Background: To clone and express the ss1 recombinant gene containing S gene and preS1 (10-50 AA) gene in P. pastoris expression system.
Methods: The fusion gene ss1 containing the S (1-222 AA) gene and preS1 (10-50 AA) gene was constructed with PCR method. The fusion ss1 gene was cloned into the expression vector of pPIC3.5k. The linear vector DNA was transformed into the host cell of GS115 with electroporation method. After screening with G418, the product was induced to express with methanol and its antigenicity was analyzed.
Results: The molecular weight of expressed ss1 protein was about 30,000 dalton. The product was reactive to anti-HBs and anti-preS1 mAb.
Conclusion: The fusion gene was efficiently expressed in P. pastoris expression system.The expressed products have the antigenicity of both S and preS1 protein.