整合素αvβ3小分子抑制剂的设计及活性测定

Design and Activity Determination of Small Molecular Inhibitors of Integrin αvβ3

目的通过计算机虚拟筛选,寻找整合素αvβ3的小分子抑制剂,并对其活性进行测定。方法基于整合素αvβ3的胞外区及其配体复合物三维晶体结构,用DOCK(分子对接)对小分子三维数据库进行筛选。通过细胞黏附抑制实验对挑选出的化合物进行生物活性测定,然后挑选高活性的化合物进一步进行损伤迁移实验和人脐静脉内皮细胞管腔样结构形成抑制实验,验证化合物对整合素αvβ3的作用。分子图像学方法分析高活性化合物和受体之间的作用模式。结果用DOCK程序对三维化合物库筛选后挑选出得分高的前1000个化合物,按化学特性和类药性的不同将化合物分类,最终选择并购买了50个代表性化合物进行进一步生物学活性测定。50个化合物中7个化合物显著抑制细胞黏附活性,其中2个化合物的半数抑制浓度(IC50)在100μmol/L以下。选择其中活性最高的取代苯基双胍类化合物进一步进行研究,结果显示此类化合物能够剂量依赖性地抑制高表达整合素αvβ3的M21细胞在玻璃体黏连蛋白上的损伤迁移,并显著抑制碱性成纤维细胞生长因子诱导的人脐静脉内皮细胞管腔样结构的形成。分子图像学结果显示高活性化合物的双胍部分以“舒展”的方式伸入到金属离子依赖性结合位点中,并能够和其中的第220位谷氨酸(Glu)形成稳定的氢键。结论通过计算机虚拟筛选结合生物活性测试,得到了一类靶向整合素αvβ3的全新的先导化合物。

Objective To explore the of integrin αvβ3 through structure-based virtual design and activity determination of small molecular inhibitors screening. Methods Based on the crystal structure of integrin αvβ3 extracellular segment in complex with an ARG-GLY-ASP ligand, docking procedure against the receptor binding domain was performed on 3D database. Integrin αvβ3-mediated cell adhesion assay was performed to assess the adhesion-inhibiting ability of the candidate compounds. Cell migration assay and capillary-structurelike formation inhibition assay were used to estimate the effects of the compounds on integrin αvβ3. Analysis of molecular graphics was carried out to deduce a probable binding model of compound with integrin αvβ3. Resuits From the top 1 000 compounds with the best DOCK energy score, 50 compounds were selected for biological assay based on chemical and drug-like diversity. Seven of 50 compounds showed notable inhibition activity on cell adhesion, and two with half-maximum inhibition concentration （IC50） values less than 100 mol/L. The compound with best activity （1-37） showed high inhibitory activity in cell migration assay and capillary-structure-like formation inhibition assay. Molecular graphics analysis indicated that metal ion-dependent adhesion site （MIDAS） might be involved in the compound 1-37 -mediated inhibition of ligand binding with integrin αvβ3. Conclusions Through virtual screening combined with biological assay, a promising lead compound was discovered to inhibit integrin αvβ3, which embodies the rational drug design with computation aid and brings a new thought and approach to find novel inhibitors of integrin.