The behavior of the adsorption of cytochrome C on lipid monolayers: A study by the Langmuir-Blodgett technique and theoretical analysis
The behavior of the adsorption of cytochrome C on lipid monolayers: A study by the Langmuir-Blodgett technique and theoretical analysis
复制标题
细胞色素 C 在脂质单层上的吸附行为：Langmuir-Blodgett 技术和理论分析的研究。
DOI：
10.1016/j.bpc.2015.05.008
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发表时间：
2015-10-01
影响因子：
3.8
通讯作者：
Wang, Juan
中科院分区：
文献类型：
--
作者：
Li, Junhua;Sun, Runguang;Wang, Juan
细胞色素c(Cytc)是线粒体呼吸链内的重要组成部分，具有传递电子的功能。这一特点与细胞色素c与膜脂的相互作用密切相关。我们用Langmuir-Blodgett单层技术结合原子力显微镜研究了细胞色素c与空气-缓冲液界面脂单分子膜的相互作用。在我们的工作中，通过比较混合的细胞色素c-阴离子(DPPS)和细胞色素c-两性离子(DPPC/DPPE)单分子膜，细胞色素c在脂单分子膜上的吸附容量是DPPS>；DPPE>；DPPC，这归因于它们不同的头基结构。PI-A等温数据表明，Cytc(v=2.5mU L)分子在脂单分子膜上的吸附量最大。此外，如果蛋白质超过最大吸附量，Cytc分子会形成聚集体，并将一些脂类拖入亚相。PI-T曲线表明，细胞色素c分子在DPPE单层上的重排时间比在DPPC上的重排时间长。可压缩性研究表明，Cytc分子在脂单分子膜上的吸附或分子间聚集会改变膜的流态化。为了定量估计Cytc分子在脂单分子膜上的吸附性质，我们用一个简单的表面态方程对实验等温线进行了拟合。建立了分析DPPC单分子膜液态膨胀(LE)到液态凝聚(LC)相变的理论模型。理论分析的结果与实验(C)2015 Elsevier B.V.完全一致。版权所有。
Cytochrome c (Cyt c) is an essential component of the inner mitochondrial respiratory chain because of its function of transferring electrons. The feature is closely related to the interaction between Cyt c and membrane lipids. We used Langmuir-Blodgett monolayer technique combined with AFM to study the interaction of Cyt c with lipid monolayers at air-buffer interface. In our work, by comparing the mixed Cyt c-anionic (DPPS) and Cyt c-zwitterionic (DPPC/DPPE) monolayers, the adsorption capacity of Cyt c on lipid monolayers is DPPS > DPPE > DPPC, which is attributed to their different headgroup structures. pi-A isothermal data show that Cyt c (v = 2.5 mu L) molecules are at maximum adsorption quantity on lipid monolayer. Moreover, Cyt c molecules would form aggregations and drag some lipids with them into subphase if the protein exceeds the maximum adsorption quantity. pi-T curve indicates that it takes more time for Cyt c molecular conformation to rearrange on DPPE monolayer than on DPPC. The compressibility study reveals that the adsorption or intermolecular aggregation of Cyt c molecules on lipid monolayer will change the membrane fluidization. In order to quantitatively estimate Cyt c molecular adsorption properties on lipid monolayers, we fit the experimental isotherm with a simple surface state equation. A theoretical model is also introduced to analyze the liquid expanded (LE) to liquid condensed (LC) phase transition of DPPC monolayer. The results of theoretical analysis are in good agreement with the experiment (C) 2015 Elsevier B.V. All rights reserved.