Description
A his-tag (also known as histidine tag or polyhistidine tag) is a common epitope tag that typically consists of at least 6 histidine residues fused to either the carboxyl (C-) or amino (N-) terminus of a targeted recombinant protein to facilitate its purification and detection (1). The most common his-tag is the hexahistidine (His6/6-His) tag which has a theoretical molecular weight of 0.8kda (1). The histidine residues readily interact with transition metal ions such as Co2+, Ni2+, Cu2+, and Zn2+, making immobilized metal-affinity chromatography (IMAC) the preferred technique for his-tag purification (1, 2). Metal ions are immobilized and bound to by His-tags in the IMAC column via the histidine imidazole ring. The tagged protein can be eluted off the column by washing with buffers containing a low concentration of imidazole (1, 2). Due to its relatively small size, low immunogenicity, versatility under denaturing conditions, and minimal interference with the structure and function of proteins, the his-tag is one of the most widely used tags for protein purification (1-3).
References
1. Malhotra, A. (2009). Tagging for protein expression. Methods in Enzymology, Guide to Protein Purification, 2nd Edition, 463, 239-258. https://doi.org/10.1016/s0076-6879(09)63016-0
2. Terpe, K. (2003). Overview of tag protein fusions: from molecular and biochemical fundamentals to commercial systems. Applied Microbiology and Biotechnology, 60(5), 523-533. https://doi.org/10.1007/s00253-002-1158-6
3. Booth, W. T., Schlachter, C. R., Pote, S., Ussin, N., Mank, N. J., Klapper, V., ... Chruszcz, M. (2018). Impact of an N-terminal polyhistidine tag on protein thermal stability. ACS Omega, 3(1), 760-768. https://doi.org/10.1021/acsomega.7b01598
Bioinformatics
Alternate Names |
- 6 His epitope tag
- 6-His Tag
- 6X His Tag
- 6X His
- 6x-His Tag
- 6X-His
- H
- Hexa His tag
- HHHHHH epitope tag
- HHHHHH tag
- His tag
- HIS
- His6-Tag
- polyhistidine tag
- polyHistidine
- Poly-histidine
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