Sabirov R Z, Krasilnikov O V, Ternovsky V I, Merzliak P G
Institute of Physiology and Biophysics, Academy of Sciences, Tashkent, Uzbekistan.
Gen Physiol Biophys. 1993 Apr;12(2):95-111.
The effects of nonelectrolytes on conductivity and viscosity of KCl solutions as well as on ion channel conductance were studied. Mobility of ions in solutions were found to solely depend on percent concentration (w/w) of the nonelectrolytes added and to be effectively independent on their chemical nature (sugars or polyglycols) and molecular size. Proportional changes in both the ion channel conductance and the conductivity of bulk solution induced by low m. w. nonelectrolytes may be used as a criterion of diffusion mechanism of ion transport through channels. The slope of the dependence of ion channel conductance on conductivity of bulk solution containing different concentrations of nonelectrolytes is a good measure of channel permeability for nonelectrolyte. A new method of pore size determination is introduced. Results of practical application of this simple method to three types of ion channels (formed by alpha-latrotoxin, staphylococcal alpha-toxin and its N-terminal fragment) are shown. The advantages and disadvantages of the method are discussed.
研究了非电解质对氯化钾溶液电导率和粘度以及离子通道电导的影响。发现溶液中离子的迁移率仅取决于所添加非电解质的质量百分比浓度（w/w），且实际上与它们的化学性质（糖或聚乙二醇）和分子大小无关。低分子量非电解质引起的离子通道电导和本体溶液电导率的比例变化可作为离子通过通道传输扩散机制的一个标准。离子通道电导对含有不同浓度非电解质的本体溶液电导率的依赖关系的斜率是通道对非电解质渗透性的一个很好的度量。介绍了一种新的孔径测定方法。展示了这种简单方法在三种类型离子通道（由α-拉毒素、葡萄球菌α-毒素及其N端片段形成）上实际应用的结果。讨论了该方法的优缺点。
