• 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. When 15 ng/mL of biotinylated recombinant human Insulin is added to serially diluted Recombinant Human Insulin R/CD220, the concentration of Recombinant Human Insulin R/CD220 that produces 50% of the optimal binding response is 0.03?0.15 μg/mL.

• Source

  Mouse myeloma cell line, NS0-derived His28-Arg750 ( alpha subunit) & Ser751-Lys944 with a C-terminal 10-His tag ( beta subunit)

• Accession #

• N-terminal Sequence    
  Analysis

  His28 ( alpha subunit) & Ser751( beta subunit)

• Structure / Form

  Tetramer; disulfide-linked homodimer of disulfide-linked heterodimers ( alpha & beta )

• Predicted Molecular Mass

  82.9 kDa ( alpha subunit), 22.9 kDa ( beta subunit)

• SDS-PAGE

  122-135 kDa and 33-43 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: Insulin R/CD220

The Insulin Receptor (gene name INSR, designated CD220) is a type I transmembrane glycoprotein in the Insulin/IGF Receptor family of receptor tyrosine kinases that share structural similarity and overlapping intracellular signaling events (1-3). The 1370 amino acid (aa) human Insulin R preproprotein (A isoform) is processed by proteolysis to remove the signal peptide and produce an extracellular alpha portion (aa 28-750), and an extracellular/transmembrane/cytoplasmic beta subunit (aa 751-1370) (4). The extracellular domain (ECD) contains two homologous globular domains separated by a cysteine-rich domain and followed by three fibronectin type III domains. The intracellular region contains insulin-receptor substrate (IRS) docking sites, the kinase domain, and a phosphotyrosine-containing linker region. The human Insulin R ECD shares 96% aa sequence identity with mouse, rat, equine and canine Insulin R. Two alternatively spliced Insulin R isoforms differ by the absence
(IR-A) or presence (IR-B) of 12 aa between aa 743-744 in the alpha subunit (4). IR-A expression is highest in fetal tissues and cancer cells, while IR-B is concentrated in adult differentiated cells (2-5). IR-A and IR-B may homodimerize, or heterodimerize with the IGF-I receptor (1, 3, 4). All receptor combinations bind insulin, IGF-I or IGF-II, but with differing affinities; for example, IR-A has considerably higher affinity for IGF-II as compared to IR-B (2-5). This system allows fine tuning of signaling pathways according to the concentrations of insulin, IGF-I and IGF-II, and expression of receptor subunits on the cell surface (2, 3). Insulin R signaling regulates glucose uptake and metabolism, but also contributes to cell growth, differentiation and apoptosis (2, 3, 5, 6). Mutations in the Insulin R gene have been linked severe insulin resistance (type A and Rabson-Mendenhall syndrome) that may include type II diabetes mellitus and, rarely, leprechaunism (Donohue syndrome) that also includes growth delays and endocrine system abnormalities (1, 7). The R&D Systems human Insulin R consists of the entire ECD of the IR-A isoform.

• References:

1. Nakae, J. et al. (2001) Endoc. Rev. 22:818.

2. Sciacca, L. et al. (2003) Endocrinology 144:2650.

3. Belfiore, A. et al. (2009) Endocrine Rev. 30:586.

4. Lawrence, M.C. et al. (2007) Curr. Opin. Struct. Biol. 17:699.

5. Sacco, A. et al. (2009) Endocrinology 150:3594.

6. Kitamura, T. et al. (2004) J. Clin. Invest. 113:209.

7. Musso, C. et al. (2004) Medicine (Baltimore) 83:209.

• Long Name:

  Insulin Receptor

• Entrez Gene IDs:

  3643 (Human); 16337 (Mouse)

• Alternate Names:

  CD 220; CD220 antigen; CD220; EC 2.7.10; EC 2.7.10.1; HHF5; INSR; Insulin R; insulin receptor; InsulinR; IR