1,721,039 research outputs found
Fibras recombinantes de aranhas: idéia antiga e um novo e único biomaterial.
Get PDFFibras das aranhas estão entre os biomateriais mais resistentes conhecidos. São mais resistentes e flexíveis do que o aço (relação kilogramo por kilogroma). Devido a suas extraordinárias propriedades mecânicas, as fibras das aranhas tem sido estudadas, desde os tempos antigos. As aranhas fazem do uso das fibras produzidas ao longo da vida, sua quase total dependência para a sucessão evolutiva. Evoluíram a capacidade de produzir até seis diferentes fibras, que possuem diferentes pontos de tração e elasticidades. Nos últimos 150 anos, inúmeras artigos científicos e populares foram escritos. No entanto, apenas nos últimos anos emergiu uma compreensão referente aos motivos para as exclusivas propriedades mecânicas, que as fibras das aranhas possuem. Isto inclui o conhecimento sobre as seqüências das proteínas, estudos de biofísica das proteínas das fibras, o processo de produção e os estudos evolutivos. Sabemos que as fibras de aranhas são biopolímeros protéicos secretados através de células epiteliais especializadas, como precursores de proteínas solúveis a partir de blocos de seqüências primárias repetitivas. O genoma funcional das glândulas produtoras da fibras de aranhas coletadas na biodiversidade brasileira, possibilitou a prospecção de sequencias regulatórias e codificadoras associadas à produção das sedas de aranhas. A aplicação dos resultados para o desenvolvimento de fibras sintéticas não estão limitados tecnologicamente por elementos naturais. Será possível melhorar materiais biológicos além de suas capacidades naturais. Por exemplo, estruturas de proteínas como nanocristais de folhas-beta poderão ser combinadas com nanoestruturas, como nanotubos de carbono ou grafite, e assim permitir o desenvolvimento de nanocompostos com estruturas mais eficientes. As oportunidades para desenvolver materiais com propriedades mecânicas que poderão ser controladas por estímulos externos, como temperatura, pH, campos magnéticos ou elétricos tem sido avaliados. Referente a produção em larga escala, a agricultura molecular tem apresentado evidências que as plantas, de soja e tabaco, são um meio eficaz de produzir uma variedade de proteínas recombinantes. Associados a engenharia da estrutura modular de proteinas das fibras de diferentes aranhas, foram gerados eventos de soja que acumulam fibras recombinantes nas sementes de soja e bactéria geneticamente modificadas. Atualmente, existem ainda ligações-chave necessárias para um pleno entendimento e utilização comercial das fibras das aranhas, incluindo: as relações entre estrutura da proteína natural/recombinante e as propriedades mecânicas das fibras; o papel que a produção da fibra desempenha na determinação das propriedades mecânicas; a capacidade do desenvolvimento de sistemas purificação e extrusão das fibras em larga escala; e como deverão ocorrer as aplicações comerciais dos novos biomateriais.Na publicação: Elibio Rech
Genomics and synthetic biology as a viable option to intensify sustainable use of biodiversity
Get PDFThe Amazon basin is an area of mega-biodiversity. Different models have been proposed^1-8^ for the establishment of an effective conservation policy, increasing sustainability and adding value for biodiversity. Currently, a broad spectrum of technologies from genomics to synthetic biology is available, and these permit the collection, manipulation and effective evaluation of countless organisms, metabolic pathways and molecules that exist as potential products of a large, biodiverse ecosystem. The use of Genomics and synthetic biology may constitute an important tool and be a viable option for the prospection, evaluation and manipulation of biodiversity as advocated as well as be useful for developing methods for sustainable use and the production of novel molecules
Downstream process engineering evaluation of transgenic soybean seeds host for recombinant protein production.
Get PDFSoybean seeds as bioreactor to produce recombinant proteins.
