Traceless Staudinger Ligation for Bioconjugation of RNA

Staudinger ligation is an attractive bioorthogonal reaction for use in studying biomolecules due to its capacity to form a native amide bond between a tag and a biomolecule. Here, we explore the traceless variant of the Staudinger ligation for 3'-end modification of oligoribonucleotides. The procedure involves (i) synthesis of phosphine-containing reactive groups, affinity purification tags, or photoactivatable benzophenone probe, (ii) synthesis of 2'-azido dinucleotides and 24-nt RNA, and (iii) traceless Staudinger ligation experiments. Each phosphine was characterized by ¹ H, ¹³ C, and ³¹ P NMR and high-resolution spectrometry and the functionalized nucleotides were characterized by LC/MS. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Synthesis of phosphines Basic Protocol 2: Synthesis of dinucleotides 4 and 5 Basic Protocol 3: Synthesis of modified RNA 6 Basic Protocol 4: Traceless Staudinger reactions on a dinucleotide Basic Protocol 5: Traceless Staudinger reaction on RNA.