Thermochemistry of Noncovalent Metal-Ligand Bonds of Biological Relevance

玛丽·T博士韦恩州立大学的罗杰斯是资助她的研究热化学的非共价金属配体键的生物相关性的补助金在物理化学计划的化学部。她将推进她在质谱，化学反应动力学和气相离子化学领域的工作，使用流管离子生成与引导离子束串联质谱（GIBMS）相结合的技术。这些进展包括：1）开发与离子漏斗耦合的电喷雾电离（ESI）源，以能够在气相中产生非挥发性和热脆性离子，并产生多电荷物质; 2）为流管和反应区域构建其中性反应物入口的升级; 3）增强计算资源。拟议的研究强调三个相关领域：1）确定生物相关的金属-配体相互作用的绝对键能; 2）开发生物相关的非共价金属-配体相互作用的热化学数据库; 3）开发阈值碰撞诱导解离和相关方法，作为测量越来越大的系统的准确热化学数据的手段。 实验研究将得到补充性理论工作的支持和加强。该计划的主要动机是使气相研究提供的详细信息与功能生物系统之间更好的相关性。 所采取的教学方法，即从模型系统开始，逐渐增加所研究系统的复杂性，以最大限度地提高生物聚合物热力学信息的准确性和精度。金属离子参与核酸（DNA和RNA），生命分子参与的所有生物过程。 金属离子与核酸结合的影响从分子结构的稳定到细胞死亡都有。 这种效应的变化是由于金属离子可以与核酸相互作用的几个可能的位点：磷酸骨架、糖部分或碱基。 这项工作旨在提供有关金属与核酸成分相互作用强度的基本信息，以阐明特定官能团对生物相互作用的贡献。在这项工作中，一种技术，已被专门设计用于反应热化学的准确测定，并被称为引导离子束串联质谱将被用来检查金属离子与生物相关的化学物种的相互作用。实验工作与理论的结合提供了额外的洞察力，也增强了预测能力。

Dr. Mary T. Rodgers of Wayne State University is funded for her research on thermochemistry of noncovalent metal-ligand bonds of biological relevance by a grant in the Physical Chemistry program of the Chemistry Division. She will advance her work in the areas of mass spectrometry, chemical reaction dynamics, and gas-phase ion chemistry using the combined techniques of flow tube ion generation coupled with guided ion beam tandem mass spectrometry (GIBMS). These advances include: 1) development of an electrospray ionization (ESI) source coupled with an ion funnel to enable production of nonvolatile and thermally fragile ions in the gas phase and production of multiply charged species; 2) construction of an upgrade of her neutral reactant inlets for both the flow tube and the reaction region; 3) enhancement of computational resources. The proposed research emphasizes three related areas: 1) the determination of absolute bond energies for metal-ligand interactions of biological relevance; 2) development of a thermochemical database of noncovalent metal-ligand interactions of biological relevance; 3) development of threshold collision-induced dissociation and related methods as means to measure accurate thermochemical data on increasingly larger systems. Experimental studies will be supported and enhanced by complementary theoretical work. A prime motivation for this program is to make better correlations between the detailed information provided by gas-phase studies with those of functional biological systems. The pedagogical approach taken, i.e. starting with model systems and gradually increasing the complexity of the systems under investigation was chosen to maximize the probability that thermodynamic information on biological polymers can be obtained with accuracy and precision. Metal ions are involved in all biological processes that nucleic acids (DNA and RNA), the molecules of life participate in. The effects of binding a metal ion to a nucleic acid vary from stabilization of the molecular structure to cell death. This variation in effect results from several possible sites where the metal ion can interact with the nucleic acid: at the phosphate backbone, at the sugar moiety, or at the base. The work is designed to provide fundamental information about the strength of the interactions of metals with the constituents of nucleic acids to elucidate the contributions of particular functional groups to bio-interactions. In this work, a technique that has been specifically designed for the accurate determination of reaction thermochemistry and known as guided ion beam tandem mass spectrometry will be utilized to examine metal ion interactions with chemical species of biological relevance. A coupling of experimental work with theory provides additional insight and also enhances predictive capabilities.