中药活性成分对血栓素A2受体抑制作用的分子模拟

中药中黄酮类化合物和白藜芦醇等活性成分对血栓素A2受体具有抑制作用,但具体机理不详.本研究通过同源模建方法,以墨鱼视紫红质蛋白为模板,构建血栓素A2受体的蛋白质结构模型.并使用分子对接方法研究中药活性成分白藜芦醇和芹菜苷元与血栓素A2受体模型的作用方式,据此建立药效团模型,筛选其他潜在的血栓素A2受体抑制剂.结果表明:白藜芦醇等中药活性成分能与血栓素A2受体活性口袋中的残基发生氢键作用,结合方式与血栓素相似.血栓素与Ser201、Leu198、Arg295和Thr298发生氢键作用,白藜芦醇等活性成分与Ser201、Leu198和Arg295发生氢键作用.建立的药效团模型由7个药效元素以及排斥性空间元素组成,经测试对高活性的血栓素A2受体抑制剂有比较好的选择性.使用该药效团模型对中药天然产物数据库进行筛选,命中了一批可能具有血栓素A2受体抑制作用的活性化合物.其中一些已经报道有抑制血小板凝聚活性.本研究表明血栓素A2受体可能是活血化瘀类中药的一个潜在的靶点.

Molecular Simulations of the Inhibition of Active Components in Traditional Chinese Medicine on the Thromboxane A2 Receptor

Some natural products from traditional Chinese medicine (TCM) such as flavones and resveratrol have been reported to have thromboxane A2 receptor (TP) inhibiting activity.We investigated a possible inhibition mechanism by a homology model of TP, which was built based on the crystal structure of squid rhodopsin. After that, docking methods were used to investigate the binding modes of resveratrol and apigenin in the active pocket of TP. Furthermore, a three- dimensional pharmacophore model was generated for screening other potential natural TP inhibitors. The results indicate that resveratrol and apigenin bind to the active site of TP similar to the way that thromboxane A2 binds to Ser201, Leu198, Arg295, and Thr298. The former three key residues can form hydrogen bonds with the inhibitors. The pharmacophore model consisted of seven features and a set of volume spheres, which has been proven to be efficient in identifying compounds with high TP inhibition activity. In this way, a set of potential TP inhibitors were screened from a natural product database. Some of them were reported to have platelet aggregation inhibiting activities. This research indicates that TP could be an important target of TCMdrugs with blood circulation activation effects.