Cloning Of A Human Manganese-superoxide Dismutase CDNA And Its Expression In Escherichia Coli And Pichia Pastoris

The cDNA encoding human manganese-superoxide dismutase was amplified from the human liver cell (L02) total RNA by RT-PCR. The human MnSOD cDNA was inserted into expression vector pPICINUA, pPIC9K and pSE38O .The recombinant plasmids pPICINUA-MnSOD and pPIC9k-MnSOD were transformed Pichia pastoris and pSE38O-MnSOD into Escherichia co/i. The recombinant pSE38O-MnSOD was induced with IPTG to express hMnSOD in three strains ofE.co/i(DH5a,TOP1O,BL21).The activity of hMnSOD was detected and the specified protein expressed in E.coli accounted for 11.9% of the total protein of the bacteria. . SDS-PAGE gel analysis showed that the molecular mass was estimated to be 22KD. The recombinant strains of P pastoris were cultured in the inducing medium. The expression of hMnSOD was not detected by activity assay and SDS-PAGE.