Trifluoroethanol may form a solvent matrix for assisted hydrophobic interactions between peptide side chains.
Trifluoroethanol may form a solvent matrix for assisted hydrophobic interactions between peptide side chains.
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DOI：
10.1093/protein/13.11.739
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发表时间：
2000-11
期刊：
影响因子：
--
通讯作者：
H. Reiersen;A. Rees
中科院分区：
文献类型：
--
作者：
H. Reiersen;A. Rees
三氟乙醇（TFE）和肽和蛋白质之间的相互作用的几个模型最近已经提出，但没有能够合理化的令人困惑的观察，一方面，TFE可以稳定一些疏水相互作用的二级结构，但另一方面也可以融化的疏水核心的球状蛋白质。本文通过TFE对短弹性蛋白肽GVG（VPGVG）（3）的影响来说明前者，该短弹性蛋白肽通过两个转角内缬氨酸侧链之间的疏水相互作用形成稳定的II型β转角。这种折叠，通过增加大量水的熵驱动，在TFE-水混合物中和/或通过升高温度来刺激。为了解释这些明显矛盾的观察，我们提出了一个模型，其中TFE集群本地协助折叠的二级结构，首先打破界面上的肽水分子，然后提供一个溶剂基质进一步的侧链-侧链相互作用。该模型还提供了一个解释TFE诱导的二级结构之间的转换，其中的TFE集群可能会重定向非本地的相互作用。
Several models for interactions between trifluoroethanol (TFE) and peptides and proteins have recently been proposed, but none have been able to rationalize the puzzling observations that on the one hand TFE can stabilize some hydrophobic interactions in secondary structures, but on the other can also melt the hydrophobic cores of globular proteins. The former is illustrated in this paper by the effect of TFE on a short elastin peptide, GVG(VPGVG)(3), which forms type II beta-turns stabilized by hydrophobic interactions between two intra-turn valine side chains. This folding, driven by increasing the entropy of bulk water, is stimulated in TFE-water mixtures and/or by raising the temperature. To explain these apparently contradictory observations, we propose a model in which TFE clusters locally assist the folding of secondary structures by first breaking down interfacial water molecules on the peptide and then providing a solvent matrix for further side chain--side chain interactions. This model also provides an explanation for TFE-induced transitions between secondary structures, in which the TFE clusters may redirect non-local to local interactions.