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Recombinant Human IL-37/IL-1F7 Protein, CF

Catalog # 1975-IL | R&D Systems, Inc. a Bio-Techne Brand
rh IL-37 Isoform b (7585-IL) is also available!
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Key Product Details

Accession #


E. coli




Binding Activity

Product Specifications


E. coli-derived human IL-37/IL-1F7 protein
Lys27-Asp192, with an N-terminal Met


>95%, 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.

N-terminal Sequence Analysis


Predicted Molecular Mass

18.6 kDa


Measured by its binding ability in a functional ELISA.
When Recombinant Human (rh) IL‑18 R alpha/IL‑1 R5 Fc Chimera (Catalog # 816-LR) is immobilized at 2 μg/mL (100 μL/well), the concentration of rhIL-37/IL-1F7 Chimera that produces 50% optimal binding response is 20-120 ng/mL.

Formulation, Preparation and Storage

Formulation Lyophilized from a 0.2 μm filtered solution in PBS and DTT.
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-37/IL-1F7

Human Interleukin-1 family member 7 (IL-1F7), also named FIL-1 zeta, IL‑37, IL‑1H4, IL-1HL and IL‑1RP1, is an anti-inflammatory member of the IL‑1 cytokine family (1-3). Alternative splicing generates multiple isoforms (IL‑37a through e) with deletions in the N-terminal region of the molecule (4-7). The longest IL-1F7 transcript encodes IL-37b, which shares approximately 21%, 24%, and 30% aa sequence identity with mature IL-1 alpha, IL‑1 beta, and IL-1ra, respectively. Mouse IL‑37 has not been reported, but human IL‑37b is active on mouse cells. Like IL‑1 alpha, IL‑1 beta and IL‑18, all of the IL‑37 variants lack a typical signal peptide. IL-37b is up-regulated by inflammatory stimuli in peripheral blood mononuclear cells (8). Experimental over-expression of IL‑37b in vivo limits the inflammatory response and protects mice from colitis and LPS-induced shock (8, 9). Both unprocessed and mature IL‑37b can form homodimers in solution (8, 10). Although IL‑37b will bind to IL‑18 R alpha with low affinity, this has no effect on IL‑18 receptor activity (7, 10, 11). Alternatively, IL‑37b will also bind to IL‑18 BP, generating a complex that interacts with IL‑18 R beta. This has the effect of attenuating IL‑18 activity via the IL‑18 receptor (11). IL‑37b can also function intracellularly. Following LPS‑induced cleavage of its propeptide, IL‑37b associates with Smad3 and translocates to the nucleus. This results in a reduction of pro‑inflammatory cytokine secretion (12).


  1. Dinarello, C.A. and P. Bufler (2013) Sem. Immunol. 25:466.
  2. Boraschi, D. et al. (2011) Eur. Cytokine Netw. 22:127.
  3. Ding, V.A. et al. (2016) Med. Oncol. 33:68.
  4. Smith, D.E. et al. (2000) J. Biol Chem 275:1169.
  5. Kumar S. et al. (2000) J. Biol Chem 275:10308.
  6. Busfield S.J. et al. (2000) Genomics 66:213.
  7. Pan, G. et al. (2000) Cytokine 13:1.
  8. Nold, M.F. et al. (2010) Nat. Immunol. 11:1014.
  9. McNamee, E.N. et al. (2011) Proc. Natl. Acad. Sci. USA 108:16711.
  10. Kumar S. et al. (2002) Cytokine 18:61.
  11. Bufler, P. et al. (2002) Proc. Natl. Acad. Sci. USA 99:13723.
  12. Sharma, S. et al. (2008) J. Immunol. 180:5477.

Long Name

Interleukin 37

Alternate Names

FIL1 zeta, IL-1F7, IL37

Entrez Gene IDs

27178 (Human)

Gene Symbol



Product Documents for Recombinant Human IL-37/IL-1F7 Protein, CF

Certificate of Analysis

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Note: Certificate of Analysis not available for kit components.

Product Specific Notices for Recombinant Human IL-37/IL-1F7 Protein, CF

For research use only

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