Patent ID: 7915025

Claim:
A translation system, comprising: a nucleic acid comprising a selector codon, wherein the nucleic acid is homologous to a nucleic acid encoding an insulin-like growth factor (IGF); an unnatural amino acid, wherein the unnatural amino acid is a tyrosine analogue or a phenylalanine analogue; a tyrosyl orthogonal tRNA (OtRNA) that recognizes the selector codon; and, an orthogonal aminoacyl tRNA synthetase (ORS) wherein the ORS is derived from a tyrosyl synthetase and wherein the ORS comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 35-66; wherein the ORS preferentially aminoacylates the OtRNA with the unnatural amino acid; wherein a K m of the ORS for the unnatural amino acid is lower than for any naturally occurring amino acid; wherein a k cat of the ORS for aminoacylation of the OtRNA with the unnatural amino acid is higher than aminoacylation of the OtRNA with any naturally occurring amino acid; and wherein the translation system translates the nucleic acid into a polypeptide, incorporating the unnatural amino acid into the polypeptide in response to the selector codon.