Using cellulose binding module of CBM3A as the purification tag for secreted Endoglucanase A (CelA) in Bacillus subtilis

Traditional methods of recombinant protein purification are uneconomic and inconvenient to the secreted proteins at large-volume. CBM3a, a module from cellulosome’s scaffoldin of Clostridium thermocellum, directs the binding of the cellulase complex on the cheap cellulose substrate. Most of previous studies about CBM3a fused with cellulases as the purification tag were conducted in intracellular Escherichia coli system. In this research, we used the extracellular Bacillus subtilis WB800N expression system to investigate the CBM3a-tag fused with endoglucanase CelA into plasmid pHT. The results indicated that protein CelA was secrected and purified by CBM3a-tag binding on the Regenerated Amorphous Cellulose (RAC) subtrate. This can be used for further improvement in protein purification tag designing.