Purificação parcial e caracterização de uma TAG- lipase do gorgulho do milho Sitophilus zeamais

Abstract

The triacylglycerols, in class of neutral lipids, are essential to maintenance of life in most vertebrates and invertebrates, since part of the energy reserve and serve as substrates for the synthesis of secondary metabolites. Insects mobilization and digestion of this energy reserve is the action of triacylglycerol lipase (TAG- lipase) that provides these lipids in the form of diacylglycerol (DAG) and free fatty acids. Substances that interact and are able to inhibit enzymes essential to survival of insects are a promising alternative for the control of pests. Thus, this study aims to purify and characterize partially-TAG lipases of Sitophilus zeamais insect from its enzymatic extract as possible targets for the development of new forms of control. Partial purification of TAG-lipase was performed using a hydrophobic interaction column with enzymatic extract injection in which four fractions showed lipase activity. Then the fractions were immobilized by SDS-PAGE and confirmed by zymography. A lipase with a molecular mass of approximately 50 kDa. Then the four samples were bonded was taken and characterization of the lipase. It was shown that has lipase activity increasing with increasing concentration of protein, was also exposed to the ionic strength was able to inhibit the lipase activity, and that the optimum pH of the partially purified lipase was 8.5. Finally the lipase used was partially inhibited with PMSF inhibitor, showing that the isolated enzyme is serine protease characteristic of the active site.