Expression of cucumber mosaic virus coat protein gene for the production of recombinant polyclonal antibodies

This study was designed to use the recombinant expressed CMV/coat protein (CMV/CP) as an antigen for producing specific polyclonal antibodies (PAbs) in high concentration and free from plant contaminants. The coat protein gene was subcloned into a bacterial expression vector (pQE32) and expressed as a fusion protein with an N-terminal hexa-histidine tag. The yield was 8 mg native protein per liter from bacterial culture. The expressed CP (27 KDa) was identified by strong reaction with polyclonal antibodies produced against CMV purified (Ab/V) and Anti-mouse (RGS)4 antibodies specific to the 6X His-tagged fusion protein in Western blot. The Ab/V reacted specifically and strongly with the 6X His-tagged fusion protein of the recombinant clones in immunoblot assay, this result indicates that fusion CP maintains its native antigenicity and specificity. Finally, the recombinant antibodies reacted positively in western blot analysis with isolates collected from fields, suggesting that antibodies generated against recombinant CP of CMV can be used for sensitive and large-scale detection of CMV.