Fusion Protein Cleavage

Affinity tags, such as Maltose Binding Protein (MBP) or polyhistidine (His), are essential tools for the production of recombinant proteins. MBP is known to significantly enhance the solubility of many proteins, resulting in higher yield. Whereas, His-tagging is widely employed for the purification of recombinant target proteins via immobilized metal affinity chromatography (IMAC). The His-tag advantages include small tag size and high affinity and specificity of poly-His tag binding to divalent metals at neutral pH.  Despite these important advantages, it is often preferred to remove the affinity tag following purification in order to isolate the target protein. Although chemical and enzymatic methods can be used, proteolytic enzymes, such as TEV Protease (NEB #P8112) and Factor Xa (NEB #P8010) are the preferred method for cleavage of fusion proteins at designed cleavage sites.