Recombinant Cynomolgus Siglec-9 Fc Chimera Protein, CF

Recombinant Cynomolgus Siglec-9 Fc Chimera Protein, CF Summary

Product Specifications

Product Datasheets

Carrier Free

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: Siglec-9

Siglecs(1) (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 Siglec-5 to -11 (1 - 4). To date, no Siglec has been shown to recognized any cell surface ligand other than sialic acids, suggesting that interactions with glycans containing this carbohydrate are important in mediating the biological functions of Siglecs. Siglecs 5 to 11 share a high degree of sequence similarity with CD33/Siglec-3 both in their extracellular and intracellular regions. They are collectively referred to as CD33-related Siglecs. One remarkable feature of the CD33-related Siglecs is their differential expression pattern within the hematopoietic system (2, 3). This fact, together with the presence of two conserved immunoreceptor tyrosine-based inhibition motifs (ITIMs) in their cytoplasmic tails, suggests that CD33-related Siglecs are involved in the regulation of cellular activation within the immune system.

The cDNA of cynomolgus Siglec-9 encodes a 464 amino acid (aa) polypeptide. Based on the similarity as human Siglec-9,  cynomolgus Siglec-9 is predicted to contain a signal peptide, an N-terminal Ig-likeV-type domain, two Ig-like C2-type domains, a transmembrane region and a cytoplasmic tail (5, 6). In peripheral blood leukocytes, Siglec-9 is expressed on neutrophils, monocytes, a fraction of NK cells, B cells, and a minor subset of CD8+ T cells (5). It binds equally well to both 2,3- and 2,6-linked sialic acid (5, 6). Siglec-9 is closely related to Siglec-7, and they share ~80% amino acid sequence identity. The gene encoding siglec-9 was mapped to chromosome 19q13.4.

Related Research Areas

• Dendritic Cell Activation
• Dendritic Cell ITIM/ITAM Immunoreceptors
• Ig-type Lectins
• ITIM/ITAM Immunoreceptors and Related Molecules
• Search Immune Checkpoint Targets