ANT has long been thought to function asymmetrically as a homodimer of subunits in the inner mitochondrial membrane. The dimer was thought to be a gated pore through which ADP and ATP were exchanged between the mitochondrial matrix and the cytoplasm. The dimer hypothesis was first challenged when the three-dimensional structure of ANT was discovered to be a monomer. Further work has shown that ANT functions as a monomer in detergents and in mitochondrial membranes.
^Pebay-Peyroula E, Dahout-Gonzalez C, Kahn R, Trézéguet V, Lauquin GJ, Brandolin G (November 2003). "Structure of mitochondrial ADP/ATP carrier in complex with carboxyatractyloside". Nature. 426 (6962): 39–44. PMID14603310. doi:10.1038/nature02056.
^Bamber L, Slotboom DJ, Kunji ER (August 2007). "Yeast mitochondrial ADP/ATP carriers are monomeric in detergents as demonstrated by differential affinity purification". J. Mol. Biol. 371 (2): 388–95. PMID17572439. doi:10.1016/j.jmb.2007.05.072.