Vascular ATP diphosphohydrolase (ATPDase) is a plasma membrane-bound enzyme that
hydrolyses extracellular ATP and ADP to AMP. Analysis of amino acid sequences available
from various mammalian and avian ATPDases revealed their close homology with CD39, a
putative B-cell activation marker. We, therefore, isolated CD39 cDNA from human
endothelial cells and expressed this in COS-7 cells. CD39 was found to have both
immunological identity to, and functional characteristics of, the vascular ATPDase. We also …