The 6x His tag is a synthetic oligo peptide consisting of 6 consecutive histidine residues (HHHHHH). The His tag is commonly expressed as a tag at either N-or C-terminal regions of recombinant proteins to allow isolation or purification by immobilized metal affinity chromatography. Epitope tagging is a technique in which a known epitope is fused to a recombinant protein using genetic engineering. By choosing a particular epitope and recombinant protein combination, epitope tagging makes it possible to detect proteins for which no antibody is available. His epitope tagged proteins that contain a stretch of histidine residues at the carboxyl or amino terminus are used for purification of recombinant proteins by means of metal chelate chromatography due to metal binding properties of histidine clusters on His tagged proteins. For example, the affinity of the histidine-tag motif to Ni2+ by chelation is strong and selective enough to enable purification of the protein to homogeneity by affinity chromatography on a Ni2+-NTA adsorbent. His tag-specific antibodies are used to facilitate detection or coimmunopreciptation of tagged proteins.
蛋白别名: 6His tag; 6X His; His Tag; Histidine Tag