[Cloning of the glyceraldehydes 3-phosphate dehydrogenase gene of porphyromonas gingivalis and its expression in E. coli].

Objective To clone the glyceraldehydes 3-phosphate dehydrogenase(GAPDH) gene of Porphyromonas gingivalis(P.gingivalis) and to induce its fusion expression in E.coli.Methods GAPDH was obtained by PCR and was inserted into cloning vector pMD-18-T to construct clone recon.Double enzymes digest the recon pMD18-T-GAPDH and the prokaryotic expression vector pET-32a and then connect to get the expressing recon pET-32a-GAPDH.The recombinant expression plasmid which had been confirmed by enzymes digestion was transformed to E.coli competent cells BL21 and induced the expression of GAPDH with isopropyl β-D-1-thiogalactopyranoside(IPTG) of different density.Results DNA sequencing showed that the fragment was 99.802% the same to the sequence published in NCBI.Under the best density,IPTG could be highly expressed.Conclusion The GAPDH had been success-fully cloned and expressed in E.coli which gets ready for the following experiment to study the immunity of GAPDH and the homologues antibody preparation.