Myeloid cell surface antigen CD33, also known as GP67 and SIGLEC-3, is a single-pass type I transmembrane protein belonging to the sialic acid binding Ig-like lectin (SIGLEC) family in the immunoglobulin superfamily (IgSF). SIGLECs are characterized by an N-terminal Ig-like V-type domain that mediates sialic acid binding, followed by varying numbers (2 to 17) of Ig-like C2-type domains, a transmembrane region, and a cytoplasmic tail with intracellular immunoreceptor tyrosine-based inhibitory motifs (ITIM). They can be classified into two subgroups: Siglecs-1, -2, and -4 subgroup, and a Siglec-3/CD33-related subgroup (Siglecs-3, and -5 through -13), defined by sequence similarity and clustered gene localization. SIGLECs are widely expressed on hematopoietic cells, often in a cell-type-specific manner. CD33/SIGLEC-3 contains 1 Ig-like C2-type and 1 Ig-like V-type domains. CD33/SIGLEC-3 expression is restricted to cells of monocytic/myeloid lineage.  It is a putative adhesion molecule that preferentially binds sialic acid with α2,6­ linkage. CD33/SIGLEC-3 may act as an inhibitory receptor upon ligand induced tyrosine phosphorylation by recruiting cytoplasmic phosphatases. When co­crosslinking with FcγR1, CD33/SIGLEC-3 inhibits tyrosine phosphorylation and calcium mobilization.  CD33/SIGLEC-3 can also induce apoptosis in acute myeloid leukemia (AML) cells. The anti-CD33 bispecific antibody recognizes both CD33 and CD3e thus promoting T-cell-mediated anti-tumor activity after engaging with CD33 antigen.

Myeloid cell surface antigen CD33, also known as GP67 and SIGLEC-3, is a single-pass type I transmembrane protein belonging to the sialic acid binding Ig-like lectin (SIGLEC) family in the immunoglobulin superfamily (IgSF). SIGLECs are characterized by an N-terminal Ig-like V-type domain that mediates sialic acid binding, followed by varying numbers (2 to 17) of Ig-like C2-type domains, a transmembrane region, and a cytoplasmic tail with intracellular immunoreceptor tyrosine-based inhibitory motifs (ITIM). They can be classified into two subgroups: Siglecs-1, -2, and -4 subgroup, and a Siglec-3/CD33-related subgroup (Siglecs-3, and -5 through -13), defined by sequence similarity and clustered gene localization. SIGLECs are widely expressed on hematopoietic cells, often in a cell-type-specific manner. CD33/SIGLEC-3 contains 1 Ig-like C2-type and 1 Ig-like V-type domains. CD33/SIGLEC-3 expression is restricted to cells of monocytic/myeloid lineage.  It is a putative adhesion molecule that preferentially binds sialic acid with α2,6­ linkage. CD33/SIGLEC-3 may act as an inhibitory receptor upon ligand induced tyrosine phosphorylation by recruiting cytoplasmic phosphatases. When co­crosslinking with FcγR1, CD33/SIGLEC-3 inhibits tyrosine phosphorylation and calcium mobilization.  CD33/SIGLEC-3 can also induce apoptosis in acute myeloid leukemia (AML) cells. The anti-CD33 bispecific antibody recognizes both CD33 and CD3e thus promoting T-cell-mediated anti-tumor activity after engaging with CD33 antigen.

 

Product Details

 

Gene Symbol: CD33; SIGLEC3; SIGLEC-3; GP67; P67; CD3E; T3E; TCRE; IMD18; Leu-4

 

NCBI Gene ID: 945; 916 

 

Uniprot Entry: P20138; P07766

 

Construct Details: Expressed as a single-chain Fv (scFv) from anti-CD33 VH and VL region fused with a scFv of anti-CD3e VH and VL region with a His-tag at the C-terminus. Exists as a monomer under non-reducing and reducing condition.

 

Source: Mammalian cells stably expressing anti-CD33:anti-CD3e bispecific antibody (in a scFv-scFv’ format) and growing in chemical-defined media with no animal component or antibiotics.

 

M.W.: Calculated molecular mass (kDa): 55.8. Estimated by SDS-PAGE under non-reducing condition(kDa): 55-60. Calculated extinction coefficients (M-1 cm-1, at 280nm):  122660.

 

Purity: >95% judged by SDS-PAGE under reducing condition (see the gel image above, labeled as DTT "+")

 

Formulation: Supplied at 0.5 mg/ml in sterile PBS pH7.4 (concentration determined by UV spectrometry and verified by SDS-PAGE and Coomassie blue staining).

 

Endotoxin Level: <0.1 EU per 1 μg of purified recombinant protein determined by the LAL method

 

Biological Activity: Recognizes CD33 on leukemic cells and CD3e in the context of TCR complex on T cells.  Potently promotes T cell-mediated anti-tumor activity in vitro and in vivo after engaging with tumor cell surface antigen CD33.

 

  

FOR RESEARCH USE ONLY. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE IN HUMAN.

Restriction: This product is not transferable or re-sellable.  Customer obtain no right to transfer, assign, or sublicense its use rights, or to transfer, resell, package, or otherwise distribute the product, or to use the product for the benefit of any third party or for any commercial purpose.  Customer may only use the product in compliance with applicable local, state and federal laws, regulations and rules.  Customer may not directly or indirectly use the product or allow the transfer, transmission, export or re-export of all or any part of the product in violation of any export control law or regulation of the united states or any other relevant jurisdiction.  Your use of this product constitutes acceptance of the terms of this limited use agreement.  Please refer to our “terms & conditions” for details.  If you are not willing to accept the limitation of this agreement, G&P Biosciences will accept return of the product for a full/partial refund.

  

Storage

 

The product is shipped at 4°C. Upon receipt, centrifuge the product briefly before opening the vial. It is recommended to store small aliquots at the temperature below –20°C for long-term storage and the product is stable for 3 months. The undiluted protein can be stored at 4°C for no more than 2 weeks.

 

 

Use a manual defrost freezer and avoid repeated freeze-thaw cycles.

 

 

 

FOR RESEARCH USE ONLY. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE IN HUMAN.

 

References

 

1. J. Immunol. 141:2797 (1988).  

2. Blood 85:2002 (1995).  

3. J. Biol. Chem. 274:11505 (1999).  

4. Immunology 103:137 (2001).  

5. J. Biol. Chem. 277:24466 (2002).  

 

 

Documentation

 

Product datasheet (pdf) can be downloaded here: FCL2032-PDS.pdf

 

 

 

Additional supporting documents, including COA and MSDS are available upon request.

 

 

 

FOR RESEARCH USE ONLY. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE IN HUMAN.

Restriction: This product is not transferable or re-sellable.  Customer obtain no right to transfer, assign, or sublicense its use rights, or to transfer, resell, package, or otherwise distribute the product, or to use the product for the benefit of any third party or for any commercial purpose.  Customer may only use the product in compliance with applicable local, state and federal laws, regulations and rules.  Customer may not directly or indirectly use the product or allow the transfer, transmission, export or re-export of all or any part of the product in violation of any export control law or regulation of the united states or any other relevant jurisdiction.  Your use of this product constitutes acceptance of the terms of this limited use agreement.  Please refer to our “terms & conditions” for details.  If you are not willing to accept the limitation of this agreement, G&P Biosciences will accept return of the product for a full/partial refund.