Ion repulsion within membranes.
Ion repulsion within membranes.
复制标题
膜内的离子排斥。
DOI：
10.1016/s0006-3495(82)84489-5
复制
发表时间：
1982
影响因子：
3.4
通讯作者：
S. Hladky
中科院分区：
文献类型：
--
作者：
R. Tsien;S. Hladky
已知疏水性离子如四苯硼酸盐对薄脂质膜的吸附在约0.1离子/（nm）2下饱和。这种饱和可以定量地解释为离子之间的静电排斥，如果它们被视为离散的，移动的颗粒，吸附在脂质内至少部分地从水相中除去。离子的电化学电势作为其表面密度的函数可以表示为维里展开，其原则上准确地描述了物理模型的平衡性质。计算维里展开的前几项，并考虑高阶项的近似。该模型只有两个可调参数，吸附位点进入脂质的深度和在没有排斥的情况下的吸附常数。的移动的，离散电荷模型可以得到更好的拟合的平衡数据，四苯硼酸盐吸附在高达0.1离子/（nm）2的膜和单层。（Andersen等人，1978）比那些可从涂抹电荷或六边形晶格模型。
The adsorption of hydrophobic ions such as tetraphenylborate to thin lipid membranes is known to saturate at approximately 0.1 ion/(nm)2. This saturation can be quantitatively explained by electrostatic repulsion between the ions if they are treated as discrete, mobile particles that adsorb within the lipid at least partially removed from the aqueous phases. The electrochemical potential of the ions as a function of their surface density can be expressed as a virial expansion, which in principle exactly describes the equilibrium properties of the physical model. The first few terms of the virial expansion are calculated and an approximation is considered for higher-order terms. The model has only two adjustable parameters, the depth of the adsorption sites into the lipid and the adsorption constant in the absence of repulsion. The mobile, discrete charge model can give much better fits to the equilibrium data for tetraphenylborate adsorbed at up to 0.1 ion/(nm)2 to membranes and monolayers. (Andersen et al., 1978) than those obtainable from either the smeared charge or hexagonal lattice models.