Animal-Free SDF-1 alpha/CXCL12 Protein, Human (His)

The SDF-1 alpha/CXCL12 protein is a chemoattractant for immune cells. Animal-Free SDF-1 Beta/CXCL12 Protein, Human (His) is the recombinant human-derived animal-FreeSDF-1 Beta/CXCL12 protein, expressed by E. coli , with C-His labeled tag. The total length of Animal-Free SDF-1 Beta/CXCL12 Protein, Human (His) is 65 a.a., with molecular weight of ~8.55 kDa.

SDF-1 alpha/CXCL12 protein functions as a chemoattractant with specific activity on T-lymphocytes and monocytes, excluding neutrophils. Upon activation of the C-X-C chemokine receptor CXCR4, it induces a rapid and transient rise in intracellular calcium ions, facilitating chemotaxis. SDF-1-beta(3-72) and SDF-1-alpha(3-67) exhibit reduced chemotactic activity, and binding to cell surface proteoglycans appears to inhibit the formation of SDF-1-alpha(3-67), preserving activity at local sites. Additionally, it binds to the atypical chemokine receptor ACKR3, activating the beta-arrestin pathway and serving as a scavenger receptor for SDF-1. Through binding to the allosteric site (site 2) of integrins, it activates ITGAV:ITGB3, ITGA4:ITGB1, and ITGA5:ITGB1 independently of CXCR4. Acting as a positive regulator of monocyte migration and a negative regulator of monocyte adhesion via the LYN kinase, SDF-1 alpha/CXCL12 stimulates migration of monocytes and T-lymphocytes through CXCR4 and ACKR3, decreasing monocyte adherence to ICAM-1-coated surfaces, a ligand for beta-2 integrins. The SDF1A/CXCR4 signaling axis inhibits beta-2 integrin LFA-1-mediated adhesion of monocytes to ICAM-1 through LYN kinase. It inhibits CXCR4-mediated infection by T-cell line-adapted HIV-1, plays a protective role after myocardial infarction, and induces down-regulation and internalization of ACKR3 in various cells. Essential during embryonic development, it is required for B-cell lymphopoiesis, myelopoiesis in bone marrow, and heart ventricular septum formation. Furthermore, SDF-1 alpha/CXCL12 stimulates the proliferation of bone marrow-derived B-cell progenitors in the presence of IL7, as well as the growth of stromal cell-dependent pre-B-cells (By similarity). Existing in monomeric or homodimeric forms, the equilibrium is influenced by non-acidic pH, multivalent anions, and binding to CXCR4 or heparin. The monomeric form is vital for full chemotactic activity and resistance to ischemia/reperfusion injury, while the dimeric form acts as a partial agonist of CXCR4, stimulating Ca2+ mobilization without chemotactic activity, serving instead as a selective antagonist that blocks chemotaxis induced by the monomeric form. SDF-1 alpha/CXCL12 interacts with the N-terminus of ACKR3, integrin subunit ITGB3 (via the allosteric site (site 2)), and TNFAIP6 via the Link domain.

Measure by its ability to chemoattract BaF3 cells transfected with human CXCR4. The ED₅₀ for this effect is <0.5 ng/mL.

Human

E. coli

C-His

P48061-2 (V24-N88)

6387  [NCBI]

MVSLSYRCPCRFFESHVARANVKHLKILNTPNCALQIVARLKNNNRQVCIDPKLKWIQEYLEKALN

Approximately 8.55 kDa

Greater than 95% as determined by reducing SDS-PAGE.

Lyophilized powder.

Lyophilized from a solution containing 20 mM sodium citrate, 0.1 M NaCl, pH 4.5, trehalose.

<0.1 EU per 1 μg of the protein by the LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O. For long term storage it is recommended to add a carrier protein (0.1% BSA, 5% HSA, 10% FBS or 5% Trehalose).

Stored at -20°C for 2 years. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.