Relaxation and fluctuations of the number of particles in a membrane channel at arbitrary particle-channel interaction.
We analyze the relaxation of the particle number fluctuations in a membrane channel at arbitrary particle-channel interaction and derive general expressions for the relaxation time and low-frequency limit of the power spectral density. These expressions simplify significantly when the channel is symmetric. For a square-well potential of mean force that occupies the entire channel, we verify the accuracy of the analytical predictions by Brownian dynamics simulations. For such a channel we show that as the depth of the well increases, the familiar scaling of the relaxation time with the channel length squared is transformed into a linear dependence on the length.
Zitserman
Vladimir Yu
VY
Joint Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya 13/19, Moscow 125412, Russia.
Berezhkovskii
Alexander M
AM
Pustovoit
Mark A
MA
Bezrukov
Sergey M
SM
D003198:Computer Simulation; D004058:Diffusion; D007473:Ion Channels / Q000737:chemistry*; D044085:Microfluidics; D008956:Models, Chemical; D011237:Predictive Value of Tests
D007473:Ion Channels