Description
FLAG peptide is an eight amino acids peptide (Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Lys) with an enterokinase-cleavage site; designed for antibody-mediated identification and purification of recombinant proteins.In VitroFusion protein technology has become an important tool for solving numerous problems linked to recombinant protein production. The properties of the additional tag facilitate identification and provide a one-step purification procedure of the fusion protein by passing cell extracts or supernatants through columns of an appropriate matrix. FLAG peptide allows elution under non-denaturing conditions. Several antibodies against FLAG peptide have been developed. One antibody, M1, binds the peptide in the presence of bivalent metal cations, preferably Ca 2+. Elution is effected by chelating agents. Another strategy is competitive elution with excess of free FLAGe peptide. Antibodies M2 and M5 are applied in this procedure. The Flag-tag is first described as a calcium-dependent epitope of a monoclonal antibody. It is a highly acidic octapeptide which can be N-terminally fused to the protein of interest. As a very hydrophilic peptide the Flag–tag has a high surface probability. Flag-fusion proteins can be captured by an immunoaffinity column in the presence of Ca 2+ and eluted byEDTA at low concentrations, neutral pH and thus, nearly physiological conditions. MCE has not independently confirmed the accuracy of these methods. They are for reference only.Form:Solid