Navegando por Palavras-chave "Biofísica"

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    Produção e caracterização de leptina e TcPTP1 recombinantes, proteínas ligadas ao metabolismo, sinalização celular e inflamação
    (Universidade Federal de São Paulo (UNIFESP), 2010-08-25) Gallo, Gloria [UNIFESP]; Pesquero, João Bosco [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Leptin is predominantly secreted by adipocytes and plays an important role in the regulation of the energetic metabolism of mammals. Because of this, leptin is strongly involved in the regulation of obesity. After ligation, dimerization and activation of its specific receptor in the hypothalamus, leptin activates JAK kinases that phosphorylate STAT transcription factors, which in turn up-regulate energetic expenditure and lead to the inhibition of hunger. Leptin signalling is downregulated by a phosphotyrosine phosphatase named PTP1B. The aim of this work is the cloning, expression and purification of recombinant human leptin in E. coli. After induction, recombinant leptin was produced in E.coli BL21(DE3) in an insoluble form, purified by nickel-afinity chromatography, refolded using serial dialysis and concentrated up to 3mg/ml. Injection of this recombinant protein in ob/ob mice, which are devoid of leptin, leads a reduction of body weight by 8% and a reduction of food intake by 50%, thus confirming the biological activity of the protein. In order to enrich this study, we produced a targeted mutation of this recombinant leptin (called mutein) wich act as an antagonist. In other hand, Additionaly to this work, we also cloned, expressed, purified and biochemically characterized a phosphotyrosine phosphatase from Trypanosoma cruzi termed TcPTP1, which is homologous to mammalian PTP1B. TcPTP1 is an interesting medical target because of its potential influence in the regulation of cell signalling in T.cruzi. The production and biochemical characterization of TcPTP1 is the basis for functional and structural studies that can lead to the design of new inhibitors of this enzyme, which seems to be vital for the parasite.
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    Radiação ionizante: o que os olhos não veem, o coração sente
    (Universidade Federal de São Paulo (UNIFESP), 2022) Vincentin Junior, Carlos Antonio [UNIFESP]; Plens, Cláudia Regina [UNIFESP]; http://lattes.cnpq.br/2142424336909827; http://lattes.cnpq.br/3208916221283027; Universidade Federal de São Paulo (UNIFESP)
    Invisible, but as lethal as a projectile expelled by a firearm, ionizing radiation can cause irreversible damage to human beings, generating from a skin lesion to the death of the individual. Many of the effects caused by the interaction of this electromagnetic wave with the body occur late, and treatment to prevent its proliferation in the body is not possible. Countless times these biological damages generate a sudden change in the quality of life of those who interacted with radiation, whether intentionally or not. Despite these facts, there is a way to prevent its fatal effects. It is enough to have security for those who work with this type of energy and also inspections to ensure that accidents do not occur, such as the one in Goiânia with the Cesium element or the Chernobyl nuclear power plant. In other words, respecting the human rights of workers, especially those who work at risk, preserves the most precious asset of human beings: life.