• 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 NFS?60 mouse myelogenous leukemia lymphoblast cells. Holmes, K.L.     et al. (1985) Proc. Natl. Acad. Sci. USA     82:6687. The ED    ₅₀ for this effect is 1?5 ng/mL.

• Source

  E. coli-derived Ile27-Cys169, with an N-terminal Met

• Accession #

• N-terminal Sequence    
  Analysis

  Met

• Predicted Molecular Mass

  16.3 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: IL-3

Rat interleukin-3 (IL-3; also multi-CSF) is a 26 kDa, variably glycosylated monomeric polypeptide that belongs to the alpha -helix family of hematopoietic cytokines (1, 2). IL-3 has pleiotrophic activies on a number of hematopoietic-related cells (1, 3). The rat molecule has two alternate splice forms. The first is termed IL-3 beta and is synthesized as a 169 amino acid (aa) precursor that contains a 27 aa signal sequence and a 142 aa mature segment (1, 2). The second is called IL-3 alpha, and is identical to IL-3 beta, save for a three amino acid (Tyr-Pro-Gln) deletion at positions 56 - 58 (1). The beta form is considered the most common form. Each form has an alpha -helical structure with two intrachain disulfide bonds and two potential N-linked glycosylation sites. Rat IL-3 is generally considered to be species-specific in its activity. In the mature region, rat IL-3 is 55%, 30% and 24% aa identical to mouse, human and bovine IL-3, respectively. Cells known to express IL-3 include connective tissue mast cells, astrocytes, microglia, megakaryocytes, eosinophils, T cells, keratinocytes and thymic epithelium.

IL-3 exerts its biological activities by binding to a 70 kDa, low affinity, ligand-binding IL-3 R alpha subunit, (6) which then recruits a120 kDa, common beta -chain, signal transducing subunit (7) to form a functional IL-3 receptor (1, 6, 7). Receptors for IL-3 are present on bone marrow progenitors, macrophages, mast cells, eosinophils, megakaryocytes, basophils and various myeloid leukemic cells. IL-3 can stimulate the proliferation and differentiation of pluripotent hematopoietic stem cells as well as various lineage committed progenitors including those for neutrophils, macrophages, magakaryocytes, and erythroid cells. IL-3 can stimulate the growth of early B cells and mature macrophages, mast cells, eosinophils, basophils, and megakaryocytes. IL-3 augments the function activity of basophils, mast cells, eosinophils, and macrophages (1, 8). In combination with other molecules such as CD40L and or IL-4, IL-3 can stimulate production of dendritic cells (1, 2, 9, 10).

• References:

1. Martinez-Moczygemba, M. and D.P. Huston (2003) J. Allergy Clin. Immunol. 112:653.

2. Mangi, M.H. and A.C. Newland (1999) Cytokines Cell. Mol. Ther. 5:87.

3. Esandi, M. del C. et al. (1998) Gene 211:151.

4. Cohen, D.R. et al. (1986) Nucleic Acids Res. 14:3641.

5. Gebicke-Haerter, P.J. et al. (1994) J. Neuroimmunol. 50:203.

6. Chritton, S.C. and M.H. Sheng (1997) GenBank Accession # NP_640353.

7. Appel, K. et al. (1995) J. Neurosci. 15:5800.

8. Schrader, J.W. (2001) in Cytokine Reference, Oppenhiem, J.J. and M. Feldmann (eds): Academic Press, p. 855.

9. Ebner, S. et al. (2002) J. Immunol. 168:6199.

10. Buelens C. et. al. (2002) Blood 99:993.

• Long Name:

  Interleukin 3

• Entrez Gene IDs:

  3562 (Human); 16187 (Mouse); 24495 (Rat)

• Alternate Names:

  Hematopoietic growth factor; IL3; IL-3; IL-3MGC79398; interleukin 3 (colony-stimulating factor, multiple); interleukin-3; Mast cell growth factor; mast-cell growth factor; MCGFMGC79399; MULTI-CSF; multilineage-colony-stimulating factor; Multipotential colony-stimulating factor; P-cell stimulating factor; P-cell-stimulating factor