Expression and purification of the protective antigen of Bacillus anthracis in Escherichia coli

The protective antigen(PA) of Bacillus anthracis was obtained using genetic engineering technology.The pag gene coding protective antigen of Bacillus anthracis was linked with vector pET to construct the recombinant combinant plasmids,and then these plasmids were transformed into the E.coli DE3 strain.The positive clonies expressing the PA were selected.The resuluts showed that the recombinant strain expreesing PA is obtained.The purity of PA can reach 90% by nickel nitrilotriacetic acid affinity chromatogramphy and gel filtration.The purified product is of the natural biological activity.The data presented here provide an easy and convenient method for expression and purification of PA protein.