title: Ribosomal Synthesis of Peptides with Multiple β-Amino Acids.
abstract: The compatibility of β-amino acids with ribosomal translation was studied for decades, but it has been still unclear whether the ribosome can accept various β-amino acids, and whether the ribosome can introduce multiple β-amino acids in a peptide. In the present study, by using the Escherichia coli reconstituted cell-free translation system with a reprogramed genetic code, we screened β-amino acids that give high single incorporation efficiency and used them to synthesize peptides containing multiple β-amino acids. The experiments of single β-amino acid incorporation into a peptide revealed that 13 β-amino acids are compatible with ribosomal translation. Six of the tested β-amino acids (βhGly, l-βhAla, l-βhGln, l-βhPhg, l-βhMet, and d-βhPhg) showed high incorporation efficiencies, and seven (l-βhLeu, l-βhIle, l-βhAsn, l-βhPhe, l-βhLys, d-βhAla, and d-βhLeu) showed moderate incorporation efficiencies; whereas no full-length peptide was produced using other β-amino acids (l-βhPro, l-βhTrp, and l-βhGlu). Subsequent double-incorporation experiments using β-amino acids with high single incorporation efficiency revealed that elongation of peptides with successive β-amino acids is prohibited. Efficiency of the double-incorporation of the β-amino acids was restored by the insertion of Tyr or Ile between the two β-amino acids. On the basis of these experiments, we also designed mRNA sequences of peptides, and demonstrated the ribosomal synthesis of peptides containing different types of β-amino acids at multiple positions.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Nagoya University , Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
authors.forename: Tomoshige
authors.initials: T
authors.lastname: Fujino
authors.affiliation: Department of Chemistry, Graduate School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, 113-0033 Tokyo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Goto
authors.affiliation: Department of Chemistry, Graduate School of Science, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, 113-0033 Tokyo, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Suga
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Nagoya University , Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Murakami
mesh_terms: D000215:Acylation; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D012270:Ribosomes / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D010455:Peptides