H+ translocation by weak acid uncouplers is independent of H electrochemical gradient

Abstract

According to the common view, weak acid uncouplers increase proton conductance of biological (and phospholipid bilayer) membranes, thus effecting H+ fluxes driven by their electrochemical gradients. Under certain conditions, however, uncouplers can induce unexpected effects opposite to the dissipation of H+ gradients.

Results are presented here demonstrating CCCP-induced proton influx into Saccharomyces cerevisiae cytosol driven by the electrochemical potentials of CCCP and its CCCP- anions, independent of electrochemical H+-gradient. Another view of week acid uncouplers' action is proposed that is logically consistent with these observations.

Keywords

• H+ translocation
• weak acid uncouplers
• CCCP
• electrochemical gradient