title: Further comments on the logic of the application of uncoupler- inhibitor titrations for the elucidation of the mechanisms of energy coupling.
abstract: Following the appearance of two papers in this journal commenting on the logic of the application of uncoupler-inhibitor titrations as a means of discriminating between 'delocalized' and 'localized' chemiosmotic mechanisms [(1984) FEBS Lett. 176,79-82; (1985) FEBS Lett. 186, 8-10], and in contrast with the arguments presented there and elsewhere, we show that in a linear model the increase in delta mu H which accompanies partial inhibition of the ATPases always leads to a relatively higher decrease of the rate of ATP synthesis by a given concentration of uncoupler in the presence of an ATPase inhibitor than in its absence. This is due to the fact that the same titre of uncoupler leads to a higher dissipative H+ flow in the presence of inhibitor, since the driving force delta mu H is higher.
mesh_terms: D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000096:biosynthesis* / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008433:Mathematics; D008954:Models, Biological; D009840:Oligomycins / Q000494:pharmacology; D010084:Oxidation-Reduction; D010085:Oxidative Phosphorylation; D011522:Protons; D014475:Uncoupling Agents / Q000494:pharmacology*
chemical_list: D009840:Oligomycins; D011522:Protons; D014475:Uncoupling Agents; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases