Identification of the interaction domains of white spot syndrome virus envelope proteins VP28 and VP24

•The accurately interaction domains of WSSV VP28 and VP24 were mapped.•There are two VP28-binding domains in VP24 and one VP24-binding domain in VP28.•Synthetic peptides spanning the binding domains inhibit VP28–VP24 interaction.

VP28 and VP24 are two major envelope proteins of white spot syndrome virus (WSSV). The direct interaction between VP28 and VP24 has been described in previous studies. In this study, we confirmed this interaction and mapped the interaction domains of VP28 and VP24 by constructing a series of deletion mutants. By co-immunoprecipitation, two VP28-binding domains of VP24 were located at amino acid residues 46–61 and 148–160, while VP24-binding domain of VP28 was located at amino acid residues 31–45. These binding domains were further corroborated by peptide blocking assay, in which synthetic peptides spanning the binding domains were able to inhibit VP28–VP24 interaction, whereas same-size control peptides from non-binging regions did not.