I-309 is a CC chemokine that signals through the CCR8 receptor. It is secreted by T-lymphocytes, monocytes and mast cells. I-309 chemoattracts monocytes and Th2 differentiated T-cells, but not neutrophils. Human I-309 is active on murine cells. Recombinant human I-309 is an 8.5 kDa protein consisting of 74 amino acid residues that include six cysteine residues, of which four are the highly conserved cysteine residues present in CC chemokines. Unlike some CC chemokines, whose biologically active form in solution is a non-disulfide-linked dimer, the biologically active form of I-309 is monomeric.
Amino Acid Sequence
Determined by its ability to chemoattract total human T cell population using a concentration range of 10.0–100.0 ng/ml.
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. This solution can be stored at 2–8°C for up to 1 week. 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.