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Directional Potassium Transport through a Unimolecular Peptide Channel
Author(s) -
Su Ge,
Zhang Min,
Si Wen,
Li ZhanTing,
Hou JunLi
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201608428
Subject(s) - gramicidin , lipid bilayer , chemistry , vesicle , bilayer , model lipid bilayer , potassium channel , conductance , peptide , biophysics , voltage gated potassium channel , alamethicin , transmembrane channels , lipid bilayer phase behavior , ion channel , membrane , potassium , voltage gated ion channel , biochemistry , organic chemistry , mathematics , combinatorics , biology , receptor
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 NH 3 + groups at the N‐end and one to three CO 2 − 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.