Tumor Necrosis Factor (TNF)-Related Apoptosis-Inducing Ligand (TRAIL) is a type II transmembrane protein and belongs to the TNF superfamily of ligands. Trimerisation of TRAIL around a centrally positioned Zn atom is needed for maintaining its stability, solubility and biological activity as a death ligand. TRAIL exists in two forms, soluble and membrane bound.

Tumor Necrosis Factor (TNF)-Related Apoptosis-Inducing Ligand (TRAIL) activates the extrinsic apoptotic pathway by binding death receptors (DR) 4 and 5. In addition to DR 4 and 5, TRAIL activates several other receptors such as decoy receptor (DcR)1, DcR2 and a soluble receptor called osteoprotegerin. TRAIL plays a vital role in the inhibition of autoimmune inflammation and cell cycle progression. TRAIL selectively kills tumor cells without damaging normal tissues and therefore, it might act as a tumor-selective anticancer agent. TRAIL-induced apoptosis is involved in various cellular processes including activation-induced cell death, homeostasis, intrathymic negative selection, autoimmunity suppression, and immune surveillance. Repeated dosage of recombinant soluble TRAIL triggers apoptosis, inhibits tumor progression, and increases viability of mice suffering from cancer.

Solution in 20 mM HEPES, pH 7.4, 300 mM NaCl, 0.01% Tween 20, 1% sucrose, 1 mM DTT.

The extracellular domain of mouse TRAIL (aa 99-291) is fused at the N-terminus to a His-tag and a linker peptide. The active multimeric conformation is stabilized by an inserted mutation allowing an additional CC-bridge.