2D IR OF GUANIDINE IN WATER

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 最新的FTIR研究表明，水在胍溶液中的OH伸展模式发生了较大的频率漂移，使其O-H伸展模式的频率发生了较大的变化，从而引起了人们对水分子在胍离子周围的溶剂化壳结构的疑问。胍经常被用作蛋白质变性剂。它可以起到变性剂的作用，因为它直接与蛋白质结合，因为它有3个NH2基团，在氢键能力上模仿水分子。 这一项目的目标是对胍和水之间的相互作用进行微观描述，并推断为什么胍在生物学中作为变性剂是如此有效。据推测，胍改变了水网络的结构。通过使用双频2D-IR，我们能够直观地显示胍与周围水的相互作用以及水-水的相互作用。通过使用2D-IR，我们应该能够区分以下几点：周围的水分子是从主体水中分离出来的吗？溶剂化壳层的OH伸缩模的频率涨落是否表现出与离子的耦合？或者，与主体水在物理性质上相似的是围绕在胍周围的水分子吗？

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Recent FTIR investigations of the OH stretch mode of water in guanidine solutions revealed a large frequency shift to lower frequency of the O-H stretch mode after guanidine addition, arising questions about the structure of the solvation shell of water molecules around the guanidine ions. Guanidine is often used as a protein denaturant. It may act as a denaturant because it binds to proteins directly since it has 3 NH2 groups that mimic water molecules in their H-bonding ability. The goal of this project is to generate a microscopic description of the interaction between guanidine and water and deduce why guanidine is so effective as a denaturant in biology. It has been postulated that guanidine changes the structure of the water network. By using dual frequency 2D-IR, we are able to visualize the interaction between guanidine and the surrounding water as well as the water-water interactions. By using 2D-IR, we should be able to tell between the following: Are the water molecules surrounding guanidine isolated from the bulk water? Do the frequency fluctuations of the OH stretch modes of the solvation shell manifest coupling to the ion? Or are the water molecules surrounding guanidine similar in their physical properties to the bulk water?