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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Purification of mitochondrial RNase P in A. nidulans

Javadi Khomami, Pasha 01 1900 (has links)
Résumé La ribonucléase P (RNase P) est une ribonucléoprotéine omniprésente dans tous les règnes du vivant, elle est responsable de la maturation en 5’ des précurseurs des ARNs de transfert (ARNts) et quelques autres petits ARNs. L’enzyme est composée d'une sous unité catalytique d'ARN (ARN-P) et d'une ou de plusieurs protéines selon les espèces. Chez les eucaryotes, l’activité de la RNase P cytoplasmique est distincte de celles des organelles (mitochondrie et chloroplaste). Chez la plupart des espèces, les ARN-P sont constituées de plusieurs éléments structuraux secondaires critiques conservés au cours de l’évolution. En revanche, au niveau de la structure, une réduction forte été observé dans la plupart des mtARN-Ps. Le nombre de protéines composant la RNase P est extrêmement variable : une chez les bactéries, environ quatre chez les archéobactéries, et dix chez la forme cytoplasmique des eucaryotes. Cet aspect est peu connu pour les formes mitochondriales. Dans la plupart des cas, l’identification de la mtRNase P est le résultat de longues procédures de purification comprenant plusieurs étapes dans le but de réduire au minimum le nombre de protéines requises pour l’activité (exemple de la levure et A. nidulans). Cela mène régulièrement à la perte de l’activité et de l’intégrité des complexes ribonucléo-protéiques natifs. Dans ce travail, par l’utilisation de la technique de BN-PAGE, nous avons développé une procédure d’enrichissement de l’activité RNase P mitochondriale native, donnant un rendement raisonnable. Les fractions enrichies capables de cette activité enzymatique ont été analysées par LC/MS/MS et les résultats montrent que l’holoenzyme de la RNase P de chacune des fractions contient un nombre de protéines beaucoup plus grand que ce qui était connue. Nous suggérons une liste de protéines (principalement hypothétiques) qui accompagnent l’activité de la RNase P. IV De plus, la question de la localisation de la mtRNase P de A. nidulans a été étudiée, selon nos résultats, la majorité de la mtRNase P est attachée á la membrane interne de la mitochondrie. Sa solubilisation se fait par l’utilisation de différents types de détergent. Ces derniers permettent l’obtention d’un spectre de complexes de la RNase P de différentes tailles. / Abstract RNase P is a ribonucleo-protein complex (an RNA enzyme or ribozyme) that cleaves 5’ leader sequences of precursor tRNAs and a few other small RNAs. It occurs in all three domains of life, Bacteria, Archaea and Eukarya, with the latter containing distinct nuclear and organellar (mitochondrial or plastid) activities. In most instances, the complex contains a single, well-conserved RNA subunit that carries the active center of the enzyme. Yet, compare to bacterial and nuclear P RNA, most mtP RNAs are structurally highly reduced. The number of P proteins is highly variable: one in Bacteria, about four in Archaea, and ten in the cytoplasmic form of Eukarya. Much less is known in the case of mitochondria. MtRNase P is usually purified by using numerous separation steps that include unphysiological conditions, leading to complexes having a minimum number of subunits (e.g., in yeast and Aspergillus nidulans), that often loose their activity. Here, using BN PAGE, we have developed an enrichment procedure for A. nidulans mtRNase P that avoids some of the most disruptive conditions. The protein composition of active fractions was identified with LC/MS/MS, indicating that the RNase P holoenzyme is much larger than previously thought. Finally, the question of mtRNase P localization within mitochondria was investigated, by tracing its RNA subunit by RT PCR. We found that mtRNase P of A. nidulans is a predominantly membrane-attached enzyme; it is in part solubilized by detergents such as digitonin and Triton.
152

Reengineering a human-like uricase for the treatment of gout

Kratzer, James Timothy 27 August 2014 (has links)
There is an unmet medical need in the treatment of gout. This type of inflammatory arthritis can be efficiently alleviated by the enzyme uricase. This enzyme breaks down uric acid, the causative agent of gout, so it can be flushed from the body. In humans and the other great apes, uricase is a pseudogene and as such is inactive. Research on therapeutic uricases has focused on using enzymes from naturally occurring sources; however, these foreign proteins can be very antigenic and present a potentially life-threatening safety risk to patients. We address the challenges of developing a safer uricase therapeutic by exploiting evidence that, while inactive, the human pseudogene is expressed in the human body and may be recognized as self by the immune system. To develop a モhuman-likeヤ? uricase we apply the hybrid computational and experimental approach of Ancestral Sequence Reconstruction to search functional sequence space of uricase proteins to engineer an enzyme with high sequence identity to the human pseudogene, and possessing therapeutic levels of activity for the breakdown of uric acid. This dissertation describes the development and characterization of several uricase leads. The most active ancestral uricase possesses both enhanced in vitro and in vivo stability (in healthy rats) when assayed head-to-head Pegloticase, the only FDA approved uricase for the treatment of gout.
153

