Phospholipid diffusion coefficients of cushioned model membranes determined via z-scan fluorescence correlation spectroscopy.
Phospholipid diffusion coefficients of cushioned model membranes determined via z-scan fluorescence correlation spectroscopy.
复制标题
通过 z 扫描荧光相关光谱测定缓冲模型膜的磷脂扩散系数。
DOI：
10.1021/la400768s
复制
发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Neivandt,DavidJ
中科院分区：
文献类型：
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作者：
Sterling,SarahM;Allgeyer,EdwardS;Fick,Jörg;Prudovsky,Igor;Mason,MichaelD;Neivandt,DavidJ
模型细胞膜能够在受控环境中研究生物过程，并减少与活细胞或固定细胞研究相关的传统挑战。然而，基于空气/水或油/溶液界面的模型膜系统不允许跨膜蛋白的掺入或蛋白质转运机制的研究。相反，通过Langmuir-Blodgett/Langmuir-Schaefer方法沉积在水凝胶层上的磷脂双层可能是生物膜横截面的有效模拟物，并有助于蛋白质掺入和转运研究。然而，在应用之前，必须充分表征这种膜，特别是关于磷脂双层相变温度。在这里，我们提出了一个详细的表征壳聚糖支持的模型膜系统的内部和外部小叶的相变温度。具体而言，每个单独的小叶的横向扩散系数已被确定为温度的函数。利用z扫描荧光相关光谱（FCS）进行测量，这是一种产生无校准扩散信息的技术。通过Wawrezinieck及其同事的方法进行的分析表明，随着温度的升高，磷脂扩散从筏状扩散变为自由扩散，这是对先前未报道的水凝胶支撑膜的动态行为的深入了解。
Model cellular membranes enable the study of biological processes in a controlled environment and reduce the traditional challenges associated with live or fixed cell studies. However, model membrane systems based on the air/water or oil/solution interface do not allow for incorporation of transmembrane proteins or for the study of protein transport mechanisms. Conversely, a phospholipid bilayer deposited via the Langmuir–Blodgett/Langmuir–Schaefer method on a hydrogel layer is potentially an effective mimic of the cross section of a biological membrane and facilitates both protein incorporation and transport studies. Prior to application, however, such membranes must be fully characterized, particularly with respect to the phospholipid bilayer phase transition temperature. Here we present a detailed characterization of the phase transition temperature of the inner and outer leaflets of a chitosan supported model membrane system. Specifically, the lateral diffusion coefficient of each individual leaflet has been determined as a function of temperature. Measurements were performed utilizing z-scan fluorescence correlation spectroscopy (FCS), a technique that yields calibration-free diffusion information. Analysis via the method of Wawrezinieck and co-workers revealed that phospholipid diffusion changes from raftlike to free diffusion as the temperature is increasedan insight into the dynamic behavior of hydrogel supported membranes not previously reported.