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 e ster), which are thought to be components of prophenolox-idase cascade in silkworm (Bombyx mori) plasma, were activated through the action o f microbial cell wall components. The two active enzymes of the zymoge ns were studied with regard to the regulation of their activities by t wo endogenous serpins (silkworm anti-trypsin and silkworm anti-chymotr ypsin). BAEEase activity was shown to be inactivated by silkworm antit rypsin, whereas the inactivation of prophenoloxidase activating enzyme by either of silkworm antitrypsin and silkworm anti-chymotrypsin coul d not be demonstrated under the experimental conditions.