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Microwave Spectroscopy Measurements on the Hydrogen Bonding of Nucleic Acid Base Pairs and Base Pair Analogs

核酸碱基对和碱基对类似物氢键的微波光谱测量

基本信息

批准号：
1952289
负责人：
Stephen Kukolich
金额：
$ 46.18万
依托单位：
University of Arizona
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-09-15 至 2024-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1952289&HistoricalAwards=false
关键词：
Microwave Spectroscopy Measurements Hydrogen Bonding

项目摘要

In this project funded by the Chemical Structure, Dynamics, and Mechanisms A (CSDM-A) program of the Chemistry Division, Professor Stephen Kukolich of The University of Arizona is using sensitive, high-resolution microwave spectrometers to obtain new data that can be related to the structures and hydrogen bonding interactions of molecules important in molecular genetics. Hydrogen bonding is a specific kind of intermolecular interaction where a partially positively charged hydrogen atom on one molecule is attracted to a partially negatively charged oxygen atom on another molecule. In living systems, hydrogen-bonding interactions are the key interactions for making copies of the genetic information in DNA (deoxyribonucleic acid) - the molecules that make up our genes. Changes in the rotational motions of nucleic acids and their hydrogen-bonded pairs correspond to energies in the microwave region of the light spectrum. Microwave absorption by these molecules and complexes are analyzed to provide detailed structure information. The fundamental principle that the DNA bases form specific pairs responsible for copying and transcribing the genetic code was discovered may years ago by Watson and Crick. However, the details of the structures and hydrogen bonding interactions between the individual base pairs have not been completely determined. This project involves the study of individual hydrogen-bonded complexes that have been evaporated into the gas phase where they are free of the external water-filled biological environment. The research is thus revealing the intrinsic properties of the basic hydrogen bonding interactions. Revealing the intrinsic properties and behaviors of DNA molecules and base pairs has important consequences for our understanding of biomolecules in general, as well as the fundamental processes underlying living systems. The students engaged in this research project are gaining valuable experience in experimental spectroscopy and computer interfacing and calculations of molecular structures. The structures and other properties of the hydrogen-bonded complexes are being studied using three sensitive, high-resolution microwave spectrometers to accurately and precisely measure microwave rotational transition frequencies. The hydrogen-bonded complexes are formed in supersonic expansions so the rotational spectra can be measured in cold molecular beams or isolated molecules and complexes. The volatility of these larger molecules is low so higher- temperature and laser-ablation beam sources must be constructed and tested. The new moments of inertia and distortion constants obtained can be analyzed, in combination with theoretical results to yield new structure and hydrogen bonding parameter information on these important molecules. New data on multiple structural isomers may be obtained. The use of 15N substituted isotopologues substantially improves the observed signal strengths and simplify the analysis. For the smaller complexes this improves the prospects for measuring single 13C isotopologues in order to obtain more structural information. For some cases, nitrogen quadrupole coupling strengths can be obtained and provide data on the local electronic structure. Extensive theoretical calculations are also being performed along with the experiments to guide the experiments and test theoretical methods. The results of this research are likely to provide additional insights into abnormal DNA binding structures which underlie mutations and errors in transcription; these in turn underpin our understanding of biological evolution and diseases arising from genetic disorders. The graduate and undergraduate research students working in our labs can learn fundamentals of chemistry, quantum mechanics and methods and techniques involved in computer work, microwave electronics and making physical measurements through direct involvement in the proposed projects.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.

在这个由化学部化学结构，动力学和机制A（CSDM-A）计划资助的项目中，亚利桑那大学的Stephen Kukolich教授正在使用灵敏的高分辨率微波光谱仪来获得新的数据，这些数据可能与分子遗传学中重要分子的结构和氢键相互作用有关。氢键是一种特殊的分子间相互作用，其中一个分子上的部分带正电的氢原子被吸引到另一个分子上的部分带负电的氧原子。在生命系统中，氢键相互作用是复制DNA（脱氧核糖核酸）中遗传信息的关键相互作用，DNA是组成我们基因的分子。核酸及其氢键对的旋转运动的变化对应于光谱的微波区域中的能量。这些分子和配合物的微波吸收进行了分析，以提供详细的结构信息。DNA碱基形成特定的碱基对负责复制和转录遗传密码的基本原理是沃森和克里克在几年前发现的。然而，单个碱基对之间的结构和氢键相互作用的细节尚未完全确定。该项目涉及研究已蒸发到气相中的单个氢键复合物，在那里它们不受外部充满水的生物环境的影响。因此，这项研究揭示了基本氢键相互作用的内在性质。揭示DNA分子和碱基对的内在性质和行为对我们理解生物分子以及生命系统的基本过程具有重要意义。参与该研究项目的学生在实验光谱学和计算机接口以及分子结构计算方面获得了宝贵的经验。氢键复合物的结构和其他性质正在使用三个灵敏的高分辨率微波光谱仪进行研究，以准确和精确地测量微波旋转跃迁频率。氢键复合物在超声膨胀中形成，因此可以在冷分子束或孤立分子和复合物中测量转动光谱。这些较大分子的挥发性较低，因此必须构造和测试高温和激光烧蚀光束源。新的惯性矩和畸变常数得到的分析，结合理论结果，以产生新的结构和氢键参数的信息，这些重要的分子。可能获得关于多种结构异构体的新数据。15 N取代的同位素体的使用显著改善了观察到的信号强度并简化了分析。对于较小的复合物，这改善了测量单个13 C同位素体以获得更多结构信息的前景。在某些情况下，氮四极耦合强度可以获得，并提供数据的本地电子结构。大量的理论计算也在沿着实验中进行，以指导实验和检验理论方法。这项研究的结果可能会提供额外的见解异常DNA结合结构的基础突变和转录错误;这些反过来又巩固了我们对生物进化和遗传疾病引起的疾病的理解。在我们实验室工作的研究生和本科生可以通过直接参与拟议的项目来学习化学、量子力学以及计算机工作、微波电子学和物理测量所涉及的方法和技术的基础知识。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

期刊论文数量（9）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Microwave measurements and calculations for the glyoxylic acid – Formic acid hydrogen-bonded complex

乙醛酸 — 甲酸氢键配合物的微波测量和计算

DOI：
10.1016/j.jms.2023.111806
发表时间：
2023
期刊：
Journal of Molecular Spectroscopy
影响因子：
1.4
作者：
Nichols, Jack L.;Roehling, Kristen K.;Daly, Adam M.;Kukolich, Stephen G.
通讯作者：
Kukolich, Stephen G.

Microwave measurements of rotational transitions and nitrogen quadrupole coupling for 2-aminopyridine

2-氨基吡啶旋转跃迁和氮四极耦合的微波测量

DOI：
发表时间：
2021
期刊：
Journal of molecular spectroscopy
影响因子：
1.4
作者：
Zunwu, Z.;Daly, A.;Kukolich, S.
通讯作者：
Kukolich, S.

Corrections and Additions to “Microwave Spectra and Theoretical Calculations for Two Structural Isomers of Methylmanganese Pentacarbonyl”

对“五羰基甲基锰的两种结构异构体的微波光谱和理论计算”的修正和补充

DOI：
10.1021/acs.inorgchem.0c03388
发表时间：
2021
期刊：
Inorganic Chemistry
影响因子：
4.6
作者：
Tanjaroon, Chakree;Zhou, Zunwu;Mills, David;Keck, Kristen;Kukolich, Stephen G.
通讯作者：
Kukolich, Stephen G.

Measurements of microwave and NMR spectra for 15N substituted formamidinium formate

15N 取代甲脒甲酸的微波和核磁共振谱测量