Application of modular control analysis to inhibition of the adenine nucleotide translocator by palmitoyl-CoA.
Modular kinetic analysis was used to characterize inhibition of adenine nucleotide translocation by palmitoyl-CoA in isolated rat-liver mitochondria. To this purpose, oxidative phosphorylation has been divided into two modules with the fraction of matrix ATP as linking intermediate. The adenine nucleotide translocator is the matrix ATP-consuming module and the remainder of oxidative phosphorylation (ATP synthesis, respiratory chain and transport of phosphates and respiratory substrate) is the matrix ATP-producing module. We found that palmitoyl-CoA inhibits ATP-consuming module (ANT) and has no effect on ATP-producing module. There were no significant differences between kinetic curves obtained with oligomycin and myxothiazol, inhibitors that have opposite effect on membrane potential, suggesting that the use of the fraction of matrix ATP as the only intermediate is a good approximation. A new method has been used to determine the fraction of ATP in the mitochondrial matrix.
Ciapaite
J
J
Department of Molecular Cell physiology, Faculty of Earth and Life Sciences, Vrije Universiteit, Amsterdam, The Netherlands.
van Eikenhorst
G
G
Krab
K
K
D000227:Adenine Nucleotides / Q000378:metabolism; D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004791:Enzyme Inhibitors / Q000378:metabolism*; D006593:Hexokinase / Q000378:metabolism; D008297:Male; D008930:Mitochondria, Liver / Q000201:enzymology*; D000226:Mitochondrial ADP, ATP Translocases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008954:Models, Biological; D010085:Oxidative Phosphorylation; D010171:Palmitoyl Coenzyme A / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D000227:Adenine Nucleotides; D004791:Enzyme Inhibitors; D010171:Palmitoyl Coenzyme A; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D000226:Mitochondrial ADP, ATP Translocases; D006593:Hexokinase