RESUMEN
Endostatin is a potent, endogenous inhibitor of angiogenesis, which corresponds to the C-terminal fragment of collagen ⅩⅧ. The human endostatin gene was amplified from a human fetal liver cDNA library by means of PCR and was cloned into pPIC9K vector. Soluble endostatin was superexpressed in Pichia pastoris (50.5mg/L) . The recombinant protein was purified by cation exchange chromatography with the final yield of more than 95%. Western blotting analysis showed positive immunoreactivity to the expressed product. Recombinant endostatin was able to suppress the angiogenesis on the CAMs. Also, the endostatin inhibited specifically of the migration of HMECs stimulated by bFGF, with EC50 being about 0.4 ?g/ml.
RESUMEN
The fermentation process of recombinant human Endostatin expression in Escherichia coli BL21 (DE3) was studied. The effects of factors such as concentration of IPTG, induction time, cultivation temperature and feeding strategies were investigated. Beside that, by changing the temperature to 40 degrees C after induction, the high-density cultivation finished in a much shorter period. After 9 hours cultivation, the optical density (OD) at 600 nm reached 140 and the yield of inclusion body was 3 g/L. While E. coli system was used, protein with better activity and stability was obtained. The cost was much lower and the producing process was much steadier. It will meet the demands of the industrial production.