[The cloning and expression of angiogenic inhibitor tumstatin(45-132) in E. coli].

Aim: To clone tumstatin(45-132) gene and to express recombinant human tumstatin(45-132) in E. coli BL21.

Methods: Tumstatin gene was cloned by RT-PCR and then tumstatin(45-132) gene amplified from tumstatin gene was cloned into pBV220. The recombinant plasmid pBV220-tumstatin(45-132) was sequenced and transformed into E.coli BL21. E. coli BL21 transformed with the recombinant plasmid pBV220-tumstatin(45-132) was induced at 42 degrees Celsius. After the recombinant tumstatin(45-132) was purified, its bioactivity was detected by endothelia cell proliferation test.

Results: 264 bp tumstatin(45-132) fragment was cloned and its sequence was identical with that in GenBank. The tumstatin(45-132) was expressed in E. coli BL21. Expressed product accounted for about 10% of total bacterial proteins and its relative molecular mass (M(r)) was 9,600. The purified protein showed inhibitory effect on proliferation of endothelia cells ECV304 in vitro.

Conclusion: tumstatin(45-132) gene has been cloned and expressed successfully in E.coli BL21. Expressed tumstatin(45-132) can inhibit the proliferation of endothelial cell ECV304.