Mapping the membrane-aqueous border for the voltage-sensing domain of a potassium channel.

ABSTRACT: Voltage-sensing domains (VSDs) play diverse roles in biology. As integral components, they can detect changes in the membrane potential of a cell and couple these changes to activity of ion channels and enzymes. As independent proteins, homologues of the VSD can function as voltage-dependent proton channels. To sense voltage changes, the positively charged fourth transmembrane segment, S4, must move across the energetically unfavorable hydrophobic core of the bilayer, which presents a barrier to movement of both charged species and protons. To reduce the barrier to S4 movement, it has been suggested that aqueous crevices may penetrate the protein, reducing the extent of total movement. To investigate this hypothesis in a system containing fully functional channels in a native environment w

SUBMITTER: Neale EJ 

PROVIDER: S-EPMC2247411 | biostudies-literature | 2007 Dec

REPOSITORIES: biostudies-literature