Determination of the molecularity of the colicin E1 channel by stopped-flow ion flux kinetics.
Determination of the molecularity of the colicin E1 channel by stopped-flow ion flux kinetics.
复制标题
通过停流离子流动力学测定大肠菌素 E1 通道的分子数。
DOI：
10.1073/pnas.83.12.4273
复制
发表时间：
1986
影响因子：
11.1
通讯作者：
Kayalar,C
中科院分区：
文献类型：
--
作者：
Bruggemann,EP;Kayalar,C
一种荧光技术，测量快速离子通量通过脂质体膜被用来确定大肠杆菌素E1通道的分子。Tl+（用作K+类似物）进入大单层囊泡的通量率是通过其猝灭囊泡中膜不渗透荧光团的荧光的能力来测量的。Tl+通量率与囊泡悬浮液中离子载体浓度的关系揭示了离子载体的分子性。该方法用两个离子载体，valinomycin和gramicidin，其分子分别为1和2来证明。确定大肠杆菌素E1通道的分子数为1。该方法可用于研究任何介导K+通量的离子载体的性质。
A fluorescence technique that measures fast ion fluxes across liposome membranes was used to determine the molecularity of the colicin E1 channel. The rate of flux of Tl+ (used as a K+ analogue) into large unilamellar vesicles was measured by its ability to quench the fluorescence of a membrane-impermeable fluorophore entrapped in the vesicles. The dependence of Tl+ flux rate on the concentration of ionophore in the vesicle suspension reveals the molecularity of the ionophore. The method is demonstrated with two ionophores, valinomycin and gramicidin, whose molecularities are known to be one and two, respectively. The molecularity of the colicin E1 channel was determined to be one. This method can be used to study the properties of any ionophore that mediates K+ flux.