Product Specifications for Recombinant Human IL-18/IL-1F4 Protein
E. coli-derived human IL-18/IL-1F4 protein 37-193 aa
>90%, by SDS-PAGE under reducing conditions and visualized by Colloidal Coomassie® Blue stain.
<1.0 EU per 1 μg of the protein by the LAL method.
Predicted Molecular Mass
Induction of IFN-gamma by KG-1 cell [human myelomonocyte; ATCC CCL246] in response to the recombinant human IL-18 was measured using human IFN-gamma ELISA. The activity of lot 111 was as follows: IL-18 final concentration 10 ng/mL; IFN-gamma induction 48.1 IU/mL and IL-18 final concentration 20 ng/mL; IFN-gamma induction 64.3 IU/mL.
Formulation, Preparation and Storage
What does CF mean?
CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our
Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant
protein to be stored at a more dilute concentration.
The carrier free version does not contain BSA.
25 μg in PBS containing 0.1% BSA and 1% sucrose.
Reconstitute in 250 μL of ice-cold distilled water on ice.
The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage:
Store the unopened product at -20 to -70 °C. Use a manual defrost freezer and avoid repeated freeze-thaw cycles. Do not use past expiration date.
Interleukin-18 (IL-18) is a proinflammatory cytokine in the IL-1 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, gamma δ T cells, and phagocytes. The precursor is activated intracellularly by Caspase-1 mediated proteolysis to release the 17 kDa mature cytokine. The precursor can also be released by necrotic cells for extracellular cleavage by multiple proteases. IL-18 activation is induced by infection or tissue damage and contributes to disease pathology in chronic inflammation (1-3). IL-18 binds to the widely expressed IL-18 R alpha which recruits IL-18 R beta to form the signaling receptor complex (4, 5). Its bioactivity is negatively regulated by interactions with IL-18 binding proteins and virally encoded IL-18BP homologs (6). In the presence of IL-12 or IL-15, IL-18 enhances anti-viral Th1 immune responses by inducing IFN-gamma production and the cytolytic activity of CD8+ T cells and NK cells (7, 8). In the absence of IL-12 or IL-15, however, IL-18 promotes production of the Th2 cytokines IL-4 and IL-13 by CD4+ T cells and basophils (9, 10). In the presence of IL-1 beta or IL-23, IL-18 induces the antigen-independent production of IL-17 by gamma δ T cells and CD4+ T cells (11). IL-18 also promotes myeloid dendritic cell maturation and triggers neutrophil respiratory burst (12, 13). In cancer, IL-18 exhibits diverse activities including enhancing anti-tumor immunity, inhibiting or promoting angiogenesis, and promoting tumor cell metastasis (14). Mature human IL-18 shares approximately 63% amino acid sequence identity with mouse and rat IL-18 (15). Alternative splicing in human ovarian cancer generates an isoform that is resistant to Caspase-1 activation (16). A cell surface form can be expressed on M-CSF induced macrophages and released in response to bacterial endotoxin (17).
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What is the difference between the two versions of Recombinant Human IL-18, Catalog # 9124-IL and Catalog # B001-5?
Catalog # 9124-IL is manufactured by R&D Systems, while Catalog # B001-5 is manufactured by MBL. Catalog # 9124-IL is lyophilized powder whereas Catalog # B001-5 is supplied in solution (PBS with BSA and sucrose). Activity of the two proteins is measured in similar cell-based assays; please consult the respective product-specific pages for assay details. Catalog # 9124-IL is competitively priced and has higher purity and lower endotoxin than Catalog # B001-5.
Product Documents for Recombinant Human IL-18/IL-1F4 Protein
Which Brands are Currently Available on bio‑techne.com? R&D Systems, Tocris Bioscience and ProteinSimple branded products are available to purchase through bio‑techne.com. ProteinSimple branded instruments are available to quote. ACD branded products will be available on bio‑techne.com in the near future. Novus Biologicals branded products are not currently available on bio‑techne.com and can be found at novusbio.com.
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