Potassium channel, ions, and water: simulation studies based on the high resolution X-ray structure of KcsA.

ABSTRACT: Interactions of Na(+), K(+), Rb(+), and Cs(+) ions within the selectivity filter of a potassium channel have been investigated via multiple molecular dynamics simulations (total simulation time, 48 ns) based on the high resolution structure of KcsA, embedded in a phospholipid bilayer. As in simulations based on a lower resolution structure of KcsA, concerted motions of ions and water within the filter are seen. Despite the use of a higher resolution structure and the inclusion of four buried water molecules thought to stabilize the filter, this region exhibits a significant degree of flexibility. In particular, pronounced distortion of filter occurs if no ions are present within it. The two most readily permeant ions, K(+) and Rb(+), are similar in their interactions with the selectivity f

SUBMITTER: Domene C 

PROVIDER: S-EPMC1303560 | biostudies-literature | 2003 Nov

REPOSITORIES: biostudies-literature