Purification of recombinant histidine-tag streptolysin O using immobilized metal affinity expanded bed adsorption (IMA-EBA)

In this report, we describe the recombinant SLO expression as a fusion protein with a C-terminal hexahistidine tag and its purification using immobilized metal affinity expanded bed adsorption (STREAMLINE™ Chelating). In order to facilitate downstream processing of the purification, an efficient fermentation process was developed focusing on the achievement of high yields of soluble protein. The purification strategy resulted in a 40% recovery of active recombinant SLO and the protein was purified eight-fold. SDS-PAGE and Western-blot analysis of the purified protein revealed the presence of a 75 Mr form, which was the estimated relative Mass of the recombinant SLO.