THEORY OF PROTON AND HYDRIDE TRANSFER REACTION RATES

质子和氢化物转移反应速率的理论

• 批准号: 3299454
• 负责人: JAMES HYNES
• 金额: $ 10.89万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-01-01 至 1991-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3299454
• 关键词: chemical kinetics; chemical models; computer simulation; enzyme model; hydrogen transport; triose phosphate isomerase

It is proposed to construct analytic theories, perform model rate calculations, and to undertake computer simulations of proton and hydride transfer reactions in solution and in models of enzyme systems. Despite their importance in acid-base chemistry and enzyme catalysis, these reactions are not well understood at the molecular level; no theory currently exists which properly addresses such key features as quantum tunneling and the strong coupling of proton and hydride motion to a polar and ionic environment. These aspects can lead to serious departures from the conventional theoretical framework widely employed in the interpretation of kinetic isotope effects. General goals are to provide the theoretical framework for the interpretation of these reactions, to determine the role of tunneling and the environment in their reaction rates, and to predict the experimental trends which probe and reveal their molecular character. Specific aims are to construct the theory of and perform calculations for intramolecular and intermolecular proton and hydride transfers in polar solvents, and to calculate the dependence of the rate constants on isotopic substitution, tem- perature and solvent polarity and dynamics. A related theory will be developed for these transfers in general polar and ionic environments and applied to a model of a critical proton transfer step in a particular enzyme catalysis, and to a hydride transfer in a model of aspects of an enzymatic redox process. These goals will be accomplished via the use and extension of theoretical methodologies successful in the treatment of other types of charge transfer reactions. These include time correlation function methods and Molecular Dynamics computer simulation. Available ab initio potential surface information will also be used.

提出了建立分析理论，进行模型率 计算，并进行计算机模拟质子和 溶液和酶模型中氢化物转移反应 系统. 尽管它们在酸碱化学中很重要， 酶催化，这些反应并没有得到很好的理解， 分子水平;目前还没有理论， 解决了诸如量子隧穿和 质子和氢化物运动耦合到极性和离子 环境 这些方面可能导致严重偏离 传统的理论框架广泛应用于 动力学同位素效应的解释。 总的目标是提供理论框架， 这些反应的解释，以确定的作用 隧道和环境在他们的反应速率，并 预测实验趋势，探索并揭示其 分子特征 具体目标是构建 并计算分子内和分子间 质子和氢化物在极性溶剂中的转移，并计算 速率常数对同位素取代的依赖性，TEM- 温度和溶剂极性和动力学。 相关理论将 开发这些转移一般极性和离子 环境和应用到一个临界质子转移模型 在特定酶催化中的步骤，并涉及氢化物转移 在酶促氧化还原过程的各方面的模型中。 这些目标将通过使用和扩展 理论方法成功地治疗其他 电荷转移反应的类型 其中包括时间相关性 函数方法和分子动力学计算机模拟。 可用的从头计算潜在的表面信息也将是 采用