Human Sialic acid-binding Ig-like lectin 9 (Siglec 9) is a Type I transmembrane protein and a member of the Siglec family and immunoglobulin superfamily. The recombinant Siglec 9 protein dimer (CSP-25206-01) is a cis-homodimer (cis-dimer) and contains a Siglec 9 extracellular domain (UniProt# Q9Y336, amino acids Gln18-Gly348) fused with a proprietary cis-dimer motif followed by a His tag at the C-terminus. This dimeric protein is expressed in HEK293T cells. The recombinant human Siglec 9 protein dimer can potently bind Siglec 9-specific antibodies. This Siglec 9 protein dimer can be used as an antigen for in vitro assays and antibody screening, and as an immunogen for immunization to generate antibodies targeting more conformational epitopes.
Protein Name: Siglec 9
UniProt #: Q9Y336
Predicted Molecular Weight: 88 kDa
SDS PAGE Molecular Weight: The migration range of the dimer protein with glycosylation under non-reducing condition is ~190 kDa on SDS PAGE.
Protein Construct: Siglec 9 dimer protein contains a Siglec 9 extracellular domainfused with a proprietary cis-dimer motif followed by a His tag at the C-terminus.
Background
Human Sialic acid-binding Ig-like lectin 9 (Siglec 9) is a member of the Siglec family, part of the immunoglobulin superfamily, and a multifunctional immune regulator. It plays an important role in the immune system, especially in regulating inflammation and immune cell activation. Siglec 9 is also known as Cluster of Differentiation 329 (CD329), CDw329, FOAP-9, and OBBP-LIKE. Siglec 9 is a Type I transmembrane protein. It contains an extracellular domain with an N-terminal V-type immunoglobulin domain (Ig domain) and two C2-type Ig domains followed by a transmembrane domain and cytoplasmic signaling domain consisting of the immunoreceptor tyrosine-based inhibitory motif (ITIM). Siglec 9 is expressed on monocytes, neutrophils, and dendritic cells. It binds sialylated glycans on cell surfaces or secreted proteins, modulating cell-cell interactions and immune responses. Siglec 9 can form homodimers on the cell surface that plays a role in ligand binding, signal transduction, and receptor clustering. Some tumors express high levels of sialic acids to engage Siglec 9 and suppress immune attacks — potential immune evasion mechanism. The interaction of sialic acids with Siglecs is associated with suppression of anti-tumor responses has made Siglecs an emerging target for cancer therapeutics.
MW: Molecular Weight marker reduced condition
NR: Siglec 9 dimer under non-reduced condition
Immobilized human Siglec 9 protein dimer