CH-O HYDROGEN BONDS

CH-O氢键

• 批准号: 6019456
• 负责人: STEVE SCHEINER
• 金额: $ 14.57万
• 依托单位: SOUTHERN ILLINOIS UNIVERSITY CARBONDALE
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6019456
• 关键词: carbon; chemical bond; chemical structure; electronic spectra; hydrogen bond; intermolecular interaction; mathematics; molecular energy level; nucleic acids; peptides

DESCRIPTION: The central goal of this project is an understanding of the fundamental aspects of the normally weak interactions formed between a CH proton donor and an acceptor group containing the electronegative O or N atom. These so-called CH..X (or more commonly CH..O) H-bonds occur in large numbers in biological systems such as proteins and nucleic acids, yet very little is known about even such fundamental features as their strength, and the constraints that their presence places upon the three-dimensional structure of the biomolecule in which they occur. Since crystal structures can say little about the strength of any given interaction, this project turns to ab initio calculations. The formulation of appropriate model systems, coupled with the high levels of accuracy which are now feasible, enables calculations of this sort to elucidate information about these interactions which are simply not attainable by any other means. This project will represent a careful and systematic treatment of CH..X interactions, varying from very weak forces, that differ little from hydrocarbon-hydrocarbon, to those that surpass even conventional H-bonds in strength. The potential of the CH group to participate in a H-bond will be investigated for a range of systems: a) differing in sp(n) hybridization of the C atom, b) with varying proximity of an electronegative group to the CH donor, c) including different acceptor groups, d) groups that have particular biochemical relevance; e.g., the alpha-CH2 group of peptides. The work will search for various properties that may be correlated with one another. Having identified an attractive CH..O interaction, and an associated equilibrium, preferred geometry calculations will determine the sensitivity of the binding energy to stretching and bending deformations; i.e., a potential energy surface will be evaluated. Calculations will address whether cooperativity occurs in CH..X bonds, and if so, to what extent.

描述：该项目的核心目标是对 CH之间通常形成的通常弱相互作用的基本方面 质子供体和含有电负O或N的受体组 原子。 这些所谓的ch..x（或更常见的ch..o）h键发生在大的 生物系统（例如蛋白质和核酸）中的数量，但非常 关于它们的力量等基本特征以及 他们的存在置于三维的限制 发生的生物分子的结构。 由于晶体结构 对任何给定互动的强度几乎没有说明，这个项目 从头开始计算。 适当模型的配方 系统，加上现在可行的高准确性， 启用此类计算以阐明有关这些信息的信息 根本无法通过任何其他方式实现的互动。 这 项目将代表Ch..x的仔细而系统的处理 相互作用与非常虚弱的力量不同，这与 碳氢化合物 - 氢化碳，甚至超过传统的H键 力量。 CH组参与H键的潜力将是 研究了一系列系统：a）SP（n）杂交的不同 c原子，b）具有电负性基团不同的CH 供体，c）包括不同的受体组，d） 特定的生化相关性；例如，α-CH2肽组。 工作将搜索可能与一个属性相关的各种属性 其他。 已经确定了一个有吸引力的ch..o互动，一个 相关的平衡，首选几何计算将确定 结合能对拉伸和弯曲变形的敏感性； 即，将评估势能表面。 计算将 解决合作性是否发生在ch..x债券中，如果是的话， 程度。