Department of Pharmaceutical Chemistry and the Cardiovascular Research Institute , University of California San Francisco , 555 Mission Bay Boulevard South , San Francisco , California 94158 , United States.
College of Life Sciences , Zhejiang Sci-Tech University , Hangzhou 310018 , China.
J Am Chem Soc. 2018 Apr 18;140(15):4995-4999. doi: 10.1021/jacs.8b01087. Epub 2018 Apr 5.
Introducing new chemical reactivity into proteins in living cells would endow innovative covalent bonding ability to proteins for research and engineering in vivo. Latent bioreactive unnatural amino acids (Uaas) can be incorporated into proteins to react with target natural amino acid residues via proximity-enabled reactivity. To expand the diversity of proteins amenable to such reactivity in vivo, a chemical functionality that is biocompatible and able to react with multiple natural residues under physiological conditions is highly desirable. Here we report the genetic encoding of fluorosulfate-l-tyrosine (FSY), the first latent bioreactive Uaa that undergoes sulfur-fluoride exchange (SuFEx) on proteins in vivo. FSY was found nontoxic to Escherichia coli and mammalian cells; after being incorporated into proteins, it selectively reacted with proximal lysine, histidine, and tyrosine via SuFEx, generating covalent intraprotein bridge and interprotein cross-link of interacting proteins directly in living cells. The proximity-activatable reactivity, multitargeting ability, and excellent biocompatibility of FSY will be invaluable for covalent manipulation of proteins in vivo. Moreover, genetically encoded FSY hereby empowers general proteins with the next generation of click chemistry, SuFEx, which will afford broad utilities in chemical biology, drug discovery, and biotherapeutics.
在活细胞中的蛋白质中引入新的化学反应性，将为蛋白质赋予创新的共价键合能力，用于体内的研究和工程。潜伏的生物反应性非天然氨基酸（Uaas）可以被整合到蛋白质中，通过邻近引发的反应与目标天然氨基酸残基反应。为了扩大体内这种反应性的蛋白质的多样性，需要一种在生理条件下与多种天然残基反应、生物相容性好的化学官能团。在这里，我们报告了氟硫酸-L-酪氨酸（FSY）的遗传编码，FSY 是第一个在体内的蛋白质上经历硫氟交换（SuFEx）的潜伏生物反应性 Uaa。FSY 对大肠杆菌和哺乳动物细胞没有毒性；在被整合到蛋白质中后，它通过 SuFEx 选择性地与邻近的赖氨酸、组氨酸和酪氨酸反应，直接在活细胞中生成蛋白质内桥和相互作用蛋白质的蛋白质间交联。FSY 的邻近激活反应性、多靶向能力和优异的生物相容性，对于体内蛋白质的共价操作将是非常宝贵的。此外，本文通过遗传编码赋予普通蛋白质下一代点击化学 SuFEx，这将在化学生物学、药物发现和生物治疗学中提供广泛的应用。
