In enzymology, a nucleotide diphosphatase (EC 3.6.1.9) is an enzyme that catalyzes the chemical reaction:a dinucleotide + H2O 2 mononucleotides. Thus, the two substrates of this enzyme are dinucleotide and H2O, whereas its product is mononucleotide. This enzyme belongs to the family of hydrolases, specifically those acting on acid anhydrides in phosphorus-containing anhydrides. This enzyme participates in 5 metabolic pathways:purine metabolism, starch and sucrose metabolism, riboflavin metabolism, nicotinate and nicotinamide metabolism, and pantothenate and coa biosynthesis.http://www.creative-enzymes.com/product/Native-Crotalus-Adamanteus-Venom-Pyrophosphatase-Nucleotide_1427.html