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

Immobilized Recombinant Cynomolgus Monkey Siglec‑2/CD22 (Catalog # 9864-SL) supports the adhesion of human red blood cells.The ED50 for this effect is 0.07-0.42 μg/mL.

2 μg/lane of Recombinant Cynomolgus Monkey Siglec‑2 was resolved with SDS-PAGEunder reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at ~110 kDa.

• Reactivity: Pm-Cm
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Cynomolgus Siglec-2/CD22 His-tag Protein, CF Summary

• 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 ED₅₀ for this effect is 0.07-0.42 µg/mL.
• Source: Human embryonic kidney cell, HEK293-derived cynomolgus monkey Siglec-2/CD22 protein
  Asp20-Arg687, with a C-terminal 6-His tag
• Accession #: EHH59463
• N-terminal Sequence: Asp20
• 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
• Theoretical MW: 76 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: 100-113 kDa, 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 °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.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS.
• 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 Cynomolgus Siglec-2/CD22 His-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

Siglecs are sialic acid specific I‑type lectins that are characterized by an extracellular domain (ECD) with an N‑terminal Ig‑like V-type domain followed by varying numbers of Ig‑like C2-type domains (1, 2). 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. In humans, two distinct Siglec-2 cDNAs that arise from differential RNA processing of the same gene have been isolated. The predominant Siglec-2 (Isoform 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 four immunoreceptor tyrosine-based inhibition motifs (ITIMs) (3). The variant Siglec-2 (Isoform CD22-alpha) encodes a 647 aa polypeptide missing two Ig-like C2-type domains and has a truncated (23 aa) cytoplasmic tail (4). Within the ECD, cynomolgus Siglec-2 shares 85%, and 55% aa 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. Interaction of Siglec-2 with trans ligands on opposing cells is found to be favored over the binding of ligands in cis (5). Consistent with a single ligand-binding region, the first two N-terminal Ig-like domains mediated CD22 adhesion with lymphocytes, neutrophils, monocytes, and erythrocytes (6). Besides its role as an adhesion molecule, Siglec-2 is a co-receptor 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 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 (7, 8).

1. Varki, A. and T. Angata (2006) Glycobiology 16:1R.
2. Crocker, P.R. et al. (2007) Nat. Rev. Immunol. 7:255.
3. Wilson, G.L et al. (1991) J. Exp. Med. 173:137.
4. Stamenkovic, I. and B. Seed (1990) Nature 345:74.
5. Collins, B.E. et al. (2004) Proc. Natl. Acad. Sci. 101:6104.
6. Engel, P. et al. (1995) J Exp Med. 181:1581
7. Ravetch, J.V. and L.L. Lanier (2000) Science 290:84.
8. Wienands, Y.J. et al. (1999) J. Biol. Chem. 274:18769.

FAQs for Siglec-2/CD22 (9864-SL). (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:
  • EHH59463()