Reversible Ion Transportation Switch by a Ligand-Gated Synthetic Supramolecular Ion Channel

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• 作者：Takahiro Muraoka ; Takahiro Endo ; Kazuhito V. Tabata ; Hiroyuki Noji ; Satoru Nagatoishi ; Kouhei Tsumoto ; Rui Li ; Kazushi Kinbara
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：November 5, 2014
• 年：2014
• 卷：136
• 期：44
• 页码：15584-15595
• 全文大小：696K
• ISSN：1520-5126

文摘

Inspired by the regulation of cellular activities found in the ion channel proteins, here we developed membrane-embedded synthetic chiral receptors 1 and 2 with different terminal structures, where receptor 1 has hydrophobic triisopropylsilyl (TIPS) groups and receptor 2 has hydrophilic hydroxy groups. The receptors have ligand-binding units that interact with cationic amphiphiles such as 2-phenethylamine (PA). Conductance study revealed that the receptors hardly show ion transportation at the ligand-free state. After ligand binding involving a conformational change, receptor 1 bearing TIPS termini displays a significant current enhancement due to ion transportation. The current substantially diminishes upon addition of 尾-cyclodextrin (尾CD) that scavenges the ligand from the receptor. Importantly, the receptor again turns into the conductive state by the second addition of PA, and the activation/deactivation of the ion transportation can be repeated. In contrast, receptor 2 bearing the hydroxy terminal groups hardly exhibits ion transportation, suggesting the importance of terminal TIPS groups of 1 that likely anchor the receptor in the membrane.