Recombinant Equine IL-1ra/IL-1F3 Protein

• Reactivity: Eq
• Applications: Bioactivity

Recombinant Equine IL-1ra/IL-1F3 Protein Summary

• Details of Functionality: Measured by its ability to inhibit IL-1 alpha -dependent proliferation in D10.G4.1 mouse helper T cells. Symons, J.A. et al. (1987) in Lymphokines and Interferons, a Practical Approach. Clemens, M.J. et al. (eds): IRL Press. 272. The ED₅₀ for this effect is 0.75-3.0 µg/mL in the presence of 50 pg/mL of rhIL-1 alpha .
• Source: E. coli-derived equine IL-1ra/IL-1F3 protein
  His26-Gln177, with an N-terminal Met
• Accession #: O18999.1
• N-terminal Sequence: Met
• Protein/Peptide Type: Recombinant Proteins
• Purity: >97%, by SDS-PAGE under reducing conditions and visualized by silver stain
• Endotoxin Note: <0.01 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 17.5 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.

Packaging, Storage & Formulations

• 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.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS and DTT with BSA as a carrier protein.
• Purity: >97%, by SDS-PAGE under reducing conditions and visualized by silver stain
• Reconstitution Instructions: Reconstitute at 100 μg/mL in sterile PBS containing at least 0.1% human or bovine serum albumin.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Equine IL-1ra/IL-1F3 Protein

• DIRA
• ICIL-1ra
• IL1F3
• IL-1F3
• IL1ra
• IL-1ra
• IL-1ra3
• IL1RN
• IL-1RN
• interleukin 1 receptor antagonist
• IRAP
• MVCD4

Background

Secreted equine IL-1 receptor antagonist (IL-1ra) is a presumably 22 - 25 kDa glycoprotein produced by variety of cell types that antagonizes IL-1 activity (1 - 3). It is a member of the IL-1 family of proteins that includes IL-1 alpha and IL-1 beta . Although there is little amino acid (aa) identity (< 30%) among the three IL-1 family members, all molecules bind to the same receptors, all show a beta -trefoil structure, and all are believed to have evolved from a common ancestral gene (1 - 4). Equine IL-1ra is synthesized as a 177 aa precursor that contains a 25 aa signal sequence plus a 152 aa mature region. There is one intrachain disulfide bond and one potential N-linked glycosylation site (3, 5, 6). Mature equine sIL-1ra is 78%, 78%, 80%, 82%, and 76% aa identical to mature mouse, human, porcine, canine and bovine IL-1ra, respectively. In human, three non-secreted IL-1ra isoforms have also been identified. It is unknown if such an analogous situation exists in equine. Cells known to secrete IL-1ra include fibroblasts, vascular smooth muscle cells, intestinal columnar epithelium, chondrocytes, macrophages, mast cells, neutrophils and hepatocytes.

There are two type I transmembrane glycoprotein receptors for IL-1ra. The first is the bioactive 80 kDa type I IL-1 receptor (IL-1 RI), and the second is the inert (decoy) 65 kDa type II IL-1 receptor. IL-1ra binding to IL-1 RI competitively blocks IL-1 ( alpha or beta ) binding to the same receptor. This results in receptor ligation without activation (1, 7). The type II IL-1 receptor is inert, and any binding of IL-1ra not only fails to block co-existing IL-1 activity, but may actually potentiate it by removing an IL-1 antagonist. Functionally, all activities attributed to IL-1ra are explained by its role as a competitive inhibitor of IL-1 binding to IL-1 RI (1, 2, 8, 9).

1. Arend, W.P. et al. (1998) Annu. Rev. Immunol. 16:27.
2. Roux-Lombard, P. (1998) Eur. Cytokine Netw. 9:565.
3. Dayer-J-M. (2002) Clin. Exp. Rheumatol. 20(27):S14.
4. Eisenberg, S.P. et al. (1991) Proc. Natl. Acad. Sci. USA 88:5232.
5. Kato, H. et al. (1997) Vet. Immunol. Immunopathol. 56:221.
6. Howard, R.D. et al. (1998) Am. J. Vet. Res. 59:712.
7. Dinarello, C.A. (1997) Semin. Oncol. (Suppl 9):S9.
8. Irikura, V.M. et al. (2002) J. Immunol. 169:393.
9. Arend, W.P. and C. Gabay (2000) Arth. Res. 2:245.

Publications for IL-1ra/IL-1F3/IL1RN (2466-RA)(1)

Publication using 2466-RA

• Dakin S, Smith R, Heinegard D, Onnerfjord P, Khabut A, Dudhia J Proteomic analysis of tendon extracellular matrix reveals disease stage-specific fragmentation and differential cleavage of COMP (cartilage oligomeric matrix protein). J Biol Chem, 2014-01-07;289(0):4919. 2014-01-07 [PMID: 24398684] (Bioassay, Equine)

Bioinformatics

• Uniprot:
  • O18999.1()