Inhibition study of ADP,ATP transport in mitochondria with trinitrophenyl-modified substrates

The ADP,ATP carrier of rat liver mitochondria is specifically inhibited by Meisenheimer-type trinitrophenyl (TNP) derivatives of ADP and ATP. Due to a systematic inhibition study we could show that the TNP-moiety itself, even in the 2', 3'-O-cyclic Meisenheimer complex, revealed no inhibition of mitochondrial ADP,ATP transport. Nucleosidic TNP-compounds are weak inhibitors. Introduction of a phosphate group at the 5'-position, however, enhances the inhibitory power markedly. Our findings point to a synergistic effect of the 5'-phosphate chain and the TNP-moiety. Irreversible inhibition by TNP-nucleotides can be ruled out to the fact that the inhibited ADP,ATP-transport system is fully reactivated by addition of albumin.