SDF-1 beta/CXCL12 蛋白, 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).

趋化因子基质衍生因子-1 (SDF-1) 在大多数组织中组成型表达为 SDF-1α 和 SDF-1β，由选择性基因剪接产生，调节造血、淋巴细胞归巢、B 系细胞生长和血管生成^[1][2]。SDF-1β 属于间分泌细胞因子家族（趋化因子），其特征是四个保守的半胱氨酸形成两个二硫键。此外，除血细胞外，它的表达存在于所有器官中^[3]。
SDF-1β 与 SDF-1α 几乎相同，只是第四个外显子仅由四个外显子组成连接到 C 末端的残基在体外和组织中表现出非常相似的活性，但在血液中的效力是其两倍。SDF-1α包含3个外显子，编码89个氨基酸的蛋白质，而SDF-1β包含4个外显子，编码93个氨基酸的蛋白质。两种异构体的序列高度相似，唯一的区别是 SDF1β^[1][2] C 末端多了 4 个氨基酸。此外，SDF-1β 被证明是能够支持啮齿动物 B 细胞淋巴细胞生成的充分因子。SDF-1β 表达量较低，似乎与血管系统有关。它对血液中蛋白水解作用具有更强的抵抗力，使其易于发挥这一作用^[3]。
小鼠脑微血管的内皮细胞选择性表达 SDF-1β。它的上调是在局灶性脑缺血后发现的，并且与表达 CXCR4 的外周血细胞（例如巨噬细胞）的浸润有关。SDF-1β 对人微血管内皮细胞 (HMEC) 的血管生成也有较大影响^[3]。与 SDF-1α 相比，SDF-1β 更能抵抗血液依赖性降解，刺激血管生成，并且存在于高度血管化的器官中，例如：肝脏、脾脏和肾脏^[4]。

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

Measured by its ability to bind biotinylated recombinant human DPPIV in a functional ELISA.

Human

HEK293

N-hFc

P48061 (K22-M93)

6387  [NCBI]

Approximately 43 kDa

Greater than 95% as determined by reducing SDS-PAGE

无菌粉末.

Lyophilized from a 0.2 μm filtered solution of PBS, pH 7.4. Normally 5 % - 8 % trehalose, mannitol and 0.01% Tween 80 are added as protectants before lyophilization.

<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]