Ion channel selectivity through ion-modulated changes of selectivity filter p<i>K</i>_a values.

ABSTRACT: In bacterial voltage-gated sodium channels, the passage of ions through the pore is controlled by a selectivity filter (SF) composed of four glutamate residues. The mechanism of selectivity has been the subject of intense research, with suggested mechanisms based on steric effects, and ion-triggered conformational change. Here, we propose an alternative mechanism based on ion-triggered shifts in pK_a values of SF glutamates. We study the Na_vMs channel for which the open channel structure is available. Our free-energy calculations based on molecular dynamics simulations suggest that pK_a values of the four glutamates are higher in solution of K⁺ ions than in solution of Na⁺ ions. Higher pK_a in the presence

SUBMITTER: Chen AY 

PROVIDER: S-EPMC10293820 | biostudies-literature | 2023 Jun

REPOSITORIES: biostudies-literature