Biochemical Characterization of the Digestive Proteases in the Small Black and Yellow Wasp, Allantus viennensis Schr. (Hym.: Tenthredinidae)

Abstract

Knowledge on digestive proteases enzymes of insects needed for making transgenic plant expressing protease inhibitors to reach an alternative method to chemical control. In present study, biochemical properties of digestive proteases were determined in the alimentary canal of the small black and yellow wasp, Allantus viennensis as important pest of Rose bushes. Determining the proteolytic activity in gut of different larval instar of A. viennensis (2-5) showed that the enzyme activity increased with growing the larvae. The higher activity was found in the fifth instars larvae (7.46±0.06 µmol^-1min^-1mg^-1 protein). Also, comparison of proteolytic activities in different parts of digestive system of the fifth instars larvae showed that the enzyme activity in midgut was very higher than that found in the foregut and hindgut. The optimal pH and temperature for enzyme activity in gut of fifth instars larvae was found at pH 10 and 30°C, respectively. Most inhibitory effect on the protease activity was obtained by PMSF as serine proteinases inhibitor (36.85%). The results of SDS-PAGE confirm the obtained data of inhibition assay. It showed that the serine proteinases are the major hydrolysing enzymes in the gut of larvae of A. viennensis