2021-07-19Zeitschriftenartikel DOI: 10.1002/bip.23466
Toward conditional control of Smac mimetic activity by RNA‐templated reduction of azidopeptides on PNA or 2′‐OMe‐RNA
Oligonucleotide templated reactions can be used to control the activity of functional molecules based on the presence of a specific trigger sequence. We report an RNA‐controlled reaction system to conditionally restore the N‐terminal amino group and thus binding affinity of azide‐modified Smac mimetic compounds (SMCs) for their target protein X‐linked Inhibitor of Apoptosis Protein (XIAP). Two templated reactions were compared: Staudinger reduction with phosphines and a photocatalytic reaction with Ru(bpy)2(mcbpy). The latter proved faster and more efficient, especially for the activation of a bivalent SMC, which requires two consecutive reduction steps. The templated reaction proceeds with turnover when 2′‐OMe‐RNA probes are used, but is significantly more efficient with PNA, catalyzing a reaction in the presence of low, substoichiometric amounts (1%‐3%, 10 nM) of target RNA.