Adaptive Supramolecular Nanosystems Group, Institut Européen des Membranes, ENSCM-UM-CNRS UMR-5635, Place E. Bataillon, CC 047, F-34095, Montpellier Cedex 5 (France).
Petru Poni Institute of Macromolecular Chemistry of Romanian Academy, 41A Aleea Gr. Ghica Voda, Iasi (Romania).
Angew Chem Int Ed Engl. 2015 Nov 23;54(48):14473-7. doi: 10.1002/anie.201506430. Epub 2015 Oct 6.
The bacterial KcsA channel conducts K(+) cations at high rates while excluding Na(+) cations. Herein, we report an artificial ion-channel formed by H-bonded stacks of crown-ethers, where K(+) cation conduction is highly preferred to Na(+) cations. The macrocycles aligned along the central pore surround the K(+) cations in a similar manner to the water around the hydrated cation, compensating for the energetic cost of their dehydration. In contrast, the Na(+) cation does not fit the macrocyclic binding sites, so its dehydration is not completely compensated. The present highly K(+)-selective macrocyclic channel may be regarded as a biomimetic of the KcsA channel.
细菌 KcsA 通道以高速传导 K(+)阳离子，同时排斥 Na(+)阳离子。在此，我们报告了一种由氢键堆积的冠醚形成的人工离子通道，其中 K(+)阳离子的传导比 Na(+)阳离子具有更高的偏好性。这些沿着中央孔排列的大环以类似于水合阳离子周围的水的方式围绕 K(+)阳离子，补偿了它们去水合的能量成本。相比之下，Na(+)阳离子不符合大环的结合位点，因此其去水合作用不能完全得到补偿。目前这种具有高度选择性的大环通道可以被视为 KcsA 通道的仿生模型。
