Protein and peptide (epitope) tag sequences are attached to proteins to facilitate easy detection and purification of expressed proteins. In addition, they can also be used to identify potential binding partners for your protein of interest.
Tags available incorporated at N or C-Terminus of peptides, lyophilized material, as well as on solid phase.
FLAG-tag – (FLAG octapeptide, or FLAG epitope, DYKDDDDK), is a polypeptide protein tag that can be added to a protein, commonly used as 3xFLAG peptide: DYKDHD-G-DYKDHD-I-DYKDDDDK. It is one of the most specific tags and it is an artificial antigen to which specific, high affinity monoclonal antibodies have been developed and hence can be used for protein purification by affinity chromatography.
The FLAG tag is more hydrophilic compared to other tags in its class so they do not denature or inactivate the proteins to which they are attached.
Human influenza hemagglutinin (HA, YPYDVPDYA) is a peptide sequence derived from the surface glycoprotein that facilitates the ability of the influenza virus to infect its host and is recognized by numerous commercial antibodies. The HA tag is not suitable for detection or purification of proteins from apoptotic cells since it is cleaved by Caspase-3 and/or Caspase-7.
Polyhistidine-tag (hexa histidine-tag, 6xHis-tag, His6 tag)consists of 6-8 histidine residues, often at the N- or C-terminus of the protein. His tag is by far the most popular affinity tag for purification of recombinant proteins, often separated by a protease-cleavage site. The presence of a His tag enables the use of IMAC for purification.
Myc tag – (EQKLISEEDL)derived from the c-myc gene product and recognized by numerous commercial antibodies. It can be added to a protein using recombinant DNA technology and may be used for affinity chromatography and for isolating protein complexes with multiple subunits.
V5 tag (GKPIPNPLLGLDST), is from the P/V proteins of paramyxovirus SV5. V5 tag antibodies provide a dependable method for the detection and purification of tagged target proteins without a protein-specific antibody or probe. The tag tends to be useful to enable protein detection, such as in Western blotting, immunofluorescence and immunoprecipitation experiments.