Inhibition of prophenoloxidase-activating enzyme from Bombyx mori by endogenous chymotrypsin inhibitors.

Abstract

Inhibitory activities for the activation of prophenoloxidase with its activating enzyme were detected in the gel-filtration fractions of hemolymph from Bombyx mori. The fractions with the highest activity contained chymotrypsin inhibitors; CI-13a, 13b, and 13c. They inhibited the activation of prophenoloxidase. The activating enzyme affected a synthetic substrate for trypsin, Boc-Gln-Ala-Arg-MCA: Km = 0.62 mM. CI-13c partially suppressed the peptidase activity.