SDF-1 beta/CXCL12 Protein, Human (HEK293, Fc)

SDF-1 beta (Stromal-derived factor-1β, SDF-1β) is a stromal derived CXC chemokine that signal through the CXCR4 receptor. SDF-1β has chemotactic activity on B and T cells^[1][2]. SDF-1 beta/CXCL12 Protein, Human (HEK293, Fc) is produced in HEK293 cells with a N-Terminal Fc-tag. It consists of 72 amino acids (K22-M93).

The chemokine stromal-derived factor-1 (SDF-1), which is constitutively expressed in most tissues as SDF-1α and SDF-1β resulting from alternative gene splicing, regulates hematopoiesis, lymphocyte homing, B-lineage cell growth, and angiogenesis^[1][2]. SDF-1β is assigned to the intercrine cytokine family (chemokines) which is characterized by four conserved cysteines that form two disulfide bonds. Furthermore its expression is found in all organs except in blood cells^[3].
SDF-1β which is virtually the same as SDF-1α, except in that the fourth exon consists of only four residues attached to a C-terminus, shows very similar activity in vitro and in tissues, but is twice as potent in the blood. SDF-1α comprises 3 exons and encodes a protein of 89 amino acids whereas SDF-1β consists of 4 exons and encodes a protein of 93 amino acids. Both isoforms are highly similar regarding their sequences with the only difference of 4 additional amino acids at the C-terminus of SDF1β^[1][2]. In addition, SDF-1β is shown to be a sufficient factor capable of supporting rodent B-cell lymphopoiesis. SDF-1β is expressed less abundantly and seems to be related to the vascular system. Its greater resistance to proteolysis within the blood predispose it to this role^[3].
Endothelial cells of cerebral microvessels in mice express SDF-1β selectively. Its upregulation is found following focal cerebral ischemia and is associated with the infiltration of CXCR4-expressing peripheral blood cells, such as macrophages. SDF-1β also has a greater effect on angiogenesis in human microvascular endothelial cells (HMEC)^[3]. Compared with SDF-1α, SDF-1β is more resistant to blood-dependent degradation, stimulates angiogenesis and is present in highly vascularized organs such as: the liver, spleen and kidneys^[4].

Recombinant human SDF-1β (1, 25, 5 and 1 ng/mL) induces apoptosis of A549 cells^[4].

Measured by its ability to chemoattract BaF3 mouse pro-B cells transfected with human CXCR4. The ED₅₀ for this effect is 0.7795 ng/mL, corresponding to a specific activity is 1.283×10⁶ U/mg.

Human

HEK293

N-hFc

P48061-1 (K22-M93)

6387  [NCBI]

KPVSLSYRCPCRFFESHVARANVKHLKILNTPNCALQIVARLKNNNRQVCIDPKLKWIQEYLEKALNKRFKM

Approximately 38-42 kDa due to the glycosylation.

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

Lyophilized powder

Lyophilized from a 0.2 μm filtered solution of PBS, pH 7.4, 8% trehalose.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O.

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.

• [1]. Maria De La Luz Sierra, et al. Differential processing of stromal-derived factor-1alpha and stromal-derived factor-1beta explains functional diversity. Blood. 2004 Apr 1;103(7):2452-9.  [Content Brief]

  [2]. Zheng Jiang, et al. Contribution of SDF-1α/CXCR4 signaling to brain development and glioma progression. Neurosignals. 2013;21(3-4):240-58.  [Content Brief]

  [3]. Miroslaw Janowski. Functional diversity of SDF-1 splicing variants. Cell Adh Migr. 2009 Jul-Sep;3(3):243-9.  [Content Brief]

  [4]. Kleanthis Fytianos, et al. Anti-Fibrotic Effect of SDF-1β Overexpression in Bleomycin-Injured Rat Lung. Pharmaceutics. 2022 Aug 27;14(9):1803.  [Content Brief]