Activity identity and application of recombinant Mycobacterium tuberculosis CFP10-ESAT-6 or EAST-6-CFP10 fusion protein

  Objective   To study the immunological characteristics of the secreted proteins CFP10-ESAT-6 or EAST-6- CFP10 of Mycobacterium tuberculosis by fused expression.

  Methods   Apair of oligodeox ynucleotide named linker encoding 12 glycines and 3 serines was synthesized and cloned into plasmid pET32c(+)to construct pET32c(+)-linker.The CF P10 and ESAT-6 gene were amplified by PCR reaction and cloned into pET32c(+)-linker either ahead of or follow ing linker.the recombinant CFP10-ESAT-6 or EAST-6-CFP10 fusion protein was expressed in E.coli.BL21.Their antig enicity were confirmed by western blot.

  Results   The sequence of recombinant plasmid pET32c(+)-CFP10-ESAT-6 or pET32c(+)-EAST- 6-CFP10 was identical to the predicted sequence.The recombinant proteins(rCFP10-ESAT-6 or rEAST-6-CFP10)can expressed effectively in the cytoplasm BL21.Western blot showed that the rCFP10-ESAT-6 or rEAST-6-CFP10 had good immuoreactivity with sera from patients with activetuberculosis.

  Conclusion   Multi-antigen plasmid encoding CFP10 and ESAT-6 of Mycobacterium tuberculosis was constructed successfully.The fusion protein CFP10-ESAT-6 or EAST-6-CFP10 was obtained.The fusion proteins have antigenicity of EAST-6 and CFP10.