Microscopic model for selective permeation in ion channels

Collective diffusion model for water permeation through microscopic channels.

Water permeation through nanometric channels, generally a coupled many-body process, is described in this study by a single collective coordinate. A collective diffusion model is proposed in which water movement at equilibrium is characterized as an unbiased diffusion along this coordinate and water transport in the presence of a chemical potential difference is described as one-dimensional dif...

Models of permeation in ion channels

Ion channels are formed by specific proteins embedded in the cell membrane and provide pathways for fast and controlled flow of selected ions down their electrochemical gradient. This activity generates action potentials in nerves, muscles and other excitable cells, and forms the basis of all movement, sensation and thought processes in living beings. While the functional properties of ion chan...

Gating and Permeation in Ion Channels

Collective diffusion model for ion conduction through microscopic channels.

Ion conduction through microscopic channels is of central importance in both biology and nanotechnology. To better understand the current-voltage (I-V) dependence of ion channels, here we describe and prove a collective diffusion model that quantitatively relates the spontaneous ion permeation at equilibrium to the stationary ionic fluxes driven by small voltages. The model makes it possible to...

Structural basis of ion permeation gating in Slo2.1 K+ channels

The activation gate of ion channels controls the transmembrane flux of permeant ions. In voltage-gated K(+) channels, the aperture formed by the S6 bundle crossing can widen to open or narrow to close the ion permeation pathway, whereas the selectivity filter gates ion flux in cyclic-nucleotide gated (CNG) and Slo1 channels. Here we explore the structural basis of the activation gate for Slo2.1...