Spectroscopic Signatures of Divalent Metal ion Binding to Anionic Surfactants and Local Mechanics of Embedded Groups in Two-Dimensional Water Networks Through Cryogenic Cluster

二价金属离子与阴离子表面活性剂结合的光谱特征以及通过低温团簇嵌入二维水网络中基团的局部力学

• 批准号: 1900119
• 负责人: Mark Johnson
• 金额: $ 40.47万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1900119&HistoricalAwards=false
• 关键词: Spectroscopic; Signatures; Divalent; Metal; ion

In this project funded by the Chemical Structure, Dynamics and Mechanism (CSDM-A) program of the Chemistry Division, Professor Mark A. Johnson of Yale University is using advanced instrumentation to determine how large molecules flex in response to the presence of calcium ions that are critical to biological function. Although calcium is well known to be essential for the formation of permanent structures like bone, it is also present in the blood (a liquid that is basically salty water). Most of the salt is just dissolved NaCl, common table salt, where the positive charge carrier is the sodium ion, Na+. Calcium has much stronger interactions with molecules because it carries two positive charges (Ca2+). Direct contacts with doubly charged (divalent) ions like Ca2+ control how large molecules (like proteins) undergo chemical reactions, but it has been difficult to identify exactly where these ions are attached to the proteins using conventional methods of chemical analysis. Professor Johnson and his research group are able to determine these contact points by measuring changes in the oscillation frequencies of the molecules' chemical bonds. These oscillation frequencies typically correspond to infrared (IR) radiation, the same type of light used in night vision goggles. With IR lasers and other specialized instruments, the changes in the oscillation frequencies of biological molecules with and without Ca2+ ions binding to them can be detected. These changes provide clues to where on the molecule the Ca2+ ion is attached. The measurements are carried out with custom-built instruments, much of which are actually built by the students involved in the project. Thus, in addition to gaining knowledge about metal-ion interactions with large molecules in biological systems, the students also receive training in instrument design and construction, as well as in computer modeling of both the instruments and the chemical systems. This research may have implications in human health. This project uses recent advances in the combination of mass spectrometry with laser spectroscopy to establish how the infrared signatures of divalent metal ion binding to surfactants and peptides, observed in solution, are generated at the molecular level. In this approach, ionic assemblies are extracted from solution using electrospray ionization, captured in a temperature controlled radiofrequency (FRF) ion trap, and characterized with vibrational spectroscopy. The vibrational spectra are obtained in an action mode by the photoinduced mass loss caused by the evaporation of weakly bound adducts such as rare gas atoms or H2 molecules. Because these assemblies often occur in multiple isomeric forms upon cooling, the spectrometer is equipped with the ability to carry out isomer-specific spectroscopy using a two-color, IR-IR photobleaching approach. This method isolates the spectra of different structural isomers by systematically removing each of them from the ion ensemble with a tunable IR laser, while monitoring changes across the spectrum with a second IR laser. An important class of such isomers is that created when an isotopically labeled water molecule is introduced into a cluster containing many water molecules. Because chemical exchange of H and D atoms between water molecules does not occur in small clusters, it is possible to isolate a single, intact H2O molecule in a surrounding network consisting entirely of D2O molecules. This situation provides an opportunity to monitor the spectral response associated with the individual hydrogen bonding sites within an extended water network. Part of this program is, therefore, directed at elucidating fundamental aspects of water structure and dynamics, which are important for understanding and predicting the behavior of water when it is in contact with biological media such as enzymes and DNA. The broader impacts of this research include the development of new types of instrumentation for chemical analysis of complex media and the formulation of a "rule book" for decoding the structural information contained in the vibrational bands of anionic domains bound to divalent metal ions in aqueous solution. The students involved in this project integrate a wide spectrum of skills including laser development, electronics (digital, analogue, high voltage and RF), computer control over complex experiments, electronic structure calculations, construction and use of high vacuum apparatus, fundamental aspects of ion beam and mass spectrometer design, cryogenics, and synthesis.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

