Membrane potential stimulates ADP import and ATP export by the mitochondrial ADP/ATP carrier due to its positively charged binding site.

ABSTRACT: The mitochondrial adenosine 5'-diphosphate (ADP)/adenosine 5'-triphosphate (ATP) carrier imports ADP into the mitochondrion and exports ATP to the cell. Here, we demonstrate that 3.3 positive charges are translocated with the negatively charged substrate in each transport step. They can be assigned to three positively charged residues of the central substrate-binding site and two asparagine/arginine pairs. In this way, the membrane potential stimulates not only the ATP^4- export step, as a net -0.7 charge is transported, but also the ADP^3- import step, as a net +0.3 charge is transported with the electric field. These positive charge movements also inhibit the import of ATP and export of ADP in the presence of a membrane potential, allowing these nucleotides to be main

SUBMITTER: Mavridou V 

PROVIDER: S-EPMC11529707 | biostudies-literature | 2024 Nov

REPOSITORIES: biostudies-literature