S100A9 Protein, Human

S100A9 Protein is an acidic protein. S100A9 Protein activates pro-inflammatory signaling pathways by binding to TLR4/MD2 and RAGE receptors, regulating transcription factors such as NF-κB, CREB-1, STAT3/STAT5, etc. S100A9 Protein forms a heterodimer (calprotectin) with S100A8. S100A9 Protein enhances cytokine secretion under inflammatory stimulation, promotes immune cell migration, regulates vascular endothelial permeability, induces tumor cell apoptosis, and exerts antibacterial effects through metal ion chelation.

S100A9 protein belongs to the S100 calcium-binding protein family. The members of this family contain EF-hand domains and have calcium-dependent regulatory functions^[3][7]. S100A9 protein is an acidic protein expressed by myeloid cells such as monocytes and neutrophils. It often forms a heterodimer with S100A8 (calprotectin) and participates in inflammation, immunity and host defense processes^[1][2][5]. S100A9 Protein activates pro-inflammatory signaling pathways by binding to TLR4/MD2 and RAGE receptors, regulates transcription factors such as NF-κB, CREB-1, STAT3/STAT5, and affects the secretion of cytokines (such as IL-8); regulates cytoskeleton reorganization by interacting with tubulin, and promotes transendothelial migration of phagocytes; and can also exert antibacterial activity or induce tumor cell apoptosis by chelating zinc ions^{[1][4][5][6][7]}. S100A9 Protein is mainly expressed in the cytoplasm of neutrophils and monocytes. It can be secreted outside the cells under inflammatory conditions and enriched on the surface of endothelial cells and in body fluids at the site of inflammation^[1][5][7]. S100A9 Protein, Human is highly conserved in amino acid sequence and function with its homologous proteins in other species such as mice. Both proteins mediate biological effects through calcium/zinc ion-dependent conformational changes, but some regulatory sites (such as the lack of Thr113 phosphorylation site in mouse S100A9) differ^[4][7]. S100A9 Protein, Human consists of 119 amino acids with a molecular weight of approximately 14 kDa. It contains two EF-hand calcium-binding domains and can form homodimers or heterodimers with S100A8. Its activity depends on the cooperative binding of calcium/zinc ions and phosphorylation modification by kinases such as p38 MAPK^[1][4][7]. S100A9 Protein, Human Enhances cytokine secretion under inflammatory stimulation, promotes immune cell migration, regulates vascular endothelial permeability, induces tumor cell apoptosis, and exerts antibacterial effects through metal ion chelation^[1][5][6][7].

S100A9 Protein, Human (10 μg/mL; 30 min) can enhance fMLP- or GM-CSF-stimulated IL-8 production by activating transcription factors such as NF-κB and CREB-1^[1].
S100A9 Protein, Human (1.25-10 μM; 1-4 d) induces apoptosis in MM46 mouse breast cancer cells^[6].

Measured by its ability to induce CXCL1/KC secretion by C3H10T1/2 mouse embryonic fibroblast cells. The ED₅₀ for this effect is 1.616 - 3.731 μg/mL.

• 
  Measured by its ability to enhance CXCL1secretion by C3H/10T1/2 Mouse embryonic fibroblasts. The ED₅₀ for this effect is 3.295 μg/mL, corresponding to a specific activity is 303.4901 U/mg.

Human

E. coli

Tag Free

P06702 (T2-P114)

6280  [NCBI]

TCKMSQLERNIETIINTFHQYSVKLGHPDTLNQGEFKELVRKDLQNFLKKENKNEKVIEHIMEDLDTNADKQLSFEEFIMLMARLTWASHEKMHEGDEGPGHHHKPGLGEGTP

Approximately 14.0 kDa

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

Lyophilized powder.

Lyophilized from a 0.2 μm filtered solution of PBS, pH 7.4 or 50 mM Tris-HCL, 300 mM NaCL, pH 8.0 or 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. 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 from date of receipt. 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]. Simard JC, et al. Human S100A9 potentiates IL-8 production in response to GM-CSF or fMLP via activation of a different set of transcription factors in neutrophils. FEBS Lett. 2014 Jun 13;588(13):2141-6.  [Content Brief]

  [2]. Miyasaki KT, et al. In vitro antimicrobial activity of the human neutrophil cytosolic S-100 protein complex, calprotectin, against Capnocytophaga sputigena. J Dent Res. 1993 Feb;72(2):517-23.  [Content Brief]

  [3]. Fanò G, et al. The S-100: a protein family in search of a function. Prog Neurobiol. 1995 May;46(1):71-82.  [Content Brief]

  [4]. Vogl T, et al. MRP8 and MRP14 control microtubule reorganization during transendothelial migration of phagocytes. Blood. 2004 Dec 15;104(13):4260-8.  [Content Brief]

  [5]. Viemann D, et al. Myeloid-related proteins 8 and 14 induce a specific inflammatory response in human microvascular endothelial cells. Blood. 2005 Apr 1;105(7):2955-62.  [Content Brief]

  [6]. Nakatani Y, et al. Regulation of S100A8/A9 (calprotectin) binding to tumor cells by zinc ion and its implication for apoptosis-inducing activity. Mediators Inflamm. 2005 Oct 24;2005(5):280-92.  [Content Brief]

  [7]. Björk P, et al. Identification of human S100A9 as a novel target for treatment of autoimmune disease via binding to quinoline-3-carboxamides. PLoS Biol. 2009 Apr 28;7(4):e97.  [Content Brief]