De novo designed voltage-gated anion channels suppress neuron firing

Abstract

Design of ion channels responsive to environmental cues has significant implications in modulating cellular activities and sensor development, but it remains a significant challenge due to the complexities involved in designing stimuli-induced conformational changes in proteins. Here, we report the accurate de novo design of voltage-gated anion channels, namely dVGACs. dVGACs adopt a 15-helix pentameric architecture featuring arginine constrictions within the transmembrane span and show voltage-dependent anions currents in patch-clamp experiments. Cryo-electron microscopy (cryo-EM) structures of dVGACs closely align with the design models. Cryo-EM structures and molecular dynamics simulations suggest that the arginine constrictions undergo voltage-induced conformational changes, serving as both a voltage sensor and a selectivity filter as designed. Notably, the anion selectivity and voltage sensitivity of dVGACs can be tuned through targeted mutations for suppressing neuronal firing in situ. The ability to create ion channels with custom-designed conformational changes refreshes our insights into membrane biophysics and unveils diverse potential applications.

Keywords: chloride channel; conformational changes; cryogenic electron microscopy; de novo protein design; deep learning; ion selectivity; neuronal firing; transmembrane protein; tunable ion selectivity and voltage sensitivity; voltage-gated ion channel.