Wang Dongyuan, Yu Mengying, Liu Na, Lian Chenshan, Hou Zhanfeng, Wang Rui, Zhao Rongtong, Li Wenjun, Jiang Yixiang, Shi Xiaodong, Li Shuiming, Yin Feng, Li Zigang
State Key Laboratory of Chemical Oncogenomics , School of Chemical Biology and Biotechnology , Peking University Shenzhen Graduate School , Shenzhen , 518055 , China . Email:
Department of Biomedical Sciences , City University of Hong Kong , Kowloon , Hong Kong . Email:
Chem Sci. 2019 Mar 25;10(19):4966-4972. doi: 10.1039/c9sc00034h. eCollection 2019 May 21.
Significant efforts have been invested to develop site-specific protein modification methodologies in the past two decades. In most cases, a reactive moiety was installed onto ligands with the sole purpose of reacting with specific residues in proteins. Herein, we report a unique peptide macrocyclization method the bis-alkylation between methionine and cysteine to generate cyclic peptides with significantly enhanced stability and cellular uptake. Notably, when the cyclized peptide ligand selectively recognizes its protein target with a proximate cysteine, a rapid nucleophilic substitution could occur between the protein Cys and the sulfonium center on the peptide to form a conjugate. The conjugation reaction is rapid, facile and selective, triggered solely by proximity. The high target specificity is further proved in cell lysate and hints at its further application in activity based protein profiling. This method enhances the peptide's biophysical properties and generates a selective ligand-directed reactive site for protein modification and fulfills multiple purposes by one modification. This proof-of-concept study reveals its potential for further broad biological applications.
在过去二十年中，人们投入了大量精力来开发位点特异性蛋白质修饰方法。在大多数情况下，反应性部分被安装到配体上，其唯一目的是与蛋白质中的特定残基发生反应。在此，我们报告了一种独特的肽大环化方法——甲硫氨酸和半胱氨酸之间的双烷基化反应，以生成稳定性和细胞摄取显著增强的环肽。值得注意的是，当环化肽配体通过邻近的半胱氨酸选择性识别其蛋白质靶点时，蛋白质半胱氨酸与肽上的锍中心之间会发生快速亲核取代反应，形成共轭物。共轭反应快速、简便且具有选择性，仅由邻近性触发。在细胞裂解物中进一步证明了高靶向特异性，并暗示了其在基于活性的蛋白质谱分析中的进一步应用。该方法增强了肽的生物物理性质，并为蛋白质修饰产生了一个选择性的配体导向反应位点，通过一次修饰实现多种目的。这项概念验证研究揭示了其在更广泛生物应用中的潜力。
