MeSH secundário: Erwinia/enzimologia
Frutanos/genética
Frutanos/isolamento & purificação
Halomonas/enzimologia
Hexosiltransferases/metabolismo
Seres Humanos
Hidrólise
Intestinos/microbiologia
Peso Molecular
Oligossacarídeos/metabolismo
Pseudomonas syringae/enzimologia
Homologia de Sequência
Especificidade por Substrato
Zymomonas/enzimologia
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Fructans); 0 (Oligosaccharides); 0 (fructooligosaccharide); EC 2.4.1.- (Hexosyltransferases); EC 2.4.1.10 (levansucrase); EC 3.2.1.- (Glycoside Hydrolases); EC 3.2.1.65 (levanase)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170821
[Lr] Data última revisão:
170821
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170120
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0169989



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