A TARGET PROTEASE ACTIVITY OF SERPINS IN INSECT HEMOLYMPH

Two zymogens of the serine enzymes (prophenoloxidase activating enzyme and BAEEase, an enzyme hydrolyzing N-alpha-benzoyl-L-arginine ethyl ester), which are thought to be components of prophenolox-idase cascade in silkworm (Bombyx mori) plasma, were activated through the action of microbial cell wall components. The two active enzymes of the zymogens were studied with regard to the regulation of their activities by two endogenous serpins (silkworm anti-trypsin and silkworm anti-chymotrypsin). BAEEase activity was shown to be inactivated by silkworm antitrypsin, whereas the inactivation of prophenoloxidase activating enzyme by either of silkworm antitrypsin and silkworm anti-chymotrypsin could not be demonstrated under the experimental conditions.