Fibronectin 蛋白, Human

Fibronectin is a glycoprotein located in the extracellular matrix that can bind to collagen, fibrin, heparin, DNA, and actin. Fibronectin is involved in cell adhesion, movement, conditioning, wound healing, and maintaining cell shape. Additionally, by binding to the LILRB4 receptor, Fibronectin can inhibit monocyte activation mediated by FCGR1A/CD64, thereby exerting immune regulatory effects. Human Fibronectin is a recombinant protein dimer complex with a full length of 573 amino acids (P1270-S1546 & A1721-T2016), expressed in E. coli and is untagged^{[1][2][3][4][5][6][7][8][9][10][11][12]}.

纤连蛋白是细胞外基质中的一种糖蛋白，在细胞粘附、伤口愈合、胚胎发育、免疫调节等过程发挥作用。伤口愈合包括炎症期、增生期 (肉芽组织形成) 和重塑期。受伤后 Fibronectin 蛋白的过量或异常沉积可能导致纤维化或动脉粥样硬化等疾病。Fibronectin 蛋白在伤口愈合过程中发挥着关键的功能，其作用涉及到伤口的初期修复、细胞迁移、组织重塑以及愈合的最终阶段^[1]。
(1) 炎症期：Fibronectin 蛋白表达在 TGF-β 刺激下上调，并与血小板上的整合素结合，促进血块的形成和细胞的初步附着。整合素的激活增强了纤连蛋白在伤口部位的聚集，并促进了血小板的黏附和凝血因子的释放^[2]。
(2) 增生期：Fibronectin 与整合素 (如 α5β1 整合素) 结合，并激活激活 β-连环蛋白，促进细胞的附着、迁移和增殖^[3]。
(3) 重塑期：Fibronectin 蛋白的降解和重构依赖 MMPs (基质金属蛋白酶) 和 TIMPs (基质金属蛋白酶抑制因子) 信号通路，MMPs 降解临时细胞外基质 (ECM) 矩阵中的 Fibronectin 蛋白，TIMPs 则抑制 MMPs 的活性，确保 ECM 的适当重塑^[4]。
(4) 愈合：Fibronectin 蛋白与整合素 (α5β1 整合素) 结合，促进细胞的凋亡和血管的重建。TGF-β 通过调节纤连蛋白的表达，减少过度的纤维化和瘢痕形成^[5]。Fibronectin 蛋白在血管伤口愈合过程中同样有助于支持新血管的形成和修复，Fibronectin 蛋白增加的同时内皮细胞开始增殖，并且毛细血管开始向内生长^[6]。
Fibronectin 蛋白表达上调也可能与肿瘤形成有关，Fibronectin 蛋白 ED-A 区段的mRNA 选择性剪切在人肝肿瘤组织中失调，与门静脉肿瘤血栓（PVTT）形成和肿瘤肝内转移密切相关^[7]。
Fibronectin 蛋白可以与 Anastellin 结合形成纤连蛋白聚合物，称为Superfibronectin，具有强化的粘附性能。Superfibronecin 可抑制肿瘤生长、血管生成和转移。其中 Anastellin 可激活 p38 MAPK 并抑制溶血磷脂信号传导^[8]。
Fibronectin 还能够抑制单核细胞活化发挥免疫调节作用，Fibronectin 蛋白 (Rat) (与人源 Fibronectin 蛋白相似度 92.1%) 在慢性肾炎 Wistar 大鼠模型被发现发挥了有效的抗炎作用^[9][10]。

Fibronectin 蛋白 (Human) (2-40 nM，24-100 h) 以剂量依赖地方式促进缺乏内源性纤维连接蛋白的小鼠胚胎细胞生长^[11]。
Fibronectin 蛋白 (Human) 对人类 LILRB4 受体和其在小鼠中的直系同源物 gp49B 受体具有较高的结合亲和力，K_D值分别为 421 nM 和 50.1 nM^[12]。

FN30-Fc 是由 Fibronectin 蛋白 (Human) 的 N 端 30 kDa (FN30) 与小鼠 IgG2a Fc 融合形成的重组蛋白。FN30-Fc (200 μg，10 周龄小鼠，腹腔注射，共 2 次，间隔 2 周) 在 BXSB/Yaa 红斑狼疮 (SLE) 小鼠模型具有改善其自身免疫性肾炎的作用^[12]。

1.Measured by its ability to support cell attachment and spreading when used as a substratum for cell culture. The ED₅₀ for this effect is ≤ 385.7 ng/mL.
2.Measured by the ability of the immobilized protein to support the adhesion of B16-F1 mouse melanoma cells. The ED₅₀ for this effect is ≤182.9 ng/mL, corresponding to a specific activity is ≥5.467×10³ units/mg.

