Biotin as a Reactive Handle to Selectively Label Proteins and DNA with Small Molecules

Here we report the reaction between biotin and azide-labelled oxaziridine reagents in aqueous conditions at room temperature. This method, which we call biotin redox-activated chemical tagging (BioReACT), achieves efficient and stable labelling of proteins with oxaziridine reagents. We functionally validate the method by generating an antibody-drug conjugate and numerous flow-cytometry reagents. Finally, we conjugate a functional click handle to a biotinylated oligonucleotide. These studies show that the biotin–oxaziridine reaction is a powerful approach for the efficient synthesis of stable protein and DNA bioconjugates.