Mechanism of inhibition of mouse Slo3 (KCa 5.1) potassium channels by quinine, quinidine and barium.

ABSTRACT:

Background and purpose

The Slo3 (KCa 5.1) channel is a major component of mammalian KSper (sperm potassium conductance) channels and inhibition of these channels by quinine and barium alters sperm motility. The aim of this investigation was to determine the mechanism by which these drugs inhibit Slo3 channels.

Experimental approach

Mouse (m) Slo3 (KCa 5.1) channels or mutant forms were expressed in Xenopus oocytes and currents recorded with 2-electrode voltage-clamp. Gain-of-function mSlo3 mutations were used to explore the state-dependence of the inhibition. The interaction between quinidine and mSlo3 channels was modelled by in silico docking.

Key results

Several drugs known to block KSper also affected mSlo3 channels with similar levels of inhibition. The inhibitio

SUBMITTER: Wrighton DC 

PROVIDER: S-EPMC4556473 | biostudies-literature | 2015 Sep

REPOSITORIES: biostudies-literature