酯酶活力下降迅速及酰基迁移加剧等问题严重制约酶法在结构脂肪合成中应用。从酶微观结构变化及酶与底物形成过渡态中间体角度考虑反应因素对酶活力影响有助于深入阐明酯酶失活机理。本项目在前期研究基础上，利用酶催化樟树籽油合成OMO型结构脂肪为研究对象，围绕反应过程中，酯酶活力下降及酰基迁移加剧等问题，采用X-射线衍射、圆二色谱及生物信息学研究酶微观结构变化，利用MATLAB建立反应动力学模型，等温滴定量热法观察反应热力学参数，并结合量子化学与分子动力学联用（QM/MM）理论，分析反应过渡态中间体形成及解离信息、底物酯键断裂及重构电子转移路径及能量变化，理论与实验相结合，探讨反应因素（溶剂分子、底物比、温度、水分、时间等）— 酶催化位点及过渡态中间体变化 — 酶活力下降及酰基迁移规律性，从微观结构及能量变化角度深入阐明酶失活机理及其调控机制。通过本项目的实施为油脂工业酶法合成结构脂肪提供理论依据。

The decrease of lipase activity and exacerbation of acyl migration are “bottle-neck” problems in development of structural lipids. The study of the formation of the transition state intermediate and the microstructure changes of the enzyme can help to elucidate the mechanism of inactivation of the lipase during the reaction. Based on the preliminary study, the project will continue to use camphor seed oil to synthesize OMO-type structured lipid by lipozyme RM IM. The aim of this project focuses on better understanding of the mechanism of lipase inactivation and acyl migration. In the present study, X- ray diffraction，circular dichroism spectroscopy and bioinformatics will be adopted to observe the microstructure change of lipase; the kinetic model of the reactions are established by MATLAB and the thermodynamic parameters are obtained by isothermal titration calorimetry. To further study the mechanism of the lipase inactivation from the point view of molecular level, the theoretical calculation combined quantum chemistry and molecular dynamics (QM / MM) will be utilized. The formation and dissociation of transition state intermediate, the cleavage and reconstruction of substrate ester bond, the electron transfer pathway and energy changes of the substrate will be analyzed by QM/MM. From the perspectives of theory and experiment to observe the microstructure and energy changes of lipase during reaction, the deactivation mechanism of lipase and its regulation mechanism will be elucidated through exploring reaction factors (solvent, substrate ratio, temperature, moisture, time, etc.) - the catalytic site of the enzyme and transition state Intermediate changes – the decrease of enzyme activity and the regularity of acyl migration. We hope that the results of current study could provide a theoretical basis and technical supports in application of lipase synthesis of fats or oils to produce structured lipids in oil industry.