2008, Weidemüller, Christian, Hauser, Karin

The Na+/K+-ATPase pumps ions across the membrane which is necessary for maintaining the membrane potential. The energy for this active ion transport is provided by binding and hydrolysis of ATP and has to be transferred from the cytoplasmic nucleotide binding site to the transmembrane domain of ion transport. This transport cycle can also be induced experimentally by applying voltage jumps across the membrane. We simulated the applied electric field by an ionic capacitor and studied the impact on the Na+/K+-ATPase by a combination of multiconformation continuum electrostatics (MCCE) and molecular dynamics (MD). Our calculations show a selective activation of the helices M5, M6 and M8 by the electric field. Those helices are likely to act as energy transduction elements.