Cation-Selective Channel Regulated by Anions According to Their Hofmeister Ranking.

ABSTRACT: Specificity of small ions, the Hofmeister ranking, is long-known and has many applications including medicine. Yet it evades consistent theoretical description. Here we study the effect of Hofmeister anions on gramicidin A channels in lipid membranes. Counterintuitively, we find that conductance of this perfectly cation-selective channel increases about two-fold in the H₂ PO₄^- - ≈Br^- ≈NO₃^- 4^- - series. Channel dissociation kinetics show even stronger dependence, with the dwell time increasing about 20-fold. While the conductance can be quantitatively explained by the changes in membrane surface potential due to exclusion of kosmotropes from (or accumulation of chaotropes

SUBMITTER: Gurnev PA 

PROVIDER: S-EPMC5518747 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature