• Purity

  >90%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie? Blue Staining.

• Endotoxin Level

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

• Activity

  Measured by its binding ability in a functional ELISA. Immobilized rmIL-6 Ra at 5 μg/mL (100 μL/well) on Mouse Anti-polyHistidine Monoclonal Antibody (Catalog # ) coated plates (0.25 μg/well) can bind rmIL-6 with a linear range of 0.8-50 ng/mL.

• Source

  Mouse myeloma cell line, NS0-derived Leu20-Glu357, with a C-terminal 10-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  Leu20

• Predicted Molecular Mass

  39 kDa (monomer)

• SDS-PAGE

  60-66 kDa, reducing conditions

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: IL-6 R alpha

Interleukin 6 (IL-6) is a multifunctional cytokine that exerts its activities by binding to a high-affinity receptor complex consisting of two membrane glycoproteins: an 80 kDa ligand binding subunit (IL-6 R alpha /CD126) and a 130 kDa nonligand-binding signal-transducing subunit (gp130/CD130) (1 - 4). The mouse IL-6 R alpha cDNA encodes a precursor type I transmembrane protein of 460 amino acids (aa) that contains a 19 aa signal sequence, a 345 aa extracellular ligand binding domain, a 21 aa transmembrane region, and a 75 aa cytoplasmic segment (2). The extracellular segment contains an Ig-like and a fibronectin-type III domain, plus a membrane proximal WSXWS motif. In their extracellular regions, mouse IL-6 R alpha shares 89%, 51% and 50% aa identity with rat, human and porcine IL-6 R alpha, respectively. Unlike gp130 that is expressed ubiquitously, the cellular distribution of IL-6 R alpha is predominantly limited to hepatocytes and leukocyte subpopulations such as monocytes, neutrophils, T and B cells. Soluble IL-6R alpha has been found in various body fluids (5). Two soluble receptor isoforms that arise either from proteolytic cleavage of the membrane-bound IL-6R alpha, or by alternative mRNA splicing (reported only in human) have been described (6, 7). Soluble IL-6 R alpha binds IL-6 with an affinity similar to that of the membrane-bound IL-6 R alpha. More importantly, the soluble IL-6 R alpha /IL-6 complex is capable of interacting with the membrane-bound gp130 to activate cells that lack an integral membrane IL-6 R alpha. It has been documented that elevated soluble IL-6 R is associated with numerous diseases including arthritic lesions, multiple myeloma and Crohn’s disease (6, 7).

• References:

1. Yamasaki, K. et al. (1988) Science 241:825.

2. Sugita, T. et al. (1990) J. Exp. Med. 171:2001.

3. Hibi, M. et al. (1990) Cell 63:1149.

4. Saito, M. et al. (1992) J. Immunol. 148:4066.

5. Novick, D. et al. (1989) J. Exp. Med. 170:1409.

6. Jones, S.A. et al. (2001) FASEB J. 15:43.

7. Jones, S.A. and S. Rose-John (2002) Biochim. Biophys. Acta 1592:251.

• Long Name:

  Interleukin 6 Receptor alpha

• Entrez Gene IDs:

  3570 (Human); 16194 (Mouse)

• Alternate Names:

  CD126; IL-6 R alpha; IL6R alpha; IL6R; IL-6Ra