What is an epitope protein tag?
What is an epitope protein tag?
Epitope tagging is a method of expressing proteins whereby an epitope for a specific monoclonal antibody is fused to a target protein using recombinant DNA techniques. The fusion gene is cloned into an appropriate expression vector for the experimental cell type and host cells are transfected.
What are epitope tags used for?
Epitope tagging is a technique in which a known epitope is fused to a recombinant protein using genetic engineering. Epitope tags make it possible to detect proteins when no antibody is available. This technique can be used to characterize newly discovered proteins and low abundant proteins.
How do I choose an epitope tag?
Choice of an epitope tag depends on many factors, but downstream application is the most important one. If the desired downstream application is recombinant protein purification, epitope tags like 6X-His, GST (Glutathione-S-transferase), and MBP (Maltose Binding Protein) are widely used in affinity purification.
Where does the protein tag go?
If protein is multimeric, undergoes post translational modification with cleavage at N, C terminals. Then do tag at either N terminal or C terminal purify protein.
What is Flag tag used for?
A FLAG-tag can be used in many different assays that require recognition by an antibody. If there is no antibody against a given protein, adding a FLAG-tag to a protein allows the protein to be studied with an antibody against the FLAG sequence.
What are the applications of epitope-tagging?
Perhaps the single most important application of epitope-tagging is co-immunoprecipitation. In this technique, a bait protein fused to an epitope tag is transfected into cells. Following lysis of the transfected cells, the expressed bait protein is immunoprecipitated with anti-tag antibody coupled to beads.
What does it mean to tag a protein with epitopes?
Tagging a protein with an existing epitope is a simple procedure that allows researchers to readily purify or follow proteins through meaningful and revealing experiments quite promptly after expressing a cloned sequence.
What is an S-peptide tag?
Another type of tag is the S-peptide tag that binds to the S-protein derived from pancreatic RNase A ( 16 ). Epitope tagging is accomplished by fusion of the target protein with the tag of choice. This is accomplished by insertion of the target gene into a host cell–specific expression vector that also encodes the epitope tag.
What is the recognition sequence for protease enterokinase?
In many cases, the recognition sequence for a protease is included after the coding sequence of the epitope tag to allow for release of the epitope tag. In the case of the FLAG tag, the epitope includes the recognition sequence for the protease enterokinase.
