Storage protein uptake in Helicoverpa zea. Purification of the very high density lipoprotein receptor from perivisceral fat body.

In prepupae of the corn earworm, Helicoverpa zea, storage proteins are taken up by perivisceral fat body, a specialized storage tissue. In this study, the receptor protein for one of these storage proteins, a very high density lipoprotein, was identified, extracted, and purified to homogeneity. The very high density lipoprotein receptor is a glycosylated basic protein with a pI of 8.2 and an apparent molecular weight of 80,000. Binding requires the presence of Ca2+ and has a pH optimum of 7.0. Electron micrographs of immunogold labeled sections show that the receptor is located in the plasma membrane of perivisceral fat body. No receptor is detectable in peripheral fat body which does not sequester storage proteins.