Molecular Characterization of Apolipophorin-III in the Fall Webworm, Hyphantria cunea Drury

We isolated and sequenced a cDNA clone corresponding to apolipophorin-III (apoLp-III) from the fall webworm, Hyphantria cunea. The cDNA for apoLp-III codes fer a 187-residue protein (561 bp) with a predicted molecular mass of 20 kDa. The calculated isoelectric point is 8.76. Multiple alignment analysis of the amino acid sequence revealed that H. cunea apoLp-III is most similar to that of Spodoptera litura (71.5% identity), followed by that of Manduca sexta (69.7% identity). They share five amphipathic $\alpha$-helices that are proposed to play a critical role in the binding of apoLp-III to lipophorin.