Side pockets provide the basis for a new mechanism of Kv channel-specific inhibition.
Nat Chem Biol
; 9(8): 507-13, 2013 Aug.
Article
em En
| MEDLINE
| ID: mdl-23728494
ABSTRACT
Most known small-molecule inhibitors of voltage-gated ion channels have poor subtype specificity because they interact with a highly conserved binding site in the central cavity. Using alanine-scanning mutagenesis, electrophysiological recordings and molecular modeling, we have identified a new drug-binding site in Kv1.x channels. We report that Psora-4 can discriminate between related Kv channel subtypes because, in addition to binding the central pore cavity, it binds a second, less conserved site located in side pockets formed by the backsides of S5 and S6, the S4-S5 linker, part of the voltage sensor and the pore helix. Simultaneous drug occupation of both binding sites results in an extremely stable nonconducting state that confers high affinity, cooperativity, use-dependence and selectivity to Psora-4 inhibition of Kv1.x channels. This new mechanism of inhibition represents a molecular basis for the development of a new class of allosteric and selective voltage-gated channel inhibitors.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Canal de Potássio Kv1.5
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article