Recombinant Human Siglec-2/CD22 Fc Avi-tag Protein, CF

In a functional ELISA, Biotinylated Recombinant Human Siglec-2/CD22 Fc Chimera Avi-tag Protein (Catalog # AVI1968) binds to Human Siglec-2/CD22 Antibody (MAB19681) with an ED50 of 1.50-18.0 ng/mL.

2 μg/lane of Recombinant Human Siglec-2/CD22 Fc Avi-tag Protein (AVI1968) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 120-140 kDa and 240-280 kDa, respectively.

• Reactivity: Hu
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Human Siglec-2/CD22 Fc Avi-tag Protein, CF Summary

• Additional Information: Biotinylated
• Details of Functionality: Measured by the ability of the immobilized protein to support the adhesion of human red blood cells. Kelm, S. et al. (1994) Current Biology 4:965. The ED 50 for this effect is 0.1-0.9 μg/mL. Measured by its binding ability in a functional ELISA. Biotinylated Recombinant Human Siglec-2/CD22 Fc Chimera Avi-tag (Catalog # AVI1968) binds to Human Siglec-2/CD22 Antibody (Catalog # MAB19681) with an ED 50 of 1.50-18.0 ng/mL.
• Source: Chinese Hamster Ovary cell line, CHO-derived human Siglec-2/CD22 protein

  Human Siglec-2/CD22 (Asp20-Arg687) Accession # CAA42006.1

  IEGRMD

  Human IgG 1 (Pro100-Lys330)

  Avi-tag

  N-terminus

  C-terminus

• Accession #: CAA42006.1
• N-terminal Sequence: Asp20
• Structure / Form: Disulfide-linked homodimer, biotinylated via Avi-tag
• Protein/Peptide Type: Recombinant Proteins
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
  • Bioactivity2
• Theoretical MW: 104 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 120-140 kDa, under reducing conditions.

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  12 months from date of receipt, -20 to -70 degreesC as supplied. 1 month, 2 to 8 degreesC under sterile conditions after reconstitution. 3 months, -20 to -70 degreesC under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining
• Reconstitution Instructions: Reconstitute at 500 μg/mL in PBS.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant Human Siglec-2/CD22 Fc Avi-tag Protein, CF

• B-cell receptor CD22
• BL-CAM
• B-lymphocyte cell adhesion molecule
• CD22 antigenMGC130020
• CD22 molecule
• CD22
• sialic acid binding Ig-like lectin 2
• Sialic acid-binding Ig-like lectin 2
• Siglec2
• Siglec-2
• SIGLEC2FLJ22814
• T-cell surface antigen Leu-14

Background

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 human Siglec-2 shares 59% and 58% amino acid sequence identity with mouse and rat 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). Our Avi-tag Biotinylated Recombinant Human Siglec-2 features biotinylation at a single site contained within the Avi-tag, a unique 15 amino acid peptide. Protein orientation will be uniform when bound to streptavidin-coated surface due to the precise control of biotinylation and the rest of the protein is unchanged so there is no interference in the protein's bioactivity.

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, JV. et al. (2019) Nature. 568:7751.
7. Clark, E.A. et al. (2018) Front Immunol. 9:2235.

FAQs for Siglec-2/CD22 (AVI1968). (Showing 1 - 1 of 1 FAQ).

1. I am interested in buying a CD22 antibody for fluorescence microscopy and FACS I red on your web page that you also offer to label your antibodies, if required, is that correct?
   • We do have the ability to perform custom conjugations on certain antibodies, including some to the CD22 protein. If you send me the conjugate you are interested in I can provide you with a quote.

Bioinformatics

• Uniprot:
  • CAA42006.1()