Cathepsin D-like aspartic proteinase occurring in a maize weevil, Sitophilus zeamais, as a candidate digestive enzyme.

The maize weevil, Sitophilus zeamais, is an insect pest infesting rice and corn seeds. We identified an aspartic proteinase (AP) digesting rice glutelin in the alimentary tract of S. zeamais. The mRNA encoding the AP (SAP1) was expressed in the larvae foregut and in the adult midgut. These results indicate that SAP1 is probably digestive enzyme of S. zeamais.