Warias Jonas E, Reise Franziska, Hövelmann Svenja C, Giri Rajendra P, Röhrl Michael, Kuhn Jule, Jacobsen Malte, Chatterjee Kuntal, Arnold Thomas, Shen Chen, Festersen Sven, Sartori Andrea, Jordt Philipp, Magnussen Olaf M, Lindhorst Thisbe K, Murphy Bridget M
Institute of Experimental and Applied Physics, Kiel University, Leibnizstr. 19, 24118, Kiel, Germany.
Otto Diels Institute of Organic Chemistry, Kiel University, Otto-Hahn-Platz 3-4, 24118, Kiel, Germany.
Sci Rep. 2023 Jul 16;13(1):11480. doi: 10.1038/s41598-023-38336-x.
Following the reaction of biological membranes to external stimuli reveals fundamental insights into cellular function. Here, self-assembled lipid monolayers act as model membranes containing photoswitchable azobenzene glycolipids for investigating structural response during isomerization by combining Langmuir isotherms with X-ray scattering. Controlled in-situ trans/cis photoswitching of the azobenzene N = N double bond alters the DPPC monolayer structure, causing reproducible changes in surface pressure and layer thickness, indicating monolayer reorientation. Interestingly, for monolayers containing azobenzene glycolipids, along with the expected DPPC phase transitions an additional discontinuity is observed. The associated reorintation represents a crossover point, with the surface pressure and layer thickness changing in opposite directions above and below. This is evidence that the azobenzene glycolipids themselves change orientation within the monolayer. Such behaviour suggests that azobenzene glycolipids can act as a bidirectional switch in DPPC monolayers providing a tool to investigate membrane structure-function relationships in depth.
追踪生物膜对外部刺激的反应揭示了细胞功能的基本见解。在这里，自组装脂质单分子层充当含有可光开关偶氮苯糖脂的模型膜，通过将朗缪尔等温线与X射线散射相结合来研究异构化过程中的结构响应。偶氮苯N=N双键的可控原位反式/顺式光开关改变了DPPC单分子层结构，导致表面压力和层厚度发生可重复的变化，表明单分子层重新取向。有趣的是，对于含有偶氮苯糖脂的单分子层，除了预期的DPPC相变外，还观察到一个额外的不连续性。相关的重新取向代表一个交叉点，表面压力和层厚度在其上下方向相反地变化。这证明偶氮苯糖脂本身在单分子层内改变了取向。这种行为表明，偶氮苯糖脂可以在DPPC单分子层中充当双向开关，为深入研究膜结构-功能关系提供了一种工具。
