Objective This study is aimed to construct prokaryotic expression plasmid PTD4-Cu/ZnSOD and purify PTD4-Cu/ZnSOD fusion protein,to explore the property of intercellular transport. Methods The primers of hCu/ZnSOD were designed and synthesized to amplify full-length hCu/ZnSOD cDNA by PCR cloning assay. After double-enzyme digestion, the linearized PET16 b-PTD4 and hCu/ZnSOD cDNA was ligated with PCR cloning reaction to construct PET16 b-PTD4-Cu/ZnSOD. The recombinant plasmid was verified by PCR and DNA seque...