Proteases of Stored Product Insects and their Inhibition by Specific Protease Inhibitors from Soybeans and Wheat Grain

摘要

Specific protease inhibitors, which inhibit digestive proteases of insects, have evolved in plants. These inhibitors are of potential interest in protection of valuable crops from damage by insects. It has been the objective of the present study to isolate and characterize digestive proteases of several model insect pests and to investigate their naturally-occurring inhibitors from legume seeds and grains. The separation and partial characterization of trypsin and chymotrypsin-like enzymes from the digestive tracts of the insects Tenebrio molitor, Tribolium castaneum and Locusta migratoria and the inhibitability of these enzymes by proteinaceous trypsin-chymotroypsin inhibitors from soybeans and chick peas suggest that these insects may be affected by the inhibitors in vivo. The lack of disulfide bridges in the insects proteases suggest a difference in their conformation and assembly from that known for the respective mammalian enzymes.