Spot size variation FCS in simulations of the 2D Ising model
Spot size variation FCS in simulations of the 2D Ising model
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DOI：
10.1088/0022-3727/49/21/214001
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发表时间：
2016-06-02
影响因子：
3.4
通讯作者：
Veatch, Sarah L.
中科院分区：
文献类型：
--
作者：
Burns, Margaret C.;Nouri, Mariam;Veatch, Sarah L.
斑点变异荧光相关光谱（svFCS）是一种用于研究单分子在细胞膜中运动和组织的光谱技术。该实验技术改变照明区域的大小，同时使用标准荧光相关方法及时测量相关性。通常，这些数据被解释使用的假设，相关测量反映了单分子运动的动力学，而不是运动的平均组成。在这里，我们探讨如何svFCS测量报告的动态组件扩散的二维伊辛模型与保守的序参数的模拟。模拟相关函数报告单组分流动性的快速动态和平均组成的较慢动态。在一系列的模拟条件下，一个传统的svFCS分析表明存在异常扩散，即使单分子运动在这些模拟中是近布朗。当荧光标记的表面密度升高时，这种误解是最显著的，因此我们建议在示踪剂密度的范围内进行未来的测量。一些模拟条件再现发表的svFCS实验数据的定性特征。总体而言，这项工作强调需要探测膜使用多种互补的实验方法，以得出结论，在这些系统中的空间和动态异质性的性质。
Spot variation fluorescence correlation spectroscopy (svFCS) was developed to study the movement and organization of single molecules in plasma membranes. This experimental technique varies the size of an illumination area while measuring correlations in time using standard fluorescence correlation methods. Frequently, this data is interpreted using the assumption that correlation measurements reflect the dynamics of single molecule motions, and not motions of the average composition. Here, we explore how svFCS measurements report on the dynamics of components diffusing within simulations of a 2D Ising model with a conserved order parameter. Simulated correlation functions report on both the fast dynamics of single component mobility and the slower dynamics of the average composition. Over a range of simulation conditions, a conventional svFCS analysis suggests the presence of anomalous diffusion even though single molecule motions are nearly Brownian in these simulations. This misinterpretation is most significant when the surface density of the fluorescent label is elevated, therefore we suggest future measurements be made over a range of tracer densities. Some simulation conditions reproduce qualitative features of published svFCS experimental data. Overall, this work emphasizes the need to probe membranes using multiple complimentary experimental methodologies in order to draw conclusions regarding the nature of spatial and dynamical heterogeneity in these systems.