Abstract:

Early pregnancy factor (EPF) is a pregnancy-associated protein that has immune-suppressive and growth-regulatory activities. It is regarded as a biochemical index by which super-early pregnancy can be determined. The objective of the study was to express the recombinant EPF protein in Escherichia coli (E. coli). The EPF gene amplified by PCR was sub-cloned into a pGEX-6P-1 vector fused with GST gene to construct a recombinant plasmid. The recombinant plasmid was then transformed into E. coli BL21.The expression of recombinant protein was analyzed by SDS-PAGE and Western blot after induction by IPTG. The recombinant protein was purified by high-affinity GST resin chromatography. The prokaryotic expression plasmid pGEX6P-EPF for producing EPF protein was constructed and the recombinant protein with a molecular weight of 37.3 kDa was expressed successfully in E. coli, which was recognized by the anti-GST monoclonal antibody in Western blot analysis. The recombinant EPF protein was obtained after GST affinity purification.