The cloning,expression and purification of cDNA in E.coli / 中国免疫学杂志

ABSTRACT

Objective:The human heparin-binding growth factor Midkine(hMK) gene was constructed and expressed in E.coli, and the activity of MK protein was tested.Methods:The MK gene was amplificated from the tissue of human embryo kidney by RT-PCR techniques. The MK fragment without signal peptide was inserted into plasmid pET30a. The gene was expressed in E.coli, the protein was purificated by affinity chromatography, and the activity was tested by ~3H-TdR method.Results:The sequence of hMK in our experiment was as same as the sequence published in Genebank. The activity assay was shown high activity of MK protein in our experiment.Conclusion:The expression carrier of hMK was established successful and it can expression high activity hMK protein in E.coli.