Progress of Novel Tag Protein Fusions for the Recombinant Protein Purification

Recombinant protein expression and purification is one of the vital sections for structure determination and function study of proteins. Detection and selection of host strain containing target protein, low-yield recombinant protein expression by insolubility, low-recovery ratio, instability and proteolysis etc., which always lead to difficulties in high-throughput protein purification processes. Recently, the co-expression methods of target protein fused polypeptides or protein as tag have successfully overcome this problem to a large extent. Therefore, selecting appropriate tag of protein purification for various property of proteins is the key portion. In this paper, the progresses on several traditional tag proteins(His-tag, Arg-tag, Flag-tag, GST-tag, MBP-tag etc.) are reviewed. Moreover,several recently developed tag proteins(Si-tag, Halo-tag, intein-CBD-tag, ELPs-tag etc.) and the prospective in this field are also discussed.