S1 domain of the porcine epidemic diarrhea virus spike protein as a vaccine antigen

Makadiya, Niraj; Brownlie, Robert; van den Hurk, Jan; Berube, Nathalie; Allan, Brenda; Gerdts, Volker; Zakhartchouk, Alexander

To increase the PEDV S1 protein yield and to achieve a full-length S1 protein expression, a baculovirus expression system was employed. To this end, histidine-tagged PEDV S1 gene was cloned into a BACMID containing the genome of baculovirus, transfected into Sf9 cells and the recombinant baculovirus was recovered. Small scale PEDV S1 protein expression in the recombinant baculovirus infected cells was analysed by Western blotting using the anti-his antibody at days 1 to 7 post-infection (Fig. 2a) . The S1 protein was detected as a distinct 100 kDa band and band intensity increased on each subsequent day. Size and integrity of affinity purified S1 from the cell culture medium of baculovirus infected cells was found to be of the same size (Fig. 2b ) as detected earlier (Fig. 2a) with the yield of 3.9 mg/L.