| phosphocreatine | <biochemistry> Present in high concentration (about 20mM) in striated muscle and is synthesised and broken down by creatine phosphokinase to buffer ATP concentration. It acts as an immediate energy reserve for muscle. (18 Nov 1997) |
|---|---|
| phosphodiester | A diesterified orthophosphoric acid, RO-(PO2H)-OR', as in the nucleic acids. (05 Mar 2000) |
| phosphodiester bond | <chemistry> Not a precise term. Refers to any molecule in which two parts are joined through a phosphate group. Examples are found in RNA, DNA, phospholipids, cyclic nucleotides, nucleotide diphosphates and triphosphates. (18 Nov 1997) |
| phosphodiester hydrolases | Enzymes (EC sub-subclass 3.1.4) cleaving phosphodiester bonds, such as those in cAMP or between nucleotides in nucleic acids, liberating smaller poly-or oligonucleotide units or mononucleotides but not inorganic phosphate. Synonym: phosphodiester hydrolases. (05 Mar 2000) |
| phosphodiester linkage | <biochemistry> A chemical linkage in which two alcohols are esterically boundto a bridging molecule of phosphoric acid. (31 Dec 1997) |
| phosphodiesterase | <enzyme> An enzyme that cleaves phosphodiesters to give a phosphomonoester and a free hydroxyl group. Examples include RNase, DNase, phospholipases C and D and the enzymes that convert cyclic nucleotides to the monoester forms. In casual usage the cAMP phosphodiesterase is usually meant. (18 Nov 1997) |
| phosphodiesterase inhibitors | Compounds which inhibit or antagonise the biosynthesis or actions of phosphodiesterases. (12 Dec 1998) |
| phosphodiesterase-phosphomonoesterase | <enzyme> From fusarium moniliforme; hydrolyzes both phosphodiesters and phosphomonoesters Registry number: EC 3.1.- Synonym: pdmase (26 Jun 1999) |
| phosphodiesterases | Enzymes (EC sub-subclass 3.1.4) cleaving phosphodiester bonds, such as those in cAMP or between nucleotides in nucleic acids, liberating smaller poly-or oligonucleotide units or mononucleotides but not inorganic phosphate. Synonym: phosphodiester hydrolases. (05 Mar 2000) |
| phosphodimethylethanolamine N-methyltransferase | <enzyme> Final step in the sequential methylation of phosphoethanolamine to phosphocholine Registry number: EC 2.1.1- Synonym: pme2etn methyltransferase (26 Jun 1999) |
| phosphodismutase | One of a number of enzymes (mutases) (EC sub-subclass 5.4.2) that apparently catalyze intramolecular transfer because the donor is regenerated (e.g., phosphoglyceromutase, phosphoglucomutase). Synonym: phosphodismutase. (05 Mar 2000) |
| phosphoenolpyruvate | <biochemistry> An important metabolic intermediate. The enol (less stable) form of pyruvic acid is trapped as its phosphate ester, giving the molecule a high phosphate transfer potential. Formed from 2 phosphoglycerate by the action of enolase. (31 Dec 1997) |
| phosphoenolpyruvate carboxykinase | phosphoenolpyruvic acid carboxykinase |
| phosphoenolpyruvate carboxykinase (ATP) | <enzyme> An enzyme of the lyase class that catalyses the conversion of ATP and oxaloacetate to ADP, phosphoenolpyruvate, and carbon dioxide. The enzyme is found in some bacteria, yeast, and trypanosoma, and is important for the photosynthetic assimilation of carbon dioxide in some plants. Chemical name: ATP:oxaloacetate carboxy-lyase (transphosphorylating) Registry number: EC 4.1.1.49 (12 Dec 1998) |
| phosphoenolpyruvate carboxykinase (GTP) | <enzyme> An enzyme of the lyase class that catalyses the conversion of GTP and oxaloacetate to GDP, phosphoenolpyruvate, and carbon dioxide. This reaction is part of gluconeogenesis in the liver. The enzyme occurs in both the mitochondria and cytosol of mammalian liver. Chemical name: GTP:oxaloacetate carboxy-lyase (transphosphorylating) Registry number: EC 4.1.1.32 (12 Dec 1998) |