Expression of the G1 epitope of bovine ephemeral fever virus G glycoprotein gene by pET24-G1 recombinant construct in Escherichia coli

Bovine ephemeral fever (BEF) is a viral disease of cattle and water buffalo seen in some provinces of Iran, generally southern and warm regions in recent years. The G glycoprotein is the main protective antigen of the bovine ephemeral fever virus (BEFV) and the target of anti-BEFV neutralizing antibodies. The aim of the present study was cloning and expression of the G1 epitope of BEF virus G glycoprotein gene in a prokaryotic system. For this purpose, the G1 epitope was cloned in a prokaryotic expression vector, pET-24a(+), under the control of the T7 promoter and subsequently the recombinant pET24-G1 construct was transformed into Rosetta strain of Escherichia coli. Expressed recombinant protein was analyzed using SDS-PAGE and immunoblotting methods. SDS-PAGE analysis showed that a protein with ~18 kDa molecular weight, consistent with the expected molecular weight of recombinant protein fused to 6xHis tag, was expressed. Immunoblotting analysis showed that the expressed G1 protein specifically reacted with a mouse polyclonal serum against BEFV. Thus, in this study the G1 protein of BEFV was successfully expressed by the pET24-G1 recombinant construct in Escherichia coli. Based on the results of this study, immunization and the efficacy of this product can be consider as a possible candidate for the production of subunit vaccine against the virus in animal models.