Research:

A potential subunit vaccine against enterotoxigenic strains of Eschericia coli that cause traveler's diarrhea was developed at the Plant Transformation Facility at Iowa State University (Chikwamba et al, 2002). The expression of the heat labile enterotoxin B subunit (LT-B) of E.coli in maize resulted in accumulation of the recombinant LT-B inside the starch granules of the transgenic maize kernels, when expressed under the 27kD gamma-zein promoter. We are using maize-derived LT-B as a model recombinant protein to study protein trafficking in the maize kernel. We are generating translational fusions with reporter genes such as the green fluorescent protein, GFP, to track the movement of the proteins during kernel development and to identify potential players in protein translocation into the amyloplast of the maize kernel. Accumulation of recombinant proteins in the starch granule presents a number of advantages for extraction and purification of recombinant proteins.

Translocation of recombinant protein to starch granules of transgenic maize kernels (Chikwamba et al, 2003)