University of Potsdam, Institute of Biochemistry and Biology, Karl-Liebknecht-Street 24-25, 14476 Potsdam, Germany.
Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo nám. 2, 16000 Prague, Czech Republic.
Biochim Biophys Acta Biomembr. 2025 Jan;1867(1):184388. doi: 10.1016/j.bbamem.2024.184388. Epub 2024 Oct 12.
Cellular membranes are composed of lipids typically organized in a double-leaflet structure. Interactions between these two leaflets - often referred to as interleaflet coupling - play a crucial role in various cellular processes. Despite extensive study, the mechanisms governing such interactions remain incompletely understood. Here, we investigate the effects of interleaflet coupling from a specific point of view, i.e. by comparing diffusive dynamics in bilayers and monolayers, focusing on potential lipid-specific interactions between opposing leaflets. Through quantitative fluorescence microscopy techniques, we characterize lipid diffusion and mean molecular area in monolayers and bilayers composed of different lipids. Our results suggest that the observed decrease in bilayer lipid diffusion compared to monolayers depends on lipid identity. Furthermore, our analysis suggests that lipid acyl chain structure and spatial configuration at the bilayer may strongly influence interleaflet interactions and dynamics in bilayers. These findings provide insights into the role of lipid structure in mediating interleaflet coupling and underscore the need for further experimental investigations to elucidate the underlying mechanisms.
细胞膜由脂质组成，通常组织成双分子层结构。这两个叶层之间的相互作用——通常称为叶层间耦合——在各种细胞过程中起着至关重要的作用。尽管进行了广泛的研究，但控制这种相互作用的机制仍不完全清楚。在这里，我们从一个特定的角度研究叶层间耦合的影响，即通过比较双层膜和单层膜中的扩散动力学，关注 opposing leaflets 之间潜在的脂质特异性相互作用。通过定量荧光显微镜技术，我们在由不同脂质组成的单层膜和双层膜中表征脂质扩散和平均分子面积。我们的结果表明，与单层膜相比，双层膜中脂质扩散的观察到的降低取决于脂质的身份。此外，我们的分析表明，双层膜中脂质酰基链结构和空间构型可能强烈影响叶层间相互作用和双层膜中的动力学。这些发现为脂质结构在介导叶层间耦合中的作用提供了新的认识，并强调需要进一步的实验研究来阐明潜在的机制。
