Urea, but not guanidinium, destabilizes proteins by forming hydrogen bonds to the peptide group
Urea, but not guanidinium, destabilizes proteins by forming hydrogen bonds to the peptide group
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DOI：
10.1073/pnas.0812588106
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发表时间：
2009-02-24
影响因子：
11.1
通讯作者：
Englander, S. Walter
中科院分区：
文献类型：
--
作者：
Lim, Woon Ki;Rosgen, Jorg;Englander, S. Walter
尿素和胍使蛋白质结构不稳定的机制是有争议的。我们测试的可能性，这些变性剂形成氢键与肽基团通过测量其阻断酸和碱催化的肽氢交换的能力。发现的肽氢键似乎足以解释尿素的热力学变性效应。然而，胍的结果与它可能形成氢键的预期相反。显然，尿素和胍虽然结构相似，但通过不同的机制使蛋白质变性。
The mechanism by which urea and guanidinium destabilize protein structure is controversial. We tested the possibility that these denaturants form hydrogen bonds with peptide groups by measuring their ability to block acid- and base-catalyzed peptide hydrogen exchange. The peptide hydrogen bonding found appears sufficient to explain the thermodynamic denaturing effect of urea. Results for guanidinium, however, are contrary to the expectation that it might H-bond. Evidently, urea and guanidinium, although structurally similar, denature proteins by different mechanisms.