[Expression of Japanese encephalitis virus E protein in methylotrophic yeast Pichia pastoris].

Aim: To express Japanese encephalitis virus (JEV) E protein in methylotrophic yeast Pichia pastoris.

Methods: The gene coding for JEV E protein was sub-cloned into vector pPIC9k. The constructed plasmid was transformed into yeast SMD1168 by electroporation. The recombinant transformants with a high copy number of the plasmid were selected by using MD plate and G418. The expression of E protein in yeast was induced by the addition of methanol and analyzed by SDS-PAGE and Western blot.

Results: The protein was produced at a yield of 50 mg per litre of culture. Owing to heterogeneous glycosylation, relative molecular mass (M(r)) of the expressed E protein was sized about 113 000 and 78 000.

Conclusion: JEV E protein was expressed successfully in yeast Pichia pastoris, which should be useful for the production of diagnostic reagents and genetically engineered vaccine of JEV.