Sun Zhanhu, Gilles Arnaud, Kocsis Istvan, Legrand Yves-Marie, Petit Eddy, Barboiu Mihail
Adaptive Supramolecular Nanosystems Group, Institut Européen des Membranes, University of Montpellier/ENSCM/CNRS 5635, Pl. Eugène Bataillon, CC 047, 34095, Montpellier, Cedex 5, France.
Chemistry. 2016 Feb;22(6):2158-2164. doi: 10.1002/chem.201503979. Epub 2016 Jan 7.
The natural KcsA K channel, one of the best-characterized biological pore structures, conducts K cations at high rates while excluding Na cations. The KcsA K channel is of primordial inspiration for the design of artificial channels. Important progress in improving conduction activity and K /Na selectivity has been achieved with artificial ion-channel systems. However, simple artificial systems exhibiting K /Na selectivity and mimicking the biofunctions of the KcsA K channel are unknown. Herein, an artificial ion channel formed by H-bonded stacks of squalyl crown ethers, in which K conduction is highly preferred to Na conduction, is reported. The K -channel behavior is interpreted as arising from discreet stacks of dimers resulting in the formation of oligomeric channels, in which transport of cations occurs through macrocycles mixed with dimeric carriers undergoing dynamic exchange within the bilayer membrane. The present highly K -selective macrocyclic channel can be regarded as a biomimetic alternative to the KcsA channel.
天然的KcsA钾通道是特征最明确的生物孔结构之一，它能高效传导钾阳离子，同时排斥钠离子。KcsA钾通道是人工通道设计的原始灵感来源。人工离子通道系统在提高传导活性和钾/钠选择性方面取得了重要进展。然而，具有钾/钠选择性并模拟KcsA钾通道生物功能的简单人工系统尚不清楚。在此，报道了一种由鲨烯基冠醚通过氢键堆叠形成的人工离子通道，其中钾传导比钠传导更受青睐。钾通道行为被解释为源于离散的二聚体堆叠，导致形成寡聚通道，阳离子在其中通过大环与在双层膜内进行动态交换的二聚体载体混合进行运输。目前这种高度钾选择性的大环通道可被视为KcsA通道的仿生替代物。
