Molecular Cloning and Expression of Bovine Viral Diarrhea Virus Nonstructural Protein 3 in Escherichia coli

Background: bovine viral diarrhea (bvd) is an economically important disease of cattle with a worldwide distribution. diagnosis of bvd relies on laboratory-based detections of its viral causing agent or virus specific antibodies. the most common laboratory method used for this purpose is the elisa. bovine viral diarrhea virus (bvdv) nonstructural protein 3 (ns3) is one of the most highly conserved immunogenic proteins of bvdv, thus, it is a proper candidate antigen to detect antibodies against the virus in the sera from infected animals.objectives: the aim of this study was to synthesize a plasmid construct for high-level expression of ns3 with more solubility in escherichia coli.materials and methods: a segment of bvdv genome encoding the ns3 protein was amplified using rt-pcr and cloned into pmal-c2x expression vector, under the control of the lac promoter. after sequencing of the amplified gene, the recombinant protein was expressed in e. coli strain bl21 and analyzed by sds-page and western blotting.results: the strong promoter of pmal-c2x vector allowed a high level expression of ns3 as a maltose binding protein-ns3 (mbp-ns3) fusion protein. expression of the expected fusion protein was confirmed by electrophoresis on sds-page and immunoblotting, using a bvdv positive bovine serum.conclusions: based on our results, it appears that this plasmid construct may be suitable for the production of ns3 recombinant antigen to develop bvdv laboratory diagnostic assays.