Gating-induced large aqueous volumetric remodeling and aspartate tolerance in the voltage sensor domain of Shaker K⁺ channels.

ABSTRACT: Neurons encode electrical signals with critically tuned voltage-gated ion channels and enzymes. Dedicated voltage sensor domains (VSDs) in these membrane proteins activate coordinately with an unresolved structural change. Such change conveys the transmembrane translocation of four positively charged arginine side chains, the voltage-sensing residues (VSRs; R1-R4). Countercharges and lipid phosphohead groups likely stabilize these VSRs within the low-dielectric core of the protein. However, the role of hydration, a sign-independent charge stabilizer, remains unclear. We replaced all VSRs and their neighboring residues with negatively charged aspartates in a voltage-gated potassium channel. The ensuing mild functional effects indicate that hydration is also important in VSR stabilization. T

SUBMITTER: Diaz-Franulic I 

PROVIDER: S-EPMC6094148 | biostudies-literature | 2018 Aug

REPOSITORIES: biostudies-literature