title: Relaxation and fluctuations of the number of particles in a membrane channel at arbitrary particle-channel interaction.
abstract: 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.
authors.affiliation: Joint Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya 13/19, Moscow 125412, Russia.
authors.forename: Vladimir Yu
authors.initials: VY
authors.lastname: Zitserman
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Berezhkovskii
authors.forename: Mark A
authors.initials: MA
authors.lastname: Pustovoit
authors.forename: Sergey M
authors.initials: SM
authors.lastname: Bezrukov
mesh_terms: D003198:Computer Simulation; D004058:Diffusion; D007473:Ion Channels / Q000737:chemistry*; D044085:Microfluidics; D008956:Models, Chemical; D011237:Predictive Value of Tests
chemical_list: D007473:Ion Channels