Methods for making a modified Cry3A toxin are disclosed. Such methods
include the insertion of a protease recognition site that is recognized
by a gut protease of a target insect, such as corn rootworm, into at
least one position of a Cry3A toxin so that a modified Cry3A toxin is
thus designed. The coding sequence of the modified Cry3A toxin may be
transformed into a host cell and the host cell grown under conditions
that allow the host cell to produce the modified Cry3A toxin. The host
cell may be a plant cell and the plant may be comprised in a transgenic
plant. Thus, the transgenic plant may be used to produce the modified
Cry3A toxin.