Active Recombinant Human CD33 protein, Fc/Avi-tagged, Biotinylated

• Cat.No.: CD33-052H
• Product Overview: Biotinylated Recombinant Human CD33(Met17-His259) protein, fused to Fc/Avi tag at the C-terminus, was expressed in HEK293 cells .

Specification

• Description: Siglecs (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 Siglecs 5 to 11 (1-3). 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 (1, 2). This fact, together with the presence of two conserved immunoreceptor tyrosine-based inhibition motifs (ITIMs) in their cytoplasma tails, suggests that CD33-related Siglecs are involved in the regulation of cellular activation within the immune system. Human Siglec-3 is alternatively known as myeloid cell surface antigen CD33 and GP67. Human Siglec-3 cDNA encodes a 364 amino acid (aa) polypeptide with a hydrophobic signal peptide, an N-terminal Ig-like V-type domain, one Ig-like C2-type domains, a transmembrane region and a cytoplasmic tail (1, 4). Siglec-3 expression is restricted to cells of myelomonocytic lineage (2). It binds sialic acid preferring alpha 2,3- linkage over alpha 2,6- linkage (5). Studies indicated that Siglec-3 recruits SHP-1 and SHP-2 to its ITIMs (6, 7). When co-crosslinking with Fc gamma R1, Siglec-3 inhibits tyrosine phosphorylation and calcium mobilization, suggesting Siglec-3 can mediate inhibitory signals (7). Our Avi-tag Biotinylated Siglec-3 features biotinylation at a single site contained within the Avi-tag, a unique 15 aa peptide. Protein orientation will be uniform when bound to streptavidin-coated surface due to the precise control of biotinylation and the rest of the protein is unchanged so there is no interference in the protein's bioactivity.
• Source: HEK293 cells
• Species: Human
• Tag: Fc/Avi
• Predicted N Terminal: Met17
• Form: Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
• Bio-activity: Measured by the ability of the immobilized protein to support the adhesion of human red blood cells. The ED50 for this effect is 0.2-1.4 μg/mL.
• Molecular Mass: 67-78 kDa, under reducing conditions
• Protein length: Met17-His259
• Endotoxin: <0.10 EU per 1 μg of the protein by the LAL method.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Applications: Bioactivity
• 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.
• Reconstitution: Reconstitute at 500 μg/mL in PBS.

Gene Information

• Gene Name: CD33 CD33 molecule [ Homo sapiens ]
• Official Symbol: CD33
• Synonyms: CD33; CD33 molecule; CD33 antigen (gp67); myeloid cell surface antigen CD33; FLJ00391; p67; sialic acid binding Ig like lectin 3; SIGLEC 3; SIGLEC3; gp67; sialic acid binding Ig-like lectin 3; sialic acid-binding Ig-like lectin 3; SIGLEC-3
• Gene ID: 945
• mRNA Refseq: NM_001082618
• Protein Refseq: NP_001076087
• MIM: 159590
• UniProt ID: P20138

Reviews

11/14/2019

Quick dissolution, easy use.

08/27/2019

Excellent solubility, no aggregates.

02/27/2019

High concentration, very effective.

Q&As

What are the implications of CD33 polymorphisms in therapeutic targeting?

Certain polymorphisms in the CD33 gene can influence its expression on the cell surface, which might affect the efficacy of CD33-targeted therapies.

What is the primary biological function of CD33 in hematopoietic cells?

CD33 is a transmembrane receptor primarily expressed on cells of myeloid lineage and is involved in modulating cellular functions, including the regulation of cellular proliferation and differentiation.

How does CD33 expression vary among different leukocyte populations?

CD33 is predominantly expressed on myeloid cells, especially on immature myeloid cells. Its expression decreases as these cells differentiate and is typically low or absent on lymphoid cells.

How has CD33 been utilized as a therapeutic target in hematological malignancies?

CD33 has been targeted for therapeutic antibodies in AML. An example is gemtuzumab ozogamicin, which targets CD33 and delivers a cytotoxic agent specifically to leukemia cells expressing CD33.

How does CD33 signaling influence myeloid cell differentiation?

While the exact signaling pathways of CD33 are still under investigation, it is believed that CD33 signaling can influence the differentiation and function of myeloid cells, potentially playing a role in immune regulation.

What role does CD33 play in acute myeloid leukemia (AML)?

CD33 is commonly expressed on the surface of AML blasts, making it a potential target for therapeutic interventions in AML.

Are there known ligands that bind specifically to CD33?

The specific ligands for CD33 are not fully characterized, but it is believed to play a role in cell-cell interactions within the immune system.