In chemistry, pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a P–O–P linkage. A number of pyrophosphate salts exist, such as disodium pyrophosphate (Na2H2P2O7) and tetrasodium pyrophosphate (Na4P2O7), among others. Often pyrophosphates are called diphosphates. The parent pyrophosphates are derived from partial or complete neutralization of pyrophosphoric acid. The pyrophosphate bond is also sometimes referred to as a phosphoanhydride bond, a naming convention which emphasizes the loss of water that occurs when two phosphates form a new P–O–P bond, and which mirrors the nomenclature for anhydrides of carboxylic acids. Pyrophosphates are found in ATP and other nucleotide triphosphates, which are important in biochemistry. The term pyrophosphate is also the name of esters formed by the condensation of a phosphorylated biological compound with inorganic phosphate, as for dimethylallyl pyrophosphate. This bond is also referred to as a high-energy phosphate bond.
High-energy phosphate can mean one of two things:
Purine metabolism refers to the metabolic pathways to synthesize and break down purines that are present in many organisms.
In enzymology, an ATP diphosphatase (EC 3.6.1.8) is an enzyme that catalyzes the chemical reaction
In enzymology, a bis(5'-adenosyl)-triphosphatase (EC 3.6.1.29) is an enzyme that catalyzes the chemical reaction
In enzymology, a dCTP diphosphatase (EC 3.6.1.12) is an enzyme that catalyzes the chemical reaction
In enzymology, a dolichyldiphosphatase (EC 3.6.1.43) is an enzyme that catalyzes the chemical reaction
In Enzymology, a dUTP diphosphatase (EC 3.6.1.23) is an enzyme that catalyzes the chemical reaction
Exopolyphosphatase (PPX) is a phosphatase enzyme which catalyzes the hydrolysis of inorganic polyphosphate, a linear molecule composed of up to 1000 or more monomers linked by phospho-anhydride bonds. PPX is a processive exophosphatase, which means that it begins at the ends of the polyphosphate chain and cleaves the phospho-anhydride bonds to release orthophosphate as it moves along the polyphosphate molecule. PPX has several characteristics which distinguish it from other known polyphosphatases, namely that it does not act on ATP, has a strong preference for long chain polyphosphate, and has a very low affinity for polyphosphate molecules with less than 15 phosphate monomers.
In enzymology, a guanosine-5'-triphosphate,3'-diphosphate diphosphatase (EC 3.6.1.40) is an enzyme that catalyzes the chemical reaction
In enzymology, a nucleoside-diphosphatase (EC 3.6.1.6) is an enzyme that catalyzes the chemical reaction
In enzymology, a nucleoside-triphosphatase(NTPase) (EC 3.6.1.15) is an enzyme that catalyzes the chemical reaction
In enzymology, a nucleoside-triphosphate diphosphatase (EC 3.6.1.19) is an enzyme that catalyzes the chemical reaction
Thiamine-triphosphatase is an enzyme involved in thiamine metabolism. It catalyzes the chemical reaction
In enzymology, a thymidine-triphosphatase (EC 3.6.1.39) is an enzyme that catalyzes the chemical reaction
The enzyme polynucleotide 5′-phosphatase (RNA 5′-triphosphatase, RTPase, EC 3.1.3.33) is an enzyme that catalyzes the reaction
In enzymology, a 3-phosphoglyceroyl-phosphate—polyphosphate phosphotransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a dolichyl-diphosphate-polyphosphate phosphotransferase is an enzyme that catalyzes the chemical reaction
In enzymology, a polyphosphate kinase, or polyphosphate polymerase, is an enzyme that catalyzes the formation of polyphosphate from ATP, with chain lengths of up to a thousand or more orthophosphate moieties.
In enzymology, a thiamine-diphosphate kinase is an enzyme involved in thiamine metabolism. It catalyzes the chemical reaction
