Rat IL-13 was initially cloned from the rat renal cortex RNA after the induction of anti-glomerular basement membrane antibody-induced glomerulonephritis. Rat IL-13 respectively shows 63% and 79% homology with the human and mouse proteins at the amino acid level. IL-13 is an immunoregulatory cytokine secreted predominantly by activated Th2 cells, and is a key mediator in the pathogenesis of allergic inflammation. IL-13 shares many functional properties with IL-4, and they share a common receptor subunit: the alpha subunit of the IL-4 receptor (IL-4Rα). IL-13 mediates its effects by interacting with a complex receptor system comprised of IL-4Rα and two IL-13 binding proteins: IL-13Rα1 and IL-13Rα2. The ligation of the IL-13 receptor complex results in signaling via the insulin receptor substrate (IRS)-1 and 2 and STAT-6 pathways. IL-13, like IL-4, is a cytokine produced by Th2 cells in response to the signaling through the T cell antigen receptor and by mast cells and basophils upon cross-linkage of the high-affinity receptor for immunoglobulin E (IgE). IL-13 has been implicated in airway hypersensitivity and mucus hypersecretion, chronic obstructive pulmonary disease (COPD), inflammatory bowel disease, and parasitic nematode expulsion.Product Details
- Rat IL-13, amino acids (Thr19 - His131) (Accession# NM_053828), was expressed in E. coli.
- Molecular Mass
- The 113 amino acid recombinant protein has a predicted molecular mass of approximately 12.3 kD. The protein migrates at approximately 9 kD in DTT-reducing and non-reducing conditions by SDS-PAGE. The predicted N-terminal amino acid is Thr.
- >95%, as determined by Coomassie stained SDS-PAGE.
- 0.22 µm filtered protein solution is in PBS, pH 7.2
- Endotoxin Level
- Less than 0.01 ng per µg cytokine as determined by the LAL method.
- 10 and 25 µg sizes are bottled at 200 µg/mL. 100 µg size and larger sizes are lot-specific and bottled at the concentration indicated on the vial (please contact technical support for concentration, or use our Lookup tool if you have a lot number.) Please note, new lots of the 100 µg size will be lot-specific and may differ from previous lots that had a fixed concentration.
- Storage & Handling
- Unopened vial can be stored between 2°C and 8°C for up to 2 weeks, at -20°C for up to six months, or at -70°C or colder until the expiration date. For maximum results, quick spin vial prior to opening. The protein can be aliquoted and stored at -20°C or colder. Stock solutions can also be prepared at 50 - 100 µg/mL in appropriate sterile buffer, carrier protein such as 0.2 - 1% BSA or HSA can be added when preparing the stock solution. Aliquots can be stored between 2°C and 8°C for up to one week and stored at -20°C or colder for up to 3 months. Avoid repeated freeze/thaw cycles.
- ED50 = 0.8 - 5.0 ng/ml, corresponding to a specific activity of 0.2 - 1.25 x 106 units/mg, as determined by the dose dependent stimulation of a TF-1 cell proliferation assay.
- Application Notes
BioLegend carrier-free recombinant proteins provided in liquid format are shipped on blue-ice. Our comparison testing data indicates that when handled and stored as recommended, the liquid format has equal or better stability and shelf-life compared to commercially available lyophilized proteins after reconstitution. Our liquid proteins are verified in-house to maintain activity after shipping on blue ice and are backed by our 100% satisfaction guarantee. If you have any concerns, contact us at email@example.com.
- IL-13 is secreted by activated T cells, Th2 cells, basophils, mast cells, activated eosinophils, natural killer cells (NK), and macrophages.
- IL-13 modulates human monocytes, macrophages, and B cells. IL-13 induces an increase of MHC class II expression in human monocytes and macrophages, and a direct inhibition of inflammatory cytokines such as TNF-α and IL-1β
- IL-13 receptors are expressed on human B cells, basophils, eosinophils, mast cells, endothelial cells, fibroblasts, monocytes, macrophages, respiratory epithelial cells, and smooth muscle cells.
- IL-4α, IL-13Rα1, and IL-13Rα2.
- Biology Area
- Cell Biology, Immunology, Neuroinflammation, Neuroscience
- Molecular Family
- Antigen References
1. Lakkis FG and Cruet EN. 1993. Biochem. Biophys. Res. Commun. 197:612.
2. Papasavvas E, et al. 2005. J. Immunol. 175:5532.
3. Kelly-Welch A, et al. 2005. Sci. STKE. 293:cm8.
4. Hershey GK. 2003. J. Allergy Clin. Immunol. 111:677.
5. Harris J, et al. 2007. Immunity 27:505.
6. LaPorte SL, et al. 2008. Cell 132:259.
7. Brightling CE, et al. 2010. Clin. Exp. Allergy 40:42.
8. De Paiva CS, et al. 2011. Mucosal Immunol. 4:397.
- Gene ID
- 116553 View all products for this Gene ID
- View information about IL-13 on UniProt.org
- Does specific activity of a recombinant protein vary between lots?
Specific activity will vary for each lot and for the type of experiment that is done to validate it, but all passed lots will have activity within the established ED50 range for the product and we guarantee that our products will have lot-to-lot consistency. Please conduct an experiment-specific validation to find the optimal ED50 for your system.
- Have your recombinants been tested for stability?
Our testing shows that the recombinant proteins are able to withstand room temperature for a week without losing activity. In addition the recombinant proteins were also found to withstand four cycles of freeze and thaw without losing activity.
- How do you convert activity as an ED50 in ng/ml to a specific activity in Units/mg?
- Use formula Specific activity (Units/mg) = 10e6/ ED50 (ng/mL)
- How does the activity of your recombinant proteins compare to competitors?
We quality control each and every lot of recombinant protein. Not only do we check its bioactivity, but we also compare it against other commercially available recombinant proteins. We make sure each recombinant protein’s activity is at least as good as or better than the competition’s. In order to provide you with the best possible product, we ensure that our testing process is rigorous and thorough. If you’re curious and eager to make the switch to BioLegend recombinants, contact your sales representative today!
- What is the specific activity or ED50 of my recombinant protein?
The specific activity range of the protein is indicated on the product datasheets. Because the exact activity values on a per unit basis can largely fluctuate depending on a number of factors, including the nature of the assay, cell density, age of cells/passage number, culture media used, and end user technique, the specific activity is best defined as a range and we guarantee the specific activity of all our lots will be within the range indicated on the datasheet. Please note this only applies to recombinants labeled for use in bioassays. ELISA standard recombinant proteins are not recommended for bioassay usage as they are not tested for these applications.