Proteomic analysis of the Decapod iridescent virus 1

Decapod iridescent virus 1 (DIV1) is one of the major pathogens of farmed shrimp. In this study, the structural proteins of DIV1 were analyzed by mass spectrometry. DIV1 virions were purified from the hemolymph of artificially infected Cherax quadricarinatus. The viral proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and a total of 28 protein bands were obtained. These protein bands were in-gel digested with trypsin and the resulting tryptic peptide mixtures were subjected to liquid chromatography with tandem mass spectrometry analysis. Thirty virus-encoded proteins were identified. Among them, 6 proteins were predicted to contain transmembrane domains, 3 proteins were predicted to contain an Arg-Gly-Asp motif. Nine proteins showed significant homology with functionally characterized proteins. Antibodies were produced for these candidate proteins and 23 of them were confirmed to be the components of DIV1 virions by Western blotting. This study provides the first proteomic analysis of DIV1, which establishes a foundation for further investigation of viral infection and replication.