GM1 clustering inhibits cholera toxin binding in supported phospholipid membranes
GM1 clustering inhibits cholera toxin binding in supported phospholipid membranes
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DOI：
10.1021/ja069375w
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发表时间：
2007-05-09
影响因子：
15
通讯作者：
Cremer, Paul S.
中科院分区：
文献类型：
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作者：
Shi, Jinjun;Yang, Tinglu;Cremer, Paul S.
本研究探索了五聚体霍乱毒素B亚基（CT B）与相应的膜配体神经节苷脂GM（1）之间的多价配体-受体相互作用。在涂覆在微流体通道的壁和底板上的支撑磷脂双层上监测CTB结合。通过全内反射荧光显微镜（TIRFM）进行测量。通过将结合数据拟合到Hill-Waud和Langmuir吸附等温方程来提取表观解离常数。研究了配体密度对CTB-GM（1）相互作用的影响，发现随着GM（1）密度从0.02mol%增加到10.0mol%，结合减弱。这一结果可能是由于GM（1）在磷脂膜上聚集，从而抑制了CTB的结合。原子力显微镜（AFM）实验直接验证了GM（1）的支持POPC双层内的集群。
The present studies explore multivalent ligand-receptor interactions between pentameric cholera toxin B subunits (CTB) and the corresponding membrane ligand, ganglioside GM(1). CTB binding was monitored on supported phospholipid bilayers coated on the walls and floors of microfluidic channels. Measurements were made by total internal reflection fluorescence microscopy (TIRFM). Apparent dissociation constants were extracted by fitting the binding data to both the Hill-Waud and Langmuir adsorption isotherm equations. Studies of the effect of ligand density on multivalent CTB-GM(1) interactions revealed that binding weakened with increasing GM(1) density from 0.02 mol % to 10.0 mol %. Such a result could be explained by the clustering of GM(1) on the supported phospholipid membranes, which in turn inhibited the binding of CTB. Atomic force microscopy (AFM) experiments directly verified GM(1) clustering within the supported POPC bilayers.