Kumpf R A, Dougherty D A
Arnold and Mabel Beckman Laboratories of Chemical Synthesis, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena 91125.
Science. 1993 Sep 24;261(5129):1708-10. doi: 10.1126/science.8378771.
A combination of computational methods has been used to evaluate the interaction between the pi face of a benzene molecule and the monovalent cations of lithium, sodium, potassium, and rubidium. In the gas phase, the ions are strongly bound, and the affinity for benzene follows the expected electrostatic trend (lithium, largest; rubidium, smallest). However, in an aqueous environment, a reordering occurs such that the potassium ion is preferred over all the other ions for 2:1 benzene:ion complexes. The selectivity sequence parallels that seen in voltage-gated potassium channels. Given that several conserved aromatic residues are present in the pore region of such channels, these results suggest that the cation-pi interaction may be responsible for the ion selectivity in potassium channels.
已使用多种计算方法来评估苯分子的π面与锂、钠、钾和铷的单价阳离子之间的相互作用。在气相中，离子被强烈束缚，对苯的亲和力遵循预期的静电趋势（锂最大；铷最小）。然而，在水性环境中会发生重新排序，使得在2:1的苯:离子络合物中，钾离子比所有其他离子更受青睐。选择性序列与电压门控钾通道中的序列相似。鉴于此类通道的孔区域中存在几个保守的芳香族残基，这些结果表明阳离子-π相互作用可能是钾通道中离子选择性的原因。
