Urea effects on protein stability: Hydrogen bonding and the hydrophobic effect
Urea effects on protein stability: Hydrogen bonding and the hydrophobic effect
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DOI：
10.1002/(sici)1097-0134(19980501)31:2
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发表时间：
1998-05
期刊：
影响因子：
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通讯作者：
Qin Zou;Susan M. Habermann‐Rottinghaus;K. Murphy
中科院分区：
文献类型：
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作者：
Qin Zou;Susan M. Habermann‐Rottinghaus;K. Murphy
已经使用模型系统研究了尿素对蛋白质稳定性的影响，在该模型系统中，我们已经使用量热法确定了在25°C下将一系列环状二肽溶解到不同浓度的尿素水溶液中的能量学。这些数据支持一种模型，其中尿素通过降低疏水作用和通过氢键直接结合到酰胺单元来使蛋白质变性。数据还表明，在水中的酰胺氢键形成的焓是相当高的比以前估计。先前的估计包括α-碳的疏水转移的贡献，导致高估了尿素和主链酰胺单元之间的结合，低估了结合焓。Proteins 31：107-115，1998.© 1998 Wiley利斯公司
The effects of urea on protein stability have been studied using a model system in which we have determined the energetics of dissolution of a homologous series of cyclic dipeptides into aqueous urea solutions of varying concentration at 25°C using calorimetry. The data support a model in which urea denatures proteins by decreasing the hydrophobic effect and by directly binding to the amide units via hydrogen bonds. The data indicate also that the enthalpy of amide hydrogen bond formation in water is considerably higher than previously estimated. Previous estimates included the contribution of hydrophobic transfer of the α‐carbon resulting in an overestimate of the binding between urea and the amide unit of the backbone and an underestimate of the binding enthalpy. Proteins 31:107–115, 1998. © 1998 Wiley‐Liss, Inc.