High Expression,Purification and Characterization of Human BLyS 78-285

Objective To clone the cDNA at extracellular domain of human B-lymphocyte stimulator (BlyS)for high expression .purification and characterization.Methods Extract the total RNA of HL-60 cell, amplify the cDNA of the 78th to 285th amino acids at extracellular region of human BlyS by RT-PCR for sequencing and construction of prokaryotic expression vector pQE-80L. Human BlyS 78-285 was expressed under induction of IPTG. purified by Ni-NTA chromatograply and detected for activity by SDS-PAGE and Western blot. Results A DNA fragment with the length of 627bp was amplified and highly expressed in E. coli . The sequence of the fragment was identical to that of BlyS 78-285 in GenBank. The expressed product stimulated the proliferation of B lymphocytes,and its purity after purification reached 98.7% .Conclusion The cDNA at extracellular region of human BlyS was successfully cloned and highly expressed , and the expressed product after purification showed biological activity.