Expression of 47 kDa recombinant protein of treponema pallidum and its potential use in serodiagnosis of syphilis

  Objective   To express the recombinant Tp47 protein of Treponema pallidum(TP)in E.Coli, and to developenzyme immunoassay(EIA)for serological diagnosis of syphilis.

  Methods   The target gene Tp47 was amplified from the Tp complete genome by polymer ase chain reaction(PCR).The PCR products were cloned into the expression vector pET-30a to generate recombinant plasmid pET-30a-Tp47.The recombinant Tp47 protein was expressed in E.Coli, and purified with affinity chr omatog raphy columns.Then it was used for the development of EIA.

  Results   T he recombinant T p47 protein with the molecular weight of 39kDa was expressed in the supernatant of E.coli and contained about 12% of the total cellular protein.The antigenicity of the precombinant T p47 protein was confir med by both western immunoblot and EIA.11 THHA(Treponema pallidum hemag glutination assay)positive and 28 negative sera were tested by the EIA, with the sensitivity of 100% (11/11)and the specificity of 96.4% (27/28).

  Conclusion   The recombinant T p47 protein can be used for development of EIA for serological diagnosis of syphilis.