CHARACTERIZATION OF A NOVEL PROTEIN ASSOCIATED WITH THE PARASITIZATION OF LEPIDOPTERAN HOSTS BY AN ENDOPARASITIC WASP

We report basic biochemical characteristics of a parasitism-specific protein (PSP) expressed in hosts (Trichopluisa ni) of a parasitic wasp (Chelonus near curvimaculatus). Size exclusion HPLC and SDS-PAGE analysis of cross-linked products indicated the native conformation of the protein is as a monomeric polypeptide with an estimated M(r) of 185,000. Resolution by non-denaturing PAGE revealed two major PSP bands with different charges, PSP-1 and PSP-2, each of which corresponded to several isoforms on native [EF with a pl range of 4.57-5.45. Sequences for the N-terminus region and internal peptides after fragmentation of purified preparations of PSP-1 and PSP-2 did not resemble the sequence of ady reported protein. Immunological characterization of PSP using antibodies generated against virus proteins from C. near curvimaculatus female wasps revealed that PSP shares a common epitope(s) with some structural components of the wasp polydnavirus.