Unit for Nano Science & Technology, Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata, 700 098, India.
Photochem Photobiol Sci. 2009 Oct;8(10):1441-7. doi: 10.1039/b906578d. Epub 2009 Jul 31.
The influence of ion dissolution in water is still controversial. The challenge posed to the existing concept of dissolved ions acting as water structure makers and structure breakers through recent studies calls for more experimental evidence. The temperature-dependent relaxation dynamics of water in bulk and in ionic salt solutions can give an idea about the hydrogen-bonded network and hence the perturbation induced in the tetrahedral structure of bulk water subsequent to ion dissolution. In our study, the temperature dependence of the observed relaxation dynamics in bulk water and guanidinium hydrochloride reveals the activation energy needed to convert water from hydrogen bonded to the free forms and hence the difference in the hydrogen-bonded network in the close vicinity of the probe molecule. The results might prove helpful to understand the interaction of hydrophobic amino acid residues with guanidinium hydrochloride during protein denaturation.
离子在水中的溶解的影响仍然存在争议。最近的研究对溶解离子作为水结构形成剂和破坏剂的现有概念提出了挑战，这需要更多的实验证据。水在本体和离子盐溶液中的温度依赖性弛豫动力学可以提供关于氢键网络的概念，从而可以了解离子溶解后对本体水的四面体结构的干扰。在我们的研究中，本体水和盐酸胍中观察到的弛豫动力学的温度依赖性揭示了将水从氢键合形式转化为自由形式所需的活化能，因此，在探针分子的近邻处氢键网络存在差异。这些结果可能有助于理解在蛋白质变性过程中疏水性氨基酸残基与盐酸胍的相互作用。
