Synthesis of a Peptidoyl RNA Hairpin via a Combination of Solid-Phase and Template-Directed Chain Assembly
Jennifer Bremer, Christian Richter, Harald Schwalbe, Clemens Richert
Peptidoyl RNAs are the products of ribosome-free, singlenucleotide translation. They contain a peptide in the backbone of the oligoribonucleotide and are interesting from a synthetic and a bioorganic point of view. A synthesis of a stabilized version of peptidoyl RNA, with an amide bond between the C -terminus of a peptide and a 3'-amino-2',3'-dideoxynucleoside in the RNA chain was developed. The preferred synthetic route used an N -Teoc-protected aminonucleoside support and involved a solution-phase coupling of the aminoterminal oligonucleotide to a dipeptido dinucleotide. Exploratory UV-melting and NMR analysis of the hairpin 5'-UUGGCGAAAGCdC-LeuLeu-AA-3' indicated that the peptidelinked RNA segments do not fold in a cooperative fashion. The synthetic access to doubly RNA-linked peptides on a scale sufficient for structural biology opens the door to the exploration of their structural and biochemical properties.