Large scale protein purification of Wt1 ZF(-/-), Wt1 ZF(-/+), and Ciao-1

Bitschy, Ami 15 December 2008 (has links)
WT1 has two main isoforms: WT1(-KTS) and WT1(+KTS). Both are known to bind to a DNA consensus sequence with different affinities, and are thus postulated to play overlapping but distinct functional roles in the cell. WT1 is also known to bind to certain RNA moieties as well as to various protein partners (e.g. Ciao-1). This study focuses on the development of large scale protein purification protocols for WT1 zinc finger (ZF) proteins as well as Ciao-1. By using a combination of his-tag affinity and size exclusion chromatography we were able to purify milligram quantities of these proteins. It was also the intention to obtain crystals of the WT1 ZF protein in complex with any one of its known binding partners, in particular the protein Ciao-1 (a WD40 protein) and the 14 mer consensus sequence of DNA (known as WTE). In conjunction with structural studies it was determined that a previously made SELEX RNA library was not selective for the (+KTS) isoform of WT1 ZF, and therefore no RNA candidate could be identified for future structural studies.
154

High-throughput protein analysis using mass spectrometry-based methods

Boström, Tove January 2014 (has links)
In the field of proteomics, proteins are analyzed and quantified in high numbers. Protein analysis is of great importance and can for example generate information regarding protein function and involvement in disease. Different strategies for protein analysis and quan- tification have emerged, suitable for different applications. The focus of this thesis lies on protein identification and quantification using different setups and method development has a central role in all included papers. The presented research can be divided into three parts. Part one describes the develop- ment of two different screening methods for His6-tagged recombinant protein fragments. In the first investigation, proteins were purified using immobilized metal ion affinity chro- matography in a 96-well plate format and in the second investigation this was downscaled to nanoliter-scale using the miniaturized sample preparation platform, integrated selective enrichment target (ISET). The aim of these investigations was to develop methods that could work as an initial screening step in high-throughput protein production projects, such as the Human Protein Atlas (HPA) project, for more efficient protein production and purification. In the second part of the thesis, focus lies on quantitative proteomics. Protein fragments were produced with incorporated heavy isotope-labeled amino acids and used as internal standards in absolute protein quantification mass spectrometry experiments. The aim of this investigation was to compare the protein levels obtained using quanti- tative mass spectrometry to mRNA levels obtained by RNA sequencing. Expression of 32 different proteins was studied in six different cell lines and a clear correlation between protein and mRNA levels was observed when analyzing genes on an individual level. The third part of the thesis involves the antibodies generated within the HPA project. In the first investigation a method for validation of antibodies using protein immunoenrichment coupled to mass spectrometry was described. In a second study, a method was developed where antibodies were used to capture tryptic peptides from a digested cell lysate with spiked in heavy isotope-labeled protein fragments, enabling quantification of 20 proteins in a multiplex format. Taken together, the presented research has expanded the pro- teomics toolbox in terms of available methods for protein analysis and quantification in a high-throughput format. / <p>QC 20141022</p>
155

Large scale protein purification of Wt1 ZF(-/-), Wt1 ZF(-/+), and Ciao-1

Bitschy, Ami 15 December 2008 (has links)
WT1 has two main isoforms: WT1(-KTS) and WT1(+KTS). Both are known to bind to a DNA consensus sequence with different affinities, and are thus postulated to play overlapping but distinct functional roles in the cell. WT1 is also known to bind to certain RNA moieties as well as to various protein partners (e.g. Ciao-1). This study focuses on the development of large scale protein purification protocols for WT1 zinc finger (ZF) proteins as well as Ciao-1. By using a combination of his-tag affinity and size exclusion chromatography we were able to purify milligram quantities of these proteins. It was also the intention to obtain crystals of the WT1 ZF protein in complex with any one of its known binding partners, in particular the protein Ciao-1 (a WD40 protein) and the 14 mer consensus sequence of DNA (known as WTE). In conjunction with structural studies it was determined that a previously made SELEX RNA library was not selective for the (+KTS) isoform of WT1 ZF, and therefore no RNA candidate could be identified for future structural studies.
156

Identificação de uma proteína ligante à quitina em sementes de Moringa oleifera Lamarck com atividades antinociceptiva e anti-inflamatória / Identification of a Chitin-Binding Protein from Moringa oleifera Lamarck Seeds with antinociceptive and anti-inflammatory effects

