Characterization of white spot syndrome virus VP52B and its interaction with VP26.

White spot syndrome virus (WSSV) is one of the major pathogens of cultured shrimp. Identification of envelope protein interactions has become a central issue for the understanding of WSSV assembly. In this paper, WSSV envelope protein VP52B was fused with GST-tag and expressed in Escherichia coli BL-21(DE3). Immunogold-electron microscopy revealed that VP52B was located on the outside surface of WSSV virions. Far-Western blotting analysis suggested that VP52B might directly interact with a major viral envelope protein VP26, and their interaction was confirmed by GST pull-down assay. Further investigation showed that the VP52B binding domain was located between residues 135-170 of VP26. These findings will enhance our understanding of the molecular mechanisms of WSSV morphogenesis.