Recombinant Human SDF-1 alpha (rHuSDF-1 alpha/CXCL12- alpha)

SDF-1α and SDF-1β, members of the chemokine α subfamily that lack the ELR domain, were initially identified using the signal sequence trap cloning strategy from a mouse bone-marrow stromal cell line. These proteins were subsequently also cloned from a human stromal cell line as cytokines that supported the proliferation of a stromal cell-dependent pre-B-cell line. SDF-1α and SDF-1β cDNAs encode precursor proteins of 89 and 93 amino acid residues, respectively. Both SDF-1α and SDF-1β are encoded by a single gene and arise by alternative splicing. The two proteins are identical except for the four amino acid residues that are present in the carboxy-terminus of SDF-1β and absent from SDF-1α. SDF-1/PBSF is highly conserved between species, with only one amino acid substitution between the mature human and mouse proteins. SDF-1/PBSF acts via the chemokine receptor CXCR4 and has been shown to be a chemoattractant for T-lymphocytes, monocytes, pro- and pre- B cells, but not neutrophils.

Product Specifications

CAS Number

9000-83-3

Endotoxin

Less than 1EU/μg of rHuSDF-1 alpha as determined by LAL method.

Purity

>97% by SDS-PAGE and HPLC analyses.

Bioactivity

Fully biologically active when compared to standard. Determined by its ability to chemoattract human peripheral T cells activated with PHA and IL-2 using a concentration range of 20.0-80.0 ng/ml, corresponding to a Specific Activity of > 1.25 x 104 IU/mg.

Reconstitution

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.

Molecular Weight

8.0 kDa, a single non-glycosylated polypeptide chain containing 68 amino acids.

Storage Conditions

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.