Expression and purification of porcine PID1 gene in Escherichia coli

In this study, in order to scale up the production of recombinant porcine phosphotyrosine interaction domain containing 1 (pPID1), a pET-28a (+)-pPID1 expression plasmid was constructed and transformed into Escherichia coli Rosetta (DE3). The recombinant pPID1 was then purified and identified by western blotting, and was also analyzed in vitro for its function. The recombinant protein was tagged with only a His6 tag at its C-terminus, which could be conveniently purified by affinity column. The protein could be induced for efficient expression with 0.75 mM IPTG for 8 h at 30 degrees C, yielding approximately 3 mg/L. In vitro biological activity assay demonstrated that the refolded purified recombinant pPID1 increased 3T3-L1 preadipocyte proliferation. This study provides a reliable technique for the recombinant expression and purification of pPID1 proteins.