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Recombinant Rat Siglec-2/CD22 His-tag Protein, CF

Catalog # 10571-SL | R&D Systems, Inc. a Bio-Techne Brand
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Product Specifications


Chinese Hamster Ovary cell line, CHO-derived rat Siglec-2/CD22 protein
Trp24-Gly690, with a C-terminal 6-His tag


>95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.

Endotoxin Level

<1.0 EU per 1 μg of the protein by the LAL method.

N-terminal Sequence Analysis


Predicted Molecular Mass

76 kDa


98-114 kDa, under reducing conditions


Measured by the ability of the immobilized protein to support the adhesion of human red blood cells.
The ED50 for this effect is 0.6-5.4 μg/mL.

Scientific Data Images for Recombinant Rat Siglec-2/CD22 His-tag Protein, CF

Recombinant Rat Siglec-2/CD22 His-tag (Catalog # 10571-SL) supports the adhesion of human red blood cells. The ED50 for this effect is 0.6-5.4 μg/mL.
2 μg/lane of Recombinant Rat Siglec-2/CD22 His-tag Protein, CF (Catalog # 10571-SL) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 98-114 kDa.

Formulation, Preparation and Storage

Formulation Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
Reconstitution Reconstitute at 500 μg/mL in PBS.
Shipping The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below.
Stability & Storage Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: Siglec-2/CD22

Sialic acid-binding immunoglobulin-like lectin 2 (Siglec-2), also known as B-cell receptor CD22 or B-lymphocyte cell adhesion molecule (BL-CAM), is a I-type (Ig-type) lectin belonging to the sialoadhesin subclass of the immunoglobulin superfamily (1). Fourteen human and nine mouse Siglecs have been characterized and are divided into 2 families: CD33 related and evolutionarily conserved (2, 3). The extracellular domain (ECD) of Siglecs are characterized by an N-terminal Ig-like V-type domain, which mediates sialic acid binding, followed by varying numbers of Ig-like C2-type domains (1 -3). The predominant form of human Siglec-2 contains a N-terminal Ig-like V-type domain, six Ig-like C2-type domains, a transmembrane region and a cytoplasmic tail with six tyrosine residues and four immunoreceptor tyrosine-based inhibition motifs (ITIMs) (1-3). A variant form of Siglec-2 missing two Ig-like C2-type domains along with a truncated cytoplasmic tail has also been identified (4). The mature ECD of rat Siglec-2 shares 58% and 76% amino acid sequence identity with human and mouse Siglec-2, respectively. Siglec-2 is an adhesion molecule that preferentially binds alpha 2,6- linked sialic acid on the same (cis) or adjacent (trans) cells (5). Besides its role as an adhesion molecule, Siglec-2 is a coreceptor that physically interacts with B-cell receptor (BCR), negatively regulating BCR signals by recruiting tyrosine phosphatase SHP-1 to its ITIMs. Phosphorylated Siglec-2 can also interact with other intracellular effector proteins such as Syk, PLC gamma, PI3 kinase and Grb-2, suggesting it may play a role in positive signaling (2). Another function of Siglec-2 is that it mediates the anti-phagocytic effect of alpha 2,6-linked sialic acid, and inhibition of Siglec-2 promotes the clearance of myelin debris, amyloid-beta oligomers and alpha -synuclein fibrils in vivo (6). Siglec-2 also plays a role in autoimmunity and has great potential for Siglec-2-based immunotherapeutics for the treatment of autoimmune diseases such as systemic lupus erythematosus (SLE) (7).


  1. Sato, S. et al. (1996) Immunity. 5:551.
  2. Crocker, P.R. and A. Varki (2001) Trends Immunol. 22:337.
  3. Macauley, M.S. et al. (2014) Nature Rev Imm. 14:653.
  4. Stamenkovic, I. and B. Seed (1990) Nature 345:74.
  5. Collins, B.E. et al. (2004) Proc. Natl. Acad. Sci. 101:6104.
  6. Pluvinage, J.V. et al. (2019) Nature. 568:7751.
  7. Clark, E.A. et al. (2018) Front Immunol. 9:2235.

Long Name

Sialic Acid Binding Ig-like Lectin 2

Alternate Names

BL-CAM, CD22, Siglec2

Entrez Gene IDs

933 (Human); 12483 (Mouse); 308501 (Rat); 102130968 (Cynomolgus Monkey)

Gene Symbol



Product Documents for Recombinant Rat Siglec-2/CD22 His-tag Protein, CF

Certificate of Analysis

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Note: Certificate of Analysis not available for kit components.

Product Specific Notices for Recombinant Rat Siglec-2/CD22 His-tag Protein, CF

For research use only

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