Condition optimization of prokaryotic expression of human interleukin-2 and protein purification

The aim of this study is to construct prokaryotic expression vector of human interleukin-2(IL-2),to optimize expression conditions and to purify the expressed product.The gene fragment of IL-2 was ligated into the vector pET100 / D-TOPO,and the recombinant plasmid was successfully constructed according to restriction endonuclease analysis and DNA sequencing.The plasmid was transformed into Eschrichia coli BL21 and induced to express protein.The analyses of SDS-PAGE and Western blot showed that the recombinant E.coli produced higher proportion of soluble protein contrast to inclusion body when induced for 5h by 0.6 mmol / L of IPTG at 25℃,and the fusion protein could be recognized by specific antibodies.The fusion protein could be highly purified by Ni-IDAresin affinity chromatography,and the purity was up to about 85%.The purification of fusion protein provides a basis for further research on the activity and function of IL-2.