Expression of human transforming growth factor β1 in E. coli (I) --Direct expression in cytoplasm

PCR technique is used to amplify the mature peptide gene of human transforming growth factor pl (hTGFβ1); the gene is verified by full-length sequence analysis. In DHSa/pBV220 expression system, hTGFβ1 attains expression in the cytoplasm ofE. coli up to 16%. The recombinant protein is proved to be the monomer of hTGFPl by N-terminal amino acids analysis and immunoblotting. After refolding of the monomer proteinin vitm in glutathione system or CHPAS/DMSO system, the dimeric protein accumulates to 30% in the refolding mixture. The recombinant protein is purified to homogeneity on silver staining, and is shown to have strong biological activity from MTT bioassay on MvlLu cells. Project supported by the National Natural Science Foundation of China (Grant No. 39580015)