vdac1 allows for the conductance of molecules into and out of the mitochondrion. its permeability is dependent on vdac1's conformational state which is determined by voltage. at low voltage (10mv), the pore is in an "open" state where the channel is weakly anion selective and allows for a greater flux of metabolites. because of the large pore size, metabolic gating under saturated atp conditions reveal a transport of 2,000,000 atp/second and a transport of 10,000 atp under physiological conditions. at a higher voltage in the positive or negative direction (>30mv), the pore is in a "closed" state and is weakly cation selective allowing for less metabolites to be transported. the flux of metabolites can be seen as negligible.this change in states is mediated by a conformational change in the protein that has yet to be discovered. since the alpha helical n-terminus segment is located in the center of the pore, it is ideally situated for metabolic gating. this lead researchers to believe that the alpha helix was a key contributor to determining the conformational states. however, more recent studies have shown the n-terminal is unnecessary for proper voltage gating and therefore suggest the flexible beta barrel as the mechanism of conformational change.