BENDING RIGIDITIES OF LIPID BILAYERS: THEIR DETERMINATION AND MAIN INPUTS IN BIOPHYSICAL STUDIES
BENDING RIGIDITIES OF LIPID BILAYERS: THEIR DETERMINATION AND MAIN INPUTS IN BIOPHYSICAL STUDIES
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DOI：
10.1016/b978-0-12-396533-2.00006-9
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发表时间：
2012-01-01
期刊：
影响因子：
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通讯作者：
Bouvrais, Helene
中科院分区：
文献类型：
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作者：
Bouvrais, Helene
由于生物膜的复杂性，人工膜常被用作生物物理研究的膜模型。对于膜的物理性质及其弹性变形的研究尤其如此。本章着重于脂质双分子层的弯曲刚度，更准确地说是它们的测定和它们在生物物理研究中的投入。有多种技术可用于确定弯曲刚度：(i)实验技术，如闪烁技术，响应机械变形或散射技术的方法，以及（ii）分子动力学（MD）模拟。闪烁技术是测定弯曲刚度最常用的方法，它首先通过相差显微镜记录巨泡膜的热波动，然后测量这些波动的幅度，这些波动取决于脂质双分子层的组成及其环境。到目前为止，弯曲刚度测量能够获得一些关于温度效应的重要信息，各种分子（如甾醇、盐或带电荷分子）的影响，以及对链长和脂质饱和度的依赖。两亲螺旋的能力，即抗肽肽，局部弯曲膜也被表征为弯曲刚度的测定。
Because of the complexity of the biological membranes, artificial membranes are often used as membrane models for biophysical studies. This is especially true for the investigation of the physical properties of the membranes and their elastic deformations. This chapter focuses on the bending rigidities of lipid bilayers, more precisely on their determination and their inputs in biophysical studies. A large variety of techniques is available to determine the bending rigidity: (i) experimental ones such as the flickering technique, the methodologies that respond to a mechanical deformation or the scattering techniques, and also (ii) Molecular Dynamics (MD) simulations. The flickering technique, which is the mostly used method to determine the bending rigidity, consists of first recording the thermal fluctuations of the membrane of giant vesicles by phase contrast microscopy and then measuring the amplitudes of these fluctuations, which depend on both the composition of the lipid bilayer and its environment. Bending rigidity measurements enabled so far to get some important information regarding the temperature effect, the impact of various molecules such as sterols, salts or charged molecules, and the dependence on the chain length and saturation of the lipid. The ability for an amphipathic helix, namely, the magainin peptide, to locally bend the membrane has also been characterized by bending rigidity determination.