Pereira, Mirella Leite January 2010 (has links)
PEREIRA, Mirella Leite. Identificação de uma proteína ligante à quitina em sementes de Moringa oleifera Lamarck com atividades antinociceptiva e anti-inflamatória. 2010. 148 f. Dissertação (Mestrado em Bioquímica) - Universidade Federal do Ceará, Fortaleza-CE, 2010. / Submitted by Eric Santiago (erichhcl@gmail.com) on 2016-06-22T12:58:11Z No. of bitstreams: 1 2010_dis_mlpereira.pdf: 2928438 bytes, checksum: baa96d60cb675c47c7cfb74d94bbcad3 (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-08-02T20:02:54Z (GMT) No. of bitstreams: 1 2010_dis_mlpereira.pdf: 2928438 bytes, checksum: baa96d60cb675c47c7cfb74d94bbcad3 (MD5) / Made available in DSpace on 2016-08-02T20:02:54Z (GMT). No. of bitstreams: 1 2010_dis_mlpereira.pdf: 2928438 bytes, checksum: baa96d60cb675c47c7cfb74d94bbcad3 (MD5) Previous issue date: 2010 / Moringa oleifera Lam. is a perennial multipurpose tree with a strong scientific evidence of its curative power and used in folk medicine to cure several inflammatory processes. This work aimed to isolate and characterize a chitin-binding protein from Moringa oleifera seeds, and evaluate its antinociceptive and anti-inflammatory effects. Chitin-binding proteins were obtained after application of albumin fraction from crude extract of M. oleifera seeds into a chitin column and the adsorbed fraction was applied in a Resource-S matrix attached to FPLC system. The fraction eluted with 50 mM sodium acetate buffer, pH 5.2, containing 0.6 M NaCl, named Mo-CBP4 was used for the experiment. Mo-CBP4 showed a single band on SDS-PAGE (molecular mass 9.8 kDa) in presence of reducing agent, however in the absence of 2-mercaptoethanol two bands corresponding to 27.5 and 16.5 kDa were observed. Bidimensional electrophoresis of this protein revealed the presence of two spots (18.7 and 13.4 kDa), with the same isoeletric point value corresponding to 10.55. Mo-CBP4 is a glycoprotein containing 2.85% neutral sugar, which failed to agglutinate untreated or trypsin-treated erythrocytes from rabbit or human origin. This protein showed coagulant activity, similar to aluminum and potassium sulfate, the coagulant most widely used in water treatment. Mo-CBP4 was subjected to in vitro digestion with pepsin, trypsin, or chymotrypsin and appeared to be markedly resistant to digestion. Acetic acid-induced abdominal constrictions, increase in vascular permeability and leukocyte migration tests were used for the antinociceptive and anti-inflammatory activities assessment. Mo-CBP4 (1.0, 3.5 and 10 mg/kg) into mice potently and significantly reduced the occurrence of abdominal writhing in a dose dependent manner by 18.9, 44.6% and 98.9%, respectively. In addition, the oral administration of the protein (10 mg/kg) resulted in 18% and 52.9% reductions in abdominal writhing when given 30 and 60 min prior to acetic acid administration, respectively. Mo-CBP4 also caused a significant and dose-dependent inhibition of peritoneal capillary permeability induced by acid acetic and significantly inhibited leukocyte accumulation in the peritoneal cavity. The effect antinociceptive appeared to be independent on the carbohydrate recognition site. However the anti-inflammatory activity was partially reversed when Mo-CBP4 was pre-incubated with specific carbohydrate ligand, showing that this effect is dependent on the carbohydrate recognition site / Moringa oleifera Lam. é uma árvore conhecida pelo seu valor medicinal, uma vez que extratos de todas as partes desta planta mostraram propriedades farmacológicas reconhecidas pelo uso popular e corroboradas pela comunidade científica. Dentre as atividades farmacológicas, destacam-se àquelas relacionadas a processos inflamatórios. Este trabalho teve como objetivo o isolamento e caracterização de uma proteína ligante à quitina de sementes de Moringa oleifera e avaliação de suas atividades antinociceptiva e anti-inflamatória. As proteínas foram extraídas da farinha delipidada de sementes e o extrato total foi fracionado em albuminas e globulinas. A fração albumínica foi submetida à cromatografia de afinidade em matriz de quitina. A fração ligante à quitina eluída com N-acetil-D-glucosamina 0,1 M foi submetida à cromatografia de troca iônica acoplada a um sistema de FPLC, rendendo cinco picos protéicos. O material eluído com tampão acetato de sódio 0,5 M, pH 5,2, contendo NaCl 0,6 M, denominado Mo-CBP4 (Mo – Moringa oleifera; “CBP – “chitin binding protein”), teve um rendimento final de 0,54% e foi escolhido para dar continuidade ao trabalho. Mo-CBP4 apresentou-se como duas bandas protéicas de massas moleculares aparentes de 27,5 e 16,5 kDa, em condições não-redutoras, e de 9,8 kDa em condições redutoras. Eletroforese bidimensional desta proteína revelou a presença de dois spots (18,7 e 13,4 kDa), com mesmo ponto isoelétrico (pI de 10,55). Trata-se de uma glicoproteína com 2,85% de carboidratos, não apresentando atividade hemaglutinante. Mo-CBP4 mostrou-se tão eficiente quanto o sulfato de alumínio e potássio na capacidade de coagular material em suspensão na água. A proteína em questão foi resistente à proteólise no teste de digestibilidade in vitro utilizando pepsina, tripsina e quimotripsina. Para avaliar os efeitos antinociceptivo e anti-inflamatório de Mo-CBP4, foi utilizado o modelo de contorções abdominais induzidas pela injeção de ácido acético 0,8% (via i.p.) em camundongos. A proteína, nas doses de 1,0, 3,5 e 10 mg/kg, foi capaz de prevenir as contorções de maneira dose dependente, chegando a 98,9% de inibição na dose de 10 mg/kg. Mo-CBP4 também apresentou atividade antinociceptiva por via oral (10 mg/kg), atingindo uma inibição de 52,9% quando administrada 60 minutos antes da injeção de ácido acético. Mo-CBP4 inibiu o aumento da permeabilidade vascular (89,1%) e a migração leucocitária (60,9%) na dose de 10 mg/kg via i.p. A propriedade antinociceptiva parece ser independente do sítio de interação ao carboidrato N-acetil-D-glucosamina, enquanto que a atividade anti-inflamatória mostrou um decréscimo quando a região de ligação ao carboidrato foi bloqueada. Os resultados apresentados suportam cientificamente o uso popular da M. oleifera e mostram que uma proteína ligante à quitina, Mo-CBP4, está associada aos efeitos antinociceptivo e anti-inflamatório das sementes
157

