title: Synthesis of novel unnatural amino acid as a building block and its incorporation into an antimicrobial peptide.
abstract: Considering the biological mechanism and in vivo stability of antimicrobial peptides, we designed and synthesized novel unnatural amino acids with more positively charged and bulky side chain group than lysine residue. The unusual amino acids, which were synthesized by either solution phase or solid phase, were incorporated into an antimicrobial peptide. Its effect on the stability, activity, and the structure of the peptide was studied to evaluate the potential of these novel unnatural amino acids as a building block for antimicrobial peptides. The incorporation of this unusual amino acid increased the resistance of the peptide against serum protease more than three times without a decrease in the activity. Circular dichroism spectra of the peptides indicated that all novel unnatural amino acids must have lower alpha helical forming propensities than lysine. Our results indicated that the unnatural amino acids synthesized in this study could be used not only as a novel building block for combinatorial libraries of antimicrobial peptides, but also for structure-activity relationship studies about antimicrobial peptides.
authors.affiliation: Protein Chemistry Laboratory, Mogam Biotechnology Research Institute, Yongin-City, Kyunggi-Do, South Korea.
authors.forename: J E
authors.initials: JE
authors.lastname: Oh
authors.forename: K H
authors.initials: KH
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry*; D000818:Animals; D000890:Anti-Infective Agents / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology; D000935:Antifungal Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D002942:Circular Dichroism; D020650:Combinatorial Chemistry Techniques; D006207:Half-Life; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: D000596:Amino Acids; D000890:Anti-Infective Agents; D000935:Antifungal Agents; D009842:Oligopeptides