High-level expression of a sika deer (Cervus nippon) Cu/Zn superoxide dismutase in Pichia pastoris and its characterization

Production of a sika deer Cu/Zn-SOD was achieved in Pichia pastoris after the reconstituted expression vector pPIC9K was transformed into the strain GS115. By employing Saccharomyces cerevisiae secretion signal peptide (α-factor) under the regulation of the methanol-inducible promoter of the gene of alcohol oxidase 1 (AOX1), sika deer Cu/Zn-SOD with a molecular mass of 16 kDa was expressed while recombinant sika deer Cu/Zn-SOD with an activity of 3500 U/mL was obtained from a 5 L bioreactor. After two successive steps of chromatography on DEAE-650 C and Superdex75, recombinant sika deer Cu/Zn-SOD was obtained with 13.8% yield, 14.5-fold purification, and a specific activity of 3447 U/mg. Its optimum temperature and optimum pH were 40 °C and 7.0, respectively.

The expressed SOD has a high thermostability.Figure optionsDownload as PowerPoint slideHighlights
► A novel Cu/Zn-SOD gene from sika deer was cloned and integrated into P. pastoris.
► The 16-kDa SOD was expressed and secreted in a bioreactor with activity of 3500 U/mL.
► The optimum temperature and pH of the SOD were 40 °C and 7.0, respectively.
► The SOD can be used in investigation on pharmacological effects of antler velvet.