Animal-Free Activin B 蛋白, Human (His)

Activin B, a TGFβ superfamily cytokine, is a homodimer of activin βB subunits. Activin B binds to type II transmembrane serine-threonine kinase receptors (ACTRIIA or ACTRIIB) which, in turn, activate type I receptors (ACTRI) that phosphorylate and activate canonical SMAD signaling pathways^[1][2]. Animal-Free Activin B Protein, Human (His), a recombinant animal-free protein, is produced in E. coli with a C-Terminal His-tag. It consists of 115 amino acids (G293-407A).

激活素是 TGF-β 超家族的成员，首先从猪卵巢卵泡液中分离出来，并被鉴定为促卵泡激素释放的激活因子。激活素 B 存在于大多数组织中，包括胎盘、生殖器官、骨髓和大脑。激活素 B 是炎症和免疫的调节剂，也参与癌症或伤口愈合过程^[1][2][3]< super>[4]。
激活素 B 在物种间高度保守，小鼠、大鼠和人类激活素 B 表现出 >97% 的序列同源性。
激活素以三种基本分子形式存在，组成为抑制素β有两个亚基：激活素A（βAβA）、激活素B（βBβB）和激活素AB（βAβB），它们的受体是ActRIA、ActRIB、ActRII A和ActRIIB。此后，这些蛋白质还被确定了不同的附加作用，包括对细胞生长和分化、胚胎发生调节、生殖系统发育、伤口愈合、干细胞分化和免疫反应调节的广泛而复杂的影响。激活素通过丝氨酸/苏氨酸蛋白激酶 (MAPK) 信号通路发挥其生物学功能。激活素 B 也可能通过 IC 型激活素受体 (ACVR1C (ALK7)) 发出信号。I 型受体通过 SMAD2/3 激活磷酸化级联，与 SMAD4 复合并易位到细胞核以调节基因转录，从而启动信号级联。激活素的作用被抑制素拮抗，抑制素通过阻断激活素与其受体的结合以及卵泡抑素^{[1][2][3].
Activin B 通过 RhoA-Rock-JNK-cJun 信号通路刺激皮肤损伤部位的细胞增殖并促进伤口愈合。一些细胞类型响应炎症刺激，激活素 B 的产生增加，最明显的是肝星状细胞、垂体细胞和小胶质细胞。激活素 B 通过诱导肌动蛋白应力纤维形成来调节细胞迁移。此外，Activin B治疗可通过SMAD依赖性方式上调整合素β3，促进II型子宫内膜癌细胞的粘附、迁移和侵袭[1][3][4]。}

Recombinant human Activin B (1  ng/mL; 48 hours) protein incubation with the normal fibroblasts (NFBs), the results show  increase expressions of Activin B, Smad2/3, TGF-β1, and endothelin-1 (ET-1) compared with the untreated NFBs. In addition, the levels of thrombospondin-1 (Tsp-1) and Oncostatin M (OSM) are significantly lower than those of the control group^[1]. Recombinant human Activin B (5  ng/mL; 24 hours) significantly decreases E-cadherin expression in both a time- and concentration-dependent manner in KLE and HEC-5 cell lines. The suppressive effects of Activin B on E-cadherin are mediated by MEK-ERK1/2-induced production of the transcription factor SNAIL^[3].

Recombinant human Activin B (5, 1 or 5  ng/mL; dorsal skin; 3 times a day for 17 days) efficiently induces the initiation of hair follicles in the skin of both cultured and neonatal mice and to promote the development of hair follicles in neonatal mouse skin. Moreover, activin-B-treated hair follicles were observed to enter the anagen stage from the telogen stage and to remain in the anagen stage^[5].

Measure by its ability to induce hemoglobin expression in K562 cells. The ED₅₀ for this effect is <0.7 ng/mL. The specific activity of recombinant human Activin B is > 1.5 x 10⁶IU/mg

Human

E. coli

C-His

P09529 (G293-407A)

3625  [NCBI]

MGLECDGRTNLCCRQQFFIDFRLIGWNDWIIAPTGYYGNYCEGSCPAYLAGVPGSASSFHTAVVNQYRMRGLNPGTVNSCCIPTKLSTMSMLYFDDEYNIVKRDVPNMIVEECGCA

Approximately 13.75 kDa

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

无菌粉末.

Lyophilized from a solution containing 1X PBS, pH 8.0.

<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 and not higher than 500 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]. Shi-Kang Deng, et al. Activin B signaling may promote the conversion of normal fibroblasts to scar fibroblasts. Medicine (Baltimore). 2020 Jun 12;99(24):e20253.  [Content Brief]

  [2]. Qin Jia, et al. Activin B promotes initiation and development of hair follicles in mice. Cells Tissues Organs. 2013;198(4):318-26.  [Content Brief]

  [3]. J M Young, et al. Activin B is produced early in antral follicular development and suppresses thecal androgen production. Reproduction. 2012 May;143(5):637-50.  [Content Brief]

  [4]. Siyuan Xiong, et al. Activin B promotes endometrial cancer cell migration by down-regulating E-cadherin via SMAD-independent MEK-ERK1/2-SNAIL signaling. Oncotarget. 2016 Jun 28;7(26):40060-40072.  [Content Brief]

  [5]. Sabine Gravelsina, et al. Potential of Activin B as a Clinical Biomarker in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). Biomolecules. 2021 Aug 11;11(8):1189.  [Content Brief]