Characterization of novel insect associated peptidases for hydrolysis of food proteins

Insects are able to feed on a broad spectrum of nutritional sources, due to a variable enzymatic system which can be endogenic or provided by associated microorganisms. This enzymatic system may be employed for the hydrolysis of industrial relevant proteins. Several grain pests were screened for their ability to hydrolyze storage proteins from wheat and rice as well as casein. Zymograms identified hydrolytic activities of the lesser grain borer Rhizopertha dominica against gluten and rice protein. Besides, R. dominica showed the highest prolyl-specific peptidase activity among all tested insects. Enzyme extracts of R. dominica were purified via anion exchange chromatography using a fast protein liquid chromatography system. Two of the purified peptidase fractions were able to hydrolyze peptides from wheat and barley relevant for celiac disease showing a proline preferential cleaving pattern.