Chloroacetamide‐Modified Nucleotide and RNA for Bioconjugations and Cross‐Linking with RNA‐Binding Proteins

Reactive RNA probes are useful for studying and identifying RNA‐binding proteins. To that end, we designed and synthesized chloroacetamide‐linked 7‐deaza‐ATP which was a good substrate for T7 RNA polymerase in in vitro transcription assay to synthesize reactive RNA probes bearing one or several reactive modifications. Modified RNA probes reacted with thiol‐containing molecules as well as with cysteine‐ or histidine‐containing peptides to form stable covalent products. They also reacted selectively with RNA‐binding proteins to form cross‐linked conjugates in high conversions thanks to proximity effect. Our modified nucleotide and RNA probes are promising tools for applications in RNA (bio)conjugations or RNA proteomics.