CCL17 is a novel CC chemokine recently identified using a signal sequence trap method. CCL17 cDNA encodes a highly basic 94 amino acid residue precursor protein with a 23 aa residue signal peptide that is cleaved to generate the 71 aa residue mature secreted protein. Among CC chemokine family members, CCL17 has approximately 24 - 29% amino acid sequence identity with RANTES, MIP-1ª, MIP-1ß, MCP-1, MCP-2, MCP-3 and I-309. The gene for human CCL17 has been mapped to chromosome 16q13 rather than chromosome 17 where the genes for many human CC chemokines are clustered. CCL17 is constitutively expressed in thymus, and at a lower level in lung, colon, and small intestine. CCL17 is also transiently expressed in stimulated peripheral blood mononuclear cells. Recombinant CCL17 has been shown to be chemotactic for T cell lines but not monocytes or neutrophils. CCL17 was recently identified to be a specific functional ligand for CCR-4, a receptor that is selectively expressed on T cells.
Amino Acid Sequence
ARGTNVGREC CLEYFKGAIP LRKLKTWYQT SEDCSRDAIV FVTVQGRAIC SDPNNKRVKN
Fully biologically active when compared to standard. The biological activity determined by a chemotaxis bioassay using human T-lymphocytes is in a concentration range of 1.0-10 ng/ml.
Sterile Filtered White lyophilized (freeze-dried) powder.
Approximately 8.1 kDa, a single non-glycosylated polypeptide chain containing 71 amino acids.
Lyophilized from a 0.2 μm filtered concentrated solution in 20mM PB, pH 7.4, 150mM NaCl.
We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile distilled water or aqueous buffer containing 0.1 % BSA to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at ≤ -20 °C. Further dilutions should be made in appropriate buffered solutions.
> 97 % by SDS-PAGE and HPLC analyses.
Less than 1 EU/μg of rHuTARC/CCL17 as determined by LAL method.
This lyophilized preparation is stable at 2-8 °C, but should be kept at -20 °C for long term storage, preferably desiccated. Upon reconstitution, the preparation is stable for up to one week at 2-8 °C. For maximal stability, apportion the reconstituted preparation into working aliquots and store at -20 °C to -70 °C. Avoid repeated freeze/thaw cycles.