Nucleoside-diphosphate kinase

Nucleoside diphosphate kinase is relatively nonspecific enzyme that transfers a phosphoryl group from a variety of nucleoside triphosphates to nucleoside diphosphates. Its biological function is presumably to use ATP to phosphoryl-ate the various ribo- and deoxyribonucleoside diphosphates to form the triphosphate derivatives need by the cell. 

Chromatographic conditions were optimized to follow the reaction in which ATP phosphorylates UDP. These nucleotides, and the products, ADP and UTP, were separated on a Beckman Ci8 LTltrasphere IP column (4.6 mm x 250 mm, 5 /u,m). The mobile phase was adjusted to pH 5.0 with H3P04 and contained 100 mM potassium phosphate, 20 mM potassium acetate, 5 mM tetrabutylammonium hydroxide, and 12% acetonitrile. The effluent was monitored at 254 nm, and quantitation was based on the percentage conversion of UDP to UTP. 

The reaction mixture contained in a volume of 0.30 mL 33 mM N-Hepes (pH 7.4) 5 mM MgCl2, 1 mM ATP, 1 mM UDP, and 1.6 fig of oligomycin. Reactions were run at 30°C for 5 minutes and were stopped by adding 0.2 mL of 0.2 M formic acid. Aliquots of these mixtures were injected directly into the HPLC system. 

The assay was suitable for measuring the activity in intact and detergent-disrupted mitochondria isolated from rat, rabbit, and pigeon tissues. 

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FIGURE 23.6 The PEP carboxykinase reaction. GTP formed in this reaction can be converted to ATP by nucleoside diphosphate kinase, althongh liver cells in some species may not contain this enzyme. 

By means of the enzyme nucleoside diphosphate kinase, UTP, GTP, and CTP can be synthesized from their diphosphates, eg,... 

The subsequent cleavage of the thio-ester succinylCoA into succinate and coenzyme A by succinic acid-CoA ligase (succinyl CoA synthetase, succinic thiokinase) is strongly exergonic and is used to synthesize a phosphoric acid anhydride bond ( substrate level phosphorylation , see p. 124). However, it is not ATP that is produced here as is otherwise usually the case, but instead guanosine triphosphate (CTP). However, GTP can be converted into ATP by a nucleoside diphosphate kinase (not shown). 

ADP as a substrate in enzyme reactions, ADENYLATE KINASE (or MYOKINASE) ATP SYNTHASE CREATINE KINASE NUCLEOSIDE DIPHOSPHATE KINASE PHOSPHOGLYCERATE KINASE PYRUVATE KINASE RIBONUCLEOTIDE REDUCTASE SULFATE ADENYLYLTRANSFERASE (ADP) [ADP]/[ATP] ratio,... 

NUCLEOSIDE DIPHOSPHATE KINASE 5-OXOPROLINASE PHENYLALANINE RACEMASE 1-PHOSPHATIDYLINOSITOL 4-KINASE PHOSPHATIDYLINOSITOL-4-PHOSPHATE 5-KINASE... 

NUCLEOSIDE DIPHOSPHATASE NUCLEOSIDE DIPHOSPHATE KINASE HALF-REACTIONS... 

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Presecan, E. Vonica, A. Lascu, L Nucleoside diphosphate kinase from human erythrocytes purification, molecular mass and subunit structure. FEBS Lett., 250, 629-632 (1989)... 

Huitorel, P. Simon, C. Pantaloni, D. Nucleoside diphosphate kinase from brain. Purification and effect on microtubule assembly in vitro. Eur. J. Biochem., 144, 233-241 (1984)... 

Kimura, N. Shimada, N. Membrane-associated nucleoside diphosphate kinase from rat liver. Purification, characterization, and comparison with cytosolic enzyme. J. Biol. Chem., 263, 4647-4653 (1988)... 

Hemmerich, S. Pecht, I. Oligomeric structure and autophosphorylation of nucleoside diphosphate kinase from rat mucosal mast cells. Biochemistry, 31, 4580-4587 (1992)... 

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