Development of an automated screen for Kv7.2 potassium channels and discovery of a new agonist chemotype

Bioorg Med Chem Lett. 2022 Sep 1:71:128841. doi: 10.1016/j.bmcl.2022.128841. Epub 2022 Jun 4.

Abstract

To identify pore domain ligands on Kv7.2 potassium ion channels, we compared wild-type (WT) and W236L mutant Kv7.2 channels in a series of assays with previously validated and novel agonist chemotypes. Positive controls were retigabine, flupirtine, and RL-81; i.e. Kv7.2 channel activators that significantly shift voltage-dependent activation to more negative potentials (ΔV50) at 5 µM. We identified 6 new compounds that exhibited differential enhancing activity between WT and W236L mutant channels. Whole cell patch-clamp electrophysiology studies were conducted to identify Kv7.2. Kv7.2/3, Kv7.4, and Kv7.5 selectivity. Our results validate the SyncroPatch platform and establish new structure activity relationships (SAR). Specifically, in addition to selective Kv7.2, Kv7.2/3, Kv7.4. and Kv7.5 agonists, we identified a novel chemotype, ZK-21, a 4-aminotetrahydroquinoline that is distinct from any of the previously described Kv7 channel modifiers. Using flexible receptor docking, ZK-21 was predicted to be stabilized by W236 and bind perpendicular to retigabine, burying the benzyl carbamate group into a tunnel reaching the core of the pore domain.

Keywords: Agonists; Potassium channels; Quinolines; SyncroPatch screen; Voltage-dependent activation.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • KCNQ Potassium Channels* / genetics
  • KCNQ Potassium Channels* / metabolism
  • KCNQ2 Potassium Channel* / genetics
  • KCNQ2 Potassium Channel* / metabolism

Substances

  • KCNQ Potassium Channels
  • KCNQ2 Potassium Channel