CD39 is an integral membrane protein with two transmembrane domains and a large extracellular region (Maliszewski et al, 1994) with nucleoside triphosphate diphosphohydrolase activity (Wang and Guidotti, 1996). CD39 hydrolyzes nucleotide substrates at extremely high turnover rates, converting ATP directly into AMP without releasing ADP (Wang and Guidotti, 1998). CD39 has six putative N-glycosylation sites within its sequence (Maliszewski et al, 1994) and is heavily glycosylated (Wang et al, 1998). Wu et al (2005) have reported that the presence or absence of certain N-linked oligosaccharides on CD39 affect its enzymatic activity. In the plasma membrane, CD39 forms oligomers that are essential for its enzymatic activity (Wang et al, 1998) CD39 functions on the outer face of the plasma membrane (Maliszewski et al, 1994; Wang and Guidotti, 1996, 1998; Marcus et al, 1997; Wang et al, 1997; Koziak et al, 2000) and is not active until it reaches the plasma membrane. Complete N-glycosylation of CD39 correlates with its enzymatic activity (Zhong et al, 2001).
CD39 has been identified originally as a cell-surface glycoprotein expressed on activated B-cells after cell activation (Maliszewski et al, 1994). CD39 is expressed also on NK-cells and subsets ofT-cells, vascular endothelial cells, macrophages, and dendritic cells (Kansas et al, 1991). Wang and Guidotti (1997, 1998) have shown that CD39 is expressed in primary neurons andastrocytes in cell culture and is expressed widely in the glial cells and neurons in the rat brain. CD39 is responsible for the inhibition of ADP-induced platelet aggregation (Kaczmarek et al, 1996; Marcus et al, 1997). Studies with knock-out mice lacking expression of CD39 have indicated that CD39 participates in the regulation of the function of the ADP-dependent purinoreceptor P2Y1 and that its absence results in disordered hemostasis and thromboregulation (Enjyoji et al, 1999). The administration of a soluble form of CD39 has been shown to reduce platelet aggregation (Gayle et al, 1998). Goepfert et al (2001) have reported that chemotaxis of monocyte and macrophages from CD39 knock-out mice to nucleotides is impaired and that CD39 plays a role in the regulation of the cellular infiltration and new vessel growth in a model of angiogenesis.
Suitable for use in Flow Cytometry, Immunoprecipitation and Western Blot. Other applications not tested.
Optimal dilutions to be determined by the researcher.
Storage and Stability:
May be stored at 4 degrees C before opening. DO NOT FREEZE! Stable at 4 degrees C as an undiluted liquid. Dilute only pror to immediate use. Freezing R-Phycoerythrin (PE) conjugates will result in a substantial loss of activity.