title: Aggregating tags for column-free protein purification.
abstract: Protein purification remains a central need for biotechnology. In recent years, a class of aggregating tags has emerged, which offers a quick, cost-effective and column-free alternative for producing recombinant proteins (and also peptides) with yield and purity comparable to that of the popular His-tag. These column-free tags induce the formation of aggregates (during or after expression) when fused to a target protein or peptide, and upon separation from soluble impurities, the target protein or peptide is subsequently released via a cleavage site. In this review, we categorize these tags as follows: (i) tags that induce inactive protein aggregates in vivo; (ii) tags that induce active protein aggregates in vivo; and (iii) tags that induce soluble expression in vivo, but aggregates in vitro. The respective advantages and disadvantages of these tags are discussed, and compared to the three conventional tags (His-tag, maltose-binding protein [MBP] tag, and intein-mediated purification with a chitin-binding tag [IMPACT-CN]). While this new class of aggregating tags is promising, more systematic tests are required to further the use. It is conceivable, however, that the combination of these tags and the more traditional columns may significantly reduce the costs for resins and columns, particularly for the industrial scale.
authors.affiliation: Department of Chemical Engineering, National Engineering Laboratory for Industrial Enzymes, Tsinghua University, Beijing, China. zhanglinlin@mail.tsinghua.edu.cn.
authors.forename: Zhanglin
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Department of Chemical Engineering, National Engineering Laboratory for Industrial Enzymes, Tsinghua University, Beijing, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: Department of Chemical Engineering, National Engineering Laboratory for Industrial Enzymes, Tsinghua University, Beijing, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Xing
authors.affiliation: Department of Chemical Engineering, National Engineering Laboratory for Industrial Enzymes, Tsinghua University, Beijing, China.
authors.forename: Bihong
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Department of Chemical Engineering, National Engineering Laboratory for Industrial Enzymes, Tsinghua University, Beijing, China.
authors.forename: Xu
authors.initials: X
authors.lastname: Wang
mesh_terms: D002846:Chromatography, Affinity; D008024:Ligands; D010455:Peptides / Q000737:chemistry* / Q000302:isolation & purification; D066329:Protein Aggregates; D015202:Protein Engineering / Q000379:methods; D011994:Recombinant Proteins / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D008024:Ligands; D010455:Peptides; D066329:Protein Aggregates; D011994:Recombinant Proteins
keywords: Aggregating tags; Cleavable tags /Column-free; Protein purification; Purification tags