title: Directional Potassium Transport through a Unimolecular Peptide Channel.
abstract: Three unimolecular peptide channels have been designed and prepared by using the β-helical conformation of gramicidin A (gA). The new peptides bear one to three NH3+groups at the N-end and one to three CO2-groups at the C-end. These zwitterionic peptides were inserted into lipid bilayers in an orientation-selective manner. Conductance experiments on planar lipid bilayers showed that this orientation bias could lead to observable directional K+transport under multi-channel conditions. This directional transport behavior can further cause the generation of a current across a planar bilayer without applying a voltage. More importantly, in vesicles with identical external and internal KCl concentrations, the channels can pump K+across the lipid bilayer and cause a membrane potential.
authors.affiliation: Department of Chemistry, Fudan University, 220 Handan Road, Shanghai, 200433, China.
authors.forename: Ge
authors.initials: G
authors.lastname: Su
authors.affiliation: Department of Chemistry, Fudan University, 220 Handan Road, Shanghai, 200433, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Fudan University, 220 Handan Road, Shanghai, 200433, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Si
authors.affiliation: Department of Chemistry, Fudan University, 220 Handan Road, Shanghai, 200433, China.
authors.forename: Zhan-Ting
authors.initials: ZT
authors.lastname: Li
authors.affiliation: Department of Chemistry, Fudan University, 220 Handan Road, Shanghai, 200433, China.
authors.forename: Jun-Li
authors.initials: JL
authors.lastname: Hou
mesh_terms: D006096:Gramicidin / Q000737:chemistry / Q000378:metabolism*; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D011188:Potassium / Q000737:chemistry / Q000378:metabolism*
chemical_list: D008051:Lipid Bilayers; D006096:Gramicidin; D011188:Potassium
keywords: conductance measurements; directional transport; ion channels; potassium; rectifying behavior