Expression of the VP2 gene of classical D78 infectious bursal disease virus in the methylotrophic yeast Pichia pastoris as a secretory protein



Infectious bursal disease virus (IBDV) is the causative agent of Gumboro disease, an infectious disease of global economic importance in poultry. The expression of heterologous proteins in P.pastoris is fast, simple and inexpensive. In this study, VP2 encoding gene of classical D78 IBDV was amplified using reverse transcription (RT) polymerase chain reaction (PCR) and cloned into pPICZαA vector. Recombinant plasmid DNA was integrated into the chromosome of the transformed Pichia pastoris by electroporation and expressed protein identified by SDS- PAGE and western blotting. A recombinant protein was secreted into the supernatant from the yeast when induced with methanol. The expressed target protein in supernatant was bound with chicken anti IBDV Polyclonal antibodies. Western blotting with antibodies against D78 IBDV indicated that the recombinant VP2 protein retained its antigenicity. The concentration of secreted VP2 protein was 0.67mg/l.The production of recombinant VP2 protein indicated that P. pastoris was an efficient secreted expression system for D78 IBDV.