Introduction
SDF-1, or stromal cell-derived factor-1, is a chemokine officially known as Chemokine (C-X-C motif) ligand 12 (CXCL12). It exists in two isoforms, SDF-1α/CXCL12a and SDF-1β/CXCL12b, generated by alternative splicing of the CXCL12 gene. Chemokines are characterized by four conserved cysteines forming two disulfide bonds. CXCL12 proteins belong to the CXC chemokine group, with a single amino acid separating the first cysteine pair. CXCL12 exhibits strong chemotactic activity for lymphocytes and plays a crucial role in cell coordination during development, including directing hematopoietic cell migration from fetal liver to bone marrow during embryogenesis. CXCL12 knockout mice are either lethal before birth or die within an hour after birth. Additionally, CXCL12a influences neuronal electrophysiology. In mice, CXCL12 expression is observed in various tissues, including the brain, thymus, heart, lung, liver, kidney, spleen, and bone marrow. CXCL12 binds to the CXCR4 receptor, previously known as fusin. While this interaction was initially considered exclusive, recent studies suggest that CXCL12 also binds to the CXCR7 receptor. The CXCL12 gene is located on human chromosome 10. Both CXCL12 and CXCR4 exhibit high sequence identity between humans and mice, with 99% and 90% similarity, respectively.
Description
SDF-1 beta Rat Recombinant, produced in E. coli, is a non-glycosylated polypeptide chain composed of 72 amino acids, with a molecular weight of 8.4 kDa. This recombinant protein is purified using proprietary chromatographic techniques.
Physical Appearance
Sterile Filtered White lyophilized (freeze-dried) powder
Formulation
The Rat SDF1B protein was lyophilized from a concentrated (1mg/ml) sterile solution containing 20mM Phosphate buffer at pH 7.4 and 0.15M NaCl.
Solubility
To reconstitute the lyophilized SDF-1b, it is recommended to dissolve it in sterile 18 MΩ-cm H2O at a concentration of at least 100 µg/ml. This solution can then be further diluted in other aqueous solutions.
Stability
Lyophilized SDF-1b remains stable at room temperature for up to 3 weeks; however, it should be stored desiccated at a temperature below -18°C. Upon reconstitution, CXCL12 should be stored at 4°C for 2-7 days. For long-term storage, it is recommended to store it at a temperature below -18°C. To enhance long-term storage stability, the addition of a carrier protein (0.1% HSA or BSA) is recommended. Avoid repeated freeze-thaw cycles.
Purity
The purity is determined by the following methods and is greater than 97.0%: (a) Analysis by RP-HPLC (b) Analysis by SDS-PAGE
Biological Activity
The specific activity of this protein is determined by its chemoattractant properties. It can effectively chemoattract human peripheral blood monocytes at concentrations between 100-150 ng/ml, corresponding to a specific activity ranging from 6,667 to 10,000 IU/mg.
Synonyms
SDF-1, CXCL12, Pre-B cell growth-stimulating factor, PBSF, hIRH, chemokine (C-X-C motif) ligand 12, SDF1, SDF1B, TPAR1, SCYB12, SDF-1b, TLSF-b, 12-O-tetradecanoylphorbol 13-acetate repressed protein 1, Thymic lymphoma cell-stimulating factor, TLSF.
Amino Acid Sequence
KPVSLSYRCP CRFFESHVAR ANVKHLKILN TPNCALQIVA RLKSNNRQVC IDPKLKWIQE YLDKALNKRL KM.
