Abstract:
To obtain recombinant hybrid human superoxide dismutase (rhSOD2/3) and investigate whether SOD2/3 fusion protein could be transduced into and inhibit the growth of human cervical carcinoma cell, the recombinant plasmid pETSOD2/3 was constructed and transformed into E. coli BL21 (DE3) to express rhSOD2/3. rhSOD2/3 was purified by NiNTA affinity chromatography with the property of its Nterminal (His)6 affinity tag. Heparin affinity chromatography was used to test the heparinbinding ability of rhSOD2/3. The purified SOD2 and SOD2/3 were incubated with Hela cells. FITC and MTT assay was used to test their antitumor growth activities. The hybrid SOD2/3 was successfully expressed in E.coli, accounted for about 30% of the total bacterial protein and had normal SOD activity. After onestep NiNTA affinity chromatography, SOD2/3 of 90% pure was obtained. rhSOD2/3 could bind on a heparin affinity column, indicating that it was successfully targeted to heparin. Cell experiment showed that rhSOD2/3 inhibited the growth of Hela cells, while SOD2 did not. Relative pure hybrid rhSOD2/3 was obtained. Compared to SOD2, rhSOD2/3 fusion protein with natural and active form could be transduced more effectively into Hela cells and inhibit more strongly cell growth. The hybrid rhSOD2/3 can bind to cell surfaces and may aid in antitumor activity of SOD2 and may function as a rational therapeutic agent for treating freeradicalmediated diseases.