Xiao-Xia XIA, Ya-Ling SHEN^*, and Dong-Zhi WEI^*
(State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology,
East China University of Science and Technology, Shanghai 200237, China)

Abstract As a potential anti-tumor protein, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has drawn considerable attention. This report presented the purification and characterization of soluble TRAIL, expressed as inclusion bodies in E. coli. sTRAIL inclusion bodies were solubilized and refolded at a high concentration up to 0.9 g/L by a simple dilution method. Refolded protein was purified to electrophoretic homogeneity by a single-step immobilized metal affinity chromatography. The purified sTRAIL had a strong cytotoxic activity against human pancreatic tumor cell line 1990, with ED50 about 1.5 mg/L. Circular dichroism and fluorescence spectrum analysis showed that the refolded sTRAIL had a structure similar to that of native protein with β-sheet secondary structure. This efficient procedure of sTRAIL renaturation may be useful for the mass production of this therapeutically important protein.

Key words sTRAIL; inclusion bodies; refolding; immobilized metal affinity chromatography; characterization

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Received: October 15, 2003 Accepted: November 27, 2003
This work was supported by a grant from the National High Technology Research and Development Program of China (No. 2002AA2Z345A) and the Key Disciplinary Foundation of Shanghai
*Corresponding author: Tel, 86-21-64252981; Fax, 86-21-64250068; E-mail, dzhwei@ecust.edu.cn & yalings@online.sh.cn