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

Ciria C Hernandez, Rahilla A Tarfa, Jose Miguel I Limcaoco, Ruiting Liu, Pravat Mondal, Clare Hill, R Keith Duncan, Thanos Tzounopoulos, Corey R J Stephenson, Matthew J O'Meara, Peter Wipf

Bioorganic & medicinal chemistry letters 2022 Sep 01

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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. Copyright © 2022. Published by Elsevier Ltd.

Citation

Ciria C Hernandez, Rahilla A Tarfa, Jose Miguel I Limcaoco, Ruiting Liu, Pravat Mondal, Clare Hill, R Keith Duncan, Thanos Tzounopoulos, Corey R J Stephenson, Matthew J O'Meara, Peter Wipf. Development of an automated screen for Kv7.2 potassium channels and discovery of a new agonist chemotype. Bioorganic & medicinal chemistry letters. 2022 Sep 01;71:128841