Protein unfolding, and the "Tuning In" of reversible intermediate states, in protic ionic liquid media
Protein unfolding, and the "Tuning In" of reversible intermediate states, in protic ionic liquid media
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DOI：
10.1016/j.jmb.2008.02.050
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发表时间：
2008-05-02
影响因子：
5.6
通讯作者：
Angell, C. A.
中科院分区：
文献类型：
--
作者：
Byrne, N.;Angell, C. A.
质子离子液体（PILs）目前被证明是有趣的和有价值的化学操作作为众所周知的非质子离子液体（APIL）。PIL具有另外的优点，即质子活性（PA）可以通过选择在其形成中使用的布朗斯台德碱和布朗斯台德酸来调节。在没有溶剂的情况下，PA在普通溶液中起pH的作用。以前，我们已经表明，在富含离子液体的溶液中的蛋白质的解决方案传达了令人惊讶的稳定对水解和聚集，允许多个展开/重折叠循环，而不损失聚集。在这里，我们表明，鸡蛋白色溶菌酶和核糖核酸酶A的变性温度是敏感的PA的PIL，因为它们是在水溶液中的pH值。一个最大的稳定性更基本的解决方案被发现，以及展开过程中所描述的两个状态（合作）模型。最后，我们表明，通过PA调谐，PILs可以选择折叠途径具有假定的中间体，使它们在展开过程中完全填充。中间体本身能够进行多次解折叠/重折叠循环，每个循环对聚集过程的损失很小。(C)2008爱思唯尔有限公司保留所有权利。
Protic ionic liquids (PILs) are currently being shown to be as interesting and valuable to chemical manipulations as the well-known aprotic ionic liquids (APIL). PILs have the additional advantage that the proton activity (PA) can be adjusted by the choice of Bronsted base and Bronsted acid used in their formation. In the absence of solvent, the PA plays the role of pH in ordinary solutions. Previously, we have shown that solution of proteins in ionic-liquid-rich solutions conveys surprising stabilization against hydrolysis and aggregation, permitting multiple unfold/refold cycles without loss to aggregation. Here, we show that the denaturing temperatures of both hen egg white lysozyme and ribonuclease A are sensitive to the PA of the PIL as much as they are to pH in aqueous solutions. A maximum stability for more basic solutions is found, and the unfolding process is well described by the two-state (cooperative) model. Finally, we show that, by PA tuning, the PILs can select folding pathways featuring the postulated intermediates so that they are fully populated during the unfolding process. The intermediates are themselves capable of multiple unfold/refold cycles with little loss per cycle to aggregation process. (C) 2008 Elsevier Ltd. All rights reserved.