Nucleoside triphosphate diphosphohydrolase

Mihaylova-Todorova ST, Todorov LD, Westfall DP (2002) Enzyme kinetics and pharmacological characterization of nucleotidases released from the guinea pig isolated vas deferens during nerve stimulation evidence for a soluble ecto-nucleoside triphosphate diphosphohydrolase-like ATPase and a soluble ecto-5 nucleotidase-like AMPase. J Pharmacol Exp Ther 302 992-1001 Moos WH, Szotek DS, Bruns RF (1985) N6-Cycloal ky I adenosines. Potent Ai-selective adenosine agonists. J Med Chem 28 1383 4... 

NTPDases Nucleoside triphosphate diphosphohydrolases also known as apyrases,... 

ATP analogues substituted at the C2 (87) or C8 (88) positions with electron-donating groups such as ethers, thioethers or amines have been synthesised and evaluated for their potency at inducing P2Y i receptor mediated activation of the phospholipase C and subsequent intracellular Ca release. These analogues were also evaluated for their chemical stability to the hydrolytic nucleoside triphosphate diphosphohydrolase enzymes. Adenine derivatives... 

Nucleoside Triphosphates and Their Analogues. - A review has been given of the most useful methods for the synthesis of nucleoside triphosphates. 5 -Triphosphates of 8-(alkylthio)adenosines have been prepared as inhibitors of nucleoside triphosphate diphosphohydrolase, and the triphosphates 202 and that derived from 2,2 -anhydrouridine have been made as agonists for P2X2-purinoceptors, but they showed lesser potencies than the parent nucleosides. Derivatives of ATP, UTP and CTP have been prepared in which methyl ketone groups are attached via spacers to the base units, in order to permit interaction with fluorescent probes after enzymic incorporation into oligonucleotides. The triphosphate was assembed by Eckstein s procedure, in which a 2, 3 -0-iso-propylidene nucleoside is treated sequentially with salicyl phosphorochloridite, pyrophosphate and an oxidant. ... 

This calcium ion-dependent enzyme [EC 3.6.1.5] (also known as ATP-diphosphatase, adenosine diphosphatase, and ATP-diphosphohydrolase) catalyzes the hydrolysis (with two H2O) of ATP to generate AMP and two orthophosphate ions. The enzyme will also utilize ADP as a substrate as well as other nucleoside triphosphates and diphosphates. 

Nucleoside di- and triphosphates are dephosphorylated by enzymes of different specificities than those which act on the monophosphates. Nucleoside triphosphates, first of all, may be dephosphorylated both to di-and monophosphates by the many enzymes which use triphosphates functionally as substrates in intermediary metabolism. In addition, they are also acted upon by several enzymes whose physiological role is not clear. For example, inorganic pyrophosphatase in the presence of Zn +, and apyrase (ATP diphosphohydrolase) degrade both ATP and ADP to adenylate. 

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