• Purity

  >97%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured in a cytotoxicity assay using L?929 mouse fibroblast cells in the presence of the metabolic inhibitor actinomycin D. Matthews, N. and M.L. Neale (1987) in Lymphokines and Interferons, A Practical Approach. Clemens, M.J.     et al. (eds): IRL Press. 221. The ED    ₅₀ for this effect is 0.6?3 ng/mL.

• Source

  E. coli-derived Val77-Leu233, with an N-terminal Met

• Accession #

• N-terminal Sequence    
  Analysis

  Met

• Predicted Molecular Mass

  17.3 kDa

Carrier Free

What does CF mean?

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

What formulation is right for me?

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: TNF-alpha

Tumor necrosis factor alpha (TNF-alpha ), also known as cachectin and TNFSF2, is the prototypic ligand of the TNF superfamily. It is a pleiotropic molecule that plays a central role in inflammation, immune system development, apoptosis, and lipid metabolism (1, 2). Canine TNF-alpha consisits of a 35 amino acid (aa) cytoplasmic domain, a 21 aa transmembrane segment, and a 177 aa extracellular domain (ECD) (3). Within the ECD, canine TNF-alpha shares 84% ? 94% aa sequence identity with equine, feline, human, porcine, and rhesus and 69%-77% with bovine, cotton rat, mouse, and rat with TNF-alpha. TNF-alpha is produced by a wide variety of immune, epithelial, endothelial, and tumor cells (1, 2). TNF-alpha is assembled intracellularly to form a noncovalently linked homotrimer which is expressed on the cell surface (4). Cell surface TNF-alpha can induce the lysis of neighboring tumor cells and virus infected cells, and it can generate its own downstream cell signaling following ligation by soluble TNFR I (2, 5). Shedding of membrane bound TNF-alpha by TACE/ADAM17 releases the bioactive cytokine, a 55 kDa soluble trimer of the TNF-alpha extracellular domain (6-8). TNF-alpha binds the ubiquitous 55-60 kDa TNF RI (9, 10) and the hematopoietic cell-restricted 80 kDa TNF RII (11, 12), both of which are also expressed as homotrimers (1, 2, 13). Both type I and type II receptors bind TNF-alpha with comparable affinity (14), although only TNF RI contains a cytoplasmic death domain which triggers the activation of apoptosis. Soluble forms of both types of receptors are released and can neutralize the biological activity of TNF-alpha (15).

• References:

1. Zelova, H. and J. Hosek (2013) Inflamm. Res. 62:641.

2. Juhasz, K. et al. (2013) Expert Rev. Clin. Immunol. 9:335.

3. Zucker, K. et al. (1994) Lymphokine Res. 13:191.

4. Tang, P. et al. (1996) Biochemistry 35:8216.

5. Perez, C. et al. (1990) Cell 63:251.

6. Black, R.A. et al. (1997) Nature 385:729.

7. Moss, M.L. et al. (1997) Nature 385:733.

8. Gearing, A.J.H. et al. (1994) Nature 370:555.

9. Schall, T.J. et al. (1990) Cell 61:361.

10. Loetscher, H. et al. (1990) Cell 61:351.

11. Dembic, Z. et al. (1990) Cytokine 2:231.

12. Smith, C.A. et al. (1990) Science 248:1019.

13. Loetscher, H. et al. (1991) J. Biol. Chem. 266:18324.

14. Pinckard, J.K. et al. (1997) J. Biol. Chem. 272:10784.

15. Engelmann, H. et al. (1990) J. Biol. Chem. 265:1531.

• Long Name:

  Tumor Necrosis Factor alpha

• Entrez Gene IDs:

  7124 (Human); 21926 (Mouse); 24835 (Rat); 397086 (Porcine); 280943 (Bovine); 403922 (Canine); 100033834 (Equine); 493755 (Feline); 100009088 (Rabbit)

• Alternate Names:

  APC1 protein; Cachectin; Cachetin; DIF; TNF; TNF, monocyte-derived; tnfa; tnf-a; TNFalpha; TNF-alpha; TNF-alphacachectin; TNFATNF, macrophage-derived; TNFSF1A; TNFSF2; TNFSF2TNF superfamily, member 2; tumor necrosis factor (TNF superfamily, member 2); tumor necrosis factor alpha; Tumor necrosis factor ligand superfamily member 2; tumor necrosis factor; tumor necrosis factor-alpha