Cook Gabriel A, Pajewski Robert, Aburi Mahalaxmi, Smith Paul E, Prakash Om, Tomich John M, Gokel George W
Departments of Biochemistry and Chemistry, Kansas State University, Manhattan, Kansas 66506, USA.
J Am Chem Soc. 2006 Feb 8;128(5):1633-8. doi: 10.1021/ja055887j.
The synthetic peptide (C(18)H(37))(2)NCOCH(2)OCH(2)CON-(Gly)(3)-Pro-(Gly)(3)-OCH(2)Ph forms chloride-selective channels in liposomes and exhibits voltage-gating properties in planar phospholipid bilayers. The peptide fragment of the channel is based on a conserved motif in naturally occurring chloride transporters. Membrane-anchoring residues at the N- and C-terminal ends augment the peptide. NMR spectra (1D and 2D) of the channel in CDCl(3) showed significant variation in the absence and presence of stoichiometric tetrabutylammonium chloride (Bu(4)NCl). One-dimensional solution-state NMR titration studies combined with computational molecular simulation studies indicate that the peptide interacts with the salt as an ion pair and H-bonds chloride. To our knowledge, this is the first structural analysis of any synthetic anion-channel salt complex.
