Protein:protein-interactions (PPI) govern almost all important processes in living organisms. Thus, their rapid and accurate determination and investigation is a major challenge in life sciences.

Based on its Twin-Strep-tag® (formerly known as One-STrEP)/Strep-Tactin® system IBA provides optimal solutions with its different determination systems for protein:protein-interaction analysis based on the procedure described in Rigaut et al., 1999.

 

"Protein Complex Analysis combining a one-step co-purification with a mass spectrometry approach"

Rigaut et al., 1999

Twin-Strep tag for protein interaction analysis using mass spectrometry

Step 1-3 Protein complex purification; Step 4 Protein complex analysis
 
1.   A tagged bait protein is expressed in the target cell. At a given time point, cells are harvested and lysed.
2.   The lysate containing the bait with putatively interacting preys is subjected to tag-based affinity chromatography.
3.   Isolated protein complexes are analyzed by SDS-PAGE and silver staining, and compared to mock isolates.
4.   Potential preys could be identified by mass spectrometry or verified by Western blots with specific antibodies.

This is the basic principle for affinity tag based protein complex isolation and protein interaction analysis. The further developed determination systems are described in the following sections: