Recombinant Human Interleukin-13 protein (IL13) is produced in an E. coli expression system and comes in a tag-free format. The protein covers the full length of the mature protein, from amino acids 35 to 146. SDS-PAGE analysis confirms a high purity level exceeding 97%. The protein maintains full biological activity, showing an ED50 of less than 1 ng/ml in cell proliferation assays with human TF-1 cells and specific activity greater than 1.0 × 10^6 IU/mg. Endotoxin levels remain tightly controlled at less than 1.0 EU/µg, as measured by the LAL method.
Interleukin-13 (IL13) is a cytokine that T helper 2 (Th2) cells primarily produce. This protein appears to play a crucial role in immune system regulation, particularly in controlling inflammatory responses during allergic reactions and asthma. IL13 is likely involved in pathways that influence immunoglobulin E (IgE) production and may promote B cell differentiation. Its importance in research stems from its involvement in immune responses and potential therapeutic applications in conditions where excessive inflammation occurs.
Potential Applications
Note: The applications listed below are based on what we know about this protein's biological functions, published research, and experience from experts in the field. However, we haven't fully tested all of these applications ourselves yet. We'd recommend running some preliminary tests first to make sure they work for your specific research goals.
1. Cell Proliferation and Viability Assays
This recombinant IL-13 protein is confirmed to be biologically active (ED₅₀ < 1 ng/ml in TF-1 cell proliferation) and suitable for studying IL-13-responsive cell lines. The high purity (>97%) and low endotoxin levels (<1.0 EU/μg) ensure reliable results in dose-response experiments. Researchers can use this protein to examine proliferation kinetics, optimize culture conditions, and investigate IL-13's effects on various hematopoietic and immune cell types with confidence in its functional activity.
2. Cytokine Receptor Binding Studies
The demonstrated biological activity confirms proper folding for receptor engagement, making this IL-13 protein appropriate for binding studies with IL-13Rα1 and IL-13Rα2. Techniques like surface plasmon resonance or competitive binding assays can quantify binding kinetics and affinity constants. The tag-free design and high purity minimize interference, ensuring accurate measurements of IL-13-receptor interactions.
3. Signal Transduction Pathway Analysis
This biologically active IL-13 protein is validated for studying downstream signaling cascades, particularly JAK-STAT pathway activation. Researchers can reliably use it to examine phosphorylation events, transcription factor activation, and gene expression changes in target cells through Western blotting, immunofluorescence, or qRT-PCR. The confirmed ED₅₀ ensures consistent pathway activation across experiments.
4. Antibody Development and Validation
The high-purity, tag-free IL-13 protein serves as an excellent immunogen for antibody development and as a standard for validation assays. The confirmed biological activity enables functional neutralization assays to evaluate antibody effectiveness. This protein is suitable for ELISA development, Western blot validation, and immunoprecipitation, with the specific activity (>1.0×10⁶ IU/mg) providing a quantitative reference standard.
5. Protein-Protein Interaction Studies
This recombinant IL-13 can be used in interaction studies, but caution is needed for interactions beyond known receptors. The tag-free design and confirmed activity support studies with IL-13 receptors, but novel interaction partners identified through co-IP or pull-down assays should be validated with native IL-13 from mammalian systems, as E. coli expression lacks mammalian post-translational modifications that might affect some interactions.
Final Recommendation & Action Plan
This E. coli-expressed Human IL-13 protein is a highly reliable research tool suitable for all proposed applications due to its validated biological activity, high purity, and low endotoxin levels. For immediate use, prioritize functional assays (TF-1 cell proliferation) to establish dose-response relationships. For signaling studies, the confirmed activity ensures consistent JAK-STAT pathway activation. When developing antibodies, use this protein for both immunization and neutralization assays. While the E. coli expression system produces a non-glycosylated form, the demonstrated bioactivity confirms proper folding for receptor engagement and signaling. For interaction studies beyond known receptors, validate any novel partners with mammalian-expressed IL-13 to account for potential glycosylation effects. Always include proper controls (vehicle and activity confirmation) in experiments to ensure data quality.
