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arXiv 1301.6986cond-mat.softcond-mat.stat-mechphysics.bio-ph
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从弱静电排斥到高渗透压控制支撑双层膜中的相互作用

Controlling interactions in supported bilayers from weak electrostatic repulsion to high osmotic pressure

Arnaud Hemmerle, Linda Malaquin, Thierry Charitat, Sigolène Lecuyer, Giovanna Fragneto, Jean Daillant

摘要:

了解膜之间的相互作用需要在接近自然条件的良好控制系统上进行测量,其中波动起着重要作用。我们已经确定,通过掠入射X射线散射,两个脂质双层之间的相互作用潜力,一个吸附在固体表面和其他浮动接近。我们发现,在这个高度水合的模型系统中的相互作用是两个数量级软比以前报道的工作多层堆栈。这是由于弱的静电斥力,由于小部分的离子化的脂质在支持的双层具有较低数量的缺陷。我们的数据是一致的泊松-玻尔兹曼理论,在该制度的排斥占主导地位的反离子的熵。我们也有独特的访问非常弱的熵排斥势,这使我们能够区分在文献中提出的各种模型。我们进一步证明,支持的双层之间的相互作用潜力可以调整将通过施加渗透压,提供了一种方法来操纵这些模型膜,从而大大扩大了可以解决的生物或物理问题的范围。

英文摘要:

Understanding interactions between membranes requires measurements on well-controlled systems close to natural conditions, in which fluctuations play an important role. We have determined, by grazing incidence X-ray scattering, the interaction potential between two lipid bilayers, one adsorbed on a solid surface and the other floating close by. We find that interactions in this highly hydrated model system are two orders of magnitude softer than in previously reported work on multilayer stacks. This is attributed to the weak electrostatic repulsion due to the small fraction of ionized lipids in supported bilayers with a lower number of defects. Our data are consistent with the Poisson-Boltzmann theory, in the regime where repulsion is dominated by the entropy of counter ions. We also have unique access to very weak entropic repulsion potentials, which allowed us to discriminate between the various models proposed in the literature. We further demonstrate that the interaction potential between supported bilayers can be tuned at will by applying osmotic pressure, providing a way to manipulate these model membranes, thus considerably enlarging the range of biological or physical problems that can be addressed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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