- Other Names
- CD170, Sialic acid-binding Ig-like lectin E, Siglec 9, Siglecl1
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- Product Citations
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Siglecs (sialic acid binding Ig-like lectins) are type I membrane proteins with an extracellular region containing a sialic acid binding V-set Ig-like domain at the N-terminus, followed by varying numbers of C2-set Ig domains. The cytoplasmic tails of all siglecs have one or more tyrosines within potential signalling motifs. Siglecs are widely expressed on hematopoietic cells, often in a cell-type-specific manner. Their ligands, sialic acids, are negatively charged monosaccharides found on cell-surface glycoproteins and glycolipids. Studies suggest that siglecs may participate in cell-cell interactions or act as receptors for the entry of viral or bacterial pathogens. In addition, the presence of immunoreceptor tyrosine-based inhibitory motifs (ITIM) in their cytoplasmic domain indicates that these molecules may play a role in the suppression of immunoreceptor signaling. The siglecs can be classified into two subgroups, with Siglec-1, -2, and -4 as one group and a Siglec-3/CD33-related subgroup (Siglec-3, and -5 through -13) as the second. Siglec E is a mouse CD33-related siglec that selectively regulates early recruitment of neutrophils to the lung in acute lung inflammation induced by lipopolysaccharide. Siglec E-deficient mice exhibit exaggerated neutrophil recruitment that is reversible by using a blockade of the β2 integrin, CD11b. In addition, sialidase treatment of fibrinogen reverses the suppressive effect of Siglec E on CD11b signaling, suggesting that sialic acid recognition by Siglec E is required for its inhibitory function. These findings indicate that Siglec E is an important negative regulator of neutrophil recruitment to the lung and β2 integrin-dependent signaling.Product Details
- Mouse Siglec E, amino acids (Gln20-Phe355) (Accession# NP_112458.2), was expressed in 293E with a C-terminal human IgG1-Fc tag.
- Molecular Mass
- This 570 amino acid recombinant protein has a predicted molecular mass of approximately 63 kD. The protein migrates at about 80 - 90 kD by SDS-PAGE in DTT-reducing conditions and about 180 - 200 kD in non-reducing conditions. The predicted N-terminal amino acid is Gly.
- >95%, as determined by Coomassie stained SDS-PAGE.
- 0.22 µm filtered protein solution is in PBS.
- Endotoxin Level
- Less than 1.0 EU per µg of protein as determine by the LAL method.
- 25 µg size is bottled at 100 µg/mL. 100 µg size is 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.
- Recombinant mouse Siglec E is able to agglutinate human red blood cells with an ED50 of 0.625 - 2.5 µg/ml.
- 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 validated 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 firstname.lastname@example.org.
- Product Citations
- Murine Siglec E is expressed by neutrophils, NK cells, monocytes, macrophages, dendritic cells, and B1 cells.
- Siglec E regulates neutrophil recruitment. Siglec E signaling negatively regulates the LPS-induced production of TNF-α and IL-6 by macrophages. It is upregulated by a variety of TLR agonists.
- α2,8-linked disialic acid.
- Mouse Siglec E is able to bind and agglutinate human red blood cells.
- Cell Type
- Hematopoietic stem and progenitors
- Biology Area
- Stem Cells
- Molecular Family
- Siglec Molecules
- Antigen References
1. McMillan SJ, et al. 2013. Blood. 121:2084.
2. Bax M, et al. 2010. Ann. Rheum. Dis. 69:42.
3. Angata T and Varki A. 2000. J. Biol.Chem. 275:22127.
4. Zhang JQ, et al. 2004. Eur. J. Immunol. 34:1175.
5. Yu Z, et al. 2001. Biochem. J. 353:483.
- Gene ID
- 83382 View all products for this Gene ID
- View information about Siglec E 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.