D/H Amide Isotope Effect in Model α-Helical Peptides
D/H Amide Isotope Effect in Model α-Helical Peptides
复制标题
α-螺旋肽模型中的 D/H 酰胺同位素效应
DOI：
10.1021/ja027740n
复制
发表时间：
2002
影响因子：
15
通讯作者：
T. Sosnick
中科院分区：
文献类型：
--
作者：
Zhengshuang Shi;C. A. Olson;N. Kallenbach;T. Sosnick
酰胺相关的氢键对蛋白质稳定性的贡献最近已经使用“Cm实验”进行了评估，该实验测量蛋白质中的D/H酰胺同位素效应。我们使用分离的α-螺旋肽表明，变性剂浓度对测得的D/H同位素效应有显著影响，不同蛋白质的有效比较需要校正变性剂（GdmHCl）浓度的差异。最后，我们的研究结果表明，H-键在一个孤立的α-螺旋可能有助于更多的螺旋稳定性，因为较少的应变相比，在螺旋蛋白和螺旋蛋白中的掩埋螺旋H-键不一定是更有利的能量比溶剂暴露的H-键在孤立的螺旋。
The contribution of amide related hydrogen bonds to protein stability has recently been evaluated using the “Cm experiment”, which measures the D/H amide isotope effect in proteins. We show here using isolated α-helical peptides that there is a significant effect of denaturant concentration on the measured D/H isotope effect, and that valid comparison of different proteins requires correcting for differences in denaturant (GdmHCl) concentration. Finally our results suggest that H-bonds in an isolated α-helix may contribute more to helix stability because of less strain compared to those in helical proteins and that the buried helical H-bonds in helical proteins are not necessarily energetically more favorable than solvent exposed H-bonds in isolated helices.