Accepted name: apyrase
Reaction: a nucleoside 5′-triphosphate + 2 H2O = a nucleoside 5′-phosphate + 2 phosphate (overall reaction)
(1a) a nucleoside 5′-triphosphate + H2O = a nucleoside 5′-diphosphate + phosphate
(1b) a nucleoside 5′-diphosphate + H2O = a nucleoside 5′-phosphate + phosphate
Other name(s): ATP-diphosphatase (ambiguous); adenosine diphosphatase; ADPase; ATP diphosphohydrolase [ambiguous]
Systematic name: nucleoside triphosphate phosphohydrolase (nucleoside monophosphoate-forming)
Comments: Apyrases are active against both di- and triphosphate nucleotides (NDPs and NTPs) and hydrolyse NTPs to nucleotide monophosphates (NMPs) in two distinct successive phosphate-releasing steps, with NDPs as intermediates. They differ from ATPases, which specifically hydrolyse ATP, by hydrolysing both ATP and ADP. The eukaryotic enzymes requires Ca2+, but Mg2+ can substitute. Most of the ecto-ATPases that occur on the cell surface and hydrolyse extracellular nucleotides belong to this enzyme family.
1.  Krishnan, P.S. Apyrase, pyrophosphatase and metaphosphatase of Penicillium chrysogenum. Arch. Biochem. Biophys. 37 (1952) 224–234. [PMID: 14953432]
2.  Liébecq, C., Lallemand, A. and Degueldre-Guillaume, M.-J. [Partial purification and properties of potato apyrase.] Bull. Soc. Chim. Biol. 45 (1963) 573–594. [PMID: 13930517] (in French)
3.  Chen, Y.R., Datta, N. and Roux, S.J. Purification and partial characterization of a calmodulin-stimulated nucleoside triphosphatase from pea nuclei. J. Biol. Chem. 262 (1987) 10689–10694. [PMID: 3038893]
4.  Christoforidis, S., Papamarcaki, T., Galaris, D., Kellner, R. and Tsolas, O. Purification and properties of human placental ATP diphosphohydrolase. Eur. J. Biochem. 234 (1995) 66–74. [PMID: 8529670]
5.  Wang, T.F. and Guidotti, G. CD39 is an ecto-(Ca2+,Mg2+)-apyrase. J. Biol. Chem. 271 (1996) 9898–9901. [PMID: 8626624]
6.  Gao, X.D., Kaigorodov, V. and Jigami, Y. YND1, a homologue of GDA1, encodes membrane-bound apyrase required for Golgi N- and O-glycosylation in Saccharomyces cerevisiae. J. Biol. Chem. 274 (1999) 21450–21456. [PMID: 10409709]
7.  Xu, W., Jones, C.R., Dunn, C.A. and Bessman, M.J. Gene ytkD of Bacillus subtilis encodes an atypical nucleoside triphosphatase member of the Nudix hydrolase superfamily. J. Bacteriol. 186 (2004) 8380–8384. [PMID: 15576788]
[EC created 1961, modified 1976, modified 2000, modified 2013]