在这个由化学系化学结构、动力学和机理（CSDM-A）项目资助的项目中，Mark A。耶鲁大学的约翰逊正在使用先进的仪器来确定大分子如何对生物功能至关重要的钙离子的存在做出反应。虽然钙是众所周知的是必不可少的永久性结构的形成，如骨骼，它也存在于血液（一种液体，基本上是盐水）。大部分的盐都是溶解的氯化钠，普通的食盐，其中正电荷载体是钠离子，Na+。钙与分子的相互作用要强得多，因为它带有两个正电荷（Ca 2+）。与双电荷（二价）离子（如Ca 2+）的直接接触控制大分子（如蛋白质）如何进行化学反应，但使用常规化学分析方法很难准确识别这些离子与蛋白质的连接位置。约翰逊教授和他的研究小组能够通过测量分子化学键振荡频率的变化来确定这些接触点。这些振荡频率通常对应于红外（IR）辐射，与夜视镜中使用的光类型相同。利用红外激光器和其他专用仪器，可以检测到生物分子在有和没有Ca 2+离子结合的情况下振荡频率的变化。这些变化为Ca 2+离子附着在分子上的位置提供了线索。测量是用定制的仪器进行的，其中大部分实际上是由参与该项目的学生制造的。因此，除了获得有关金属离子与生物系统中大分子相互作用的知识外，学生还接受仪器设计和构造以及仪器和化学系统的计算机建模方面的培训。这项研究可能对人类健康有影响。该项目使用质谱与激光光谱相结合的最新进展，以确定在溶液中观察到的二价金属离子与表面活性剂和肽结合的红外特征如何在分子水平上产生。在这种方法中，使用电喷雾电离从溶液中提取离子组件，在温控射频（FRF）离子阱中捕获，并用振动光谱进行表征。振动光谱是通过稀有气体原子或H2分子等弱结合加合物的蒸发引起的光致质量损失在作用模式下获得的。由于这些组件通常在冷却时以多种异构形式出现，因此光谱仪配备有使用双色IR-IR光漂白方法进行异构体特定光谱的能力。该方法通过用可调谐IR激光器从离子系综中系统地去除不同结构异构体中的每一个来分离不同结构异构体的光谱，同时用第二IR激光器监测光谱的变化。这类异构体的一个重要类别是当同位素标记的水分子被引入包含许多水分子的簇中时产生的。由于水分子之间的H和D原子的化学交换不会发生在小簇中，因此可以在完全由D2 O分子组成的周围网络中分离出单个完整的H2O分子。这种情况提供了一个机会，以监测与扩展的水网络内的各个氢键合位点相关的光谱响应。因此，该计划的一部分是针对阐明水结构和动力学的基本方面，这对于理解和预测水与酶和DNA等生物介质接触时的行为非常重要。这项研究的更广泛的影响包括开发新型的复杂介质的化学分析仪器，以及制定一个“规则手册”，用于解码水溶液中与二价金属离子结合的阴离子结构域的振动带中所含的结构信息。参与该项目的学生整合了广泛的技能，包括激光开发，电子（数字、模拟、高压和射频）、复杂实验的计算机控制、电子结构计算、高真空装置的构造和使用、离子束和质谱仪设计的基本方面、低温学，该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估的支持。

项目成果

Spectroscopic Characterization of the Divalent Metal Docking Motif to Isolated Cyanobenzoate: Direct Observation of Tridentate Binding to ortho -Cyanobenzoate and Implications for the CN Response

分离的氰基苯甲酸酯的二价金属对接基序的光谱表征：直接观察三齿酸与邻氰基苯甲酸酯的结合以及对 CN 响应的影响

• DOI: 10.1021/acs.jpca.2c07658
• 发表时间: 2023
• 期刊: The Journal of Physical Chemistry A
• 作者: Mohamed, Ahmed;Edington, Sean C.;Secor, Maxim;Breton, James R.;Hammes-Schiffer, Sharon;Johnson, Mark A.
• 通讯作者: Johnson, Mark A.

Isolating the Contributions of Specific Network Sites to the Diffuse Vibrational Spectrum of Interfacial Water with Isotopomer-Selective Spectroscopy of Cold Clusters

用冷团簇同位素选择性光谱法分离特定网络位点对界面水漫反射振动谱的贡献

• DOI: 10.1021/acs.jpca.0c07795
• 发表时间: 2020
• 期刊: The Journal of Physical Chemistry A
• 作者: Yang, Nan;Khuu, Thien;Mitra, Sayoni;Duong, Chinh H.;Johnson, Mark A.;DiRisio, Ryan J.;McCoy, Anne B.;Miliordos, Evangelos;Xantheas, Sotiris S.
• 通讯作者: Xantheas, Sotiris S.

Capturing intrinsic site-dependent spectral signatures and lifetimes of isolated OH oscillators in extended water networks

捕获扩展水网络中孤立 OH 振荡器的固有位置相关光谱特征和寿命

• DOI: 10.1038/s41557-019-0376-9
• 发表时间: 2020
• 期刊: Nature Chemistry
• 影响因子: 21.8
• 作者: Yang, Nan;Duong, Chinh H.;Kelleher, Patrick J.;Johnson, Mark A.
• 通讯作者: Johnson, Mark A.

Spectroscopic Signatures of Mode-Dependent Tunnel Splitting in the Iodide–Water Binary Complex

碘化物-水二元复合物中模式相关隧道分裂的光谱特征

• DOI: 10.1021/acs.jpca.0c00853
• 发表时间: 2020
• 期刊: The Journal of Physical Chemistry A
• 作者: Talbot, Justin J.;Yang, Nan;Huang, Meng;Duong, Chinh H.;McCoy, Anne B.;Steele, Ryan P.;Johnson, Mark A.
• 通讯作者: Johnson, Mark A.