Recombinant Human IL-5 R alpha Protein

R&D Systems, part of Bio-Techne | Catalog # 253-5R

Catalog #
Availability
Size / Price
Qty
Carrier Free
253-5R-025/CF
Catalog #
Availability
Size / Price
Qty
With Carrier
253-5R-025
Print Quote
Bulk Order
100% Guarantee

Key Product Details

  • R&D Systems Sf 21 (baculovirus)-derived Recombinant Human IL-5 R alpha Protein (253-5R)
  • Quality control testing to verify active proteins with lot specific assays by in-house scientists
  • All R&D Systems proteins are covered with a 100% guarantee

Source

Sf 21 (baculovirus)

Accession #

Q01344

Conjugate

Unconjugated

Applications

Bioactivity

View all IL-5 R alpha/CD125 Proteins and Enzymes »

Product Specifications

Source

Spodoptera frugiperda, Sf 21 (baculovirus)-derived human IL-5 R alpha/CD125 protein
Asp21-Glu335

Purity

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

Endotoxin Level

<1.0 EU per 1 μg of the protein by the LAL method.

N-terminal Sequence Analysis

Asp21

Predicted Molecular Mass

38 kDa

SDS-PAGE

43 kDa, reducing conditions

Activity

Measured by its ability to inhibit IL-5-dependent proliferation of TF-1 human erythroleukemic cells. Kitamura, T. et al. (1989) J. Cell Physiol. 140:323.
The ED50 for this effect is 0.5-2 µg/mL in the presence of 0.5 ng/mL of rhIL-5.

Formulation, Preparation and Storage

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.

Carrier: 253-5R
Formulation Lyophilized from a 0.2 μm filtered solution in PBS with BSA as a carrier protein.
Reconstitution Reconstitute at 100 μg/mL in sterile PBS containing at least 0.1% human or bovine serum albumin.
Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
Carrier Free: 253-5R/CF
Formulation Lyophilized from a 0.2 μm filtered solution in PBS.
Reconstitution Reconstitute at 100 μg/mL in sterile PBS.
Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: IL-5 R alpha/CD125

Interleukin-5 Receptor alpha (IL-5 R alpha), also known as CD125, is a 60 kDa hematopoietin receptor that plays a dominant role in eosinophil biology (1 - 3). Mature human IL-5 R alpha consists of a 322 amino acid (aa) extracellular domain (ECD) with a WSxWS motif and a four cysteine motif, a 20 aa transmembrane segment, and a 58 aa cytoplasmic domain (4, 5). Within the ECD, human IL-5 R alpha shares 71% aa sequence identity with mouse and rat IL-5 R alpha. Alternate splicing of human IL-5 R alpha generates soluble secreted forms which function as IL-5 antagonists (5 - 7). The high affinity receptor for IL-5 is a complex that consists of the ligand binding IL‑5 R alpha and the transmembrane common beta chain ( betac/CD131) which is shared with the receptor complexes for IL-3 and GM-CSF (4). IL-5 R alpha binds IL-5 at low affinity and then associates with preformed betac oligomers to form the signaling-competent receptor complex (8). IL-5 stimulation of CD34+ hematopoietic progenitor cells induces the upregulation of transmembrane IL-5 R alpha followed by eosinophilic differentiation and activation (9 - 11). IL‑5 R alpha also promotes the differentiation of basophils and B cells (12, 13). Exposure of mature eosinophils to IL-5 attenuates their IL-5 responsiveness by inducing the downregulation of surface IL-5 R alpha and increased production of soluble IL-5 R alpha (14, 15). Elevated production of IL-5 at sites of allergic inflammation induces eosinophilia and exacerbation of immune cell infiltration, tissue damage, and remodeling (2, 3).

References

  1. Martinez-Moczygemba, M. and D.P. Huston (2003) J. Allergy Clin. Immunol. 112:653.
  2. Rothenberg, M.E. and S.P. Hogan (2005) Annu. Rev. Immunol. 24:147.
  3. Elsas, X.P. and M.I.G. Elsas (2007) Curr. Med. Chem. 14:1925.
  4. Tavernier, J. et al. (1991) Cell 66:1175.
  5. Murata, Y. et al. (1992) J. Exp. Med. 175:341.
  6. Tavernier, J. et al. (1992) Proc. Natl. Acad. Sci. 89:7041.
  7. Cameron, L. et al. (2000) J. Immunol. 164:1538.
  8. Zaks-Zilberman, M. et al. (2008) J. Biol. Chem. 283:13398.
  9. Tavernier, J. et al. (2000) Blood 95:1600.
  10. Clutterbuck, E.J. et al. (1989) Blood 73:1504.
  11. Lopez, A.F. et al. (1988) J. Exp. Med. 167:219.
  12. Denburg, J.A. et al. (1991) Blood 77:1462.
  13. Hasbold, J. et al. (2004) Nat. Immunol. 5:55.
  14. Gregory, B. et al. (2003) J. Immunol. 170:5359.
  15. Liu, L.Y. et al. (2002) J. Immunol. 169:6459.

Long Name

Interleukin 5 Receptor alpha

Alternate Names

CD125, IL-5Ra, IL5R alpha, IL5RA

Entrez Gene IDs

3568 (Human); 16192 (Mouse)

Gene Symbol

IL5RA

UniProt

Q01344

Additional IL-5 R alpha/CD125 Products

Product Documents for Recombinant Human IL-5 R alpha Protein

Product Datasheets

Certificate of Analysis

To download a Certificate of Analysis, please enter a lot number in the search box below.

Note: Certificate of Analysis not available for kit components.

Download SDS 253-5R (with carrier)
Download SDS 253-5R/CF (carrier free)

Product Specific Notices for Recombinant Human IL-5 R alpha Protein

For research use only

Privacy Policy
Cookie Policy
Site Map
© Copyright 2026 Bio-Techne. All Rights Reserved. All trademarks and registered trademarks are the property of Bio-Techne and its brands unless otherwise specified.