Anti-Human CD39 (ENTPD1) (Clone CPTC-ENTPD1-1) – Purified No Carrier Protein

Synthetic peptide SLSNYPFDFQGAR

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

EB0118B-5C10-H3/K1 activity is directed against human ENTPD1 peptide sequence SLSNYPFDFQGAR.

CPTC-ENTPD1-1

ENTPD1 (also known as CD39) is an ectonucleotidase that performs the rate limiting step in the generation of adenosine, a molecule that can alter CD4 and CD8 T cell and natural killer cell antitumor activities¹. ENTPD1 hydrolyzes extracellular ATP and ADP into AMP. The AMP is then processed into immunosuppressive adenosine by CD73, an ecto-5’-nucleotidase. The adenosine produced is a critical regulator of innate and adaptive immunity, and, via binding to the A2A receptors, inhibits effector T-lymphocyte proliferation and secretion of inflammatory cytokines. Additionally, adenosine inhibits phagocytosis by macrophages and affects the ability of monocytes to differentiate into dendritic cells, both of which can negatively affect the clearance of dying cancer cells. ENTPD1 can also promote tumor growth by decreasing extracellular levels of ATP in the tumor microenvironment. ATP acts as a ‘find-me’ signal that recruits phagocytes and is therefore important to the clearance of dying cancer cells and presentation of tumor antigens by antigen-presenting cells. Anti- ENTPD1 blockade is being investigated for the treatment of cancer.

EB0118B-5C10-H3/K1 was generated in rabbit for use in immuno-MRM assays using a synthetic peptide derived from residues 155-167 of human ENTPD1, SLSNYPFDFQGAR². EB0118B-5C10-H3/K1 can detect ENTPD1 by immunohistochemistry and Western blotting³. EB0118B-5C10-H3/K1 does not detect ENTPD1 by immunofluorescence or reverse phase protein array.

ENTPD1 is a cell surface enzyme primarily expressed on activated lymphoid cells, particularly regulatory T cells, as well as on monocytes, neutrophils, B cells, and peripheral blood mononuclear cells. The degree of expression on Tregs in healthy humans varies from 2 to 60%. ENTPD1 is also expressed on endothelial tissues.

ATP, ADP

1 Bastid J, Cottalorda-Regairaz A, Alberici G, et al. Oncogene. 32(14):1743-1751. 2013.
2 Whiteaker JR, Lundeen RA, Zhao L, et al. Front Immunol. 12:765898. 2021.
3 https://antibodies.cancer.gov/detail/EctonucleosideTriphosphateDiphosphohydrolase1Peptide1#CPTC-ENTPD1-1