title: Leucyl/phenylalanyl(L/F)-tRNA-protein transferase-mediated aminoacyl transfer of a nonnatural amino acid to the N-terminus of peptides and proteins and subsequent functionalization by bioorthogonal reactions.
abstract: We report here a new strategy for derivatizing peptides and proteins at the N-terminus. To achieve this, a nonnatural amino acid was charged onto a tRNA and then enzymatically transferred to a lysine (Lys) unit at the N-terminus of a peptide or a protein by using L/F-tRNA-protein transferase. By using the chemoenzymatic technique, beta-(2-quinolyl)-L-alanine, p-azido-L-phenylalanine, and p-acetyl-L-phenylalanine were introduced to the N-terminus. The latter two nonnatural amino acids possess bioorthogonal functional groups to which artificial tags can be introduced. Actually, a biotin tag was coupled to the bioorthogonal ketone group of acetylphenylalanine at the N-terminus of a peptide. N-terminal-specific biotinylation and fluorescence derivatization of the bioorthogonal azido-containing protein or peptide was also carried out based on a [3 + 2] cycloaddition. The enzymatic transfer of a nonnatural amino acid to the N-terminus of target peptides or proteins was also successfully achieved in the presence of other peptides or crude protein mixtures.
authors.affiliation: Department of Bioscience and Biotechnology, Faculty of Engineering, Okayama University, 3-1-1 Tsushimanaka, Okayama, Japan. taki@biotech.okayama-u.ac.jp
authors.forename: Masumi
authors.initials: M
authors.lastname: Taki
authors.forename: Masahiko
authors.initials: M
authors.lastname: Sisido
mesh_terms: D041721:3T3-L1 Cells; D019881:Aminoacyltransferases / Q000378:metabolism*; D000818:Animals; D066298:In Vitro Techniques; D051379:Mice; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D014176:Protein Biosynthesis; D011506:Proteins / Q000737:chemistry*
chemical_list: D010455:Peptides; D011506:Proteins; D019881:Aminoacyltransferases; C021511:leucyltransferase