Abstract: he gene of structural protein VP1 was cloned from chicken-embryo-adapted attenuated vaccine strain MY of duck hepatitis type 1 virus by nested-PCR. Then, the VP1 gene was subcloned into the vector pMD18-T, and the gene fragment was 714 bp. In GenBank submitted for GU363950. The main antigen sites of VP1 gene from strain MY was predicted, and the segment containing 208-222 amino acid exhibited high hydrophilicity, antigenic index and surface probability. After being double digested by EcoR Ⅰand XhoⅠ, VP1 gene was subcloned into prokaryotic expression vector pET32a (+) to construct expression plasmid pET-VP1. The pET-VP1 was transformed into BL21 PLyss (DE3) and induced by IPTG. SDS-PAGE analyses showed that a fusion protein with relative molecular mass of 47 ku was expressed in Escherichia coli. Western blotting analyses showed that specific immune response could occur with this protein and duck hepatitis virus positive serum, and this protein had good reactionogenicity.

Key words: duck hepatitis; prokaryotic expression; SDS-PAGE; Western blotting