N. V. Nalyvajko, L. S. Vovkanych, L. O. Dubitsky
Kinetic analysis reveals the mainly competitive inhibition of Na+-dependent Ca2+ efflux from mitochondria by cations of monovalent metals. Potency of the inhibitory effect of metals’ cations on Na+-dependent Ca2+ efflux from mitochondria matrix increases in such an order (I50, mM): Cs+ (137.11) < Rb+ (122.63) < Li+ (24.59) < Tl+ (0.541). The results of correlation analysis show that sodium ions translocation by mitochondrial exchanger and its inhibition by the cations of monovalent metals is determined by their affinity for the oxygen-containing ligands and are accompanied with the ions dehydration. Inhibition of the mitochondrial Na+/Ca2+ exchanger by monovalent metal cations is also accompanied with the inhibition of cooperative interactions of metal ions with the ion-binding centers during transport cycle, which can be one of the mechanisms of the inhibition of ions translocation by this ion-transporting system.
Key words: mitochondria, Na+-dependent Са2+ efflux, cations of monovalent metals.
The original article in Ukrainian is available for download in PDF format.
© The Ukrainian Biochemical Journal