Geração de clones de células HEK293 superprodutores de isoformas recombinantes de VEGF-A (Fator de Crescimento Endotelial Vascular A) humano visando à produção de biofármacos para terapia molecular e engenharia tecidual / Generation of HEK293 cell clones overexpressing recombinant isoforms of human VEGF-A (Vascular Endothelial Growth Factor A) with the aim of producing biopharmaceuticals for molecular therapy and tissue engineering

Gustavo Gross Belchior 25 April 2014 (has links)
Os primeiros vasos sanguíneos do embrião de vertebrados, formados de novo a partir de células originadas da mesoderme, originam os vasos linfáticos em um processo denominado vasculogênese. Já no adulto, novos vasos são formados principalmente através da angiogênese (ou linfoangiogênese) a partir da vasculatura pré-existente. Em indivíduos saudáveis, a arquitetura vascular é relativamente estática, sendo que o excesso ou a insuficiência de vasos são comumente relacionados à angiogênese patológica, vinculada a diversas doenças, como câncer, degeneração macular relacionada à idade, isquemia de membros e muitas outras. Dessa forma, o controle local da densidade de vasos sanguíneos torna-se interessante para o tratamento de condições patológicas visando melhoria de prognóstico e cura. Dentre os diversos fatores de crescimento conhecidos, o fator de crescimento endotelial vascular, VEGF, destaca-se como o principal regulador do processo de angiogênese através de isoformas pró-angiogênicas (VEGFxxx) e antiangiogênicas (VEGFxxxb) do gene VEGF-A. Consequentemente, as proteínas codificadas por esse gene constituem um alvo com alto potencial terapêutico. No presente estudo, propusemos a produção das isoformas proteicas recombinantes rhVEGF165, rhVEGF165b e rhVEGF121, oriundas do gene VEGF-A humano, visando à geração de biofármacos que podem ser utilizados para terapia molecular e engenharia tecidual. As sequências codificadoras das isoformas rhVEGF165 e rhVEGF121 foram amplificadas a partir do cDNA total sintetizado de amostras de RNA total de pulmão humano, enquanto que a da isoforma rhVEGF165b foi gerada através da mutação sítio-dirigida da sequência de rhVEGF165. As sequências foram clonadas no vetor de clonagem pGEM®-T Easy, sendo em seguida subclonadas no vetor pLV-eGFP, um vetor plasmidial de transferência lentiviral, que permite a expressão de transgenes em células de mamíferos e, também, da proteína repórter eGFP. Células humanas HEK293 em cultura aderente foram independentemente cotransfectadas com cada uma das construções geradas (pLV-rhVEGF165, pLV-rhVEGF165b e pLV-rhVEGFl21) juntamente com o vetor pTK-Hyg na proporção de 40:1 (m/m), viabilizando a seleção dos transfectantes com o antibiótico higromicina B, além da detecção de eGFP. Os clones celulares superprodutores das proteínas de interesse foram avaliados quanto à cinética de expressão em meio carente de soro e adaptados para a cultura em suspensão estática na presença de meio na ausência de componentes derivados de animais, demostrando a capacidade de expressão das isoformas rhVEGFs nestas condições de cultivo. Para o nosso conhecimento, este é o primeiro trabalho a descrever a expressão de isoformas de VEGF-A em células HEK293 mantidas em suspensão. As isoformas rhVEGF165 e rhVEGF165b foram purificadas por cromatografia de afinidade a heparina, a partir do meio condicionado pelos clones superprodutores gerados. Ensaios in vitro, utilizando o AngioPhaseTM Kit, e in vivo, através do ensaio da membrana corioalantoide em embriões de galinha (CAM Assay), ambos próprios para avaliação da atividade pró- e antiangiogênica de diferentes compostos, demonstraram que a isoforma rhVEGF165 possui atividade biológica, enquanto a isoforma rhVEGF165b não apresentou a atividade esperada (inibição da angiogênese). Estas isoformas foram testadas em modelo murino