Adsorption, folding, and packing of an amphiphilic peptide at the air/water interface.
Adsorption, folding, and packing of an amphiphilic peptide at the air/water interface.
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两亲肽在空气/水界面的吸附、折叠和堆积。
DOI：
--
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发表时间：
2012
影响因子：
3.3
通讯作者：
M. Sayar
中科院分区：
文献类型：
--
作者：
O. Engin;M. Sayar
多肽低聚物在识别蛋白质结构形成和蛋白质聚集中的关键基序方面发挥着重要的作用。在这里，我们介绍了我们的结果，基于广泛的分子动力学模拟，吸附，折叠和堆积在表面单层的两亲性多肽在空气/水界面。实验结果表明，这些分子自发地在界面上形成有序的单分子膜，在表面层内采用β发夹状结构。结果表明，无论是在气液界面还是在气液界面，都可以观察到β-发夹结构。然而，界面的存在导致了疏水和亲水残基的理想分配，从而减少了分子的构象空间，增加了发夹结构的稳定性。得到了单个β-发夹在空气/水界面上的吸附自由能，并分析了吸附自由能的焓和熵贡献。吸附过程主要受两个因素的影响：(1)由于多肽疏水侧链的解溶和水分子的释放而降低了自由能，水分子在主体水中形成了一个笼子包围着这些疏水基团。(2)由于多肽两亲分子的吸附，减少了界面上的总空气/水接触面积。通过对原始分子进行突变，我们展示了该肽的关键设计特征的相对作用。最后，通过分析界面上两个多肽之间的平均作用力势，我们研究了这些分子在表面单分子层内可能的堆积机制。
Peptide oligomers play an essential role as model compounds for identifying key motifs in protein structure formation and protein aggregation. Here, we present our results, based on extensive molecular dynamics simulations, on adsorption, folding, and packing within a surface monolayer of an amphiphilic peptide at the air/water interface. Experimental results suggest that these molecules spontaneously form ordered monolayers at the interface, adopting a β-hairpin-like structure within the surface layer. Our results reveal that the β-hairpin structure can be observed both in bulk and at the air/water interface. However, the presence of an interface leads to ideal partitioning of the hydrophobic and hydrophilic residues, and therefore reduces the conformational space for the molecule and increases the stability of the hairpin structure. We obtained the adsorption free energy of a single β-hairpin at the air/water interface, and analyzed the enthalpic and entropic contributions. The adsorption process is favored by two main factors: (1) Free-energy reduction due to desolvation of the hydrophobic side chains of the peptide and release of the water molecules which form a cage around these hydrophobic groups in bulk water. (2) Reduction of the total air/water contact area at the interface upon adsorption of the peptide amphiphile. By performing mutations on the original molecule, we demonstrated the relative role of key design features of the peptide. Finally, by analyzing the potential of mean force among two peptides at the interface, we investigated possible packing mechanisms for these molecules within the surface monolayer.
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影响因子：
14
作者：
Chow, Lesley W.;Wang, Ling-jia;Kaufman, Dixon B.;Stupp, Samuel I.
通讯作者：
Stupp, Samuel I.
影响因子：
9.7
作者：
Branco, Monica C.;Schneider, Joel P.
通讯作者：
Schneider, Joel P.
DOI：
10.1021/jp910465e
发表时间：
2010-03-04
期刊：
The journal of physical chemistry. B
影响因子：
--
作者：
Hatfield MP;Murphy RF;Lovas S
通讯作者：
Lovas S
影响因子：
15
作者：
Dupuis, Nicholas F.;Wu, Chun;Shea, Joan-Emma;Bowers, Michael T.
通讯作者：
Bowers, Michael T.