Solvation, water permeation, and ionic selectivity of a putative model for the pore region of the voltage-gated sodium channel

Chandralekha Singh, R. Sankararamakrishnan, Shankar Subramaniam, Eric Jakobsson

Research output: Contribution to journalArticlepeer-review

Abstract

This paper describes a molecular dynamics and molecular mechanics study of the solvation and selectivity of the narrow pore and vestibule region of a model-built structure for the voltage-gated sodium channel. The particular structure used was one proposed by Guy and Durell. However, many of the features we saw would likely be shared with other possible models for this channel, such as the one proposed by Lipkind and Fozzard. It was found that the water mobility was reduced in the channel and the water orientations were significantly ordered by the channel environment. Water mobility depended on protein mobility; in a computer experiment in which the protein was artificially frozen, channel water at 300°K was immobilized. Water motions were defined in significant part by a series of discrete moves from one pattern of hydrogen bonding with particular amino acids to another. However, there are so many different hydrogen bonding patterns that a description of the motion in terms of transitions among a small number of discrete states is not appropriate. In the model whose solvation we explored, several charged residues seem to play a particularly significant role in determining solvation and water motions. Based on energy minimization studies, the structure clearly shows selectivity for univalent cations over anions.

Original languageEnglish (US)
Pages (from-to)2276-2288
Number of pages13
JournalBiophysical journal
Volume71
Issue number5
DOIs
StatePublished - Nov 1996

ASJC Scopus subject areas

  • Biophysics

Fingerprint

Dive into the research topics of 'Solvation, water permeation, and ionic selectivity of a putative model for the pore region of the voltage-gated sodium channel'. Together they form a unique fingerprint.

Cite this