Recombinant Mouse Siglec-3/CD33 Fc Chimera Protein, CF

Recombinant Mouse Siglec-3/CD33 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-3/CD33

Siglec-3 (sialic acid binding Ig-like lectin 3), also known as myeloid cell surface antigen CD33 and GP67, is an I-type (Ig-type) lectin belonging to the Ig superfamily. 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, 2). Fourteen human and nine mouse Siglecs have been characterized and are divided into 2 families: CD33 related and evolutionarily conserved (3). Mature mouse Siglec-3 consists of a 224 amino acid (aa) extracellular domain (ECD), containing one IgV and one IgC2 domain and shares 56% aa identity with human Siglec-3. Mouse Siglec-3 is expressed on myeloid precursors in the bone marrow, mostly in the mature stages of the granulocytic lineage (4). Each Siglec has a distinct preference for binding the various types of sialylated glycans found on the surface of mammalian cells and they most likely evolved to regulate host immune responses via the recognition of self-glycans (5). Unlike human Siglec-3, mouse Siglec-3 lacks a canonical cytoplasmic ITIM domain. Instead, mouse Siglec-3 possesses a charged amino acid in its transmembrane domain, which may interact with an ITAM adaptor protein (6). Additionally, mouse Siglec-3 binds sialic acids found on mucins rather than alpha 2-3- or alpha 2-6-linked sialic acids on lactosamine units to which human Siglec-3 binds (7, 8). These differences suggest mouse and human Siglec-3 might not be functionally identical (8). Human Siglec-3 continues to be a therapeutic target for the treatment of acute myeloid leukemia and is a high potential risk factor for Alzheimer's (9).

Manufacturing Specifications

1. Crocker, P.R. and Varki, A. (2001) Trends Immunol. 22:337.
2. Crocker, P.R. and Varki, A. (2001) Immunology 103:137.
3. Macauley, M.S. et al. (2014) Nat. Rev. Immunol. 14:653.
4. Varki, A. et al. (2017) Essentials of Glycobiology. Chapter 35.
5. Paulson, J. et al. (2012) Ann. N. Y. Acad. Sci. 1253:37.
6. Pillai, S. et al. (2012) Ann. Rev. Immunol. 30:357.
7. Brinkman-Van der Linden, E.C. and Varki, A. (2000) J. Bio. Chem. 275:8633.
8. Brinkman-Van der Linden, E.C. et al. (2003) Mol. Cell. Bio. 23:4199.
9. Malik, M. et al. (2013) J. Neurosci. 33:13320.

Related Research Areas

• Acute Lymphoblastic Leukemia
• Acute Myeloid Leukemia
• Common Macrophage Markers
• Dendritic Cell Activation
• Dendritic Cell ITIM/ITAM Immunoreceptors
• Ig-type Lectins
• ITIM/ITAM Immunoreceptors and Related Molecules
• Microglia Activation Markers
• Monocyte Markers
• Myeloid Lineage Markers
• Myeloid-derived Suppressor Cells (MDSC)
• Search Immune Checkpoint Targets