Muranaka, N., Hohsaka, T. and Sisido, M.
Notes: The authors devised an mRNA display system to generate a peptide library with multiple nonnatural amino acids incorporated into the proteins, an important feature of peptide libraries for successful drug discovery. An mRNA with 3 four-base codons at a random position was used as a template in an in vitro translation system in the presence of charged tRNAs carrying four-base codons. In vitro translations were performed using 3.6 × 1013 molecules of mRNA template and the E. coli S30 Extract System. The mRNA template contained a T7 tag sequence, so the translation products could be detected using an anti-T7 tag antibody and the Anti-Mouse IgG (H+L), AP Conjugate. The mRNA-displayed peptides also incorporated a polyhistidine tag so that they could be purified using the MagneHis™ Ni-Particles. After selecting for the desired protein characteristic, the mRNA portion of the mRNA-displayed peptides was reverse transcribed and quantitated by real-time PCR. PCR products were cloned into the pGEM®-T Vector prior to sequencing. (3651)