Atomic-scale structure of interfacial water on gel and liquid phase lipid membranes.
Atomic-scale structure of interfacial water on gel and liquid phase lipid membranes.
复制标题
凝胶和液相脂膜上界面水的原子尺度结构。
DOI：
10.1039/d3fd00094j
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发表时间：
2024
影响因子：
3.4
通讯作者：
Benaglia S
中科院分区：
文献类型：
--
作者：
Benaglia S
生物膜的水合作用是广泛的生物过程所必需的。特别是，它与脂质热力学性质有着内在的联系，而脂质热力学性质反过来又影响关键的细胞功能，如离子渗透和蛋白质迁移。生物膜表面的实验和理论研究揭示了界面排斥力的存在，这与水合作用或位阻效应有关。在这里，我们通过三维原子力显微镜（3D AFM）直接表征了凝胶和液相中1,2-二肉豆醇- n-甘油-3-磷酸胆碱支撑脂膜附近的水的原子尺度结构。首先，我们展示了使用超尖锐尖端以亚分子分辨率探测两相中脂质双层界面水形态的能力。然后，我们将不同温度下脂质表面水的分子排列可视化。我们的实验表明，水在固体有序和液体无序的脂质相上被组织成多个水合层。此外，我们观察到一个单调的排斥力，这只在液相中是相关的。这些结果为研究软性生物表面附近的水结构提供了新的见解，并证明了用垂直和横向亚分子分辨率研究它的重要性。
Hydration of biological membranes is essential to a wide range of biological processes. In particular, it is intrinsically linked to lipid thermodynamic properties, which in turn influence key cell functions such as ion permeation and protein mobility. Experimental and theoretical studies of the surface of biomembranes have revealed the presence of an interfacial repulsive force, which has been linked to hydration or steric effects. Here, we directly characterise the atomic-scale structure of water near supported lipid membranes of 1,2-dimyristoyl-sn-glycero-3-phosphocholine in their gel and liquid phase through three-dimensional atomic force microscopy (3D AFM). First, we demonstrate the ability to probe the morphology of interfacial water of lipid bilayers in both phases with sub-molecular resolution by using ultrasharp tips. We then visualise the molecular arrangement of water at the lipid surface at different temperatures. Our experiments reveal that water is organised in multiple hydration layers on both the solid-ordered and liquid-disordered lipid phases. Furthermore, we observe a monotonic repulsive force, which becomes relevant only in the liquid phase. These results offer new insights into the water structuring near soft biological surfaces, and demonstrate the importance of investigating it with vertical and lateral sub-molecular resolution.