In recent years it has become possible to genetically encode an expanded set of designer amino acids with tailored chemical and physical properties (dubbed unnatural amino acids, UAAs) into proteins in living cells by expanding the genetic code. Together with developments in chemistries that are amenable to and selective within physiological settings, these strategies have started to have a big impact on biological studies, as they enable exciting in cellulo applications. Here we highlight recent advances to covalently stabilize transient protein-protein interactions and capture enzyme substrate-complexes in living cells using proximity-triggered and residue-selective photo-induced crosslinking approaches. Furthermore, we describe recent efforts in controlling enzyme activity with photocaged UAAs and in extending their application to a variety of enzymatic scaffolds. In addition, we discuss the site-specific incorporation of UAAs mimicking post-translational modifications (PTMs) and approaches to generate natively-linked ubiquitin-protein conjugates to probe the role of PTMs in modulating complex cellular networks.

中文翻译：

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通过遗传密码扩展增加活细胞中蛋白质的化学空间。

近年来，通过扩展遗传密码，可以将一组扩展的具有定制化学和物理特性的设计氨基酸（称为非天然氨基酸，UAA）遗传编码到活细胞中的蛋白质中。连同在生理环境中具有适应性和选择性的化学发展，这些策略已开始对生物学研究产生重大影响，因为它们使纤维素应用令人兴奋。在这里，我们重点介绍了使用邻近触发和残基选择性光诱导交联方法共价稳定瞬时蛋白质-蛋白质相互作用和捕获活细胞中的酶底物复合物的最新进展。此外，我们描述了最近在用光笼化 UAA 控制酶活性以及将其应用扩展到各种酶支架方面的努力。此外，我们讨论了模拟翻译后修饰 (PTM) 的 UAA 的位点特异性掺入，以及生成天然连接的泛素-蛋白质偶联物的方法，以探讨 PTM 在调节复杂细胞网络中的作用。