Thermochemistry of Noncovalent Interactions and Metal-Ligand Bonds of Biological Relevance

在这个由化学系化学结构、动力学和机理-A (CSDM-A) 项目资助的项目中，韦恩州立大学的 Mary T. Rodgers 教授正在使用质谱技术来获取有关将两个或多个分子结合在一起而不形成强“共价”键的弱相互作用的信息。 共价键涉及两个分子之间实际共享电子。 “非共价”相互作用通常弱于共价键。 它们起着诸如液体沸点和昆虫粘附墙壁的能力等作用。 Rodgers 教授的研究重点是与生命系统相关的非共价相互作用，例如金属原子与核酸分子（DNA 的组成部分）的结合以及肽分子（蛋白质的组成部分）的结合。 这项研究的结果可能会增进我们对生物过程化学基础的理解，并有助于设计用于传感生物相关分子的新技术。参与该项目的研究生和本科生在化学、生物化学、化学物理和质谱等多学科研究环境中获得了宝贵的经验。由此产生的热化学数据正在被编译并通过基于网络的热化学数据库、美国国家标准与技术研究院 (NIST) 化学网络书和 CRC 化学和物理手册提供给社区。在这项工作中，实验测量和理论计算协同结合，以阐明定量热化学数据以及有关非共价相互作用和生物相关金属配体键的动态和结构信息。采用引导离子束串联质谱 (GIBMS) 实验来探测感兴趣物种的能量分辨碰撞诱导解离 (CID) 行为。电子结构计算表征了感兴趣的物种及其 CID 路径的结构和能量。实验数据的热化学分析产生了关于非共价相互作用或在 CID 上裂解的金属-配体键的能量和结构信息，以及关于观察到的激活解离途径的机制和能量势垒的信息。这项工作的预期成果是继续开发定制的 GIBMS 仪器和相关的数据分析程序，这可能有助于未来对日益复杂的系统进行研究。

In this project funded by the Chemical Structure, Dynamics and Mechanisms-A (CSDM-A) Program in the Division of Chemistry, Professor Mary T. Rodgers of Wayne State University is using mass spectrometry techniques to obtain information about the weak interactions that hold two or more molecules together without the formation of a strong "covalent" bond. Covalent bonds involve the actual sharing of electrons between the two molecules. "Non-covalent" interactions are generally weaker than covalent bonds. They play roles such things as the boiling point of liquids and the ability of insects to stick to walls. Professor Rodgers' research focuses on non-covalent interactions relevant to living systems, for example metal atom binding with nucleic molecules (these are constituents of DNA) and the binding of peptide molecules (constituents of proteins). The results of this research may advance our understanding of the chemical basis for biological processes and aid in the design of new technologies for sensing biologically relevant molecules. Graduate and undergraduate students involved in this project are gaining valuable experience in a multidisciplinary research environment encompassing chemistry, biochemistry, chemical physics and mass spectrometry. The resulting thermochemical data are being compiled and made available to the community via a web-based thermochemical database, the National Institutes of Standards and Technology (NIST) Chemistry Webbook and the CRC Handbook of Chemistry and Physics.In this work, experimental measurements and theoretical calculations are synergistically combined to elucidate quantitative thermochemical data and dynamical and structural information regarding noncovalent interactions and metal-ligand bonds of biological relevance. Guided ion beam tandem mass spectrometry (GIBMS) experiments are employed to probe the energy-resolved collision-induced dissociation (CID) behavior of the species of interest. Electronic structure calculations characterize the structures and energetics of the species of interest and their CID pathways. Thermochemical analysis of the experimental data are yielding energetic and structural information on the noncovalent interactions or metal-ligand bonds that are cleaved upon CID and on the mechanisms and energetic barrier(s) for the observed activated dissociation pathways. Continued development of the custom-built GIBMS instrument and associated data analysis procedures is an expected outcome of this work that may enable future studies on increasingly complex systems.