Human IL18 Recombinant Protein (E.coli Expression) — Tag Free
Price range: $198.00 through $3,600.00
HEK293 × Chaperone-Assisted Technology
Produced using our proprietary Z-Active® platform — HEK293 mammalian expression with chaperone-assisted folding for proper disulfide bonding, N-linked glycosylation, and 5–10× higher bioactivity vs Leading Suppliers.
Overview
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).
Specifications
- Species: human
- Expression System: E.coli
- Sequence: Asn37-Ser193
- Tag: Tag Free
- Molecular Weight: 18.1 KDa
- Purity: > 95% by Tris-Bis PAGE;> 95% by SEC-HPLC
- Endotoxin: < 1 EU/μg of the protein by LAL method.
- UniProt/Swiss-Prot: Q14116
- Available Sizes: 10 µg, 50 µg, 1 mg
Bioactivity
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 1.5-9 ng/mL.
Formulation & Reconstitution
Formulation: 0.22 μm filtered solution of PBS, pH 7.4.
Reconstitution: 0.2 mg/mL in sterile PBS, pH7.4
Storage & Stability
Aliquot and store at -80°C. Avoid repeated freeze/thaw cycles.
Quality Assurance
Each lot is tested for purity (SDS-PAGE, SEC-HPLC), endotoxin levels (LAL method), and bioactivity. A Certificate of Analysis (COA) is provided with every order.
Safety Data Sheets & Documentation
Protocols & Support
Reconstitution Protocol
1. Briefly centrifuge the vial to collect lyophilized powder at the bottom.
2. Reconstitute in sterile deionized water or PBS to a concentration of 0.2–1.0 mg/mL.
3. Gently pipette up and down to dissolve. Do not vortex.
4. Aliquot and store at -20°C to -80°C. Avoid repeated freeze-thaw cycles.
Download Data Sheet
Complete product data sheet including batch-specific QC data, sequence information, and storage guidelines.
Download PDF Data Sheet
