SDF-1 alpha/CXCL12 Protein, Human

SDF-1 alpha (CXCL12α) belongs to the CXC chemokine family and is encoded by the CXCL12 gene. SDF-1 alpha mediates cell chemotaxis and tissue repair through CXCR4/CXCR7, activates AMPK to inhibit NLRP3 inflammasome and pyroptosis; SDF-1 alpha promotes autophagy through the PI3K-mTOR pathway, is induced by upstream inflammatory factors such as TNF-α, and recruits integrins downstream to promote cell adhesion^[1]. SDF-1 alpha/CXCL12 Protein, Human is the recombinant human-derived SDF-1 alpha/CXCL12 protein, expressed by E. coli, with tag free.

SDF-1 alpha (stromal cell-derived factor 1 alpha, CXCL12α) is a member of the CXC chemokine family. It is encoded by the CXCL12 gene and contains four conserved cysteines that form two disulfide bonds (Cys9-Cys34, Cys11-Cys50). It lacks an ELR (Glu-Leu-Arg) domain. The mature peptide of SDF-1 alpha generally contains 68 amino acids and has a molecular weight of approximately 8 kDa. It is the main active isomer of SDF-1 (the other isomer is SDF-1β)^[1].
SDF-1 alpha mediates cell chemotaxis (such as hematopoietic stem cells, T cells, and monocytes) through the receptor CXCR4, regulating tissue repair, angiogenesis, and inflammatory responses. SDF-1 alpha is involved in the AMPK pathway: In osteoarthritis (OA) synovial fibroblasts, SDF-1α activates AMPK and inhibits NLRP3 inflammasome (NLRP3/ASC/caspase-1) and pyroptosis (GSDMD/IL-1β). SDF-1 alpha is also involved in the PI3K-mTOR pathway: PI3K-mTOR is activated through CXCR4 to promote autophagy (such as increased LC3II and decreased p62 in chondrocytes), but this pathway does not directly mediate inflammation inhibition. SDF-1 alpha is first induced by upstream inflammatory factors (such as TNF-α and IL-1β), and recruits integrins (such as VLA-4) through downstream CXCR4 to promote cell adhesion and migration^[1].
SDF-1 alpha can be used to study diseases or mechanisms such as osteoarthritis (OA), inflammation, and autophagy. For example, intra-articular injection of SDF-1 alpha can alleviate collagenase-induced OA in mice, inhibit synovial inflammation and cartilage degradation; SDF-1 alpha promotes autophagy in chondrocytes through the CXCR4/mTOR axis, protecting cells from stress damage^[1]. In stem cell biology, SDF-1 alpha also regulates hematopoietic stem cell homing (such as enhancing CXCR4 expression in bone marrow transplantation)^[2].

1. Full biological activity determined by a chemotaxis bioassay using PHA and rHuIL-2 activated human peripheral blood T-lymphocytes is in a concentration range of 20-80 ng/mL.
2. Measured by its ability to chemoattract IL-2-activated human T cells. The ED₅₀ for this effect is approximately ≤45.17 ng/mL, corresponding to a specific activity is ≥2.214×10⁴ U/mg.
3. Measured by its ability to chemoattract BaF3 mouse pro B cells transfected with human CXCR4. The ED₅₀ for this effect is 0.3-1.0 ng/mL.

• 
  Measured by its ability to chemoattract BaF3 mouse pro B cells transfected with human CXCR4. The ED₅₀ for this effect is 0.3559 ng/mL, corresponding to a specific activity is 2.810×10⁶ U/mg.

Human

E. coli

Tag Free

P48061-2 (K22-K89)

6387  [NCBI]

Full Length of Isoform-2 Mature Protein

KPVSLSYRCPCRFFESHVARANVKHLKILNTPNCALQIVARLKNNNRQVCIDPKLKWIQEYLEKALNK

Approximately 8 kDa, based on SDS-PAGE under reducing conditions.

• 
  ≥ 95%, as determined by reducing SDS-PAGE.

Lyophilized powder

1.Lyophilized from a 0.22 μm filtered solution of 20 mM PB, 150 mM NaCl, pH 7.4.
2.Lyophilized from a 0.22 μm filtered solution of 20 mM PB, 130 mM NaCl, pH 7.3.
3.Lyophilized from a 0.22 μm filtered solution of PBS, pH 7.4.
Please refer to the lot-specific COA for specific buffer information.

<1 EU/μg, determined by 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 from date of receipt. 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.

• [1]. Wang S, et al. Exogenous stromal cell-derived factor-1 (SDF-1) suppresses the NLRP3 inflammasome and inhibits pyroptosis in synoviocytes from osteoarthritic joints via activation of the AMPK signaling pathway. Inflammopharmacology. 2021 Jun;29(3):695-704.  [Content Brief]

  [2]. Hayakawa J, et al. Dextran sulfate and stromal cell derived factor-1 promote CXCR4 expression and improve bone marrow homing efficiency of infused hematopoietic stem cells. J Nippon Med Sch. 2009 Aug;76(4):198-208.  [Content Brief]

  [3]. Warner JA, et al. Human cytomegalovirus infection inhibits CXCL12- mediated migration and invasion of human extravillous cytotrophoblasts. Virol J. 2012 Nov 1;9:255.  [Content Brief]

  [4]. Yadav SS, et al. CXCL12 is a key regulator in tumor microenvironment of cervical cancer: an in vitro study. Clin Exp Metastasis. 2016 Jun;33(5):431-9.  [Content Brief]

  [5]. Hoh BL, et al. Stromal cell-derived factor-1 promoted angiogenesis and inflammatory cell infiltration in aneurysm walls. J Neurosurg. 2014 Jan;120(1):73-86.  [Content Brief]