Cloning, purification and enzymatic characterization of recombinant human Superoxide dismutase 1 expressed in Escherichia coli

Abstract

Superoxide dismutase 1 (SOD1) is a metalloenzyme that catalyzes disproportion-action superoxide into molecular oxygen and hydrogen peroxide. In this study, the human SOD1 (hSOD1) gene was cloned, expressed, and purified. The hSOD1 gene was amplified from a pool of Bxpc3 cell cDNAs by PCR and cloned into expression vector pET-28a (+). The recombinant soluble hSOD1 was expressed in E.coli BL21 (DE3) at 37°C and purified by Nickel column affinity chromatography. The soluble hSOD1 was produced with a yield of 5.9 ug/mL medium. Considering that metal ions have a certain influence on the structure and activity of protein, we researched the influences of different concentrations of Cu2+ and Zn2+ on hSOD1 activity at induction and the time of activity detection. The results implied Cu2+ and Zn2+ can’t enhance SOD1 expression, however can improve the catalytic activity at induction. Furthermore, most of bivalent cations have an improve effect on enzyme activity at the time of detection.