de engenharia tecidual do intestino curto, com indícios de que poderiam contribuir para o uso terapêutico neste contexto. A purificação da isoforma rhVEGF121, bem como as análises estruturais das proteínas produzidas, estão em processo de otimização. / The first blood vessels of the vertebrate embryo are formed de novo from mesoderm-derived cells and give rise to lymph vessels in a process termed vasculogenesis. In the adult, new blood vessels are formed mainly through angiogenesis (or lymphangiogenesis) from the pre-existing vasculature. In healthy individuals, the vascular architecture is fairly static, and both the excess and the insufficiency of vessels comprise a pathological angiogenic state, to which is credited the onset and/or progression of several diseases such as cancer, age-related macular degeneration, limb ischemia, and many others. Therefore, locally controlling the blood vessel density becomes interesting for the treatment of pathological conditions aiming at prognosis improvement and cure. Among the various known growth factors, the vascular endothelial growth factor, VEGF, stands out as the major regulator of the angiogenic process. This process is mediated through the action of pro- (VEGFxxx) and antiangiogenic (VEGFxxxb) isoforms, which are derived from the VEGF-A gene. Consequently, the proteins encoded by this gene are potential therapeutic targets. In this work, we set out to produce the recombinant protein isoforms rhVEGF165, rhVEGF165b, and rhVEGF121, which originate from the human VEGF-A gene, with the aim of generating biopharmaceuticals to be used for molecular therapy and tissue engineering. The rhVEGF165 and rhVEGF121 coding sequences were amplified from total cDNA sythesized from human lung total RNA. Conversely, the rhVEGF165b coding sequence was generated by site-directed mutagenesis of the rhVEGF165 sequence. The sequences were cloned into the pGEM®-T Easy cloning vector. These cDNAs were then subcloned into pLV-eGFP, a plasmid lentiviral transfer vector that allows for expression of transgenes and the eGFP reporter protein in mammalian cells. Human HEK293 cells cultivated under adherent conditions were independently co-transfected with each of the obtained constructs (pLV-rhVEGF165, pLV-rhVEGF165b, and pLV-rhVEGF121) and the pTK-Hyg vector at a proportion of 40:1 (m/m), enabling for the selection of transfectants with hygromycin B, apart from the detection of eGFP. The cell clones overexpressing the proteins of interest were evaluated for expression kinetics in serum-deprived conditioned media and adapted to static suspension culture in medium free of animal-derived components, demonstrating that expression of the protein isoforms was possible in these culture conditions. To the best of our knowledge, this is the first work that describes the expression of VEGF-A isoforms in HEK293 cells in suspension culture. The rhVEGF165 and rhVEGF165b isoforms were purified by affinity chromatography from media previously conditioned by the overexpressing cell clones. The biological activity of rhVEGF165 was demonstrated in vitro, by the AngioPhaseTM Kit assay, and in vivo with the CAM (chorioallantoic membrane) assay, both of which are suitable for evaluating the pro- and antiangiogenic activity of different compounds. The rhVEGF165b did not show the expected antiangiogenic activity. These isoforms were tested in a model of murine tissue-engineered small intestine, indicating a possible contribution to therapeutic use in this context. The purification of rhVEGF121, as well as the structural analysis of all three proteins, are in the process of being optimized.
158

Adsorção de ige humana a partir de amostras sericas ou plasmaticas em lectinas imobilizadas em agarose / Adsorption of human ige from sera or plasma samples on lectins immobilized on agarose

