Monte Carlo simulations of ion selectivity in a biological Na channel: Charge-space competition

D. Boda, David D. Busath, Bob Eisenberg, Douglas Henderson, Wolfgang Nonner

Research output: Contribution to journalArticle

59 Citations (Scopus)

Abstract

Na channels that produce the action potentials of nerve and muscle include a selectivity filter formed by both positively and negatively charged amino acid residues in a molecular pore. Here we present Monte Carlo simulations of equilibrium ion absorption in such a system. Ions are treated as charged hard spheres in a uniform dielectric. Tethered carboxylate and amino groups known to line the selectivity filter of the Na channel are represented as charged hard spheres and restricted to the filter region of the channel. Consistent with experiments, we find (1) that absorption of Ca2+ into the filter exceeds absorption of Na+ only when the concentration of Ca2+ is some tenfold larger than physiological; (2) the model channel absorbs smaller alkali metal ions preferentially compared to larger ones. The alkali metal selectivity involves volume exclusion of larger ions from the center of the filter region.

Original languageEnglish
Pages (from-to)5154-5160
Number of pages7
JournalPhysical Chemistry Chemical Physics
Volume4
Issue number20
DOIs
Publication statusPublished - 2002

Fingerprint

Alkali Metals
Electric space charge
space charge
selectivity
Ions
filters
Heavy ions
Metal ions
Muscle
ions
simulation
alkali metals
Amino Acids
nerves
muscles
exclusion
Experiments
carboxylates
amino acids
metal ions

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Atomic and Molecular Physics, and Optics

Cite this

Monte Carlo simulations of ion selectivity in a biological Na channel : Charge-space competition. / Boda, D.; Busath, David D.; Eisenberg, Bob; Henderson, Douglas; Nonner, Wolfgang.

In: Physical Chemistry Chemical Physics, Vol. 4, No. 20, 2002, p. 5154-5160.

Research output: Contribution to journalArticle

Boda, D. ; Busath, David D. ; Eisenberg, Bob ; Henderson, Douglas ; Nonner, Wolfgang. / Monte Carlo simulations of ion selectivity in a biological Na channel : Charge-space competition. In: Physical Chemistry Chemical Physics. 2002 ; Vol. 4, No. 20. pp. 5154-5160.
@article{15122d3a9d7343c6b013c8fb619b7c32,
title = "Monte Carlo simulations of ion selectivity in a biological Na channel: Charge-space competition",
abstract = "Na channels that produce the action potentials of nerve and muscle include a selectivity filter formed by both positively and negatively charged amino acid residues in a molecular pore. Here we present Monte Carlo simulations of equilibrium ion absorption in such a system. Ions are treated as charged hard spheres in a uniform dielectric. Tethered carboxylate and amino groups known to line the selectivity filter of the Na channel are represented as charged hard spheres and restricted to the filter region of the channel. Consistent with experiments, we find (1) that absorption of Ca2+ into the filter exceeds absorption of Na+ only when the concentration of Ca2+ is some tenfold larger than physiological; (2) the model channel absorbs smaller alkali metal ions preferentially compared to larger ones. The alkali metal selectivity involves volume exclusion of larger ions from the center of the filter region.",
author = "D. Boda and Busath, {David D.} and Bob Eisenberg and Douglas Henderson and Wolfgang Nonner",
year = "2002",
doi = "10.1039/b203686j",
language = "English",
volume = "4",
pages = "5154--5160",
journal = "Physical Chemistry Chemical Physics",
issn = "1463-9076",
publisher = "Royal Society of Chemistry",
number = "20",

}

TY - JOUR

T1 - Monte Carlo simulations of ion selectivity in a biological Na channel

T2 - Charge-space competition

AU - Boda, D.

AU - Busath, David D.

AU - Eisenberg, Bob

AU - Henderson, Douglas

AU - Nonner, Wolfgang

PY - 2002

Y1 - 2002

N2 - Na channels that produce the action potentials of nerve and muscle include a selectivity filter formed by both positively and negatively charged amino acid residues in a molecular pore. Here we present Monte Carlo simulations of equilibrium ion absorption in such a system. Ions are treated as charged hard spheres in a uniform dielectric. Tethered carboxylate and amino groups known to line the selectivity filter of the Na channel are represented as charged hard spheres and restricted to the filter region of the channel. Consistent with experiments, we find (1) that absorption of Ca2+ into the filter exceeds absorption of Na+ only when the concentration of Ca2+ is some tenfold larger than physiological; (2) the model channel absorbs smaller alkali metal ions preferentially compared to larger ones. The alkali metal selectivity involves volume exclusion of larger ions from the center of the filter region.

AB - Na channels that produce the action potentials of nerve and muscle include a selectivity filter formed by both positively and negatively charged amino acid residues in a molecular pore. Here we present Monte Carlo simulations of equilibrium ion absorption in such a system. Ions are treated as charged hard spheres in a uniform dielectric. Tethered carboxylate and amino groups known to line the selectivity filter of the Na channel are represented as charged hard spheres and restricted to the filter region of the channel. Consistent with experiments, we find (1) that absorption of Ca2+ into the filter exceeds absorption of Na+ only when the concentration of Ca2+ is some tenfold larger than physiological; (2) the model channel absorbs smaller alkali metal ions preferentially compared to larger ones. The alkali metal selectivity involves volume exclusion of larger ions from the center of the filter region.

UR - http://www.scopus.com/inward/record.url?scp=0036399649&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036399649&partnerID=8YFLogxK

U2 - 10.1039/b203686j

DO - 10.1039/b203686j

M3 - Article

AN - SCOPUS:0036399649

VL - 4

SP - 5154

EP - 5160

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

IS - 20

ER -