Spontaneous Onset of Coherence and Energy Storage by Membrane Transporters in an RLC Electric Circuit

Recent experiments have shown that oscillating or fluctuating electric fields can drive thermodynamically uphill transport of ions catalyzed by a molecular ion pump, the Na,K-ATPase. Theory suggests that if the transport reaction is very far from equilibrium the energy flow can be reversed, i.e., power can flow from the downhill transport process into the electric field. Here we show that in an electric circuit with inductance, if the transport reaction is far from equilibrium, small fluctuations in the net polarization of the transporter proteins in the membrane can be spontaneously amplified, resulting in the onset of coherent behavior, and energy transfer from the chemical gradient to the electric circuit.