Selecting ions by size in a calcium channel: The ryanodine receptor case study

  • Gillespie D
  • Xu L
  • Meissner G
  • 9

    Readers

    Mendeley users who have this article in their library.
  • 8

    Citations

    Citations of this article.

Abstract

Many calcium channels can distinguish between ions of the same charge but different size. For example, when cations are in direct competition with each other, the ryanodine receptor (RyR) calcium channel preferentially conducts smaller cations such as Li+and Na+over larger ones such as K+and Cs+. Here, we analyze the physical basis for this preference using a previously established model of RyR permeation and selectivity. Like other calcium channels, RyR has four aspartate residues in its GGGIGDE selectivity filter. These aspartates have their terminal carboxyl group in the pore lumen, which take up much of the available space for permeating ions. We find that small ions are preferred by RyR because they can fit into this crowded environment more easily.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

  • Dirk Gillespie

  • Le Xu

  • Gerhard Meissner

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free