Duarte, Isa Santos 02 October 2006 (has links)
Orientadores : Sonia Maria Alves Bueno, Ricardo de Lima Zollner / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-06T11:50:08Z (GMT). No. of bitstreams: 1 Duarte_IsaSantos_D.pdf: 749498 bytes, checksum: 83d66753c75e7828fd4a8b858aecf473 (MD5) Previous issue date: 2006 / Resumo: A alergia é uma enfermidade do sistema imunológico que afeta aproximadamente de 20 a 30% da população mundial. Dentre as reações alérgicas, a reação de hipersensibilidade imediata é mediada pelas imunoglobulinas E (IgE). Os indivíduos geneticamente predispostos a manifestar reações por hipersensibilidade imediata e polissensibilizados aos alérgenos ambientais são considerados atópicos e, geralmente, possuem teores de IgE total até 10.000 vezes mais elevados do que as pessoas não-atópicas. O conhecimento das interações entre a IgE e ligantes de afinidade pode levar ao desenvolvimento de novos tratamentos da hipersensibilidade imediata, por exemplo a terapia de adsorção seletiva através de circulação extracorpórea, assim como ao desenvolvimento de métodos de obtenção de IgE purificada, para aplicação nas áreas de diagnóstico, pesquisa molecular, dentre outras. Os adsorventes empregados na terapia de adsorção seletiva, bem como na purificação de IgE, geralmente são anticorpos anti-IgE imobilizados em agarose, os quais são de alto custo e difícil obtenção. Este trabalho avaliou o desempenho de adsorventes alternativos ao Sepharose-anti-IgE, visando a remoção de IgE total e específica aos ácaros Dermatophagoides pteronyssinus e Blomia tropicalis de amostras plasmáticas e a preparação de soluções enriquecidas em IgE, como uma das etapas do processo de purificação de IgE. Os adsorventes estudados constituíram-se de lectinas (concanavalina A e Lens culinaris), aminas (poli-L-lisina e aminohexil) e o aminoácido D-triptofano, imobilizados em agarose. Dentre eles, o gel agarose-Lens culinaris mostrou-se o mais promissor para aplicação na terapia de adsorção seletiva de IgE e o gel Sepharose-concanavalina A mostrou-se o mais adequado para ser usado na obtenção de soluções enriquecidas em IgE. Experimentos cromatográficos foram realizados visando estabelecer condições experimentais (velocidade superficial, número de passagens de plasma pela coluna, temperatura e razão entre volume de plasma e volume de leito) mais favoráveis à adsorção de IgE em agarose-Lens culinaris. Posteriormente, essas condições foram utilizadas nos experimentos de simulação in vitro de circulação extracorpórea, nos quais o gel agarose-Lens culinaris removeu de 40,7 a 42,8% de IgE¿s total e específicas. A obtenção da solução enriquecida em IgE foi realizada por meio de duas etapas cromatográficas, empregando-se os princípios de afinidade (colunas agarosejacalina e Sepharose-concanavalina A) e de exclusão por tamanho (permeação em gel). A solução final enriquecida em IgE obtida, continha como principais impurezas, IgA e IgG. Como resultado das duas etapas, 36,6% de IgE foi recuperada e o fator de enriquecimento em IgE, em relação a IgA, IgG, IgM e albumina, foi de 75,8. Apesar do gel Sepharose-anti- IgE apresentar desempenho melhor tanto na remoção quanto na purificação de IgE, os adsorventes agarose-Lens culinaris e Sepharose-concanavalina A apresentam custos mais atrativos / Abstract: Allergy is a disorder of the imune system, affecting approximately 20%-30% of the general population. Among allergic reactions, immediate hypersensitivity is mediated by immunoglobulin E (IgE). Individuals that have a genetic predisposition for responses to immediate hypersensitivity are named atopic and generally have elevated serum IgE concentration, up to 10,000-fold higher than in the normal population. The knowledge of the interactions between IgE and affinity ligands may lead to the development of new methods of treatment for immediate hypersensitivity, for example, IgE selective adsorption therapy through extracorporeal circulation, as well as to new methods for obtaining purified IgE, which is employed in diagnostic and in molecular research. The adsorbents employed in IgE selective adsorption therapy, as well as in IgE purification, are usually antibodies anti-IgE immobilized on agarose, which have high costs and are difficult to obtain. This work assessed the performance of adsorbents (alternative to Sepharose-anti-IgE) for the removal of total IgE and IgE specific for the airbone allergens Dermatophagoides pteronyssinus and Blomia tropicalis from plasma samples, as well as in the production of IgE enriched solutions, considered as a step of IgE purification. The adsorbents studied were lectins (concanavalina A and Lens culinaris), amines (poli-L-lisina e aminohexil) and the aminoacid D-tryptophan, all of them immobilized on agarose. Among them, Lens culinaris-agarose showed the best performance for IgE selective adsorption therapy, and Sepharose¿concanavalin A was considered the most appropriate for the production of IgE enriched solutions. Chromatographic experiments were accomplished in order to determine operating conditions (superficial velocity, number of times the plasma passed through the column, temperature, and ratio of plasma volume to bed volume) more favorable to IgE adsorption on Lens culinaris-agarose. The selected conditions were utilized in in vitro simulation assays of extracorporeal circulation, in which the Lens culinaris-agarose removed from 40.7% to 42.8% of total and specific IgE. The production of IgE enriched solutions was carried out with two chromatographic steps, employing affinity (columns jacalin-agarose and Sepharose-concanavalin A) and size exclusion (gel permeation) principles. The IgE enriched final solution contained IgA and IgG as the major impurities. As a result of both steps, 36.6% of IgE was recovered and the IgE enrichement number concerning IgA, IgG, IgM, and albumin was 75.8. Despite Sepharose-anti-IgE has better performance in removal and purification of IgE, Lens culinaris-agarose and Sepharose-concanavalin A adsorbents have more attractive costs / Doutorado / Desenvolvimento de Processos Biotecnologicos / Doutora em Engenharia Quimica
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IdentificaÃÃo de uma proteÃna ligante à quitina em sementes de Moringa oleifera Lamarck com atividades antinociceptiva e anti-inflamatÃria / Identification of a Chitin-Binding Protein from Moringa oleifera Lamarck Seeds with antinociceptive and anti-inflammatory effects

