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Construção e caracterização de uma enzima quimérica obtida pela fusão gênica endoglucanase-xilanase de Trichoderma harzianum
(Universidade Federal de São Carlos, 2013-02-05) Santiago, Adelita Carolina; Silva, Flávio Henrique da; https://lattes.cnpq.br/1757309852446263; https://lattes.cnpq.br/8140765349742143
The sugarcane bagasse is a lignocellulosic material that can be converted into ethanol by action of cellulases and xylanases. These enzymes act synergistically to convert cellulose and hemicellulose into glucose. In order to obtain an enzyme that can perform dual function, a chimeric enzyme cellulase-xylanase denominated ThEg3Xyn3, was constructed by gene fusion in our laboratory. The fusion was performed by binding the C-terminus of an endoglucanase from Trichoderma harzianum to the N-terminus of a xylanase of the same fungus, separated by a linker. The chimeric enzyme was recombinantly produced in Pichia pastoris and purified for kinetic and biochemical characterization. The chimera demonstrated activity of both enzymes with maximum activity at 38 °C and pH 6.0, under these conditions, cellulolytic and xylanolytic activity was greater than of the parental enzymes. The results demonstrate that the chimeric enzyme can be efficient in hydrolysis of the biomass and satisfactory for the production of ethanol by the process of simultaneous saccharification and fermentation.
Obtenção e caracterização de microesferas de copolímero PLDLA contendo paclitaxel
(Universidade Federal de São Carlos, 2013-02-05) Martins, Kelly Fernanda; Duek, Eliana Aparecida de Rezende; https://lattes.cnpq.br/4147198882685212; https://lattes.cnpq.br/9137548650745170; Leite, Fábio de Lima; http://lattes.cnpq.br/5490031389817518
In order to minimize the side effects of chemotherapy concurrently with the enhancement of its therapeutic action is to use it on devices that enable a controlled drug release, by vectors, such as polymeric microspheres, which act as a drug carrier, modifying its distribution pattern in the organism. Paclitaxel ((Taxol®) is a drug used primarily in the treatment of ovarian, breast, lung and bladder cancer. Due to its antimitotic and antiproliferative action, there is a potential interest in cancer therapy. However, the success of this clinical application is limited to low solubility in water and toxic action. The objective of this study was to obtain and characterize physic-chemically the bioresorbable and biocompatible copolymer poly (L-co-D, L lactic acid) (PLDLA) microspheres encapsulating the paclitaxel chemotherapy. The simple emulsion technique allowed to obtain spherical microspheres, verified by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The average size of the microspheres PLDA pure and containing paclitaxel were, respectively, 10.3 μm ± 1.7 and 12.7 μm ± 1.3, obtained by the technique of laser light scattering (LLS). Moreover the essay of differential scanning calorimetry (DSC) suggests that the drug paclitaxel is homogeneously dispersed in the microspheres PLDLA. The encapsulation efficiency of the microspheres PLDLA paclitaxel was 98.0% ± 0.3, obtained by high performance liquid chromatography (HPLC). The in vitro release study performed on HPLC showed initial burst release followed by a slower release, which characterizes large diameter distribution systems. PLDLA microspheres released 90% ± 4.0 of the drug paclitaxel up to 30th day of study while the degradation process occurred. Thus, the microspheres obtained PLDLA devices are promising as carriers of paclitaxel, with potential for future applications in drug delivery systems.