IL-18 Protein, Human

IL-18 protein is a pro-inflammatory cytokine that plays a critical role in epithelial barrier repair and polarized immune responses involving Th1 cells and NK cells. After binding to IL18R1 and IL18RAP, it forms a signaling ternary complex that activates NF-kappa-B, leading to the synthesis of inflammatory mediators. IL-18 Protein, Human is the recombinant human-derived IL-18 protein, expressed by E. coli , with tag free. The total length of IL-18 Protein, Human is 157 a.a., with molecular weight of 17-19 kDa.

IL-18 Protein is a pro-inflammatory cytokine with pivotal roles in epithelial barrier repair and orchestrating polarized immune responses involving T-helper 1 (Th1) cells and natural killer (NK) cells. Upon binding to IL18R1 and IL18RAP, IL-18 forms a signaling ternary complex that activates NF-kappa-B, leading to the synthesis of inflammatory mediators. It synergizes with IL-12 to induce IFNG synthesis in Th1 cells and NK cells. Notably, IL-18 is involved in transduction of inflammation downstream of pyroptosis, where its mature form is released into the extracellular milieu by passing through the gasdermin-D (GSDMD) pore. At the plasma membrane, IL-18 forms a ternary complex with the ligand-binding receptor subunit IL18R1 and signaling receptor subunit IL18RAP, initiating intracellular signaling. Additionally, IL-18 interacts with the cargo receptor TMED10, facilitating its translocation from the cytoplasm into the endoplasmic reticulum-Golgi intermediate compartment (ERGIC) and subsequent secretion.

Measured by its ability to induce IFN-gamma secretion by KG-1 human acute myelogenous leukemia cells in the presence of TNF-alpha. The ED₅₀ for this effect is ≤15.26 ng/mL in the presence of 15 ng/mL TNF-alpha, corresponding to a specific activity is ≥6.55×10⁴ U/mg.

Human

E. coli

Tag Free

Q14116 (Y37-D193)

3606  [NCBI]

YFGKLESKLSVIRNLNDQVLFIDQGNRPLFEDMTDSDCRDNAPRTIFIISMYKDSQPRGMAVTISVKCEKISTLSCENKIISFKEMNPPDNIKDTKSDIIFFQRSVPGHDNKMQFESSSYEGYFLACEKERDLFKLILKKEDELGDRSIMFTVQNED

17-19 kDa

• 
  Greater than 95% as determined by reducing SDS-PAGE.
• 
  Measured by its ability to induce IFN-gamma secretion by KG‑1 human acute myelogenous leukemia cells in the presence of TNF-alpha. The ED₅₀ for this effect is 14 ng/ml in the presence of 15 ng/mL TNF-alpha, corresponding to a specific activity is 7.14×10₄ U/mg.

Lyophilized powder

Lyophilized from a 0.2 μm filtered solution of PBS, pH 7.4.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O. For long term storage it is recommended to add a carrier protein (0.1% BSA, 5% HSA, 10% FBS or 5% Trehalose).

Stored at -20°C for 2 years. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.