Mirella Leite Pereira 16 March 2010 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Moringa oleifera Lam. à uma Ãrvore conhecida pelo seu valor medicinal, uma vez que extratos de todas as partes desta planta mostraram propriedades farmacolÃgicas reconhecidas pelo uso popular e corroboradas pela comunidade cientÃfica. Dentre as atividades farmacolÃgicas, destacam-se Ãquelas relacionadas a processos inflamatÃrios. Este trabalho teve como objetivo o isolamento e caracterizaÃÃo de uma proteÃna ligante à quitina de sementes de Moringa oleifera e avaliaÃÃo de suas atividades antinociceptiva e anti-inflamatÃria. As proteÃnas foram extraÃdas da farinha delipidada de sementes e o extrato total foi fracionado em albuminas e globulinas. A fraÃÃo albumÃnica foi submetida à cromatografia de afinidade em matriz de quitina. A fraÃÃo ligante à quitina eluÃda com N-acetil-D-glucosamina 0,1 M foi submetida à cromatografia de troca iÃnica acoplada a um sistema de FPLC, rendendo cinco picos protÃicos. O material eluÃdo com tampÃo acetato de sÃdio 0,5 M, pH 5,2, contendo NaCl 0,6 M, denominado Mo-CBP4 (Mo â Moringa oleifera; âCBP â âchitin binding proteinâ), teve um rendimento final de 0,54% e foi escolhido para dar continuidade ao trabalho. Mo-CBP4 apresentou-se como duas bandas protÃicas de massas moleculares aparentes de 27,5 e 16,5 kDa, em condiÃÃes nÃo-redutoras, e de 9,8 kDa em condiÃÃes redutoras. Eletroforese bidimensional desta proteÃna revelou a presenÃa de dois spots (18,7 e 13,4 kDa), com mesmo ponto isoelÃtrico (pI de 10,55). Trata-se de uma glicoproteÃna com 2,85% de carboidratos, nÃo apresentando atividade hemaglutinante. Mo-CBP4 mostrou-se tÃo eficiente quanto o sulfato de alumÃnio e potÃssio na capacidade de coagular material em suspensÃo na Ãgua. A proteÃna em questÃo foi resistente à proteÃlise no teste de digestibilidade in vitro utilizando pepsina, tripsina e quimotripsina. Para avaliar os efeitos antinociceptivo e anti-inflamatÃrio de Mo-CBP4, foi utilizado o modelo de contorÃÃes abdominais induzidas pela injeÃÃo de Ãcido acÃtico 0,8% (via i.p.) em camundongos. A proteÃna, nas doses de 1,0, 3,5 e 10 mg/kg, foi capaz de prevenir as contorÃÃes de maneira dose dependente, chegando a 98,9% de inibiÃÃo na dose de 10 mg/kg. Mo-CBP4 tambÃm apresentou atividade antinociceptiva por via oral (10 mg/kg), atingindo uma inibiÃÃo de 52,9% quando administrada 60 minutos antes da injeÃÃo de Ãcido acÃtico. Mo-CBP4 inibiu o aumento da permeabilidade vascular (89,1%) e a migraÃÃo leucocitÃria (60,9%) na dose de 10 mg/kg via i.p. A propriedade antinociceptiva parece ser independente do sÃtio de interaÃÃo ao carboidrato N-acetil-D-glucosamina, enquanto que a atividade anti-inflamatÃria mostrou um decrÃscimo quando a regiÃo de ligaÃÃo ao carboidrato foi bloqueada. Os resultados apresentados suportam cientificamente o uso popular da M. oleifera e mostram que uma proteÃna ligante à quitina, Mo-CBP4, està associada aos efeitos antinociceptivo e anti-inflamatÃrio das sementes / Moringa oleifera Lam. is a perennial multipurpose tree with a strong scientific evidence of its curative power and used in folk medicine to cure several inflammatory processes. This work aimed to isolate and characterize a chitin-binding protein from Moringa oleifera seeds, and evaluate its antinociceptive and anti-inflammatory effects. Chitin-binding proteins were obtained after application of albumin fraction from crude extract of M. oleifera seeds into a chitin column and the adsorbed fraction was applied in a Resource-S matrix attached to FPLC system. The fraction eluted with 50 mM sodium acetate buffer, pH 5.2, containing 0.6 M NaCl, named Mo-CBP4 was used for the experiment. Mo-CBP4 showed a single band on SDS-PAGE (molecular mass 9.8 kDa) in presence of reducing agent, however in the absence of 2-mercaptoethanol two bands corresponding to 27.5 and 16.5 kDa were observed. Bidimensional electrophoresis of this protein revealed the presence of two spots (18.7 and 13.4 kDa), with the same isoeletric point value corresponding to 10.55. Mo-CBP4 is a glycoprotein containing 2.85% neutral sugar, which failed to agglutinate untreated or trypsin-treated erythrocytes from rabbit or human origin. This protein showed coagulant activity, similar to aluminum and potassium sulfate, the coagulant most widely used in water treatment. Mo-CBP4 was subjected to in vitro digestion with pepsin, trypsin, or chymotrypsin and appeared to be markedly resistant to digestion. Acetic acid-induced abdominal constrictions, increase in vascular permeability and leukocyte migration tests were used for the antinociceptive and anti-inflammatory activities assessment. Mo-CBP4 (1.0, 3.5 and 10 mg/kg) into mice potently and significantly reduced the occurrence of abdominal writhing in a dose dependent manner by 18.9, 44.6% and 98.9%, respectively. In addition, the oral administration of the protein (10 mg/kg) resulted in 18% and 52.9% reductions in abdominal writhing when given 30 and 60 min prior to acetic acid administration, respectively. Mo-CBP4 also caused a significant and dose-dependent inhibition of peritoneal capillary permeability induced by acid acetic and significantly inhibited leukocyte accumulation in the peritoneal cavity. The effect antinociceptive appeared to be independent on the carbohydrate recognition site. However the anti-inflammatory activity was partially reversed when Mo-CBP4 was pre-incubated with specific carbohydrate ligand, showing that this effect is dependent on the carbohydrate recognition site
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Desenvolvimento do processo de purificação da proteína A de superfície de pneumococo do clado 4 (PspA4Pro). / Development of the purification process of pneumococcal surface protein A clade 4 (PspA4Pro).

