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Previous issue date: 2012-02-16 / Financiadora de Estudos e Projetos / In recent years, the technology animal cells culture has allowed the development of many byproducts, especially those with pharmacological interest. Some of these products, the recombinant proteins, can be produced by heterologous expression systems on a commercial scale. Bacteria, yeast, mammalian cells and insects are some of the hosts used in these processes. As source of proteins with farmacological interest, the catterpillar Lonomia obliqua hemolinph was demonstrated to be a helpful organismo. Antiviral, antiapoptotic, antimicrobial and inducing growth proteins, are some of examples. Since the control of viral infections is a major interest to public health, the searching for new antiviral drugs has utmost importance. Several studies have reported the presence of active principles in the arthropods hemolymph. Recently, we demonstrated the existence of an antiviral protein in the hemolymph of the caterpillar Lonomia obliqua. This purified protein induced viral production reduction (TCID50 mL-1) over 157 times in cells infected with the measles virus, 61 times for polio and 61 times for influenza virus H1N1 infections. Thus, the present goals were building and expression of a recombinant plasmid contained coding sequences for expression of viral proteins (using baculovirus) in insect cell Sf-9 system. By this process, it was aimed to test biological activity of the protein. Further sequence analyses of this protein were performed using bioinformatics tools. The RNA of L. obliqua was extracted with Trizol reagent. RNA product was used in RT-PCR reactions with primers specific for the antiviral protein, based on the sequence of the cDNA libraries of L. obliqua tegument and spines, using all possible frame of translation for each cDNA. Restriction sites were inserted in cDNA sequence to insert it in pFastBacTM1 donor vector (Invitrogen). The sequence contained in selected clone of Escherichia coli DH5α was used for transformation into E. coli DH10Bac to obtain a bacmid by transposition process. This bacmid was used for antiviral recombinant protein expression in Sf-9 cells. This recombinant protein activity was tested in Picorna (EMC enchephalomiocardite), Rubeola and Herpes virus. In these trials, it was observed a replication reduction of 10,000, 10,000 and 1,000000 times, respectively. The bioinformatics analysis demonstrated that this protein is secreted, globular and probably belongs to a new class of proteins. / A tecnologia de cultivo de celulas animais tem permitido nos ultimos anos o desenvolvimento de inumeros bioprodutos. Principalmente com interesse farmacologico, alguns desses produtos, as proteinas recombinantes, podem ser produzidas em sistemas de expressao heterologos em escala comercial. Bacterias, leveduras, celulas de mamiferos e de insetos sao alguns dos hospedeiros utilizados nestes processos. Como fonte de proteinas de interesse farmacologico, a hemolinfa da lagarta Lonomia obliqua mostrou-se um organismo bastante promissor. Proteinas antivirais, antiapoptoticas, antimicrobianas e indutoras de crescimento sao alguns destes exemplos. Como o controle das infeccoes virais e de grande interesse pra saude publica, a busca por novos antivirais e de extrema importancia. Diversos estudos relatam a presenca de principios ativos na hemolinfa de artropodes. Recentemente nos demonstramos a existencia de uma proteina antiviral na hemolinfa da lagarta Lonomia obliqua. Esta proteina purificada mostrou-se capaz de reduzir a producao viral (TCID50 mL 1) mais de 157 vezes o virus do sarampo, 61 vezes para o virus da polio e 61 vezes para o virus influenza H1N1. Assim, este estudo objetivou a construcao e expressao de um recombinante contendo sequencias de codificacao da proteina antiviral para a expressao em sistema baculovirus/celula de inseto Sf-9 e a realizacao de testes de atividade biologica e caracterizacao por bioinformatica. Para sintetizar cDNA, o RNA de L. obliqua foi extraido com o reagente Trizol e usado nas reacoes de RT-PCR com primers especificos para a proteina antiviral, com base na sequencia das bibliotecas de cDNA de L. obliqua de tegumento e espiculas, utilizando todos os frames de traducao possiveis para cada cDNA. Sitios de restricao foram inseridos no cDNA para ligacao ao vetor doador pFastBacTM 1 (Invitrogen). O plasmideo recombinante selecionado em Escherichia coli DH5α foi utilizado na transformacao em E. coli DH10Bac para a obtencao do bacmideo pelo processo de transposicao. O bacmideo recombinante foi utilizado para a expressao da proteina antiviral em celulas SF-9. A atividade desta proteina recombinante foi testada em Picornavirus (EMC - encephalomiocardite), Rubeola e Herpes. Nestes testes foi observado que a proteina reduziu em 10.000, 10.000 e 1.000.000 a titulacao viral, respectivamente. As analises de bioinformatica demonstraram que esta proteina e secretada, globular e provavelmente pertenca a uma nova classe de proteinas.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufscar.br:ufscar/258 |
| Date | 16 February 2012 |
| Creators | Carmo, Ana Carolina Viegas |
| Contributors | Mendonça, Ronaldo Zucatelli |
| Publisher | Universidade Federal de São Carlos, Programa de Pós-graduação em Biotecnologia, UFSCar, BR |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFSCAR, instname:Universidade Federal de São Carlos, instacron:UFSCAR |
| Rights | info:eu-repo/semantics/openAccess |
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