- Other Names
- FCER2, Leu-20, FcεRII, IgE Fc receptor, BLAST-2, B6, Immunoglobulin E-binding factor, IGEBF, C-type lectin domain family 4 member J, CLEC4J, low affinity IgE receptor, Low affinity immunoglobulin epsilon Fc receptor, Lymphocyte IgE receptor
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- Product Citations
CD23 is a 45 kD type II transmembrane glycoprotein that is a member of the subgroup of the C-type lectin superfamily. CD23 is a low affinity receptor for IgE, CR2/CD21, CD11b, and CD11c. CD23 is expressed by a wide variety of cell types and has essential function in the regulation of IgE production and in the differentiation of B cells. Soluble CD23 induces IgE secretion by binding to CD21. On the other hand, secreted IgE will bind CD23 on B-cell membranes, preventing its cleavage, and thus shutting down further IgE production. In human monocytes, CD23 interaction with CD11b and CD11c results in the release of pro-inflammatory cytokines. CD23 can be proteolytically cleaved to generate soluble CD23 fragments of various molecular weights. Both soluble and membrane bound CD23 show bioactivity.Product Details
- Host Species
- CHO cells
- Human CD23, amino acid Asp48-Ser321 (Accession # P06734) with a C-terminal 6x His tag, was expressed in CHO cells.
- Molecular Mass
- The 284 amino acid recombinant protein has a predicted molecular mass of approximately 32.1 kD. Both the DTT-reduced and non-reduced proteins migrate at approximately 40 kD by SDS-PAGE. The predicted N-terminal amino acid is Asp.
- >95%, as determined by Coomassie stained SDS-PAGE.
- 0.22 µm filtered protein solution is in PBS, pH 7.2.
- Endotoxin Level
- Less than 0.1 EU per μg protein as determined by the LAL method.
- 10-25 µg sizes are bottled at 200 µg/mL. 100 µg 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.)
- 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.
- When human CD23 is immobilized at 2.0 µg/mL, human IgE binds with an EC50 of 0.1 - 0.4 µg/mL. Biotin anti-human IgE Antibody (Cat. No. 325503) was used for detection.
- 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.
B cells, widely expressed with highest expression in adrenal gland
- Low-affinity receptor for immunoglobulin E (IgE) and CR2/CD21. Has essential roles in the regulation of IgE production and in the differentiation of B-cells (it is a B-cell-specific antigen).
- B cells, monocytes
- IgE, CD21, CD11b, CD11c
- Measured in a binding assay with human IgE
- Cell Type
- B cells, Dendritic cells, Macrophages, Monocytes
- Biology Area
- Molecular Family
- CD Molecules, Fc Receptors, Soluble Receptors
- Antigen References
- Delespesse G, et al. 1989. J. Immunol. 142:134-8.
- Lecoanet-Henchoz S, et al. 1995. Immunity. 3:119-25.
- Hibbert RG, et al. 2005. J. Exp. Med. 202:751-60.
- Weskamp G, et al. 2006. Nat. Immunol. 7:1293-8.
- Wurzburg BA, et al. 2006. Structure. 14:1049-58.
- Gene ID
- 2208 View all products for this Gene ID
- View information about CD23/FCER2 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.