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The bacterium Pseudomonas fluorescens 07A produces a protease with potential for industrial application. In order to remedy problems associated with the use of free enzymes and allow its reuse, the protease was immobilized on DEAE Sephacel® resin via three different strategies based on ionic interaction and covalent bonding. The matrix-bound enzymes were characterized in relation to their activity (pH, temperature and stability), reuse and storage. Immobilization raised the optimum temperature of activity from 37 °C to 50 °C, whereas the pH of highest activity changed from 7.5 to 7.0 or 8.0, depending on the immobilization strategy. Immobilization proved to be efficient for successive reuses, even leading to an increase in the enzymatic activity along the use. The immobilized enzyme also presented greater stability to high temperatures and storage conditions and has potential as a biocatalyst for industrial applications due to its high efficiency, stability and easy recovery.

Chagas disease is a potentially fatal infection in 21 endemic Latin America countries for which the effectiveness of reference antiparasitic chemotherapy is limited. Thus, we developed three biopharmaceuticals and evaluated the effectiveness of different immunization strategies (recombinant protein NTPDase-1 [rNTPDase-1], DNA plasmid encoding Trypanosoma cruzi NTPDase-1 [TcNTPDase-1] and DNA-NTPDase-1 prime/rNTPDase-1 boost [Prime-boost]) based on the surface ecto-nucleoside triphosphate diphosphohydrolase (ecto-NTPDase) enzyme of T. cruzi in animals challenged with a virulent strain (Y) of this parasite. BALB/c mice were immunized three times at 30 days intervals, challenged with T. cruzi 15 days after the last immunization, and euthanized 30 days after T. cruzi challenge. Our results showed limited polarization of specific anti-ecto-NTPDase immunoglobulins in mice receiving both immunization protocols. Conversely, the Prime-boost strategy stimulated the Th1 protective phenotype, upregulating TNF-α and downregulating IL-10 production while increasing the activation/distribution of CD3