Backgound

Interleukin18 (IL18) is a proinflammatory cytokine in the IL1 family that exerts distinct immune effects depending on the local cytokine environment. It is expressed as a 24 kDa precursor by endothelial and epithelial cells, keratinocytes, γδT cells, and phagocytes. The precursor is activated intracellularly by Caspase1  mediated proteolysis to release the 17 kDa mature cytokine. The precursor can also be released by necrotic cells for extracellular cleavage by multiple proteases.IL18 activation is induced by infection or tissue damage and contributes to disease pathology in chronic inflammation. IL18 binds to the widely expressed IL18 Rα which recruits IL18 Rβ to form the signaling

 receptor complex. Its bioactivity is negatively regulated by interactions with IL18 binding proteins and virally encoded IL18BP homologs 

Source

Recombinant Human IL-18 is expressed from Escherichia coli. It contains AA Tyr 37 - Asp 193. Predicted molecular mass 21.0 kDa. This protein carries a polyhistidine tag at the N-terminus.

Recombinant Human IL-18 is expressed from Escherichia coli

Endotoxin

Less than 1.0 EU per μg by the LAL method. 

AA Sequence

YFGK LESKLSVIRN LNDQVLFIDQ GNRPLFEDMT DSDCRDNAPR TIFIISMYKD SQPRGMAVTI SVKCEKISTL SCENKIISFK EMNPPDNIKD TKSDIIFFQR SVPGHDNKMQ FESSSYEGYF LACEKERDLF KLILKKEDEL GDRSIMFTVQ NED

Purity

Purity >90% as determined by SDS-PAGE.

Formulation

Lyophilized from 0.22 μm filtered solution in PBS, pH7.4. Normally trehalose is added as protectant before lyophilization. Contact us for customized product form or formulation.

Reconstitution

Reconstitute in sterile distilled water or aqueous buffer containing 0.1% BSA to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at < -20°C. Further dilutions should be made in appropriate buffered solutions.

Storage

For long term storage, the product should be stored at lyophilized state at -20°C or lower.

Please avoid repeated freeze-thaw cycles.

This product is stable after storage at:

-20°C to -70°C for 12 months in lyophilized state;

-70°C for 3 months under sterile conditions after reconstitution.

SDS-PAGE

Human IL-18, His Tag on SDS-PAGE under reducing (R) condition

Human IL-18, His Tag on SDS-PAGE under reducing (R) condition. The gel was stained overnight with Coomassie Blue. The purity of the protein is greater than 90%.