Electrostatic tuning of ion conductance in potassium channels. Academic Article uri icon

Overview

abstract

  • Members of the K(+) channel family display remarkable conservation of sequence and structure of the ion selectivity filter, whereas the rates of K(+) turnover vary widely within the family. Here we show that channel conductance is strongly influenced by charge at the channel's intracellular mouth. Introduction of a ring of negative charges at this position in KcsA, a bacterial K(+) channel, augments the conductance in a pH-dependent manner. These results are explained by a simple electrostatic effect based on known channel structures, where the negative charges serve to alter the electrical potential at the inner mouth and, thus, to increase the local K(+) concentration. In addition, removal of the conserved negative charges at equivalent positions in a high-conductance eukaryotic K(+) channel leads to a decrease in conductance.

publication date

  • August 12, 2003

Research

keywords

  • Bacterial Proteins
  • Electric Conductivity
  • Ion Channel Gating
  • Membrane Potentials
  • Potassium Channels

Identity

Scopus Document Identifier

  • 0043074453

Digital Object Identifier (DOI)

  • 10.1021/bi0348720

PubMed ID

  • 12899612

Additional Document Info

volume

  • 42

issue

  • 31