White spot syndrome virus (WSSV) is one of the most virulent pathogens causing high mortality in shrimp. Herein, the characterization of VP24, a major structural protein of WSSV, is described. When purified virions were subjected to Nonidet P-40 treatment to separate the envelopes from the nucleocapsids, VP24 was found to be present exclusively in the envelope fraction. Triton X-114 extraction also indicated that VP24 behaves as an envelope protein. Immunoelectron microscopy further confirmed that VP24 is located in the virion envelope. Far-Western experiments showed that VP24 interacts with VP28, another major envelope protein of the WSSV virion. To investigate the function of VP24, WSSV was neutralized with various amounts of anti-VP24 IgG and injected into crayfish. The results showed that anti-VP24 IgG could partially attenuate infection with WSSV. It is concluded that VP24 is an envelope protein and functions at an early stage in virus infection.
Identification and characterization of a prawn white spot syndrome virus gene that encodes an envelope protein VP31
