Tripsinas do peixe guarajuba (Carangoides bartholomaei): extração, purificação e caracterização

Abstract

In recent years, fish consumption has increased, and its production has almost tripled in recent decades. The species Carangoides bartholomaei is a medium to large marine fish widely consumed on the northeastern coast. Within this context, the waste accumulation generated by the processing of consumed fish causes an environmental problem due water and soil pollution when improperly discarded. However, several studies show that these wastes can be important sources of bioactive molecules that can be applied in biotechnological and industrial processes. Therefore, the aim of this study was to extract, purify and characterize trypsin-like enzymes present in the pyloric cecum of the C. bartholomaei. Trypsins were purified by salting out and affinity liquid chromatography. Enzyme activity was determined using BApNA as substrate. The effects of chemical agents, pH and temperature on enzymatic activity were evaluated. The compatibility of C. bartholomaei trypsins with commercial detergents was evaluated. The trypsins showed important characteristics such as an optimal temperature of 50 °C, being stable between 25 °C and 40 °C for 60 min. The optimal pH for enzymatic activity was pH 8.0 and it was stable from pH 5.0 to pH 11.5. The Km was determined to be 0.73 mM for BApNA. The Trypsins were completely inhibited by TLCK inhibitor. The ion HgCl2 promoted a high enzymatic inhibition at all concentrations, while AlCl3 promoted slight activation in the same concentrations. Through SDS-PAGE it was possible to identificate two bands: one of 20 kDa and another of 24 kDa. C. bartholomaei trypsins maintained high activity in the presence of commercial detergents. The results suggest that the pyloric caecum of C. bartholomaei is a source for obtaining trypsins compatible with the commercial detergents. The physicochemical characteristics of these trypsins suggest that it’s are promising enzymes in biotechnological and industrial applications.