TNF-related apoptosis-inducing ligand (TRAIL) belongs to the tumor necrosis factor (TNF) cytokine family and induces rapid apoptosis in a wide variety of tumor cell lines upon binding to the death-signalling receptors on the cell membrane. TRAIL binds to one of four receptors that have been identified in humans, including TRAIL-R1/DR4, TRAIL- R2/KILLER/DR5, TRAIL-R3/DcR1/TRID, and TRAIL-R4/DcR2/TRUNDD. Both DR4 and DR5 are pro-apoptotic receptors, which contain a cytoplasmic death domain and mediate apoptosis on binding to TRAIL. By contrast, TRID and TRUNDD do not contain a cytoplasmic death domain and block the function of TRAIL by competing with DR4 and DR5 for binding of TRAIL. Recombinant protein corresponding to aa114-281 from human TRAIL, expressed in E. coli. Molecular Weight: ~19.6kD (169aa) Endotoxin: <1EU/1ug (determined by LAL method) Biological Activity: Measured in a cell cytotoxicity assay using Jurkat human T lymphocyte. The ED50 for this effect is 1ng/ml. AA Sequence: MVRERGPQRV AAHITGTRGR SNTLSSPNSK NEKALGRKIN SWESSRSGHS FLSNLHLRNG ELVIHEKGFY YIYSQTYFRF QEEIKENTKN DKQMVQYIYK YTSYPDPILL MKSARNSCWS KDAEYGLYSI YQGGIFELKE NDRIFVSVTN EHLIDMDHEA SFFGAFLVG Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for 12 months after receipt. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.