One of the most challenging requirements associated with combinatorial chemistry is the recovery of sequence information of the oligonucleotide or peptide selected by the screening assay. A method1 has been developed to generate a fusion product between mRNA and the polypeptide it encodes using in vitro translation of synthetic RNAs 3’-labeled with puromycin, an antibiotic that mimics transfer RNA. Puromycin binds in the ribosome’s A site, forms a peptide bond with the growing peptide chain, and blocks further peptide elongation. By linking puromycin to mRNA, a peptide-RNA fusion product results from the translation of the message linking the encoding mRNA with its peptide product.
(1) R.W. Roberts and J.W. Szostak, Proc. Natl. Acad. Sci. USA, 1997, 94, 12297-302.