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. SDF-1 beta/CXCL12 Protein, Mouse is produced in E. coli, and 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. 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.
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. 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.
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). 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.

Recombinant mouse SDF-1β (5 mg/kg; tail vein; twice a week; for 3 months) injected into mice bearing type 2 diabetes (T2D). SDF-1β prevents T2D-induced cardiac dysfunction and fibrosis and T2D-down-regulated KLF15 expression in wild-type diabetic heart tissue^[5].

1. The biological activity determined by a chemotaxis bioassay using human peripheral blood monocytes is in a concentration range of 50-100 ng/ml.
2. Measured in a cell proliferation assay using Jurkat cells. The ED50 this effect is 2.589 ng/mL, corresponding to a specific activity is 3.86×10^5 units/mg.

• 
  Measured in a cell proliferation assay using Jurkat cells. The ED₅₀ for this effect is 2.589 ng/mL, corresponding to a specific activity is 3.86×10⁵ units/mg.

Mouse

E. coli

Tag Free

P40224-2 (K22-M93)

20315  [NCBI]

KPVSLSYRCPCRFFESHIARANVKHLKILNTPNCALQIVARLKNNNRQVCIDPKLKWIQEYLEKALNKRLKM

Approximately 10.74 kDa

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

Lyophilized powder

Lyophilized from a 0.2 μm filtered solution of 20 mM PB, 150 mM NaCl, pH 7.4.

<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. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer. It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.