Electrogenic Cation Binding in the Electroneutral Na+/H+ Antiporter of Pyrococcus abyssi.

ABSTRACT: Na⁺/H⁺ antiporters in the CPA1 branch of the cation proton antiporter family drive the electroneutral exchange of H⁺ against Na⁺ ions and ensure pH homeostasis in eukaryotic and prokaryotic organisms. Although their transport cycle is overall electroneutral, specific partial reactions are electrogenic. Here, we present an electrophysiological study of the PaNhaP Na⁺/H⁺ antiporter from Pyrococcus abyssi reconstituted into liposomes. Positive transient currents were recorded upon addition of Na⁺ to PaNhaP proteoliposomes, indicating a reaction where positive charge is rapidly displaced into the proteoliposomes with a rate constant of k >200 s^-1 We attribute the recorded currents to an electrogenic reactio

SUBMITTER: Calinescu O 

PROVIDER: S-EPMC5207186 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature