scholarly journals The Adenosine Triphosphate-Adenosine Diphosphate Exchange Reaction of Oxidative Phosphorylation

1958 ◽  
Vol 233 (6) ◽  
pp. 1589-1597 ◽  
Author(s):  
Charles L. Wadkins ◽  
Albert L. Lehninger
Keyword(s):  
Oxidative Phosphorylation ◽  
Exchange Reaction ◽  
Adenosine Triphosphate ◽  
Adenosine Diphosphate

scholarly journals Effects of arginine and some analogues of the partial adenosine triphosphate-adenosine diphosphate exchange reaction catalysed by arginine kinase. Evolutionary divergence in the mechanism of action of a monomer and a dimer arginine kinase

1976 ◽  
Vol 155 (3) ◽  
pp. 689-693 ◽  
Author(s):  
E O Anosike ◽  
D C Watts
Keyword(s):  
Exchange Reaction ◽  
Adenosine Triphosphate ◽  
Mechanism Of Action ◽  
Arginine Kinase ◽  
Adenosine Diphosphate ◽  
Normal Rate ◽  
Evolutionary Divergence ◽  
Kinase Reaction ◽  
Dead End ◽  
Related Compounds

1. Both the monomer arginine kinase from lobster muscle and the dimer arginine kinase from Holothuria forskali catalyse the ATP-ADP partial exchange reaction at rates equal to 3 and 0.6% of the normal rate of transphosphorylation respectively. The Mg2+-nucleotide complex is the substrate for this as it is for the kinase reaction. 2. Analogues of arginine inhibit the exchange reaction of the lobster enzyme but enhance that of the Holothuria enzyme. 3. With the lobster enzyme NO3- has no effect on the exchange reaction alone and inhibit only slightly the apparent enhancement of the exchange reaction produced by the addition of arginine. This is compatible with previous findings for this enzyme that formation of the anion-stabilized dead-end complex, enzyme-arginine-MgADP-NO3-, does not occur to any marked degree. 4. About 80% of the ADP-ATP exchange reaction of the lobster enzyme remains after inhibition with iodoacetamide. This is further decreased to 65% by the addition of L-arginine, indicating that this substrate does bind to the thiolmodified enzyme. 5. It is concluded that the partial exchange reaction is a genuine phenomenon not mediated by trace amounts of arginine. From the effects of arginine and related compounds it would appear that during the normal kinase reaction the partial ATP-ADP exchange reaction is suppressed in the lobster enzyme but enhanced in the Holothuria enzyme. This reflects a remarkable evolutionary divergence of two homologous enzymes.

UNCOUPLING OF OXIDATIVE PHOSPHORYLATION BY VANADATE

1966 ◽  
Vol 44 (7) ◽  
pp. 983-988 ◽  
Author(s):  
John N. Hathcock ◽  
C. H. Hill ◽  
S. B. Tove
Keyword(s):  
Electron Transport ◽  
Oxidative Phosphorylation ◽  
Adenosine Triphosphate ◽  
Adenosine Diphosphate ◽  
Liver Mitochondria ◽  
In Vitro Studies ◽  
Exchange Reactions ◽  
Uncoupling Of Oxidative Phosphorylation

The addition of ammonium metavanadate to the diet of chicks at a level to supply 25 parts per million vanadium uncoupled oxidative phosphorylation in mitochondria isolated from the livers. In vitro studies revealed that 1 mM vanadate uncoupled oxidative phosphorylation in liver mitochondria. This uncoupling was manifest whether succinate or β-hydroxybutyrate was used as the substrate, suggesting that all three phosphorylating sites associated with electron transport were uncoupled.At a concentration of 0.1 mM, vanadate increased the destruction of adenosine triphosphate by mitochondria. As the concentration of vanadate was increased the destruction of adenosine triphosphate became progressively less. The exchange reactions of adenosine triphosphate with orthophosphate and with adenosine diphosphate, catalyzed by liver mitochondria, were inhibited by 0.1 mM vanadate. These results suggest the possibility that the known toxic effects of vanadium in vivo are related to the uncoupling of oxidative phosphorylation.

Effects of 2,4-D and Other Herbicides on Oxidative Phosphorylation in Mitochondria from Cabbage

Weed Science ◽  
1968 ◽  
Vol 16 (2) ◽  
pp. 161-165 ◽  
Author(s):  
Prabhakar D. Lotlikar ◽  
LeMar F. Remmert ◽  
Virgil H. Freed
Keyword(s):  
Electron Transport ◽  
Oxygen Uptake ◽  
Oxidative Phosphorylation ◽  
Atpase Activity ◽  
Exchange Reaction ◽  
Adenosine Triphosphatase ◽  
Adenosine Diphosphate ◽  
Sodium Chlorate ◽  
Dichlorophenoxyacetic Acid ◽  
2,4 Dichlorophenoxyacetic Acid

The effects of 22 herbicides on oxidative phosphorylation in mitochondria from cabbage (Brassica oleracea var. capitata L.) have been studied. Carbamates, phenoxyacids, 3,5-dimethyltetrahydro-l,3,5,2H-thiadiazine-2-thione (DMTT), N-1-napthylphthalamic acid (NPA), 2,3,6-trichlorobenzoic acid (2,3,6-TBA), 3-(p-chlorophenyl)-1,1-dimethylurea (monuron), and 2-chloro-2-N,N-diallylacetamide (CDAA) inhibited phosphorylation to a greater extent than oxygen uptake in cabbage mitochondria. The compounds 1,2-dihydropyridazine-3,6-dione (MH), 2,2-dichloropropionic acid (dalapon), 2,2,3-trichloropropionic acid (hereinafter referred to as 2,2,3-TPA), sodium chlorate, and 3-amino-l,2,4-triazole (amitrole) at concentrations as high as 1 × 10–2 M did not have a large effect on oxidative phosphorylation in cabbage mitochondria. Respiration which was stimulated by 2,4-dinitrophenol (DNP) or adenosine diphosphate (ADP) was inhibited by 2,4-dichlorophenoxyacetic acid (2,4-D). Although 2,4-D did not affect Mg++-stimulated adenosine triphosphatase (ATPase), it inhibited an oleate-stimulated ATPase activity and the ATP-32Pi exchange reaction in cabbage mitochondria. The results suggest that 2,4-D may inhibit respiration in cabbage mitochondria by an effect on a reaction involved in coupling phosphorylation with electron transport.

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