Ion channels: molecular basis of ion selectivity

A physical mechanism for large-ion selectivity of ion channels

a Department of Physiology and Biophysics, University of Miami School of Medicine, P. O. Box 016430, Miami, FL 33101, USA. E-mail: [email protected]; [email protected] b Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 86402-5700, USA. E-mail: [email protected] c Department of Molecular Biophysics and Physiology, Rush Medical College, 1750 W. Har...

Molecular basis of permeation in voltage-gated ion channels.

J on channels are pore-forming macromolecules that provide a passive conduit for ion transfer across membranes. Although simple ionophores such as gramicidin and nystatin' fall within this legalistic definition, the ion channels of eukaryotic cells are integral membrane proteins, many of which have now been isolated biochemically, reconstituted, cloned, and expressed. These fascinating proteins...

Ion conduction and selectivity in K(+) channels.

Potassium (K(+)) channels are tetrameric membrane-spanning proteins that provide a selective pore for the conductance of K(+) across the cell membranes. These channels are most remarkable in their ability to discriminate K(+) from Na(+) by more than a thousandfold and conduct at a throughput rate near diffusion limit. The recent progress in the structural characterization of K(+) channel provid...

Dynamic Selectivity Filters in Ion Channels

was permeable to molecules as large as the 630 Da YO-Pasadena, California 91125 PRO-1 dye. This experiment demonstrated, for the first time, real time changes in ion selectivity for a molecularly defined, single ion channel species (but see Petrou et Membrane ion channels contain integral pores that pre-al., 1997). cisely select their permeant ions. This selectivity an-P2X Structure-Function Ba...

Ion Conduction and Selectivity in K+ Channels