The Construction of pQE-TGF-β1 Recombinant Expression Plasmids and Expression in Escherichia Coli

Objective:To further understand the function and biological activity of TGF-β, and to provide the production of biologically active TGF-β protein. Method:The TGF-β cDNA was cloned into a procaryotic expression vector…… pQE30 and the monomeric form of the recombinant TGF-β1 expressed in E.coli M 15 ; then Ni-NTA agarose column were used to purify the TGF-β protein. The monomeric protein was refolded and in vitro activity test was assayed by MTT. Result:With digestion of the enzymes and sequencing, we identified that the TGF-β1 matured peptide gene was inserted into procaryotic expression vector pQE30. After purified,the expression product of the plasmid in E.coli showed a single protein on SDS-PAGE, and its expression level was about 20% of the total bacterial protein. The dimeric protein, which is biologically active, was obtained by refolding. Conclusion:The construction of the recombinant plasmid and the preparation of the active protein of TGF-β1 have laid a solid foundation for further studying the function of TGF-β1.