Recent Advances in In Vitro Translation and Selection of Bioactive Nonstandard Peptides

摘要

The translational tolerance of ribosome enables the introduction of diverse chemical functions beyond those of the 20 proteinogenic side chains to proteins. To accomplish mRNA-lemplaled synthesis of nonstandard amino acid (nsAA)-containing polypeptides, assignment of the nsAA in the codon table by the deliberate misacylation of tRNA is the most critical step.' In this regard, flexible in vitro translation (FIT) system has shown an innovative approach for codon vacation and reassignment by utilizing promiscuous aminoacylation ribozymes, the so-called fiexizymes.2 Flcxizymcs are sophisticaledly engineered artificial aminoa-cyl tRNA synthetases that can recognize virtually any nsAAs and charge them onto any tRNAs, allowing the use of multiple codons to incorporate multiple nsAAs."' The FIT system combined with the high tolerance of ribosome has facilitated extensive genetic code reprogramming so that hundreds of uncommon polypeptide substrates could be produced by the protein translation machinery.