FITC-Labeled Siglec-3/CD33 Protein, Human (HEK293, Fc)

Siglec-3/CD33 protein is a sialic acid-binding lectin that mediates cell-cell interactions and maintains immune cell quiescence. It prefers α-2,3- and α-2,6-linked glycans with sialic acid. FITC-Labeled Siglec-3/CD33 Protein, Human (HEK293, Fc) is the recombinant human-derived FITC-Labeled Siglec-3/CD33 protein, expressed by HEK293 , with Fc labeled tag. The total length of FITC-Labeled Siglec-3/CD33 Protein, Human (HEK293, Fc) is 242 a.a., with molecular weight of 70-90 kDa.

The Siglec-3/CD33 protein, a sialic-acid-binding immunoglobulin-like lectin, plays a crucial role in mediating cell-cell interactions and maintaining immune cells in a resting state. It exhibits a preference for recognizing and binding alpha-2,3- and more avidly alpha-2,6-linked sialic acid-bearing glycans. Upon engagement with ligands like C1q or sialylated glycoproteins, two immunoreceptor tyrosine-based inhibitory motifs (ITIMs) within CD33's cytoplasmic tail undergo phosphorylation by Src-like kinases such as LCK. These phosphorylated ITIMs serve as docking sites for recruiting and activating protein-tyrosine phosphatases PTPN6/SHP-1 and PTPN11/SHP-2, which, in turn, regulate downstream pathways through dephosphorylation of signaling molecules. CD33's repressive effect on monocyte activation involves phosphoinositide 3-kinase/PI3K. Structurally, the protein forms homodimers through disulfide linkages and interacts with PTPN6/SHP-1 and PTPN11/SHP-2 upon phosphorylation. It also engages with C1QA via its C-terminus, activating CD33 inhibitory motifs.

Human

HEK293

Fc

P20138 (D18-H259)

945

70-90 kDa

Greater than 90% as determined by reducing SDS-PAGE.

<1 EU/μg, determined by LAL method.