Trypsins: Structural Characterization and Inhibition Focus in Insects

Abstract

Serine proteases are considered the main class of protein digestive enzymes present in the midgut of many lepidopteran species and are the focus of the review in this chapter. Among them, trypsin and chymotrypsin are the most studied and participate in a great diversity of physiological processes that include, in addition to digestion, activation of specific proteins, such as in the coagulation cascades, in the immune system of insects and plants, in the development and production of biologically active peptides, in signal transduction, hormone activation, and development. In this chapter, a review was made of the structural characteristics of trypsins, specifically of Lepidoptera insects, main experimental and theoretical techniques for the study of their function and structure, and interaction with other proteins and ligands as protease inhibitors. Finally, it was described how this type of hydrolases can be a focus of inhibition in pests to the detriment of the development and death of the target insect. Until now, the main strategies of agricultural crop management, especially of large crops, consist of the use of inorganic pesticides and transgenic cultivars containing Bacillus thuringiensis toxins. Therefore, new and ecologically friendly strategies are necessary, such as the use of protease inhibitors.