中国生物工程杂志

NK4 protein is considered as the best antagonist of hepatocyte growth factor in recent years. In order to produce and study the biological characteristics of NK4 protein, the complete coding sequences of NK4 gene were cloned into vector pET-26b(+) to construct recombinant prokaryotic expression vector pET-26b(+)-NK4. After induction with IPTG, the strain of E. coli Rosseta (DE3) transformed successfully with the recombinant expression vector expressed recombinant protein existed in format of inclusion body strongly. The inclusion body, 42% of the total protein in E. coli, was dissolved by guanidine hydrochloride and purified by NiNTA column. The purified protein, about 95% purity, was confirmed by Western blot as NK4 protein. These results showed that recombinant protein could inhibit adherence, migration and induce apoptosis of Hela cell, which suggested that NK4 protein acquired retained its biological activity. The findings will be helpful to further study of NK4 function associated.