A Synthetic Transmembrane Channel Active in Lipid Bilayers

摘要

In the last decade numerous studies have focused on the synthesis of artificial devices designed to mimic natural ion channel protein. Only few of them clearly showed single-channel activity. Recently, we reported that the 21 amino acid peptide 1 bearing six [21]crown-7 moieties displayed ion transport ability similar to that of gramicidin A in a vesicle experiment. The crown rings are proposed to align to form a transmembrane channel Furthermore, because the peptide contains 15 L-leucine residues itis both sufficiently hydrophobic to be incorporated in lipid bilayers and favofs a-helical conformation. In this form the crown ether rings in 1 are almost perfectly aligned (Figure 1). Herein we present the results of studies on the conformation of 1 and its incorporation in planar lipid bilayers, confirming that the hexacrown peptide 1 possesses the features of a functional ion channel.