Temperature dependence of diffusion in model and live cell membranes characterized by imaging fluorescence correlation spectroscopy
Temperature dependence of diffusion in model and live cell membranes characterized by imaging fluorescence correlation spectroscopy
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DOI：
10.1016/j.bbamem.2013.10.009
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发表时间：
2014-03-01
影响因子：
3.4
通讯作者：
Wohland, Thorsten
中科院分区：
文献类型：
--
作者：
Bag, Nirmalya;Yap, Darilyn Hui Xin;Wohland, Thorsten
质膜的组织由液体有序（L-o）和液体无序（L-d）相之间的动态平衡调节。L-o相的丰度被认为是胆固醇和其他脂质之间相互作用的结果，否则这些脂质处于L-d或凝胶（S-o）相。在这些阶段的特点脂质包装在各自的横向动力学的显着差异的结果。在这项研究中，成像全内反射荧光相关光谱（ITIR-FCS）被施加到监测内的支持脂质双层（SLB）作为温度和组成的函数的扩散。我们表明，膜的横向扩散，这是参数化的阿克里欧斯活化能（E-Arr）的温度依赖性，可以解决脂质混合物的亚分辨率相行为。FCS扩散定律是ITIR-FCS中实现的一种新的膜异质性规则，它表明S-o-L-d相中的畴是静态的和大的，而L-o-L-d相中的畴是小的和动态的。在不同温度下的扩散测量和随后的FCS扩散规律分析表明，在高温（313 K）的膜动力学的调制是域熔化和刚性松弛的累积效应。最后，我们将这些研究扩展到常用的神经母细胞瘤，HeLa和成纤维细胞的质膜。神经母细胞瘤细胞的膜动力学的温度依赖性是显着不同的HeLa或成纤维细胞的细胞类型表现出高水平的组成异质性。(C)2013爱思唯尔有限公司版权所有。
The organization of the plasma membrane is regulated by the dynamic equilibrium between the liquid ordered (L-o) and liquid disordered (L-d) phases. The abundance of the L-o phase is assumed to be a consequence of the interaction between cholesterol and the other lipids, which are otherwise in either the L-d or gel (S-o) phase. The characteristic lipid packing in these phases results in significant differences in their respective lateral dynamics. In this study, imaging total internal reflection fluorescence correlation spectroscopy (ITIR-FCS) is applied to monitor the diffusion within supported lipid bilayers (SLBs) as functions of temperature and composition. We show that the temperature dependence of membrane lateral diffusion, which is parameterized by the Arrhenius activation energy (E-Arr), can resolve the sub-resolution phase behavior of lipid mixtures. The FCS diffusion law, a novel membrane heterogeneity ruler implemented in ITIR-FCS, is applied to show that the domains in the S-o-L-d phase are static and large while they are small and dynamic in the L-o-L-d phase. Diffusion measurements and the subsequent FCS diffusion law analyses at different temperatures show that the modulation in membrane dynamics at high temperature (313 K) is a cumulative effect of domain melting and rigidity relaxation. Finally, we extend these studies to the plasma membranes of commonly used neuroblastoma, HeLa and fibroblast cells. The temperature dependence of membrane dynamics for neuroblastoma cells is significantly different from that of HeLa or fibroblast cells as the different cell types exhibit a high level of compositional heterogeneity. (C) 2013 Elsevier B.V. All rights reserved.