Interleaflet coupling and domain registry in phase-separated lipid bilayers.
Interleaflet coupling and domain registry in phase-separated lipid bilayers.
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相分离脂质双层中的叶间耦合和结构域注册。
DOI：
10.1016/j.bpj.2011.01.021
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发表时间：
2011
影响因子：
3.4
通讯作者：
Schick,M
中科院分区：
文献类型：
--
作者：
Putzel,GGarbes;Uline,MarkJ;Szleifer,Igal;Schick,M
有明确的证据表明，在模型脂质/胆固醇膜表现出液-液相分离的小叶间耦合。这种耦合的强度由失配自由能γ量化。我们计算它使用的分子平均场模型的相分离的脂质/胆固醇双层，并获得的值，增加的饱和脂质的浓度在共存相的增加。这些值在0.01-0.03kBT/nm 2的范围内。通过分析耦合波动域界面的统计力学模型，我们澄清了叶间耦合和液体域的叶间对齐程度之间的关系。该模型是完全解决使用统计力学和量子力学之间的对应关系，产生的波动域注册表的特征尺寸的表达式。这种长度尺度仅微弱地依赖于叶间耦合的强度，并且不可避免地仅为纳米量级，这解释了光学显微镜没有观察到域注册的波动的实验结果。
There is clear evidence of an interleaflet coupling in model lipid/cholesterol membranes exhibiting liquid-liquid phase separation. The strength of this coupling is quantified by the mismatch free energy,γ. We calculate it using a molecular mean-field model of a phase-separated lipid/cholesterol bilayer and obtain values that increase as the concentration of saturated lipids in the coexisting phases is increased. These values lie in the range 0.01–0.03kBT/nm2. We clarify the relationship between the interleaflet coupling and the extent of interleaflet alignment of liquid domains by analyzing a statistical mechanical model of coupled fluctuating domain interfaces. The model is solved exactly using the correspondence between statistical mechanics and quantum mechanics, yielding an expression for the characteristic size of fluctuations out of domain registry. This length scale depends only weakly on the strength of the interleaflet coupling and inevitably is only of the order of nanometers, which explains the experimental result that fluctuations out of domain registry have not been observed by optical microscopy.