• 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 cell proliferation assay using rat splenocytes. The ED    ₅₀ for this effect is 1-5 ng/mL.

• Source

  E. coli-derived Cys21-Phe147, with an N-terminal Met

• Accession #

• N-terminal Sequence    
  Analysis

  Met

• Predicted Molecular Mass

  15 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: IL-4

Interleukin-4 (IL-4), also known as B cell-stimulatory factor-1, is a monomeric, approximately 13 kDa - 18 kDa Th2 cytokine that shows pleiotropic effects during immune responses (1 - 3). It is a glycosylated polypeptide that contains three intrachain disulfide bridges and adopts a bundled four alpha -helix structure (4). Cotton rat IL-4 is synthesized with a 24 amino acid (aa) signal sequence. Mature cotton rat IL-4 shares 41%, 44%, 57%, and 68% aa sequence identity with bovine, human, mouse, and rat IL-4, respectively. IL-4 exerts its effects through two receptor complexes (5, 6). The type I receptor, which is expressed on hematopoietic cells, is a heterodimer of the ligand binding IL-4 R alpha and the common gamma chain (a shared subunit of the receptors for IL-2, -7, -9, -15, and -21). The type II receptor on nonhematopoietic cells consists of IL-4 R alpha and IL-13 R alpha 1. The type II receptor also transduces IL-13 mediated signals. IL-4 is primarily expressed by Th2-biased CD4⁺ T cells, mast cells, basophils, and eosinophils (1, 2). It promotes cell proliferation, survival, and immunoglobulin class switch to IgE in B cells, acquisition of the Th2 phenotype by naïve CD4⁺ T cells, priming and chemotaxis of mast cells, eosinophils, and basophils, and the proliferation and activation of epithelial cells (7 - 10). IL-4 plays a dominant role in the development of allergic inflammation and asthma (9, 11).

• References:

1. Benczik, M. and S.L. Gaffen (2004) Immunol. Invest. 33:109.

2. Chomarat, P. and J. Banchereau (1998) Int. Rev. Immunol. 17:1.

3. Accession # AAL18820.

4. Redfield, C. et al. (1991) Biochemistry 30:11029.

5. Mueller, T.D. et al. (2002) Biochim. Biophys. Acta 1592:237.

6. Nelms, K. et al. (1999) Annu. Rev. Immunol. 17:701.

7. Paludan, S.R. (1998) Scand. J. Immunol. 48:459.

8. Corthay, A. (2006) Scand. J. Immunol. 64:93.

9. Ryan, J.J. et al. (2007) Crit. Rev. Immunol. 27:15.

10. Grone, A. (2002) Vet. Immunol. Immunopathol. 88:1.

11. Rosenberg, H.F. et al. (2007) J. Allergy Clin. Immunol. 119:1303.

• Long Name:

  Interleukin 4

• Entrez Gene IDs:

  3565 (Human); 16189 (Mouse); 287287 (Rat); 397225 (Porcine); 280824 (Bovine); 403785 (Canine); 574281 (Primate); 100302454 (Rabbit)

• Alternate Names:

  B cell growth factor 1; BCDF; B-cell stimulatory factor 1; BCGF1; BCGF-1; binetrakin; BSF1; BSF-1; IL4; IL-4; IL-4B_cell stimulatory factor 1; interleukin 4; interleukin-4; Lymphocyte stimulatory factor 1; MGC79402; pitrakinra