Pyruvate-phosphate-dikinase

Pyruvate, Pi dikinase is an enzyme encountered by Hatch and his co-workers during studies of C4 photosynthesis (Hatch and Slack, 1969). 

It is known to be light-activated and in vitro requires a thiol reagent and Mg . Its presumed role is the generation of PEP from pyruvate. 

It was first reported to occur in CAM plants by Kluge and Osmond (1971), and Sugiyama and Laetsch (1975) studied it with immunochemical techniques from Kalanchoe daigremontiana. 

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This enzyme [EC 2.7.9.1], also referred to as pyruvate, phosphate dikinase, catalyzes the reaction of ATP with pyruvate and orthophosphate to produce AMP, phos-phoenolpyruvate, and pyrophosphate (or, diphosphate). 

PYRUVATE, ORTHOPHOSPHATE DIKINASE PYRUVATE OXIDASE Pyruvate, phosphate dikinase,... 

I. Bruchhaus, E. Tannich (1993). Primary structure of the pyruvate phosphate dikinase in... 

Slamovits CH, Keeling PJ (2006) Pyruvate-phosphate dikinase of oxymonads and para-basalia and the evolution of pyrophosphate-dependent glycolysis in anaerobic eukaryotes. Eukaryot Cell 5 148-154... 

Ito, K. Nakagawa, K. Murakami, S. Arakawa, H. Maeda, M. Highly sensitive simultaneous bioluminescent measurement of acetate kinase and pyruvate phosphate dikinase activities using a firefly luciferase-luciferin reaction and its application to a tandem bioluminescent enzyme immunoassay. Anal. Sci., 19, 105-109 (2003)... 

The pyruvate formed by decarboxylation of malate in bundle-sheath cells is transferred back to the mesophyll cells, where it is converted to PEP by an unusual enzymatic reaction catalyzed by pyruvate phosphate dikinase (Fig. 20-23b). This enzyme is called a dikinase because two different molecules are simultaneously phosphorylated by one molecule of ATP pyruvate to PEP, and phosphate to pyrophosphate. The pyrophosphate is subsequently hydrolyzed to phosphate, so two high-energy phosphate groups of ATP are used in regenerating PEP. The PEP is now ready to receive another molecule of C02 in the mesophyll cell. 

Three enzymes of the C4 pathway are regulated by light, becoming more active in daylight. Malate dehydrogenase is activated by the thioredoxin-dependent reduction mechanism shown in Figure 20-19 PEP carboxylase is activated by phosphorylation of a Ser residue and pyruvate phosphate dikinase is activated by dephosphorylation. In the latter two cases, the details of how light effects phosphorylation or dephosphorylation are not known. 

Pyruvate phosphate dikinase Anaerobic protozoa None... 

Glycolysis provides the main source of ATP in Trypanosoma brucei, E histolytica, and G lamblia, which possess pyruvate kinase as well as a pyruvate phosphate dikinase for converting phosphoenolpyruvate (PEP) to pyruvate and generating ATP. Pyruvate phosphate dikinase is not a homolog of pyruvate kinase but is closely related to PEP synthase from bacteria. The enzyme catalyzes conversion of PEP to pyruvate accompanied by the synthesis of ATP from AMP and pyrophosphate. Genes encoding the enzyme have been isolated from E histolytica and G lamblia and have demonstrated considerable structural divergences. No specific inhibitor of this enzyme has yet been identified. 

Bringaud F, Baltz D, Baltz T (1998) Functional and molecular characterization of a glycosomal PPj-dependent enzyme in trypanosomatids pyruvate, phosphate dikinase. Proc Natl Acad Sci USA 95 7963-7968... 

Phosphoenolpyruvate Synthetase and Pyruvate, Phosphate Dikinase R. A. Cooper and H. L. Komberg... 

Another enzyme that uses the energy of the PPj is the pyruvate, phosphate dikinase. This enzyme converts P-enolpyruvate to pyruvate, but unlike pyruvate kinase, which uses ADP as the phosphate acceptor yielding ATP and pyruvate. This enzyme uses AMP and in combination with PPj yields ATP, Pj and pyruvate ... 

We developed a simultaneous bioluminescent assay of acetate kinase (AK) and pyruvate phosphate dikinase (PPDK). In the method, the detection limits (blank + 3SD) of AK and PPDK were 1.03x10 and 2.05x10 mol/assay, respectively. Previously, we successfully applied a tandem bioluminescent enzyme immunoassay (BL-EIA) for simultaneous measurement of insulin and c-peptide. In this study, we also applied the method to tandem BL-EIA for Angiotensin I and Endothelin-1, which are hypertension related peptides. The tandem BL-EIA used a competitive immuno-reaction for Angiotensin I and sandwich inununo-reaction for Endothelin-1. 

A NEW ASSAY FOR DETERMINING PYROPHOSPHATE USING PYRUVATE PHOSPHATE DIKINASE AND ITS APPLICATION TO DNA ANALYSIS... 

It is known that pyruvate phosphate dikinase (PPDK) catalyzes the conversion of phosphoenolpyruvate (PEP) to ATP, phosphate and pyruvate in the presence of AMP and pyrophosphate. And Sakakibara et al used the PPDK-luciferin/luciferase reaction for measurement of AMP and RNA. ... 

Determining Pyrophosphate Using Pyruvate Phosphate Dikinase... 

The existence and importance of the covalent intermediates that appear in the few such reactions in which they are involved can be rationalized in a few ways. Most can be rationalized on the basis of the principle of economy in the evolution of binding sites. In the cases of the pyrophosphoenzymes and phosphoenzymes that are intemediates in the phosphoenolpyruvate synthetase and pyruvate phosphate dikinase reactions, the same principle applies however, additional interactions are probably more important. In one instance of a phosphoenzyme, the succinyl-CoA synthetase reaction, the role of the phosphoenzyme is unclear. But even in that case an attractive rationale can be advanced as a hypothesis. 

The problem of focusing phosphorylation free energy is elegantly solved in the mechanisms of action of phosphoenolpyruvate synthetase and pyruvate phosphate dikinase. Phosphohistidyl residues are generated at the active sites of these enzymes by pyrophosphorylation of active site histidines, followed by hydrolysis... 

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