[Dimeric mechanism of the work of nigericin in bilayer lipid membranes].

The electric properties of the bilayer lethitin membranes have been studied in the presense of the antibiotic nigericin. When the antibiotic concentration is about 10(-6) M the condactivity of the BLM is increased upto 10(-7) ohm-1cm-2. The potassium ion concentration gradient gives rise to a transmembrane potential of the order of 40 mV per 10--fold concentration gradient with the side of the higher potassium concentration negative. The transmembrane potential produced by the hydrogen ion gradient is a function of the potassium ion concentration which is equal on both sides of the membrane. In order to account for the experimental results obtained, a theoretical approach has been developed based on the assumption that charge is transported across the membrane by nigericin dimers.