Fas and Fas Ligand (FasL) belong to the TNF superfamily, and are type I and type II transmembrane proteins, respectively. Binding of FasL to Fas triggers apoptosis in Fas-bearing cells. The mechanism of apoptosis involves recruitment of pro-caspase 8 through an adaptor molecule called FADD, followed by processing of the pro-enzyme into active forms. These active caspases then cleave various cellular substrates, leading to the eventual cell death. sFasR is capable of inhibiting FasL-induced apoptosis by acting as a decoy receptor that serves as a sink for FasL. The full length Fas (receptor) is a 319 amino acid type I transmembrane protein, which contains a 157 amino acid extracellular domain, a 17 amino acid transmembrane domain, and a 145 amino acid cytoplasmic domain. Recombinant Human soluble Fas (sFas Receptor) is a 157 amino acid polypeptide (17.6 kDa) corresponding to the TNFR-homologous cysteine-rich extracellular Fas domain.
Amino Acid Sequence
The ED50 was determined by its ability to inhibit the cytotoxicity of Jurkat cells is between 10–15 µg/ml in the presence of 2ng/ml of hFasL.
Endotoxin level is <0.1 ng/μg of protein (<1EU/μg).
Centrifuge the vial prior to opening. Reconstitute in water to a concentration of 0.1–1.0 mg/ml. Do not vortex. For extended storage, it is recommended to further dilute in a buffer containing a carrier protein (example 0.1% BSA) and store in working aliquots at –20°C to –80°C.