PURIFICATION AND CHARACTERIZATION OF MULTIPLE FORMS OF ODORANT PHEROMONE BINDING-PROTEINS IN THE ANTENNAE OF MAMESTRA-BRASSICAE (NOCTUIDAE)/

Proteins extracted from the antennae of Mamestra brassicae (L.) (Lepid optera: Noctuidae) adults were biochemically characterized as pheromon e-binding proteins (PBP) and general odorant-binding proteins (GOBP). PBP and GOBP were purified by two successive and different HPLC (high performance liquid chromatography) systems and native polyacrylamide g el electrophoresis (native-PAGE). Their N-terminal sequence was determ ined by Edman microsequencing, The combined results showed evidence fo r three different PBPs in males, and two different PBPs in females, In addition, one GOBP was characterized in both males than in females an tennae, In the males, two isoforms of PBP have the same N-terminal seq uence, but different apparent mobilities and hydrophobicities: they co uld be separated by electrophoresis and reverse phase-HPLC (RP-HPLC). The other PBP sequence (SQEIM) showed particularly high homology (88%) with the PBP of Heliothis virescens, another noctuid moth. The existe nce of several forms of PBP in the same animal strongly supports the h ypothesis of the specificity of binding between the proteins and their odorant ligands, the pheromonal compounds. The observed microdiversit y at the soluble proteins level could provide a good model for studyin g their involvement in the initial stages of odor discrimination.