Acridine-Labeled Primers as Tools for the Study of Nonenzymatic RNA Oligomerization

Article abstract of DOI:10.1002/hlca.19980810528

Short, dye-labeled oligonucleotides have been used as primers in template-controlled polymerization reactions of RNA. The synthesis of appropriate acridine derivatives and their attachment to nucleic acids is described. In the nonenzymatic oligomerization of 2-methyl-1H-imidazole-activated guanosine 5′-monophosphate, two observations deserve special notice: 1) reaction rates are almost unchanged by variations of the Na⁺ concentration; 2) the conformational type of the primer-template duplex (A vs. B) has considerable influence on the rates and yields of RNA oligomerization. When the incorporation of cytidine was studied in the presence of 1M Na⁺ or K⁺, the process was almost inhibited by quadruplex formation of the oligo-dG template. However, if these cations were omitted, an efficient primer extension could be observed using template concentrations as high as 100 μM. The chances for nonenzymatic self-replication of RNA thus might be distinctly better than previously assumed.