[Nature of endogenous proton conductance of the inner mitochondrial membrane. Role of Ca2+ transport system in proton transfer].
In order to elucidate the nature of endogenous proton conductance of rat liver inner mitochondrial membrane, the dependence of the rate of Ca2+ transport on pH was studied. It was found that the inhibiting effect of H+ is independent of protonation of functional groups of hypothetical Ca2+ carrier, but results from electrogenic transfer of H+ across the membrane, which is highly permeable for the proton. The adsorption of H+ by mitochondria is inhibited by ruthenium red and other specific inhibitors of Ca2+ transport. It is concluded that endogenous proton conductance of the inner mitochondrial membrane depends on the functioning of the same transport system essential for membrane permeability for Ca2+ and other bivalent cations. The correlation observed between the rates of H+ and Ca2+ transport in mitochondria and the ratio of cation mobilities in aqueous solutions is in favour of a "porous" mechanism of cation transport across the mitochondrial membrane.
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007425:Intracellular Membranes / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism*; D051381:Rats; D012430:Ruthenium Red / Q000494:pharmacology
D012430:Ruthenium Red; D002118:Calcium
Priroda éndogennoi protonnoi provodimosti vnutrennei membrany mitokhondrii. Uchastie Ca2+-transportiruiushchei sistemy v perenose protona.