Expression and Purification of a Novel Influenza Virus Subunit Vaccine / 中国生物工程杂志

The influenza A virus matrix protein2 gene(M2)which deleted transmembrane region was amplified by overlap extending PCR,and the multiepitope gene of hemagglutinin(HA)was PCR amplified with seven continuous synthesized segments by designing primer.The two gene segments were separately cloned into pMD18T vector to sequence analysis and prokarytic expression vector pET28a+ to construct the recombinant plasmid pET28a+M2dHA.The recombinant plasmid was transformed into E.coli BL21(DE3),and the high expression strain was obtained by screening monoclones.The recombinant protein existed as inclusion bodies,which accounted about 45% of the total cellular protein.The inclusion bodies were washed with 1% Triton X100 solution twice,and dissolved in 8 mol/L urea solution.The solution protein was purified by Ni+2 affinity chromatography,and refolded by dilution renaturation,then purified by Q Sepharose FF cation exchange column.The purity of the protein was over 90% by HPLC analysis.The result of Western blot showed it has good antigenicity and specificity.These results strongly supported for the further study of the broadspectrum influenza virus subunit vaccine.