Peptide-Oligonucleotide Conjugates: Catalytic Preparation in Aqueous Solution or On-Column.

Peptide-oligonucleotide conjugates (POCs) are synthesized through a novel catalytic and sustainable approach. The amide coupling between peptide and oligonucleotide is facilitated by 1,4-diazabicyclo[2.2.2]octane (DABCO) as catalyst and 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) as a stoichiometric activating agent. Two distinct methods are described for the POC synthesis: the first involves an on-column conjugation in an anhydrous environment, while the second enables a post-synthetic conjugation in an aqueous buffer. This last approach has been successfully extended to an iterative process, offering significant potential for the development of DNA-encoded libraries.© 2025 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: On-column conjugation of an amino acid or of a peptide to an oligonucleotide Support Protocol: Deprotection of the Boc-protected amine of the lysine Basic Protocol 2: In-solution conjugation of an amino acid or of a peptide on an oligonucleotide Basic Protocol 3: Iterative process for the preparation of a peptide-oligonucleotide conjugate.