Identification by MALDI-TOF MS and expression pattern of a low molecular weight protein, Apolipophorin III, from hemolymph in the silkworm Bombyx mori

We used SDS-PAGE electrophoresis to study hemolymph at diffirent stages. We found a low molecular weight protein from hemolymph in silkworm Bombyx mori, whose expression level increase sharply at the stage of moth. By using two-dimensional polyacrylamide gel electrophesis and PMF, we identified the protein as Apolipophorin Ⅲ. RT-PCR analysis indicated that the transcript of Apolipophorin Ⅲ was expressed in all tissues tested except to malpighian tube. These results suggest that Apolipophorin Ⅲ played not only in the movement of moth, but also involve in other important biological processes of larve and pupa.