基于钾离子通道开放的中药降压成分发现研究

该文以降压靶标膜ATP敏感钾通道(ATP-sensitive potassium channel,KATP)为研究对象,构建其基于配体和基于受体结构的药效团模型,并分别筛选中药化学成分数据库(traditional Chinese medicine database,TCMD),利用分子对接评价筛选结果,发现具有潜在KATP开放作用的中药降压活性成分。其中,基于配体的药效团模型(ligand based pharmacophore,LBP)以对人源KATP具有开放活性的48个化合物为研究对象,利用Hypogen模块进行构建,最优模型由1个氢键受体、1个氢键供体、1个疏水基团、1个芳香环和5个排除体积组成,预测训练集化合物活性相关系数为0.876 4,测试集相关系数为0.705 8,辨识有效性指数N为3.304,综合评价指数CAI为2.616;以KATP同源模建模型(PM0079770)为研究对象,构建基于受体的药效团模型(structure-based pharmacophore,SBP),最优模型具有6个氢键受体、8个氢键供体、7个疏水基团和18个排除体积,辨识有效性指数N为2.200,综合评价指数CAI为2.017。分别用2个最优模型对TCMD数据库进行筛选,对候选化合物进行Lipinski五规则及ADMET性质预测研究,LBP模型命中171个化合物,SBP模型命中178个化合物。利用分子对接技术分别对上述2组潜在中药活性成分进行评价,按照打分值由大到小的排序,分别选取对接pose个数的前3%为潜在活性化合物。得到由LBP模型虚拟筛选得到的10个化合物、由SBP模型虚拟筛选得到的2个化合物,共12个具有潜在KATP开放活性的中药成分。该研究为发现新的KATP开放剂提供了思路。

Discovery of potential ATP-sensitive potassium channel openers with potential hypotensive activity from Chinese herbs based on molecular simulation

In this research, a combined method of ligand-based pharmacophore (LBP), structure-based pharmacophore (SBP), and molecular docking was applied for virtual screening potential ATP-sensitive potassium channel (K_ATP) openers from Chinese herbs. LBP models were generated by 3D-QSAR pharmacophore(hypogen) program, based on the training set composed of 48 K_ATP agonists. The best LBP model consisted of one hydrogen-bond acceptor, one hydrogen-bond donor, one hydrophobic feature, one aromatic ring and five excluded volumes. Besides, the correlation coefficient of training set and test set, N, and CAI value of the model were 0.876 4, 0.705 8, 3.304, and 2.616 respectively. Meanwhile, SBP models were also generated based on a 3D structure of K_ATP (PMID: PM0079770). The best SBP model consisted of six hydrogen-bond acceptors, eight hydrogen-bond donors, seven hydrophobic features and eighteen excluded volumes. The corresponding N and CAI value were 2.200 and 2.017. Then, the best LBP model and SBP model were applied to identify potential K_ATP openers from Traditional Chinese Medicine Database(TCMD), respectively. 349 hits were obtained after analyzed by drug-likeness rules. Moreover, 12 compounds with high docking scores were reserved after molecular docking evaluation. Interestingly, part of the results had been verified as hypotensive active ingredients by literatures. Therefore, this study uncovers a specific target effect contained in TCMD, and provides candidates for new K_ATP openers' research.