Macromolecular crowding at membrane interfaces:: Adsorption and alignment of membrane peptides
Macromolecular crowding at membrane interfaces:: Adsorption and alignment of membrane peptides
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DOI：
10.1016/j.jmb.2007.10.053
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发表时间：
2008-01-11
影响因子：
5.6
通讯作者：
Groebner, Gerhard
中科院分区：
文献类型：
--
作者：
Aisenbrey, Christopher;Bechinger, Burkhard;Groebner, Gerhard
蛋白质与细胞膜的结合涉及各种生物过程。已经开发了各种理论模型来描述这种吸附机制，通常意味着理想溶液的概念。然而，由于膜表面的二维特征，吸附分子之间的分子间相互作用变得重要。因此，先前吸附的分子可以影响额外的蛋白质分子的吸附行为及其膜相关结构。使用模型肽LAH（4），其在膜吸附时可以采用跨膜以及平面内构型，我们对膜中肽浓度与该膜相关多肽的拓扑结构之间的相关性进行了系统研究。我们可以通过建立一个概念来描述所观察到的结合行为，该概念包括尺度粒子理论中的分子间相互作用。肽的高表面浓度使分子从平面内构象转变为跨膜构象，这是由每个分子占据的表面积的减少驱动的过程。在细胞环境中，拥挤依赖性排列可能为细胞提供分子开关，以感知和控制其膜占有率。此外，拥挤可能对生物事件有显著影响，如抗菌肽的协同行为和膜触发的淀粉样蛋白生成肽聚集。(C)2007爱思唯尔有限公司保留所有权利。
Association of proteins to cellular membranes is involved in various biological processes. Various theoretical models have been developed to describe this adsorption mechanism, commonly implying the concept of an ideal solution. However, due to the two-dimensional character of membrane surfaces intermolecular interactions between the adsorbed molecules become important. Therefore previously adsorbed molecules can influence the adsorption behavior of additional protein molecules and their membrane-associated structure. Using the model peptide LAH(4), which upon membrane-adsorption can adopt a transmembrane as well as an in-planar configuration, we carried out a systematic study of the correlation between the peptide concentration in the membrane and the topology of this membrane-associated polypeptide. We could describe the observed binding behavior by establishing a concept, which includes intermolecular interactions in terms of a scaled particle theory. High surface concentration of the peptide shifts the molecules from an inplanar into a transmembrane conformation, a process driven by the reduction of occupied surface area per molecule. In a cellular context, the crowding-dependent alignment might provide a molecular switch for a cell to sense and control its membrane occupancy. Furthermore, crowding might have pronounced effects on biological events, such as the cooperative behavior of antimicrobial peptides and the membrane triggered aggregation of amyloidogenic peptides. (C) 2007 Elsevier Ltd. All rights reserved.