Cloning, Expression of the Major Capsid Protein Gene from Marine Algae Emiliania huxleyi Virus and the Possible Use in Detection of Virus Infection

Here we described the cloning, bioinformatic characterization and expression in Escherichia coli of the major capsid protein (MCP) from marine unicellular algae Emiliania huxleyi virus EhV-99B1 isolate. The purified recombinant MCP was used to develop a polyclonal antibody for testing viral infection. The full length open-reading frame (ORF) of MCP encodes a protein of 496 amino acids with a calculated molecular mass of 55 kDa and Ip 6.34. Hydropathy analysis of MCP showed that there were 6 largely hydrophobic domains, which may be important for the interaction with the envelope protein. The conserved region of EhV strains MCP had high similarity in amino acid sequence and secondary structure which allow us to develop a specific biomarker for EhVs infection detection. The full length ORF was subcloned into expression vector pGEX-4T-3 for overexpression in E. coli as glutathione-Stransferase-L1 (GST-L1) fusion protein and the soluble recombinant protein was used to generate polyclonal antibodies in mice. The obtained antisera reacted in Western immunoblots with the same protein both in purified EhV-99B1 virions and infected host cells sample. These shows that the antiserum against recombinant EhV-MCP offers the potential to develop immunofluorescence techniques for the detection of EhVs infected cells.