A small molecule approach to spatial and temporal control of covalent protein inhibition in cells

共价修饰蛋白质的小分子是有价值的治疗药物和生物发现的化学探针。例如，广谱反应性探针可以用来识别蛋白质中可能被小分子靶向的新的可连接位点，并描述自然界用来调节蛋白质功能的蛋白质修饰。修饰蛋白质靶标的共价抑制剂是一类重要的、不断增长的药物。然而，这些抑制物总是“开启”的。蛋白质在细胞中的构象、修饰和位置是生物功能的关键决定因素，该项目的目标是开发一种可在细胞内开启的共价抑制剂，以研究特定位置和特定时间的蛋白质的生物学。这个项目将开发化学来标记细胞中的蛋白质半胱氨酸，使用具有空间和时间控制的共价抑制剂。半胱氨酸是共价抑制剂中最常见的靶向残基，也是生物学中参与氧化还原过程和其他蛋白质修饰的有趣残基。我们将半胱氨酸反应性抑制剂关在笼子里，产生可以进入细胞的化合物，然后在我们选择的时间和地点取消对蛋白质的标记。这种方法将使我们能够克服共价探针潜在的广泛毒性，并控制抑制的时间和位置(例如细胞器或组织)。

Small molecules that covalently modify proteins are valuable therapeutics and chemical probes for biological discovery. For example, broad-spectrum reactive probes can be used to identify new ligandable sites in proteins that could be targeted by small molecules, and to profile protein modifications that nature uses to modulate protein function. Covalent inhibitors that modify a protein target are an important and growing class of drugs. However, these inhibitors are always "on". The conformations, modifications and locations of proteins in cells are key determinants of biological function, and the goal of this project is to develop a covalent inhibitor that can be switched on in the cell to study the biology of a protein in a defined location and at a specific time. This project will develop chemistry to label protein cysteines in cells using covalent inhibitors with spatial and temporal control. Cysteines are the most frequently targeted residue in covalent inhibitors and are functionally interesting residues that are involved in redox processes and other protein modifications in biology. We will cage cysteine-reactive inhibitors, generating compounds that can enter cells and subsequently be uncaged at a time and place of our choosing to label proteins. This approach would allow us to overcome the potential broad toxicity of covalent probes, and control the time and location (e.g. organelle or tissue) of inhibition.