[Prokaryotic expression, purification and antigenicity identification of human GRP78 protein].

AIM

To construct a recombinant plasmid pGEX-4T-1-GRP78, express it and purify human glucose regulated protein 78 (GRP78).

METHODS

GRP78 gene was amplified by PCR from the recombinant vector constructed in our laboratory. The PCR product was inserted into pGEX-4T-1 prokaryotic expression vector to generate pGEX-4T-1-GRP78. The pGEX-4T-1-GRP78 was then transformed into BL21 and GRP78 was expressed on induction of IPTG. After purification, GRP78 was released by thrombin cleavage, and its antigenicity was identified by ELISA.

RESULTS

The GRP78 prokaryotic expression vector was successfully constructed as confirmed by enzyme digestion and DNA sequencing. ELISA demonstrated the antigenicity of the purified GRP78 protein.

CONCLUSION

The recombinant prokaryotic expression vector pGEX-4T-1-GRP78 has been constructed successfully. The purified GRP78 has been obtained with good antigenicity, which will be used for GRP78-based serum diagnosis of hepatocellular carcinoma.