FasL, the T4 Foldon and Strep-tag^®

- The winning combination -

Type II transmembrane protein FasL is localized in the cell membrane of T-cells. Its homotrimerization is a prerequisite for apoptotic activity. Thus, the stabilization of the functional conformation of the trimeric extracellular receptor binding domain (RBD) of FasL is mandatory for its use as apoptotic reagent.
A stable trimeric conformation of FasL has been engineered by introduction of the "T4-FOLDON", a small trimeric globular domain derived from the C-terminus of the bacteriophage T4 protein fibritin. In contrast to commonly used N-terminal fused coiled-coil structures, C-terminal fusion of the T4-FOLDON to the FasL-RBD results in superior bioactive, stable, well defined trimers.
In addition to the T4-FOLDON, the FasL reagent contains a Strep-tag^® fused to each of the three monomers. The Strep-tag^® allows not only an optimal purification but also immobilization and detection of the FasL reagent. Thus Strep-tag^® is ideal for the handling of this novel FasL-reagent named FasL-Strep.

Advantages of FasL-Strep

• Defined trimeric structure
  
• High stability
  
• Efficient apoptosis induction
  
• Easy handling (detection, immobilization, isolation) via Strep-tag^®
  
• Competitive pricing