Recombinant Human IL-18 Rβ

Beta chain of interleukin-18 receptor (IL-18Rbeta) is an accessory protein-like molecule that is required for signaling¹ IL-18 signals through its specific cell surface receptor IL-18R, which comprises two subunits: IL-18Rα and IL-18Rβ. IL-18Rα alone has a weak affinity for IL-18 binding, while the IL-18Rα/β complex has a high affinity.² IL-18 Rβ is detected in numerous tissues including lung, spleen, leukocytes and colon.³

The biological activity of Human IL-18 Rβ was determined byits ability to inhibit IL-18 induced response on KG-1 cells, in the presence of soluble IL-18 Rα/Fc. The expected ED₅₀ for this effect is typically 2 - 6 μg/mL in the presence of 30 μg/mL of soluble IL-18 Rα/Fc and 40 ng/mL of human IL-18.

The DNA sequence encoding amino acid residues 1 - 356 of the extracellular domain of human interleukin 18 receptor beta (Born, T.L. et al., 1998, J. Biol. Chem. 273:29445 - 29450) was fused to the Fc region of human IgG1 via a polypeptide linker, inserted into a mammalian expression vector and expressed in NSO cells.

Phe20

Lyophilized

The predicted molecular weight of Recombinant Human IL-18 Rβ is Mr 65.1 kDa. However, the actual molecular weight as observed by migration on SDS Page is Mr 90-100 kDa.

65.1

This lyophilized protein is stable for six to twelve months when stored desiccated at -20°C to -70°C. After aseptic reconstitution, this protein may be stored at 2°C to 8°C for one month or at -20°C to -70°C in a manual defrost freezer. Avoid Repeated Freeze Thaw Cycles. See Product Insert for exact lot specific storage instructions.

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1. Churakowa, T. et al. (2000) J. Immunol. 165: 4950
2. Ghayur, T. et al. (2003) J. Immunol. 170: 5571
3. Born, TL. et al. (2000) J. Biol. Chem. 273: 29445