Tab2, a novel recombinant polypeptide tag offering sensitive and specific protein detection and reliable affinity purification

The detection and purification of proteins are often time-consuming and frequently involve complicated protocols. The addition of a peptide tag to recombinant proteins can make this process more efficient. Many of the commonly used tags, such as Flag™, Myc, HA and V5 are recognized by specific monoclonal antibodies and therefore, allow immunoaffinity-based purification. Enhancing the current scope of flexibility in using diverse peptide tags, we report here the development of a novel, short polypeptide tag (Tab2) for detection and purification of recombinant proteins. The Tab2 epitope corresponds to the NH₂-terminal seven amino acid residues of human TGF. A monoclonal anti-Tab2 antibody was raised and characterized. To investigate the potential of this peptide sequence as a novel tag for recombinant proteins, we expressed several different recombinant proteins containing this tag in E. coli, baculovirus, and mammalian cells. The data presented demonstrates the Tab2 tag–anti-Tab2 antibody combination is a reliable tool enabling specific Western blot detection, FACS analysis, and immunoprecipitation as well as non-denaturing protein affinity purification.