CYP2C19新突变体底物特异性的分子机制和功能研究

CYP2C19遗传多态性是导致底物药物疗效摇摆的重要原因。研究表明，CYP2C19突变体对底物的代谢动力学特征呈现显著差异，即使同一种突变体代谢底物的能力也明显不同，然而其具体机理仍不清晰。本课题前期研究发现，CYP2C19*29新突变体对氟西汀和西酞普兰的代谢具有显著特异性，变构所致的血红素与底物的距离改变可能是决定这种特异性的关键原因。因此，我们假设CYP2C19新突变体引起的底物亲和力变化决定了其底物特异性。本研究拟(1)构建CYP2C19新突变体的底物催化活性数据库，寻找底物特异性与变异位点、化学结构等因素的相关性；(2)利用等温滴定量热(ITC)和X-射线晶体学进一步探讨底物特异性的分子机制；(3)构建人源化CYP2C19小鼠模型，找出CYP2C19新突变体的代谢表型。本项目旨在构建“CYP2C19基因-分子结构-功能表型”三角关系，为实现CYP2C19个体化用药提供理论依据。

Cytochrome P450 2C19 (CYP2C19) genetic polymorphism is an important reason for the fluctuation of the efficacy of substrate drugs. Studies have shown that CYP2C19 variants exhibit significant differences in the metabolic kinetic characteristics of substrates, and the same variant also has different catalytic activities for different drugs, but the specific mechanism is still unclear. The preliminary study of this project found that the novel CYP2C19*29 variant had significant substrate specificity for the metabolism of fluoxetine and citalopram. The change in the distance caused by allostery between heme and substrate may be the key reason for determining this specificity. Therefore, we hypothesize that the change in substrate affinity caused by the novel CYP2C19 variant determines its substrate specificity. This project intends to (1) Construct a database of substrate catalytic activity of novel CYP2C19 variants, and look for the correlation between substrate specificity, mutation sites, chemical structure and other factors; (2) Use isothermal titration calorimetry (ITC) and X-ray crystallography to further explore the molecular mechanism of substrate specificity; (3) Establish a humanized CYP2C19 mouse model and search for the metabolic phenotype of this novel CYP2C19 variant. This project aims to establish the "CYP2C19 gene-molecular structure-functional phenotype" triangle relationship, which provides a theoretical basis for CYP2C19 personalized medicine.