Source:

Escherichia coli.

Molecular Weight:

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

Purity:

>97% by SDS-PAGE and HPLC analyses.

Biological activity:

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.

AA Sequence:

KPVSLSYRCP CRFFESHVAR ANVKHLKILN TPNCALQIVA RLKNNNRQVC IDPKLKWIQE YLEKALNK

Endotoxin:

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

Formulation:

Lyophilized from a 0.2μm filtered concentrated solution in 20mM PB, pH 130mM NaCl.

Background:

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.

Usage:

This material is offered by USA Bioworld biotech for research, laboratory or further evaluation purposes. NOT FOR HUMAN USE.

Physical Appearance:

Sterile Filtered White lyophilized (freeze-dried) powder.

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.

Storage:

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.