Angiostatin is a recently discovered angiogenesis inhibitor

capable in inhibitting the proliferation of endothelial cells and the growth of tumor and has the potential for clinical application.Human angiostatin gene was cloned on the BamHI site of pET 17b resulting in the plasmid PETA 2 which was then transformed into E coli BL21(DE3). Angiostatin was efficently expressed in recombinant strain E coli BL21(DE3

pETA2) by IPTG induction. The expression product constitutes about 37 2% of the total soluble protein and exsists in the form of inclusion body. Western blot analysis demonstrates that it reacts positively with goat anti human plasminogen antisera.