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 p rotein (PSP) expressed in hosts (Trichopluisa ni) of a parasitic wasp (Chelonus near curvimaculatus). Size exclusion HPLC and SDS-PAGE analy sis of cross-linked products indicated the native conformation of the protein is as a monomeric polypeptide with an estimated M(r) of 185,00 0. Resolution by non-denaturing PAGE revealed two major PSP bands with different charges, PSP-1 and PSP-2, each of which corresponded to sev eral isoforms on native [EF with a pl range of 4.57-5.45. Sequences fo r the N-terminus region and internal peptides after fragmentation of p urified preparations of PSP-1 and PSP-2 did not resemble the sequence of ady reported protein. Immunological characterization of PSP using a ntibodies generated against virus proteins from C. near curvimaculatus female wasps revealed that PSP shares a common epitope(s) with some s tructural components of the wasp polydnavirus.