Douglas Borges de Figueiredo 23 September 2014 (has links)
A proteína A de superfície de pneumococo (PspA) é encontrada na superfície de todas as cepas de Streptococcus pneumoniae e candidata promissora para novas vacinas pneumocócicas. Foi desenvolvido um processo de purificação da PspA4Pro cujas etapas iniciais foram: ruptura da biomassa celular, precipitação do homogenato obtido com o detergente brometo de cetiltrimetilamônio (CTAB) e remoção do precipitado por centrifugação. Foram avaliadas cromatografias de troca iônica (aniônica, catiônica), afinidade por metais, interação hidrofóbica e mista de troca catiônica e hidrofóbica. Utilizando precipitação com CTAB, cromatografia de troca aniônica, crioprecipitação em pH4,0 e cromatografia de troca catiônica atingiu-se a pureza requerida de PspA4Pro (>95%) com recuperação entre 14% e 33%. O processo alcançou níveis aceitáveis de endotoxina no produto final e a PspA4Pro purificada foi reconhecida por anticorpos anti-PspA4, manteve sua atividade e sua estrutura secundária. / Pneumococcal surface protein A (PspA) is found in all Streptococcus pneumoniae strains and is a promising candidate to be used in new pneumococcal vaccines. A purification process for PspA4Pro which inicial steps were: cell disruption, precipitation of the homogenate with the cationic detergent cetyltrimethylammonium bromide (CTAB) and pellet removal by centrifugation. The chromatographic techniques tested were ion exchange (anionic and cationic), immobilized metal affinity, hydrophobic interaction and mix mode with hydrophobic and cationic ligands. Using CTAB precipitation, anion exchange chromatography, crioprecipitation in pH4.0 and cation exchange chromatography the PspA reached the required purity (>95%) with recovery between 14% and 33% . The process reached acceptable levels of endotoxin in the final product and the purified PspA4Pro was recognized by anti-PspA4 antibodies and manteined its activity and secondary structure.

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