• 
  Measured by the ability of the immobilized protein to support the adhesion of B16-F1 mouse melanoma cells. The ED₅₀ for this effect is 124.5 ng/mL, corresponding to a specific activity is 8.03×10³ units/mg.

Human

E. coli

Tag Free

P02751-1 (P1270-S1546 & A1721-T2016)

2335  [NCBI]

PTDLRFTNIGPDTMRVTWAPPPSIDLTNFLVRYSPVKNEEDVAELSISPSDNAVVLTNLLPGTEYVVSVSSVYEQHESTPLRGRQKTGLDSPTGIDFSDITANSFTVHWIAPRATITGYRIRHHPEHFSGRPREDRVPHSRNSITLTNLTPGTEYVVSIVALNGREESPLLIGQQSTVSDVPRDLEVVAATPTSLLISWDAPAVTVRYYRITYGETGGNSPVQEFTVPGSKSTATISGLKPGVDYTITVYAVTGRGDSPASSKPISINYRTEIDKPS&AIPAPTDLKFTQVTPTSLSAQWTPPNVQLTGYRVRVTPKEKTGPMKEINLAPDSSSVVVSGLMVATKYEVSVYALKDTLTSRPAQGVVTTLENVSPPRRARVTDATETTITISWRTKTETITGFQVDAVPANGQTPIQRTIKPDVRSYTITGLQPGTDYKIYLYTLNDNARSSPVVIDASTAIDAPSNLRFLATTPNSLLVSWQPPRARITGYIIKYEKPGSPPREVVPRPRPGVTEATITGLEPGTEYTIYVIALKNNQKSEPLIGRKKTDELPQLVTLPHPNLHGPEILDVPST

Approximately 56-76 kDa due to the glycosylation.

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

无菌粉末

Lyophilized from a 0.2 μm filtered solution of 12.5 mM Sodium Citrate, 1.25% Sucrose, pH 5.5 or PBS, pH 6.8, 5% trehalose, 5% mannitol and 0.01% Tween 80.

<0.01 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. 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]. Patten J, Wang K. Fibronectin in development and wound healing. Adv Drug Deliv Rev. 2021 Mar;170:353-368.  [Content Brief]

  [2]. Lenselink EA. Role of fibronectin in normal wound healing. Int Wound J. 2015 Jun;12(3):313-6. doi: 10.1111/iwj.12109. Epub 2013 Jun 7.  [Content Brief]

  [3]. Bielefeld K A, et al. Fibronectin and β-catenin act in a regulatory loop in dermal fibroblasts to modulate cutaneous healing[J]. Journal of Biological Chemistry, 2011, 286(31): 27687-27697.  [Content Brief]

  [4]. Shi F, et al. MT1-MMP regulates the turnover and endocytosis of extracellular matrix fibronectin[J]. Journal of cell science, 2011, 124(23): 4039-4050.  [Content Brief]

  [5]. Lefcort F, et al. Regulation of expression of fibronectin and its receptor, α5β1, during development and regeneration of peripheral nerve[J]. Development, 1992, 116(3): 767-782.

  [6]. Clark RA, et al. Blood vessel fibronectin increases in conjunction with endothelial cell proliferation and capillary ingrowth during wound healing. J Invest Dermatol. 1982 Nov;79(5):269-76.  [Content Brief]

  [7]. Oyama F, et al. Deregulation of alternative splicing of fibronectin pre-mRNA in malignant human liver tumors. J Biol Chem. 1989 Jun 25;264(18):10331-4.  [Content Brief]

  [8]. Yi M, Ruoslahti E. A fibronectin fragment inhibits tumor growth, angiogenesis, and metastasis. Proc Natl Acad Sci U S A. 2001 Jan 16;98(2):620-4.  [Content Brief]

  [9]. Quirós J, et al. Beneficial effect of fibronectin administration on chronic nephritis in rats. Arthritis Rheum. 1990 May;33(5):685-92.  [Content Brief]

  [10]. Su MT, et al. Blockade of checkpoint ILT3/LILRB4/gp49B binding to fibronectin ameliorates autoimmune disease in BXSB/Yaa mice. Int Immunol. 2021 Jul 23;33(8):447-458.  [Content Brief]

  [11]. Sottile J, et al. Fibronectin matrix assembly enhances adhesion-dependent cell growth. J Cell Sci. 1998 Oct;111 ( Pt 19):2933-43.  [Content Brief]