Identification of epitope on DNA-binding protein expressed in insect cell infected by baculovirus.

DNA-binding protein (DBP) is an early gene product produced during viral replication. Polyclonal anti-DBP was produced using rabbit by intradermal injections of Escherichia coli-expressed purified recombinant DBP. Prepared anti-DBP completely blocked the replication of baculovirus in insect cells. The anti-DBP binding to DBP was confirmed by both Western blotting with Tn-5B1-4 insect cell lysates as well as immunostained baculovirus-infected Tn-5B1-4 insect cells. To determine the anti-DBP epitope 12 peptides were synthesized and their specific-binding activities were measured using ELISA. Based on specific-binding activity against anti-DBP the epitope was predicted to be between amino acid residues 248-265 (QRMSVEDFDRLFEMDKID). Especially from 18 amino acid residues it was further to be narrowed between amino acid residues 260-265 (EMDKID) which showed a critical role in specific-binding activity.