eIF4A不但与肿瘤的发生发展和预后有着紧密的联系，而且与抗肿瘤候选化合物pateamine A在体内直接结合，是一个潜在的新的肿瘤治疗靶标。eIF4A本身的ATP水解酶和RNA解旋酶之间的动态催化机制尚不明确；以及现有的eIF4A的小分子配体均为天然产物，结构较为复杂，难以大量获得，这些因素妨碍了针对eIF4AI分子探针的结构优化，也限制了对eIF4A的生物功能的深入研究和后续的临床转化研究。申请人运用计算生物学结合药物设计、生物化学等研究手段，发现并验证磷酸的释放可能与eIF4AI两种酶活的偶联有关；初步预测和验证了PatA的结合位点。本项目拟在此前期研究基础上，进一步揭示eIF4AI两种酶活的偶联机制，阐明其动态催化机制；并针对eIF4AI功能循环中的不同构象状态，设计和筛选特异性的小分子探针，通过化学干预探究其生物功能和临床应用。

eIF4A is not only related to tumorigenesis and prognosis, but also the target of natural product, pateamine A, suggesting that eIF4AI is a potential drug target for tumor therapy. However, the internal catalytic mechanism of ATPase and RNA helicase of eIF4A remains unclear, which prevents the understanding of the biological function of eIF4AI and clinical application as a therapeutic target. In addition, all known inhibitors of eIF4AI were isolated from natural resources and their complex structures make them difficult to be synthesized for the structural optimization and future pre-clinical research. Our preliminary data implicate that the speed of Pi release will possibly determine the conformation change and coupling between ATPase and Helicase of eIF4AI. The binding sites of PatA were predicted through molecular docking and partially confirmed by the enzymatic assay in vitro. In this proposal, we will consequentially verify that Pi release is a key step to the conformation circulation of eIF4AI and eventually demonstrate the dynamically catalytic mechanism of eIF4AI. Moreover, we will screen for the novel chemical entities of the inhibitor of eIF4AI through the virtual screening or in vitro enzymatic screening in the light of the conclusion from the study of catalytic mechanism of eIF4AI. The final validated candidates will be utilized for the functional study of eIF4AI in vivo and its potential application in clinical will be explored.