[Study on optimization of expression, purification, properties and biological function of recombinant human sBLyS]

The prokaryotic expression plasmid pET-30a(+)/sBLyS was constructed and transformed into E. coli BL21 (lambda DE3). The recombinant protein was found to be highly expressed by the plight of soluble part and inclusion body. For the sake of enhancing the proportion of the soluble part, inducement at 16 degrees C for 12 h was ascertained. The expressing product was then purified by Ni2+ affinity chromatography gel. PI of the recombinant human sBLyS(rhsBLyS) is about 7.1-7.3 and it assembles into a homotrimer. The effect of rhsBLyS on B lymphocytes by MTT method told us the B lymphocytes' proliferating capacity dose depended on concentration and also stimulating time of the rhsBLys. With rhsBLyS(2 micrograms/mL) stimulating 3 days, B lymphocytes can proliferate the most.