Michigan State University, Department of Chemistry, 578 S. Shaw Lane, East Lansing, MI, 48824, USA.
Michigan State University, Department of Chemistry, 578 S. Shaw Lane, East Lansing, MI, 48824, USA.
Chem Phys Lipids. 2021 Aug;238:105090. doi: 10.1016/j.chemphyslip.2021.105090. Epub 2021 May 7.
The fluidity and compositional heterogeneity of the mammalian plasma membrane play deterministic roles in a variety of membrane functions. Designing model bilayer systems allows for compositional control over these properties. Ceramide is a phospholipid capable of extensive headgroup-region hydrogen bonding, and we report here on the role of ceramide in planar model bilayers. We use fluorescence recovery after photobleaching (FRAP) to obtain translational diffusion constants of two chromophores in supported model bilayers composed of cholesterol, 1,2-dioleoyl-sn-phosphatidylcholine (DOPC), sphingomyelin, and ceramide. FRAP data for perylene report on the acyl chain region of the model bilayer and FRAP data for 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N-(lissamine rhodamine B sulfonyl) sense diffusional dynamics in the bilayer headgroup region. Dynamics in the headgroup region exhibit anomalous diffusion behavior that is characteristic of spatially heterogeneous media.
哺乳动物质膜的流动性和组成异质性在各种膜功能中起着决定性的作用。设计模型双层系统可以控制这些性质的组成。神经酰胺是一种能够进行广泛头部区域氢键形成的磷脂，我们在此报告神经酰胺在平面模型双层中的作用。我们使用光漂白后荧光恢复（FRAP）来获得由胆固醇、1,2-二油酰基-sn-磷脂酰胆碱（DOPC）、鞘磷脂和神经酰胺组成的支撑模型双层中两种发色团的平移扩散常数。对于苝的 FRAP 数据报告了模型双层的酰链区域，而对于 1,2-二油酰基-sn-甘油-3-磷酸乙醇胺-N-（lissamine rhodamine B 磺酰）的 FRAP 数据则感知双层头部区域的扩散动力学。头部区域的动力学表现出异常扩散行为，这是空间不均匀介质的特征。
