N, S-Double Labeling of N-Terminal Cysteines via an Alternative Conjugation Pathway with 2-Cyanobenzothiazole
N, S-Double Labeling of N-Terminal Cysteines via an Alternative Conjugation Pathway with 2-Cyanobenzothiazole
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DOI：
10.1021/acs.joc.9b02959
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发表时间：
2020-02-07
影响因子：
3.6
通讯作者：
Gao, Jianmin
中科院分区：
文献类型：
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作者：
Wang, Wenjian;Gao, Jianmin
2-氰基苯并噻唑(CBT)与N-末端半胱氨酸(NCys)的偶联反应通常得到荧光素产物。在此，我们报告了一种通向N-端酰胺的替代反应路径，使得侧链硫醇可用于进一步的修饰。对这一核酸偶联的多肽序列依赖性的检测揭示了一种三肽标签CIS，它允许以90%的得率轻松地对目的蛋白进行N，S双标记。CBT-NCys缩合的这种替代反应途径为特定部位的蛋白质修饰工具箱提供了一个重要的补充。
Conjugation of 2-cyanobenzothiazole (CBT) with N-terminal cysteines (NCys) typically gives a luciferin product. We herein report an alternative reaction pathway leading to an N-terminal amidine rendering the side chain thiol available for further modification. Examination of peptide sequence dependence of this amidine conjugation reveals a tripeptide tag CIS that allows facile N, S-double labeling of a protein of interest with >90% yield. This alternative reaction pathway of CBT-NCys condensation presents a significant addition to the toolbox for site-specific protein modifications.