结合光谱分析研究生化模型分子体系的分子热力学

It is well recognized that the weak intermolecular interactions play a crucial role in determining structure, property and activity of biological macromolecule. Although they have extensively studied, the mechanism is still not fully understood. Due to poor knowledge and extraordinary complexity of biological system, it is difficult to describe the weak interaction quantitatively with a simple model. The motivation of this study is to summary some regularities of biochemical model molecules on the basis of associated system of small molecule, as will help us understand the interaction of biological macromolecule better. Hydrogen bond is one of most important intermolecular interactions, which is weaker than chemical bond and much stronger than Van der Waals interaction. It can be consider as a physical effect, or chemical effect, or coaction of both. Based on statistic thermodynamics, a new semiempirical semitheoretical model is proposed for correlating chemical shifts of NMR and thermodynamic mixing properties simultaneously. Mutual predictions between the chemical shifts and the thermodynamic mixing properties are also attempted. Based on chemical theory, an elemental composition method is proposed to calculate simultaneous chemical and phase equilibrium of non-ideal mixtures. Then combined chemical associated theory, the amide-alcohol and amide-water systems are modeled to correlate the chemical shifts and thermodynamic properties. Furthermore, molecular dynamics simulation is carried out to investigate what roles do the strong O-Hᤡ䡤O and the weak C-Hᤡ䡤O interaction play respectively in aqueous solutions. Through the studies of physical model, chemical model and computer simulation, associated systems especially peptide bonds in aqueous solutions have been understanding deeper, which will assist us to explores the secret of biological macromolecule.

从分子相互作用的势能函数出发,基于统计热力学,建立一个描述混合物核磁共振化学位移的微观模型,针对生化模型体系进行研究,揭示其中的蔬水作用,无键相互作用等规律.在此基础上,提出能够同时描述宏观热力学数据与光谱数据的微观模型,这样就能把大量的光谱数据用于分子热力学研究为分子热力学研究开辟新的道路.