| RuDP carboxylase | <enzyme> A copper protein that catalyses the formation of 2 moles of 3-phosphoglycerate from ribulose 1,5-biphosphate in the presence of carbon dioxide and is responsible for carbon dioxide fixation in photosynthesis. Carbon dioxide is combined with ribulose diphosphate to give two molecules of 3 phosphoglycerate, as part of the Calvin Benson cycle. It is the sole carbon dioxide fixing enzyme in C3 plants and collaborates with PEP carboxylase in carbon dioxide fixation in C4 plants. In the presence of oxygen the products of the reaction are one molecule of phosphoglyceric acid and one molecule of phosphoglycolic acid. The latter is the initial substrate for photorespiration and this oxygenase function occurs in C3 plants where the enzyme is not protected from ambient oxygen, in C4 plants the enzyme acts exclusively as a carboxylase since it is protected from oxygen. Also called Fraction 1 protein, the major protein of leaves. Chemical name: 3-Phospho-D-glycerate carboxy-lyase (dimerizing) Registry number: EC 4.1.1.39 (12 Dec 1998) |
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| phosphoenolpyruvate carboxylase | <enzyme> An enzyme with high affinity for carbon dioxide. It catalyses irreversibly the formation of oxaloacetate from phosphoenolpyruvate and carbon dioxide. This fixation of carbon dioxide in several bacteria and some plants is the first step in the biosynthesis of glucose. Chemical name: Orthophosphate:oxaloacetate carboxy-lyase (phosphorylating) Registry number: EC 4.1.1.31 (12 Dec 1998) |
| phosphoenolpyruvate carboxylase kinase | <enzyme> From bryophyllum fedtschenkoi plant and maise; phosphorylates phosphoenolpyruvate carboxylase on serine near the n-terminus; activity controlled by circadian rhythms Registry number: EC 2.7.10.- Synonym: pep carboxylase kinase, pepc kinase (26 Jun 1999) |
| multiple carboxylase deficiency | Abnormalities in carbohydrate and branched-chain amino acid catabolism that are responsive to biotin therapy. It may be due to deficiency of propionyl-CoA carboxylase, methylcrotonyl-CoA carboxylase, biotinidase, or propionyl-CoA carboxylase, methylcrotonyl-CoA carboxylase, and pyruvate carboxylase. (12 Dec 1998) |
| polyprenyl-4-hydroxybenzoate carboxylase | <enzyme> Involved in polyprenylphenol synthesis; implicated in flagellation of salmonella typhimurium Registry number: EC 4.1.1.- Synonym: ppphb carboxylase, polyprenyl-p-hydroxybenzoate carboxylase (26 Jun 1999) |
| preprothrombin carboxylase | <enzyme> Vitamin k-dependent, membrane-bound Registry number: EC 4.1.1.- (26 Jun 1999) |
| propionyl-CoA carboxylase | <enzyme> See also propionyl CoA carboxylase (ATP-hydrolyzing) (EC 6.4.1.4) Registry number: EC 4.1.1.41 Synonym: methylmalonyl-CoA decarboxylase, propionyl-coenzyme a carboxylase (26 Jun 1999) |
| pyruvate carboxylase | <enzyme> An enzyme that catalyses the formation of oxaloacetate from pyruvate, carbon dioxide and ATP in gluconeogenesis. (18 Nov 1997) |
| pyruvate carboxylase deficiency | An autosomal recessive pyruvate metabolism disorder resulting from absent or deficient expression of pyruvate carboxylase activity. Decreased production of oxaloacetate leads to decreased gluconeogenesis, thereby causing fasting hypoglycaemia, lactic acid acidosis, and decreased synthesis of amino acid neurotransmitters. Clinical presentations include acidosis, ataxia, mental retardation; sometimes co-occurs with leigh disease. (12 Dec 1998) |
| pyruvic-malic carboxylase | <enzyme> An enzyme that catalyses the conversion of (s)-malate and NAD+ to oxaloacetate and NADH. Chemical name: (S)-Malate:NAD+ oxidoreductase Registry number: EC 1.1.1.37 (12 Dec 1998) |
| oxalosuccinic carboxylase | <enzyme> An enzyme of the oxidoreductase class that catalyses the conversion of isocitrate and NAD+ to yield 2-ketoglutarate, carbon dioxide, and NADH. It occurs in cell mitochondria. The enzyme requires magnesium, mn2+; it is activated by ADP, citrate, and calcium, and inhibited by NADH, NADPH, and ATP. The reaction is the key rate-limiting step of the citric acid (tricarboxylic) cycle. (the NADP+ enzyme is EC 1.1.1.42.) Chemical name: Isocitrate:NAD+ oxidoreductase (decarboxylating) Registry number: EC 1.1.1.41 (12 Dec 1998) |
| adenosine 5'-diphosphate | A condensation product of adenosine with pyrophosphoric acid, formed from ATP by the hydrolysis of the terminal phosphate group of the latter compound. Acronym: ADP (05 Mar 2000) |
| adenosine diphosphate | <biochemistry> ADP is used as an adenine, a ribose and a diphosphate unit. (06 May 1997) |
| adenosine diphosphate glucose | <chemical> Serves as the glycosyl donor for formation of bacterial glycogen, amylose in green algae, and amylopectin in higher plants. Chemical name: Adenosine 5'-(trihydrogen diphosphate), P'-alpha-D-glucopyranosyl ester (12 Dec 1998) |
| adenosine diphosphate ribose | <chemical> Adenosine 5'-(trihydrogen diphosphate),5'-5-ester with d-ribose. An ester formed between the aldehydic carbon of ribose and the terminal phosphate of adenosine diphosphate. Serves as a ribose carrier. Chemical name: Adenosine 5'-(trihydrogen diphosphate), P'-5-ester with D-ribose (12 Dec 1998) |