Modify-catch-release-repeat: Reversible bioconjugations for controlled release of small molecules from antibodies and their fragments

基于蛋白质的药物正在彻底改变癌症和其他复杂疾病的精确治疗，通常由抗体蛋白等大分子组成，当它们附着在小分子药物上时可以发挥作用。这种新型“生物”药物的一个例子是抗体-药物缀合物（ADC），其在癌症的个性化化疗治疗中处于领先地位，全世界有超过100种此类药物正在进行临床试验或制药管道。然而，进一步发展这一领域的瓶颈不是抗体或可用的药物，而是将这两种成分缝合在一起所需的化学，并且这一化学领域的发展落后于小分子有机化学的其他分支数十年。构建这些药物的一个主要挑战是难以在小分子和蛋白质之间建立联系，这些蛋白质在循环过程中足够稳定以在体内存活，但随后也足够不稳定以在靶向癌细胞内分解，这是完全活性所需的。该问题的理想解决方案是开发可逆连接，其在暴露于外部小分子触发物之前是稳定的，所述外部小分子触发物然后将催化连接的断裂。像这样的可逆方法也将在治疗性蛋白质的体外纯化中具有广泛的成本效益应用，包括在将抗体和其他蛋白质制备用于临床应用之前从复杂混合物中“捕捞”抗体和其他蛋白质-类似于“捕获和释放”策略。自然界大量使用类似的可逆修饰，包括糖基化、磷酸化、乙酰化和脂化，它们都起着动态开关的作用，然而我们作为化学家模拟这些酶促修饰的能力相比之下相形见绌。在这个项目中，我们将从大自然中获得灵感，并通过开发一种新的化学方法来解决这一限制，该方法将允许小分子可逆地附着到蛋白质支架上。我们的最终目标是在体外和体内部署这种方法，用于抗体片段的串联纯化和修饰，以及随后在膀胱癌细胞内控制药物的释放-这种疾病每天导致15人死亡。为了实现这一目标，我们将在约克大学组建一个具有多学科专业知识的团队，致力于小分子和蛋白质化学，糖科学，膀胱癌细胞生物学和抗体生产的界面。我们还将与一家专门开发抗体-药物偶联物（ADC）的英国生物技术公司建立合作关系。这种独特的组合将促进新型可逆蛋白质生物缀合平台方法的开发，该方法将用于克服这些世纪治疗剂生产中存在的挑战。

Protein based drugs are revolutionising the precision treatment of cancer and other complex disease, and often consist of large macromolecules like antibody proteins, that can act when they are attached to a small molecule drug. An example of this new type of "biologic" medicine are antibody-drug conjugates (ADCs) which are leading the way in personalised chemotherapy treatments for cancer, with >100 such drugs in clinical trials or pharmaceutical pipeline all over the world. However, the bottleneck in progressing this field further is not the antibodies, or the drugs available, but the chemistry required to stitch these two components together, and developments in this area of chemistry lag decades behind other branches of small molecule organic chemistry. A major challenge in the construction of these medicines is the difficulty in building linkages between small molecules and proteins that are stable enough to survive in the body during circulation, but then also labile enough to break-down inside the targeted cancer cells, which is required for full activity. An ideal solution to this problem would be the development of a reversible linkage which is stable until exposed to an external small molecule trigger which would then catalyse break-down of the linkage. A reversible method such as this would also have a wide ranging cost-effective application in the in vitro purification of therapeutic proteins, including 'fishing' antibodies and other proteins out of complex mixtures before preparing them for clinical applications- akin to a 'catch-and-release' strategy. Nature makes abundant use of similar reversible modifications including glycosylation, phosphorylation, acetylation and lipidation, which all act as dynamic switches, as yet however our ability as chemists to emulate these enzymatic modifications pales in comparison. In this project we will take inspiration from Nature and address this limitation by developing a new chemical method which will allow the reversible attachment of small molecules to protein scaffolds. We ultimately aim to deploy this method, both in vitro and in vivo, for the tandem purification and modification of antibody fragments, and the subsequent controlled release of a drug inside bladder cancer cells- a disease which results in 15 deaths every day in the UK. To achieve this goal we will assemble a team with multidisciplinary expertise at the University of York, working at the interface of small molecule and protein chemistry, glycoscience, bladder cancer cell biology, and antibody production. We will also establish a collaborative relationship with a UK biotech specialising in the development of antibody-drug conjugates (ADCs). This unique combination will facilitate the development of a novel reversible protein bioconjugation platform method, which will be used to overcome the challenges presented in the production of these 21st century therapeutics.