雷公藤甲素及其结构类似物是传统中药雷公藤的主要有效成分，具有强烈的抑制血管生成、抗癌，抗炎和免疫调节等多种药理作用，但是与其直接作用的大部分生物靶点仍不明确，涉及的信号通路也不清楚。我们的前期研究通过血管内皮细胞筛选系统检测了有机合成的150多个雷公藤甲素的结构类似物，发现真核细胞延伸因子2（eEF2）与雷公藤甲素直接相互作用，可能是其特异抑制血管生成的靶点。本项目拟首先通过质谱等方法鉴定雷公藤甲素结合eEF2的具体官能团及eEF2参与结合的具体残基或结构域，利用我们已建立的分子、生化及细胞信号转导研究领域手段，进一步鉴定所影响的下游信号通路，特别是两者结合后负调控VEGFR2和Tie2等血管生成效应分子的机理，最终阐明雷公藤甲素抑制血管生成的信号转导途径，并明确雷公藤甲素各活性区域的结构-功能关系，为开发以雷公藤甲素为基础的新型低毒高专一性抑制血管生成的小分子先导化合物奠定基础。

Triptolide, a natural product isolated from Chinese medicinal herb Lei Gong Teng (Tripterygium wilfordii Hook. F.), has potent anti-angiogenesis, antitumor, anti-inflammatory, immunosuppressive and anti-fertility activities. However, most of the direct biological targets binding to triptolide have not been reported yet and the mechanism of actions of triptolide remains to be elucidated. Our previous work discovered that eukaryotic elongation factor 2 (eEF2) was the specific binding protein of triptolide that negatively regulate angiogenesis by screening more than 150 synthesized triptolide related compounds. In this proposal, we will first identify the function group of triptolide contributed to the binding of eEF2 and the residues or domains of eEF2 related to the direct binding of triptolide by mass spectrometry assay. Then we will further identify the downstream signaling pathway after eEF2 binding to triptolide by molecular biology, biochemistry and signal transduction methods, especially the pathway related to the negative regulation of angiogenic VEGFR2 and Tie2 proteins. The goal of this proposal is to develop novel specific anti-angiogenic lead compound with low cytotoxicity based on the better understanding of triptolide's structure-function relationship.