c-Myc epitope tag (Myc tag)
Ten-residue epitope tag, EQKLISEEDL, from the c-Myc protein, recognized by the murine monoclonal antibody 9E10. Fused to a protein of interest it allows detection by western blot and flow cytometry and capture by immunoprecipitation.
Origin: c-Myc protein epitope
Characteristics
Encodes EQKLISEEDL (10 amino acids, 30 nucleotides; 1.2 kDa), with four acidic residues and one lysine. The epitope keeps its recognition by 9E10 in a different protein context, and the tag can sit at the N or C terminus, so detection works independently of the cargo. Tagged proteins can be affinity-purified on 9E10 coupled to divinyl sulfone-activated agarose, washed under physiological conditions and eluted at low pH. The tag is distinct from the c-Myc nuclear localization signal, which is a separate part (cmyc-nls).
Applications: Detection of tagged proteins by western blot, immunoprecipitation and flow cytometry, including monitoring of expression in bacteria, yeast, insect cells and mammalian cells. Co-immunopurification of interacting proteins has been reported in Agrobacterium-transformed Arabidopsis cells. Purified c-Myc-tagged proteins have been crystallized.
Limitations: Affinity purification on immobilized 9E10 requires elution at low pH, which can reduce protein activity, and the tag is rarely used for purification. A tag that is not surface-exposed in the fusion protein cannot be captured by the antibody.
Sequence
References
- K. Terpe (2003). Overview of tag protein fusions: from molecular and biochemical fundamentals to commercial systems. Appl Microbiol Biotechnol - Terpe 2003 Tag Fusions