Electroosmotic enhancement of the binding of a neutral molecule to a transmembrane pore
Electroosmotic enhancement of the binding of a neutral molecule to a transmembrane pore
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DOI：
10.1073/pnas.2531778100
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发表时间：
2003-12-23
影响因子：
11.1
通讯作者：
Bayley, H
中科院分区：
文献类型：
--
作者：
Gu, LQ;Cheley, S;Bayley, H
溶剂水的通量与离子通过蛋白质孔隙的迁移耦合是相当大的。研究了这种电渗透溶剂流动对中性分子[β -环糊精（β - acd）]与葡萄球菌α溶血素孔内位点结合的影响。利用突变的a-溶血素孔，β - acd可以从两个入口结合，通过选择孔的电荷选择性和外加电位的极性来控制水流方向。在-120 ~ +120 mV范围内，单个突变体孔隙中β - acd的K-d值变化了100倍。在所有情况下，结合自由能的变化和电位对β - acd缔合和解离速率常数的影响的迹象都与电渗透效应一致。
The flux of solvent water coupled to the transit of ions through protein pores is considerable. The effect of this electroosmotic solvent flow on the binding of a neutral molecule [beta-cyclodextrin (betaCD)] to sites within the staphylococcal alpha-hemolysin pore was investigated. Mutant a-hemolysin pores were used to which betaCD can bind from either entrance and through which the direction of water flow can be controlled by choosing the charge selectivity of the pore and the polarity of the applied potential. The K-d values for betaCD for individual mutant pores varied by >100-fold with the applied potential over a range of -120 to +120 mV. In all cases, the signs of the changes in binding free energy and the influence of potential on the association and dissociation rate constants for betaCD were consistent with an electroosmotic effect.