Affinity Tags for Protein Purification

Curr Protein Pept Sci. 2020;21(8):821-830. doi: 10.2174/1389203721666200606220109.

Abstract

The affinity tags are unique proteins/peptides that are attached at the N- or C-terminus of the recombinant proteins. These tags help in protein purification. Additionally, some affinity tags also serve a dual purpose as solubility enhancers for challenging protein targets. By applying a combinatorial approach, carefully chosen affinity tags designed in tandem have proven to be very successful in the purification of single proteins or multi-protein complexes. In this mini-review, the key features of the most commonly used affinity tags are discussed. The affinity tags have been classified into two significant categories, epitope tags, and protein/domain tags. The epitope tags are generally small peptides with high affinity towards a chromatography resin. The protein/domain tags often perform double duty as solubility enhancers as well as aid in affinity purification. Finally, protease-based affinity tag removal strategies after purification are discussed.

Keywords: Proteins; affinity tag; chromatography; protease; purification; solubility.

Publication types

  • Review

MeSH terms

  • Chromatography, Affinity / methods*
  • Epitopes / chemistry
  • Epitopes / metabolism
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism
  • Gene Expression
  • Glutathione Transferase / genetics
  • Glutathione Transferase / metabolism
  • Hemagglutinin Glycoproteins, Influenza Virus / genetics
  • Hemagglutinin Glycoproteins, Influenza Virus / metabolism
  • Histidine / genetics*
  • Histidine / metabolism
  • Maltose-Binding Proteins / genetics
  • Maltose-Binding Proteins / metabolism
  • Oligopeptides / genetics*
  • Oligopeptides / metabolism
  • Peptide Hydrolases / chemistry
  • Peptides / chemistry
  • Peptides / genetics
  • Peptides / metabolism
  • Protein Domains
  • Proteolysis
  • Recombinant Fusion Proteins / chemistry*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / isolation & purification
  • Recombinant Fusion Proteins / metabolism
  • SUMO-1 Protein / genetics
  • SUMO-1 Protein / metabolism
  • Solubility
  • Staining and Labeling / methods*
  • Transcriptional Elongation Factors / genetics
  • Transcriptional Elongation Factors / metabolism

Substances

  • Epitopes
  • Escherichia coli Proteins
  • Hemagglutinin Glycoproteins, Influenza Virus
  • His-His-His-His-His-His
  • Maltose-Binding Proteins
  • Oligopeptides
  • Peptides
  • Recombinant Fusion Proteins
  • SUMO-1 Protein
  • Transcriptional Elongation Factors
  • nusA protein, E coli
  • Histidine
  • Glutathione Transferase
  • Peptide Hydrolases