Tandem organocatalysis for the bi-functional modification of proteins

这第一笔赠款将有助于在英国约克大学化学系内建立一个新的多学科“化学生物学”团队，专注于对蛋白质进行合成化学。使用合成化学选择性地修饰和随后利用甚至调节大分子（如蛋白质和酶）的生物学特性的能力预示着全球制药工业以及相关的化学生物学领域的一场革命。例如：目前，全世界销售量最大的十种药物中有七种是“生物制剂”（即复杂蛋白质、大分子组合，通常用小的有机部分修饰），它们是使用快速发展的“生物缀合”方法构建的，而不是仅仅在十年前，该名单仅由小分子药物组成。越来越多的蛋白质也通过与具有功能增强特性的小分子标签的化学连接来修饰，用于工业和学术界。实例包括化合物如聚乙二醇（PEG）的缀合，以改善探针和治疗剂的半衰期;用于大分子的体内成像和跟踪的荧光和光谱探针的附着;以及具有天然体内修饰的“模拟物”的蛋白质的构建，其在用于治疗热带寄生虫病的先导化合物的开发中发挥了作用。然而，尽管这些构建体具有明显的实用性，但专注于大分子/小分子融合物的“生物缀合”的化学家面临有限的技术挑战，最值得注意的是努力实现化学选择性-即在许多其他人存在下选择性地修饰蛋白质骨架上仅一个特定位点的能力。这种斗争由于以下事实而变得更加复杂：这些新时代的合成挑战不能以与合成有机社区过去处理小分子和天然产物的合成相同的方式来处理-主要使用在通风橱中的有机溶剂中开创的化学，通常在高温下，在高浓度下并且在没有有害污染物的情况下。相反，使用蛋白质的生物缀合通常必须在水中、在中性pH、在稀浓度下以及在蛋白质本身的氨基酸骨架内存在的化学官能团的自助餐的存在下进行。因此，有必要继续开发在这些生物相容条件下进行的蛋白质化学修饰的新方法，以满足对具有调节功能和用途的蛋白质的不断增长的需求。在这个项目中，我们的目标是为新的蛋白质生物缀合方法的创新驱动做出贡献，同时通过重新定义一个不流行的和经常被遗弃的蛋白质基序的化学，并随后开发一种新的串联策略，用于使用化学启用和小分子催化剂控制下的蛋白质化学修饰，建立一个新的生物缀合范式。然后，我们将展示这种方法在直接治疗相关性的合作化学生物学研究中的实用性。

This first grant will help to establish a new multidisciplinary 'chemical biology' team within the Department of Chemistry at University of York, UK, focused on performing synthetic chemistry on proteins. The ability to selectively modify and subsequently harness and even tune the biological properties of macromolecules like proteins and enzymes using synthetic chemistry has heralded a revolution in the worldwide pharmaceutical industry, and the associated field of chemical biology. For example; seven out of the top ten selling drugs worldwide are now 'biologics' (i.e. complex proteins, macromolecule combinations, often decorated with small organic moieties), which are constructed using rapidly developing "bioconjugation" methods, as opposed to only a decade ago when this list was made up solely of small molecule drugs. Increasingly proteins are also modified by chemical ligation with small molecule tags with function enhancing properties for use in both industry and academia. Examples include conjugation of compounds such as polyethyleneglycol (PEG) to improve the half-life of probes and therapeutics; attachment of fluorescent and spectroscopic probes for in vivo imaging and tracking of macromolecules; and construction of proteins bearing 'mimics' of native in vivo modifications, which have played a role in the development of lead compounds for treatment of tropical parasitic diseases. Despite the obvious utility of these constructs however, there are limiting technical challenges facing chemists focusing on the 'bioconjugation' of macro/small molecule fusions, most notably the strive to achieve chemoselectivity- that is the ability to modify only one specific site on a protein backbone selectively in the presence of many others. This struggle is compounded by the fact that these new age synthetic challenges cannot be approached in the same way as the synthetic organic community has approached the synthesis of small molecules and natural products in the past- primarily using chemistry pioneered in organic solvents in a fumehood, often at elevated temperatures, at high concentration and in the absence of detrimental contaminants. Instead, bioconjugations using proteins must often take place in water, at neutral pH, at dilute concentration, and in the presence of a smorgasbord of chemical functionality present within the amino acid backbone of the protein itself. It is a necessity therefore, that new methods for the chemical modification of proteins which take place under these biologically compatible conditions continue to be developed in order to meet the ever-increasing demand for proteins with modulated function and utility. In this project we aim to contribute to this innovation drive for new protein bioconjugation methods, while also establishing a new paradigm for bioconjugation by redefining the chemistry of an unfashionable and oft forsaken protein motif and subsequently developing a new tandem strategy for the chemical modification of proteins using chemistry enabled and under the control of small molecule catalysts. We will then showcase the utility of this method in a collaborative chemical biology study of direct therapeutic relevance.