PRODUCTION OF BIOACTIVE HUMAN HEMANGIOPOIETIN IN <i>Escherichia coli</i>
To devise an efficient approach of production of human hemangiopoietin (hHAPO), the gene of hHAPO was synthesized and subcloned into the pSUMO vector with a SUMO tag at the N-terminus. The expression construct was then transformed into the expression strain <i>E. coli </i>BL21 (DE3). The fusion protein was expressed in a soluble form and identified by SDS-PAGE and Western blotting. The fusion protein was purified to purity of 90% by metallochelate chromatography with a yield of 45 mg per liter fermentation culture. The SUMO tag was removed by cleavage with SUMO protease at room temperature for 1 h, and the hHAPO was then re-purified by the metallochelate chro-matography. Finally, about 21 mg hHAPO was obtained from 1 liter fermentation culture with no less than 95% purity. The recombinant hHAPO significantly stimulated the proliferation of human umbilical vein endothelial cells (HUVEC).