Cytoplasmic Expression of Human Bone Morphogenetic Protein-7 by a Genetically Engineered Strain of Escherichia coli, SHuffle® Strain

Homodimericbone morphogenetic protein-7 (BMP-7) plays a key role in bone metabolism. The functionality of human BMP-7 protein is dependent on its disulfide bond formation and proper folding. Therefore, the expression of soluble recombinant BMP-7 using Escherichia colicells as the host remains a challenge. Given the need for these disulfide-bonded proteins for stabilized native conformation, the cytoplasm of SHuffle®T7 Express as an E. coliengineered strain can effectively fold disulfide-bonded proteins with a needfor proper oxidative folding. These cellular features turn the SHuffle®expression system into an efficient host for the recombinant production of human BMP-7 protein. A soluble dimeric form of recombinant human BMP-7 (rhBMP-7) which has a wide range of applications in medicine and can be used in the treatment of bone defects was produced using the SHuffle®strain as the expression system. This study demonstrated the production of rhBMP-7 using E. coliSHuffle®T7 Express strain. Also, an effective protocol was proposed for the expression and purification of soluble human BMP-7. In addition, it was found that the genetically engineered SHuffle®strain can efficiently enhance the solubility of recombinant human BMP-7 as a therapeutic target.