Applications
The Strep-tag protein purification system provides the reliable one-step purification of proteins suitable for any application, including:
- Structural and functional investigations
- Crystallization for determination of 3D structure
- Immunization to produce antibodies
Due to the mild conditions Strep-tag II recombinant proteins can also be used for:
- Assays involving protein-protein and protein-DNA interactions
- Investigating ligand-receptor interactions under physiological conditions
- Separating living cells for re-culturing purposes
Protein-Protein Interactions
Strep-tag as a tool for studying protein-protein interactions
>>see also: One-STrEP Protein:Protein Interaction Analysis
The isolation of unknown binding partners of a protein which is known to be part of a certain metabolic pathway is a key issue e.g. in drug discovery. Due to its mild purification procedure Strep-tag is ideally suited for the isolation of protein complexes and, therefore, for such attempts as described above. This has been exemplarily shown for the elongation Factor - Ts, where the recombinant Strep-tag fusion protein expressed in E. coli formed a complex with natural E. coli proteins. The intact complex could be purified by Strep-Tactin® affinity chromatography as the correct stochiometry of the binding partners was found in the eluate.
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The recombinant Strep-tag protein is expressed in E. coli and binds to a specific partner. The whole complex is purified via Strep-tag.
The elongation factor Ts (EF-Ts) fused to Strep-tag has been expressed in E. coli. Lane 1 shows the protein content of total cells after expression. The soluble part (lane 2) is subjected to Strep-Tactin affinity chromatography. Elution (lane 3) reveals that EF-Ts is isolated complexed with EF-Tu being the authentic binding partner of EF-Ts. |
Protocols for download
For double tag proteins with Strep-tag and 6xHistidine-tag click here. |
