Solution and interfacial self-assembly of Bacillus subtilis bacterial lipoteichoic acid (LTA): nanoclustering, and effects of Ca2+ and temperature.
Solution and interfacial self-assembly of Bacillus subtilis bacterial lipoteichoic acid (LTA): nanoclustering, and effects of Ca2+ and temperature.
复制标题
枯草芽孢杆菌细菌脂磷壁酸 (LTA) 的溶液和界面自组装：纳米簇以及 Ca2 和温度的影响。
DOI：
10.1039/d2nr00595f
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发表时间：
2022
期刊：
影响因子：
6.7
通讯作者：
Bharatiya B
中科院分区：
文献类型：
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作者：
Bharatiya B
脂磷壁酸（LTA）是革兰氏阳性菌膜上的主要结构和功能分子。了解LTA在界面上的吸附及其溶液自组装对于了解其在细菌粘附和定植、感染和炎症中的作用至关重要。在这里，我们报告的自组装行为的LTA提取枯草芽孢杆菌，革兰氏阳性菌，在水溶液中使用低温透射电子显微镜（Cryo-TEM）和小角中子散射（SANS）和它的吸附行为在固液界面使用原子力显微镜（AFM）成像和石英晶体微天平与耗散监测（QCM-D）。的Cryo-TEM结果表明，形成的球形LTA胶束，减少在添加氯化钙（CaCl 2）的大小，归因于电荷中和和可能形成的稳定的Ca 2+桥之间的磷酸基团相邻的LTA链。SANS数据的分析从多分散的LTA聚集体在溶液中使用两个洛伦兹模型揭示了存在两个相关长度，这可以分别解释LTA胶束簇的存在和LTA分子内相互作用所产生的局部结构。在CaCl 2的存在下，簇的相关长度的减少表明可能的破坏的H-键的Ca 2+，导致较差的水-LTA相互作用。在较高的温度下，对应于簇的相关长度增加，表明温度辅助的增长所造成的胶束核心的流化和极性LTA链的脱水。AFM成像表明，吸附的LTA聚集体在SiO2-水界面显着促进通过添加氯化钙，也证实了QCM-D测量。这些前所未有的纳米级结构细节的LTA聚集体在溶液中的形态，并在固液界面添加到我们的基本理解，其自组装行为迄今未充分探索。
Lipoteichoic acid (LTA) is a major structural and functional molecule in the Gram-positive bacteria membrane. Knowledge of LTA adsorption at interfaces and its solution self-assembly is crucial to understanding its role in bacterial adhesion and colonisation, infections and inflammations. Here, we report the self-assembly behaviour of LTA extracted from Bacillus subtilis, a Gram-positive bacterium, in an aqueous solution using cryogenic transmission electron microscopy (Cryo-TEM) and small-angle neutron scattering (SANS) and its adsorption behaviour at the solid–liquid interface using atomic force microscopy (AFM) imaging and quartz crystal microbalance with dissipation monitoring (QCM-D). The Cryo-TEM results indicated the formation of spherical LTA micelles that decreased in size on addition of calcium chloride (CaCl2), attributed to charge neutralisation and possible formation of stable Ca2+-bridges between the phosphate groups on neighbouring LTA chains. Analysis of the SANS data from the polydisperse LTA aggregates in solution using the two Lorentzian model revealed the existence of two correlation lengths, which could respectively account for the presence of LTA micelle clusters and the local structure arising from LTA intra-molecular interactions. In the presence of CaCl2, the decrease in the correlation lengths of the clusters indicated possible disruption of H-bonding by Ca2+, leading to poorer water-LTA interactions. At higher temperatures, the correlation length corresponding to the clusters increased, indicating a temperature assisted growth caused by the fluidization of micellar core and dehydration of the polar LTA chains. AFM imaging showed that adsorption of LTA aggregates at the SiO2–water interface was significantly prompted by the addition of CaCl2, also confirmed by QCM-D measurements. These unprecedented nanoscopic structural details on the morphology of LTA aggregates in solution and at the solid–liquid interface add to our fundamental understanding of its self-assembly behaviour hitherto underexplored.