Abstract:
A multifunctional reagent based on a coumarin scaffold was developed for derivatization of naive RNA.
The alkylating agent N3BC [7-azido-4-(bromomethyl)coumarin], obtained by Pechmann condensation, is selective for uridine. N3BC and its RNA
conjugates are pre-fluorophores which permits controlled modular and stepwise RNA derivatization.
The success of RNA alkylation by N3BC can be
monitored by photolysis of the azido moiety, which
generates a coumarin fluorophore that can be excited with UV light of 320 nm. The azidocoumarinmodified RNA can be flexibly employed in
structure-function studies. Versatile applications
include direct use in photo-crosslinking studies to
cognate proteins, as demonstrated with tRNA and
RNA fragments from the MS2 phage and the HIV
genome. Alternatively, the azide function can be
used for further derivatization by click-chemistry.
This allows e.g., the introduction of an additional
fluorophore for excitation with visible light
