Inhibits trypsin but not chymotrypsin, papain or porcine pancreatic alpha-amylase. Has insecticidal activity against A.aegypti. Functions by inhibiting the A.aegypti midgut proteases to reduce the survival of larva and adults. Preferential cleavage: Arg-|-Xaa, Lys-|-Xaa. Stable in the pH range 2.2-10.0. Stable at temperatures up to 70 degrees Celsius. Incubation at temperatures above 70 degrees Celsius steadily decreases inhibitory activity. Monomer. Belongs to the protease inhibitor I3 (leguminous Kunitz-type inhibitor) family.