I 309 Human, His

I-309, also known as CCL1 (Chemokine (C-C motif) ligand 1), is a small glycoprotein that belongs to the chemokine family of cytokines. Chemokines are known for their role in the inflammatory response and immunoregulatory processes. CCL1 is secreted by activated T-cells and is part of a larger cluster of similar chemokines located on human chromosome 17 .

The human recombinant I-309 is produced in E. coli and is fused with a 21 amino acid His tag at the N-terminus. This recombinant protein is a single, non-glycosylated polypeptide chain containing 94 amino acids (24-96 a.a.) and has a molecular mass of approximately 10.8 kDa . The His tag facilitates purification and detection of the protein.

CCL1 plays a crucial role in the immune system by acting as a chemoattractant for T lymphocytes. It is involved in the recruitment of immune cells to sites of inflammation and infection. The activity of CCL1 is measured by its ability to chemoattract specific cell lines, such as BW5147 mouse T lymphoma cells and BaF3 mouse pro-B cells transfected with human CCR8 .

The recombinant I-309 is expressed in E. coli and purified using proprietary chromatographic techniques. The protein is typically provided as a sterile filtered colorless solution with a purity greater than 85% as determined by SDS-PAGE . The formulation of I-309 includes 20mM Tris-HCl buffer (pH 7.5), 2mM DTT, 10% glycerol, and 50mM NaCl .

For optimal stability, I-309 should be stored desiccated below -18°C. For long-term storage, it is recommended to add a carrier protein such as 0.1% human serum albumin (HSA) or bovine serum albumin (BSA) to prevent freeze-thaw cycles . The protein remains stable for up to 12 months when stored at -20 to -70°C as supplied .

Recombinant I-309 is used in various research applications, including studies on immune cell migration, inflammation, and cytokine signaling pathways. It is also utilized in assays to investigate the chemotactic properties of CCL1 and its interactions with receptors such as CCR8.