Construction and expression of a recombinant expression protein of CTLA4-Ig-msBlys which modified by Th epitope

Objective To construct the prokaryotic expression plasmid pGEX-KG-CTLA4-Ig-msBlys and its expression in E.coli BL21;To detect the fusion protein.Methods The DNA fragment of msBlys gene amplified from the plasmid pCMV-sBlys by polymerase chain reaction(PCR),then connected with OVA and CTLA4-Ig fragment.The DNA fragment of CTLA4-Ig-msBlys was cloned into the prokaryotic expression vector pGEX-KG and expressed as a fusion protein in E.coli BL21 induced by IPTG.The expressed fusion protein CTLA4-Ig-msBlys was purified and identified by SDS-PAGE and Western blot.Results The recombinant expression plasmid pGEX-KG-CTLA4-Ig-msBlys was successfully constructed.The recombinant expression protein was steadily expressed in E.coli,the relative molecular mass of the expression product was identical with the value predicted.Conclusion The recombinant prokaryotic expression plasmid pGEX-KG-CTLA4-Ig-msBlys is constructed successfully transformed into E.coli BL21,then its expressed as a fusion protein CTLA4-Ig-msBlys in E.coli BL21.All that will be helpful for the further study of Blys.