Inhibits trypsin-like proteases from the guts of the insect pests P.truncatus, P.americana, Acheta sp and Gryllus sp. Optimum pH is 8.0. Alkaline pH values decrease the thermostability of this inhibitor. Thermostable. 10% inactivation is seen after incubation at 95 degrees Celsius for 2 hours at pH 9.0. Retains activity after incubation at 120 degrees Celsius for 1 hour at pH 3.0 and pH 7.0, but at pH 9.0 40% of the activity is lost. Contains disulfide bonds.