CATHEPSIN B AND AMINOPEPTIDASE ACTIVITY IN THE POSTERIOR MIDGUT OF EUSCHISTUS EUSCHISTOIDES (HEMIPTERA: PENTATOMIDAE)

Abstract
The posterior midgut of a seed-feeding pentatomid, Euschistus euschistoides (Vollenhoven), contains the proteinases cathepsin B and aminopeptidase. Cadiepsin B hydrolysis of benzoyl-DL-arginine-2-naphthylamide is activated by thiol chemicals and EDTA. Aminopeptidase hydrolysis of leucine-p-nitroanilide is activated by MgCl2 and inhibited by cysteine, glutathione, EDTA, and CaCl2. These results are similar to those obtained for cathepsin B and aminopeptidase from blood-feeding Hemiptera and support the hypothesis that catheptic proteinases are unique to this order.