TAP-MS Service

Determining intracellular protein interactions has become a hot research topic in life sciences today. Two-hybrid techniques have been widely used to study protein-protein interactions. However, it cannot meet the needs of large-scale protein research because of its complex screening steps, high number of false positive results and difficulty in quantification. Tandem affinity purification (TAP) technique has rapidly become one of the techniques for screening, discovery and identification of new interacting proteins due to its high efficiency, high purity, and its ability to highly mimic real physiological conditions. The coupling of TAP techniques with mass spectrometry and the automation of mass spectrometry now allow for the analysis of interacting proteins on a large scale.

Creative Proteomcis has established a high quality and efficient TAP tandem affinity purification platform and has extensive experience in this field. Our team of experts can customize TAP-MS experiments according to the different project needs of our customers. We offer platforms for protein-protein interaction and protein complex studies in yeast, mammals, Drosophila, bacteria and other organisms.

Process of TAP-MS

The vector containing the target gene was constructed so that the target gene was expressed fused with 2 different epitope tags, such as Flag, HA, Strep, His, CBP, SBP, etc.

N-terminal 2*strep tag+Flag tag or C-terminal 6*His tag+Flag tag double tag vectors are used.

The vector transfects cells and expresses the fusion protein "2*strep-Flag - target protein" or "6*His-Flag - target protein".

The total protein is extracted by cell lysis, purified and eluted in two steps by streptactin beads or Nickelbeads and Flag M2 beads to maximize the removal of false positive proteins.

The eluate is fed into a mass spectrometer and analyzed to identify proteins that interact with the target protein.

Workflow for the TAP-MS procedure for characterizing protein complexes (Wodak et al., 2009)

Service Advantages

• The interacting proteins obtained by TAP/MS are bound to the target proteins intracellularly, which is consistent with the real physiological situation in vivo, and the results obtained are highly reliable.
• The purification conditions of this method are mild and do not destroy weak interactions, so more physiologically significant interacting proteins can be obtained.
• The use of two-step purification can effectively reduce the binding of non-specific proteins and avoid the dissociation of complexes due to over-washing.
• A two-end tag is available to avoid loss of function at one end with the tag, broadening the scope of TAP/MS use.
• It is particularly suitable for large-scale studies at the proteomic level.