论文标题
缩聚相的跨跨构体平衡
Tautomeric equilibrium in condensed phases
论文作者
论文摘要
我们提出了在现实的实验条件下甘氨酸和丙酮水溶液的互联体平衡的依次分子动力学（MD）研究。元动力学用于加速互变异域中的质子迁移。由于复杂的水离子结构的形成涉及水性环境中的质子动力学，因此在提供对现象的一般描述时，标准增强的采样方法可能面临严重的限制。最近，我们开发了一组集体变量（CV），旨在研究复杂凝结系统中的质子转移反应[Grifoni等。 PNA，2019，116（10），4054-4057]。在这项工作中，我们将这种方法应用于研究质子解离动力学，从而导致生物学和化学相关的典型系统的互转换，即水中的甘氨酸和丙酮。尽管从化学的角度来看相对简单，但结果表明，即使对于这些小型系统，也可以观察到复杂的反应途径和非平凡的转换动力学。我们方法的一般性允许获得这些结果，而无需提供有关解离动力学的任何先前信息，但只有可以在此过程中交换质子的原子物种。我们的结果与文献估计值一致，并证明了该方法在互变异反应研究中的一般适用性。
We present an ab initio molecular dynamics (MD) investigation of the tautomeric equilibrium for aqueous solutions of glycine and acetone at realistic experimental conditions. Metadynamics is used to accelerate proton migration among tautomeric centers. Due to the formation of complex water-ion structures involved the proton dynamics in the aqueous environment, standard enhanced sampling approaches may face severe limitations in providing a general description of the phenomenon. Recently, we developed a set of Collective Variables (CVs) designed to study protons transfer reactions in complex condensed systems [Grifoni et al. PNAS, 2019, 116(10), 4054-4057]. In this work we applied this approach to study proton dissociation dynamics leading to tautomeric interconversion of biologically and chemically relevant prototypical systems, namely glycine and acetone in water. Although relatively simple from a chemical point of view, the results show that even for these small systems complex reaction pathways and non-trivial conversion dynamics are observed. The generality of our method allows obtaining these results without providing any prior information on the dissociation dynamics but only the atomic species that can exchange protons in the process. Our results agree with literature estimates and demonstrate the general applicability of this method in the study of tautomeric reactions.
