Krasilnikov O V, Sabirov R Z, Ternovsky V I, Merzliak P G, Muratkhodjaev J N
Institute of Physiology, Uzbek Academy of Sciences, Tashkent, Uzbekistan.
FEMS Microbiol Immunol. 1992 Sep;5(1-3):93-100. doi: 10.1111/j.1574-6968.1992.tb05891.x.
A new method of pore size determination is presented. The results of applying this simple method to ion channels formed by staphylococcal alpha-toxin and its N-terminal fragment as well as to cholera toxin channels are shown. The advantages and the difficulties of this method are discussed. It was found that (i) the mobility of ions in solutions depends only on the percentage of concentration of added non-electrolytes and practically not on their chemical nature (sugars or polyglycols) and molecular size; (ii) the proportional change of both ion channel conductance and bulk solution conductivity by low M. nonelectrolytes may be used as an indication of a diffusion mechanism of ion transport through channels; (iii) the slope of the dependence of the ion channel conductance on the bulk conductivity of solutions containing different concentrations of non-electrolyte is a good measure of channel permeability for non-electrolytes.
本文提出了一种测定孔径大小的新方法。展示了将这种简单方法应用于由葡萄球菌α-毒素及其N端片段形成的离子通道以及霍乱毒素通道的结果。讨论了该方法的优点和难点。研究发现：（i）溶液中离子的迁移率仅取决于添加的非电解质的浓度百分比，而实际上与它们的化学性质（糖或聚乙二醇）和分子大小无关；（ii）低分子量非电解质使离子通道电导和本体溶液电导率成比例变化，可作为离子通过通道的扩散机制的一个指标；（iii）离子通道电导对含有不同浓度非电解质的溶液本体电导率的依赖关系的斜率，是衡量通道对非电解质渗透性的一个良好指标。
