期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2003
卷号：100
期号：26
页码：15498-15503
DOI：10.1073/pnas.2531778100
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：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 ({beta}CD)] to sites within the staphylococcal -hemolysin pore was investigated. Mutant -hemolysin pores were used to which {beta}CD 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 Kd values for {beta}CD 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 {beta}CD were consistent with an electroosmotic effect.
