Bending rigidity of charged lipid bilayer membranes
Bending rigidity of charged lipid bilayer membranes
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DOI：
10.1039/c9sm00772e
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发表时间：
2019-08-07
期刊：
影响因子：
3.4
通讯作者：
Vlahovska, Petia M.
中科院分区：
文献类型：
--
作者：
Faizi, Hammad A.;Frey, Shelli L.;Vlahovska, Petia M.
我们实验研究了脂电荷对双层膜刚度的影响。膜的抗弯刚度与组合物0 - 100摩尔%的带电脂质，在不存在和存在的盐在不同浓度下，测量与闪烁光谱法，使用巨大的单层囊泡的形状波动。分析同时考虑了形状模态的均方振幅和时间自相关。我们的研究结果表明，膜电荷增加的弯曲刚度相对于不带电的膜。通过向悬浮溶液中加入一价盐来减弱该效果。膜弯曲刚度所示的趋势与zeta电位测量相关，证实了在不同盐浓度下的电荷屏蔽。在盐的存在下的实验结果与现有的膜硬化的表面电荷的理论是一致的。
We experimentally investigate the effect of lipid charge on the stiffness of bilayer membranes. The bending rigidity of membranes with composition 0-100 mol% of charged lipids, in the absence and presence of salt at different concentrations, is measured with the flicker spectroscopy method, using the shape fluctuations of giant unilamellar vesicles. The analysis considers both the mean squared amplitudes and the time autocorrelations of the shape modes. Our results show that membrane charge increases the bending rigidity relative to the charge-free membrane. The effect is diminished by the addition of monovalent salt to the suspending solutions. The trend shown by the membrane bending rigidity correlates with zeta potential measurements, confirming charge screening at different salt concentrations. The experimental results in the presence of salt are in good agreement with existing theories of membrane stiffening by surface charge.