Division of Structural Biology, Biozentrum, University of Basel, CH-4056 Basel, Switzerland.
Nat Chem. 2012 Sep;4(9):711-7. doi: 10.1038/nchem.1396. Epub 2012 Jul 8.
Hydrogen bonds are key constituents of biomolecular structures, and their response to external perturbations may reveal important insights about the most stable components of a structure. NMR spectroscopy can probe hydrogen bond deformations at very high resolution through hydrogen bond scalar couplings (HBCs). However, the small size of HBCs has so far prevented a comprehensive quantitative characterization of protein hydrogen bonds as a function of the basic thermodynamic parameters of pressure and temperature. Using a newly developed pressure cell, we have now mapped pressure- and temperature-dependent changes of 31 hydrogen bonds in ubiquitin by measuring HBCs with very high precision. Short-range hydrogen bonds are only moderately perturbed, but many hydrogen bonds with large sequence separations (high contact order) show greater changes. In contrast, other high-contact-order hydrogen bonds remain virtually unaffected. The specific stabilization of such topologically important connections may present a general principle with which to achieve protein stability and to preserve structural integrity during protein function.
氢键是生物分子结构的关键组成部分，它们对外界干扰的响应可能揭示结构中最稳定成分的重要信息。NMR 光谱学可以通过氢键标量耦合（HBC）非常高的分辨率来探测氢键的变形。然而，到目前为止，HBC 的小尺寸一直阻止了对蛋白质氢键作为压力和温度基本热力学参数的函数的全面定量表征。使用新开发的压力室，我们现在通过非常精确地测量 HBC，绘制了泛素中 31 个氢键的压力和温度依赖性变化。短程氢键仅受到适度的干扰，但许多具有大序列间隔（高接触顺序）的氢键显示出更大的变化。相比之下，其他高接触顺序的氢键几乎不受影响。这种拓扑重要连接的特异性稳定可能代表了一种普遍的原则，用于实现蛋白质稳定性，并在蛋白质功能期间保持结构完整性。
