Site‐specific incorporation of photofunctional nonnatural amino acids into a polypeptide through in vitro protein biosynthesis

Nonnatural amino acids with photofunctional groups were incorporated site-specifically into a polypeptide by using in vitro protein synthesizing system. The nonnatural amino acids were attached to tRNA(CCU) through chemical misacylation method, and added to the in vitro system with a mRNA containing a single AGG codon. L-p-Phenylazophenylalanine, L-2-anthrylalanine, L-1-naphthylalanine, L-2-naphthylalanine and L-p-biphenylalanine were successfully incorporated into a polypeptide, but l-1-pyrenylalanine was not. The polypeptides containing the nonnatural amino acids showed photofunctionalities.