Bioactivity | 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. | ||||||
Invitro | Fusion 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 Ca2+. 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[1]. 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 Ca2+ and eluted byEDTA at low concentrations, neutral pH and thus, nearly physiological conditions[2]. | ||||||
Name | FLAG peptide | ||||||
CAS | 98849-88-8 | ||||||
Sequence | Asp-Tyr-Lys-Asp-Asp-Asp-Asp-Lys | ||||||
Shortening | DYKDDDDK | ||||||
Formula | C41H60N10O20 | ||||||
Molar Mass | 1012.97 | ||||||
Transport | Room temperature in continental US; may vary elsewhere. | ||||||
Storage | Sealed storage, away from moisture and light, under nitrogen
*In solvent : -80°C, 6 months; -20°C, 1 month (sealed storage, away from moisture and light, under nitrogen) |