Further Probing of Cu2+-Dependent PNAzymes Acting as Artificial RNA Restriction Enzymes.

摘要: Peptide nucleic acid (PNA)-neocuproine conjugates have been shown to efficiently catalyse the cleavage of RNA target sequences in presence Cu2+ ions a site-specific manner. These artificial enzymes are designed force formation bulge target, sequence which has be key catalytic activity. Here, we present further investigation into action Cu2+-dependent PNAzymes with respect dependence on composition 3- and 4-nucleotide systems. were clear preference for bulges, as 3-nucleotide bulge-forming was significantly slower, is illustrated by shift half-lives from approximately 30 min 24 h. Nonetheless, nucleotide preferences at different positions displayed similar trends both Moreover, site probed introducing critical chemical modifications one nucleotides fastest cleaved bulge. Namely, exclusion exocyclic amine central adenine replacement 2′-hydroxyl nucleophile 2′-H or 2′-OMe substituents severely diminished rate PNAzyme, giving insight mechanism cleavage. shorter recognition arm RNA/PNAzyme complex modified extending PNAzyme two additional nucleobases. The new able promote when fully hybridised longer even outperform previous PNAzyme. improvement demonstrated studies stoichiometric amounts either present, extended also give turnover 10-fold excess target.