Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131, Karlsruhe, Germany.
Institut Européen de Chimie et Biologie and ISM CNRS UMR5255, Université de Bordeaux, 2 Rue Robert Escarpit, 33607, Pessac, France.
Chemistry. 2021 Nov 22;27(65):16093-16097. doi: 10.1002/chem.202103026. Epub 2021 Oct 29.
Sydnones are highly stable mesoionic 1,3-dipoles that react with cyclooctynes through strain-promoted sydnone-alkyne cycloaddition (SPSAC). Although sydnones have been shown to be valuable bioorthogonal chemical reporters for the labeling of proteins and complex glycans, nucleic acids have not yet been tagged by SPSAC. Evaluation of SPSAC kinetics with model substrates showed fast reactions with cyclooctyne probes (up to k=0.59 M s ), and two different sydnones were effectively incorporated into both 2'-deoxyuridines at position 5, and 7-deaza-2'-deoxyadenosines at position 7. These modified nucleosides were synthetically incorporated into single-stranded DNAs, which were successfully postsynthetically labeled with cyclooctyne probes both in vitro and in cells. These results show that sydnones are versatile bioorthogonal tags and have the premise to become essential tools for tracking DNA and potentially RNA in living cells.
Sydnones 是高度稳定的介离子 1,3-二极体，可通过应变促进的 sydnone-alkyne 环加成 (SPSAC) 与环辛炔反应。尽管 sydnones 已被证明是蛋白质和复杂聚糖标记的有价值的生物正交化学报告物，但核酸尚未通过 SPSAC 进行标记。使用模型底物评估 SPSAC 动力学表明，与环辛炔探针的反应非常迅速（高达 k=0.59 M s），并且两种不同的 sydnones 有效地分别在 5 位和 7 位掺入到 2'-脱氧尿苷和 7-脱氮-2'-脱氧腺苷中。这些修饰的核苷被合成掺入到单链 DNA 中，这些 DNA 可以在体外和细胞内成功地用环辛炔探针进行后合成标记。这些结果表明 sydnones 是多功能的生物正交标签，并且有可能成为在活细胞中跟踪 DNA 甚至 RNA 的重要工具。
