High-resolution orientation and depth of insertion of the voltage-sensing S4 helix of a potassium channel in lipid bilayers.

ABSTRACT: The opening and closing of voltage-gated potassium (Kv) channels are controlled by several conserved Arg residues in the S4 helix of the voltage-sensing domain. The interaction of these positively charged Arg residues with the lipid membrane has been of intense interest for understanding how membrane proteins fold to allow charged residues to insert into lipid bilayers against free-energy barriers. Using solid-state NMR, we have now determined the orientation and insertion depth of the S4 peptide of the KvAP channel in lipid bilayers. Two-dimensional (15)N correlation experiments of macroscopically oriented S4 peptide in phospholipid bilayers revealed a tilt angle of 40 degrees and two possible rotation angles differing by 180 degrees around the helix axis. Remarkably, the tilt angle and o

SUBMITTER: Doherty T 

PROVIDER: S-EPMC2918711 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature