Construction and expression of high efficiency expressing plasmid of transforming growth factor alpha-Pseudomonas aeruginosa exotoxin fusion protein TGF alpha-PE40.

The XbaI/EcoRI cleaved TGF alpha-PE40 gene from plasmid pXY382 was inserted into the same cloning site of the expression vector pCB604 resulting in the plasmid p2X-TP1. E. coli BL21 (lambda DE3) cells were transformed with the p2X-TP1 and then induced with IPTG. The product expressed was accumulated mainly in the form of inclusion bodies. The expression level was closely related to the cell density, induction temperature and medium but not to the inductor dosage and the induction period within certain range. The expressed amount of the fusion protein TGF alpha-PE40 was about 50 mg/L.