CEBA: A new heterobifunctional reagent for plasmid DNA functionalization by click chemistry

Here, we report the synthesis of 3,6,9-trioxaundecan-1-{4-[(2-Chloroethyl)Ethylamino)]-Benzylamino},11-Azide (CEBA). CEBA alkylates the N7 of guanine of DNA thanks its chloroethyl group and can be coupled by a strain-promoted azide-alkyne cycloaddition to an alkynylated molecule. The optimization of the alkylation level of pDNA reveals that the expression of the encoded gene is preserved when it is randomly modified with at most 1 CEBA molecule per 150 bp. We show that the azido group of CEBA allows the linkage via click chemistry of CEBA-pDNA with a fluorophore or a peptide containing a dibenzocyclooctyne (DBCO) function. This new heterobifunctional reagent opens new ways to equip pDNA easily with signal molecules including peptides and nucleic acids without side products providing great interest for non-viral gene therapy.