Mechanical Properties Determination of DMPC, DPPC, DSPC, and HSPC Solid-Ordered Bilayers
Mechanical Properties Determination of DMPC, DPPC, DSPC, and HSPC Solid-Ordered Bilayers
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DOI：
10.1021/acs.langmuir.0c00475
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发表时间：
2020-04-14
期刊：
影响因子：
3.9
通讯作者：
Langner, Marek
中科院分区：
文献类型：
--
作者：
Drabik, Dominik;Chodaczek, Grzegorz;Langner, Marek
脂质双层是许多重要生物过程的积极参与者。它们可以分别在不同的相态（液相和固相）中观察到。液相在生物系统中占主导地位。固相，结晶相和凝胶相，由于其对机械应力的弹性和脂质的紧密堆积而正在研究中。脂质的机械性质影响其动力学，从而影响细胞浆和内膜的转化。脂质双层的机械性质也是设计和生产超分子脂质药物递送系统的重要参数。为此，在这项工作中，我们专注于研究其结构参数和机械性能的脂质双层的固相的影响，使用理论分子动力学研究的原子模型的整个囊泡。这些参数包括单位脂质面积、膜厚度、密度囊泡轮廓、弯曲刚度系数和面积压缩性。此外，使用闪烁噪声光谱测量弯曲刚度系数。这两种方法产生了非常相似和一致的结果。我们发现，与我们的预期相反，固体有序的双层囊泡的弯曲刚度系数随着脂质转变温度的增加而降低。这种趋势在平面系统中是相反的。此外，我们还观察到膜厚度和面积可压缩性增加，单位脂质面积减少。我们希望这些结果将提供有价值的力学洞察力的行为在固相和球形和平面确认之间的差异。
Lipid bilayers are active participants in many crucial biological processes. They can be observed in different phases, liquid and solid, respectively. The liquid phase is predominant in biological systems. The solid phase, both crystalline and gel phases, is under investigation due to its resilience to mechanical stress and tight packing of lipids. The mechanical properties of lipids affect their dynamics, therefore influencing the transformation of cell plasma and the endomembrane. Mechanical properties of lipid bilayers are also an important parameter in the design and production of supramolecular lipid-based drug delivery systems. To this end, in this work, we focused on investigating the effect of solid phases of lipid bilayers on their structural parameters and mechanical properties using theoretical molecular dynamics studies on atomistic models of whole vesicles. Those include area per lipid, membrane thickness, density vesicle profiles, bending rigidity coefficient, and area compressibility. Additionally, the bending rigidity coefficient was measured using the flicker noise spectroscopy. The two approaches produced very similar and consistent results. We showed that, contrary to our expectations, bending rigidity coefficients of solid-ordered bilayers for vesicles decreased with an increase in lipid transition temperature. This tendency was reverse in planar systems. Additionally, we have observed an increase of membrane thickness and area compressibility and a decrease of area per lipid. We hope these results will provide valuable mechanical insight for the behavior in solid phases and differences between spherical and planar confirmations.