Recombinant Human Siglec-2/CD22 Protein, Atto 647N Conjugate

Fluorescent beads conjugated to anti-Human Siglec 2/CD22 Monoclonal Antibody (MAB1968) were stained with (A) Recombinant Human Siglec 2/CD22 Protein, Atto 647N Conjugate (Catalog # ATM1968) or (B) unstained.

2 μg/lane of Recombinant Human Siglec-2/CD22 Protein, Atto 647N Conjugate (Catalog # ATM1968) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 114-126 kDa and 228-252 kDa, respectively.

• Reactivity: Hu
• Applications: Bioactivity

Recombinant Human Siglec-2/CD22 Protein, Atto 647N Conjugate Summary

• Additional Information: Fc Chimera
• Details of Functionality:

  Measured by flow cytometry for its ability to bind anti-Human Siglec-2/CD22 Monoclonal Antibody conjugated fluorescent beads.

• Source: Mouse myeloma cell line, NS0-derived human Siglec-2/CD22 protein
  

  Human Siglec-2/CD22 (Asp20-Arg687) Accession # CAA42006.1	DIEGRMD	Human IgG1 (Pro100-Lys330)
  N-terminus		C-terminus

• Accession #: CAA42006.1
• N-terminal Sequence: Asp20
• Structure / Form: Disulfide-linked homodimer, labeled with Atto 647N via amines
  Excitation Wavelength: 647 nm
  Emission Wavelenght: 667 nm
• Protein/Peptide Type: Recombinant Proteins
• Purity: >80%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Endotoxin Note: <1.0 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 101.9 kDa (monomer).
  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: 114-126 kDa, under reducing conditions

Packaging, Storage & Formulations

• Storage: Protect from light. Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 6 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after opening.
  • 3 months, -20 to -70 °C under sterile conditions after opening.
• Buffer: Supplied as a 0.2 μm filtered solution in PBS with BSA as a carrier protein.
• Purity: >80%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.

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 Protein, Atto 647N Conjugate

• 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

Siglecs (sialic acid binding Ig-like lectins) are I-type (Ig-type) lectins belonging to the Ig superfamily. They 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, 2). Eleven human Siglecs have been cloned and characterized. They are sialoadhesin/CD169/Siglec-1, CD22/Siglec-2, CD33/Siglec-3, Myelin-Associated Glycoprotein (MAG/Siglec-4a) and the identified Siglecs 5 to 11 (1 ‑ 3). To date, no Siglec has been shown to recognize any cell surface ligand other than sialic acid, suggesting that interactions with glycans containing this carbohydrate are important in mediating the biological functions of Siglecs. Human Siglec-2, also known as B‑cell antigen CD22 or B‑lymphocyte cell adhesion molecule (BL-CAM), is a B‑cell restricted glycoprotein that is expressed in the cytoplasm of progenitor B and pre-B cells and on the surface of mature B cells. Two distinct human Siglec-2/CD22 cDNAs that arise from differential RNA processing of the same gene have been isolated. The predominant Siglec-2/CD22 beta encodes an 847 amino acid (aa) polypeptide with a hydrophobic signal peptide, an N-terminal Ig-like V-type domain, six Ig-like C2-type domains, a transmembrane region and a cytoplasmic tail with 4 immunoreceptor tyrosine-based inhibition motifs (ITIMs) (4). The variant Siglec-2/CD22 alpha encodes a 647 aa polypeptide missing two Ig-like C2-type domains and has a truncated (23 aa) cytoplasmic tail (5). Siglec-2/CD22 is an adhesion molecule that preferentially binds alpha 2,6- linked sialic acid on the same (cis) or adjacent (trans) cells. Interaction of CD22 with trans ligands on opposing cells was found to be favored over the binding of ligands in cis (9). Besides its role as an adhesion molecule, Siglec-2/CD22 is a coreceptor that physically interacts with B‑cell receptor (BCR) and is rapidly phosphorylated upon BCR ligation. It negatively regulates BCR signals by recruiting tyrosine phosphatase SHP-1 to its ITIMs. Phosphorylated Siglec-2/CD22 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, 7, 8).

1. Crocker, P.R. and A. Varki (2001) Trends Immunol. 22:337.
2. Crocker, P.R. and A. Varki (2001) Immunology 103:137.
3. Angata, T. et al. (2002) J. Biol. Chem. 277:24466.
4. Wilson, G.L et al. (1991) J. Exp. Med. 173:137.
5. Stamenkovic, I. and B. Seed (1990) Nature 345:74.
6. Kelm, S. et al. (1994) Current Bio. 4:965.
7. Ravetch, J.V. and L.L. Lanier (2000) Science 290:84.
8. Wienands, Y.J. et al. (1999) J. Biol. Chem. 274:18769.
9. Collins, B.E. et al. (2004) Proc. Natl. Acad. Sci. 101:6104.

FAQs for Siglec-2/CD22 (ATM1968). (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()