Get PDFThe development of technologies for the introduction and expression of foreign genes in soybean has allowed studies of gene function and resulted in important advances toward plant genetic engineering carrying several input and output traits. The production of recombinant proteins in plants has several potential advantages over current systems such as mammalian and bacterial cell cultures, including the lower costs, scalability of agricultural production and the absence of human pathogens. A large number of plant host systems has been tested, including plant cell cultures, unicellular plants, aquatic plants grown in containment, and, most notably, food and non-food crops, which can be grown in greenhouses, underground growth facilities, or the open field. The use of genetically modified (GM) plants to synthesize proteins that are subsequently processed, regulated and sold as pharmaceuticals challenges two very different established regulatory frameworks, one concerning GM plants and the other covering the development of biotechnology-derived drugs. Within these regulatory systems, specific regulations and guidelines for plant-made pharmaceuticals – also referred to as plant-derived pharmaceuticals – are still evolving (Spok et al., 2008). The products nearing commercial viability will ultimately help to road test and fine-tune these regulations, and might help to reduce regulatory uncertainties. To understand what technical or economic forces have enticed a major hole in the pharmaceutical industry into the utilization of plant, one need to look at the relation cost/added value and time to develop a product (Rech, 2009, in press). Our research group has been actively involved in the evaluation of the potential utilization of soybean seeds as novel system to manufacture biopharmaceuticals (Rech et al., 2008). The human growth hormone, human coagulation factor IX, insulin, single-chain variable domain, cyanovirin and grifitisin (microbicides), plac, gage and lack (cancer antigens) and masp1 and masp2 (biofibers) genes under control of the seed specific regulatory sequences, including the phaseolin and conglycinin promoters were linked to different signal peptides in order to direct the recombinant proteins to the protein storage vacuoles present in the soybean seed. The transgenic events have been generated utilizing the biolistic technology (Rech & Aragao, 1997). The apical meristematic region of mature soybean embryonic axes were excised, and bombarded with the plasmid DNA’s. Then, the bombarded embryonic axes were transferred to the culture medium containing MS basal salts, sucrose and cytokinin. After three to five weeks in culture, putative transgenic shoots were excised and transferred to the greenhouse to further development. Molecular and biochemical evaluation were conduct to determine integration and the recombinant proteins accumulation. We do believe that the results obtained, will form the foundation to evaluate the potential commercial utilization of soybean plants as bioreactor.Na publicação: Elibio Rech
Molecular dynamics simulations of the minor ampullate spidroin modular amino acid sequence from Parawixia bistriatra: insights into silk tertiary structure and fibre formation.
Get PDFMicroparticle bombardment of Stylosanthes guianensis: transformation parameters and expression of a methionine-rich 2S albumin gene.
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Previous issue date: 2007-01-0
Production of recombinant human coagulation Factor IX in the milk of genetically modified mice.
No full textTransgenic animals present attractive applications in biomedicine and to improve livestock production traits. Expression of biopharmaceutical proteins in transgenic animals is an attractive alternative due to the possibility of reducing production costs and to overcoming the limitations from the others expression systems. The aim ofthis work was to express the human coagulation Factor IX in transgenic mice. The human coagulation Factor IX gene was cloned into the vector pBC1 under control of beta-casein promoter that directed the expression of the gene almost exclusively to the lactating mammary gland. For the production of transgenic mice, the transgene was inserted into the host genome by microinjection. Studies were carried out to evaluate the presence of the foreign gene inserted into mice founders (Fo), F1 and F2 generations, utilizing PCR and Southern blot analysis. The human coagulation Factor IX was detected in the milk of transgenic animals by western blot and ELISA assays. Transgenic mice were capable of producing recombinant proteins secreted at levels as high as 20-35 µg/mL. in the milk. Hemoaglutination bioassays were carried to confirm protein activity demonstrating its functionality. This work will be the foundation for the future application of the DNA recombinant technology for production of pharmaceuticals recombinant proteins in a large-scale basis in other animals such as cow and goat
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