A new female-specific fat body protein of Antheraea pernyi: purification, immunological properties, developmental profile and synthesis

Abstract

A new female-specific protein has been discovered to be a major component of fat body proteins of the last larval instar of Antheraea pernyi and Antheraea yamamai. The new female-specific protein was purified to homogeneity by gel-permeation chromatographies, DE-52 cellulose column chromatography and hydroxyapatite column chromatography. The molecular weight of the protein was estimated to be 24,000 by SDS-PAGE and 43,000 by gel-permeation chromatography, suggesting that the protein is a homodimer protein. The protein was temporarily named “24 kDa peptide” (24K). Developmental changes in 24K titer were followed from the final larval ecdysis to adult emergence by immunoblotting with a specific antiserum against 24K. 24K appeared in the fat bodies at day 9 fifth instar and remained at an almost constant level up to adult emergence. Immunoblot analysis using antisera against Bm 30K proteins and BmLSP showed that the immunological properties of 24K were different from those of these proteins. In vitro culture to label fat body proteins with [ 35S]-methionine showed that the synthesis of 24K occurred in only female fat bodies. The function of 24K remains unknown.