LIPOPHORIN OF THE LARVAL STALK BORER, BUSSEOLA-FUSCA - PURIFICATION AND PROPERTIES

Lipophorin was isolated from the stalk borer, Busseola fusca, larvae b y ultracentrifugation in a KBr density-gradient. The lipophorin (M(r) approximately 700,000) is a high density lipoprotein (density = 1.13 g /ml) composed of 46% lipids and 4% carbohydrates. It consists of two a poproteins, apolipophorin-I (apoLp-I, M(r) approximately 210,000) and apolipophorin-II (apoLp-II, M(r) approximately 78,000). Both apoprotei ns are glycosylated as shown by periodate Schiff reagent staining and binding to the lectin, concanavalin A. Amino acid composition analysis of lipophorin showed predominance of aspartate (13%), glutamate (9%) and glycine (9%). In an immunoblotting experiment, both apoproteins sh owed immunoreactivity with antiserum to B. fusca lipophorin and no cro ss-reactivity occurred with any other haemolymph proteins. Immunodiffu sion studies with the same antibodies showed cross-reactivity with hae molymph derived from other Lepidoptera and not from Orthoptera, Dictyo ptera or Diptera.