Anti-Human CD33 (GP67) (Clone CPTC-CD33-1) – Purified No Carrier Protein

CD33 synthetic peptide ILIPGTLEPGHSK

This recombinant monoclonal antibody is aseptically packaged and formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 7.2 - 7.4 with no carrier protein, potassium, calcium or preservatives added. Due to inherent biochemical properties of antibodies, certain products may be prone to precipitation over time. Precipitation may be removed by aseptic centrifugation and/or filtration.

Liquid

Recombinant antibodies are manufactured in an animal free facility using only in vitro protein free cell culture techniques and are purified by a multi-step process including the use of protein A or G to assure extremely low levels of endotoxins, leachable protein A or aggregates.

This antibody may be stored sterile as received at 2-8°C for up to one month. For longer term storage, aseptically aliquot in working volumes without diluting and store at ≤ -70°C. Avoid Repeated Freeze Thaw Cycles.

Research Use Only

2 – 8° C Wet Ice

EB0134B-1D10-H4/K2 activity is directed against human CD33 peptide sequence ILIPGTLEPGHSK.

CPTC-CD33-1

Siglecs (sialic acid-binding immunoglobulin superfamily lectins) are a family of single pass, transmembrane cell surface proteins characterized by shared structural motifs and an ability to recognize sialic acids^1,2. CD33 acts as an endocytic receptor³ that mediates allergic response by suppressing mast cell activation and thereby desensitizes against subsequent allergen challenge⁴. Additionally, polymorphisms in CD33 that are associated with Alzheimer’s Disease likely inhibit activating receptors involved in microglia phagocytosis. CD33 also contributes to T cell exhaustion in cancer.

CD33 is a target for conjugated antibody chemotherapy development in patients with acute myeloid leukemia because ~90% of patients express CD33 surface antigen on myeloid blast cells, but not normal stem cells⁵, and additionally CD33 is rapidly internalized when bound⁶. As such, CD33 can efficiently transport toxic cargo by endocytosis in a tumor-specific manner⁴.

EB0134B-1D10-H4/K2 was generated in rabbit for use in immuno-MRM assays using a synthetic peptide derived from human CD33, ILIPGTLEPGHSK⁷. EB0134B-1D10-H4/K2 can detect CD33 by immunohistochemistry and Western blotting when probing recombinant protein or whole cell lysates of Jurkat or MCF7 cell lines⁸. EB0134B-1D10-H4/K2 does not detect CD33 by reverse phase protein array.

CD33 is expressed on normal multipotent myeloid precursor cells, unipotent colony-forming cells, mast cells, basophils, microglia, maturing granulocytes and monocytes, macrophages, dendritic cells, and can be displayed on subsets of B cells, activated T cells and natural killer cells. CD33 is also expressed on the surface of leukemic cell blasts in more than 90% of patients with acute myeloid leukemia but is not present on normal stem cells.

C1q, syalylated glycoproteins, PTPN6/SHP-1, PTPN11/SHP-2

1 Bochner BS. Clin Exp Allergy. 39(3):317-324. 2009.
2 Kiwamoto T, Kawasaki N, Paulson JC, et al. Pharmacol Ther. 135(3):327-336. 2012.
3 Clark MC, Stein A. Best Pract Res Clin Haematol. 33(4):101224. 2020.
4 Duan S, Paulson JC. Annu Rev Immunol. 38:365-395. 2020.
5 McGavin JK, Spencer CM. Drugs. 61(9):1317-1322; discussion 1323-1324. 2001.
6 Hamann PR, Hinman LM, Hollander I, et al. Bioconjug Chem. 13(1):47-58. 2002.
7 Whiteaker JR, Lundeen RA, Zhao L, et al. Front Immunol. 12:765898. 2021.
8 https://antibodies.cancer.gov/detail/CPTC-CD33-1