121st General Meeting of the KCS

Type Poster Presentation
Area Organic Chemistry
Room No. Event Hall
Time 4월 19일 (목요일) 11:00~12:30
Code ORGN.P-530
Subject Single Atom Mutation of a β-peptide Foldamer to Change Sidechain Orientation
Authors Byung-Chang Oh, Eun-young Yoon1, Jintaek Gong2, Hee-Seung Lee*
Department of Chemistry, Korea Advanced Institute of Science and Technology, Korea
1Korea Research Institute of Chemical Technology, Korea
2Natural Science Research Institute, Korea Advanced Institute of Science and Technology, Korea
Abstract Foldamer is an appropriate non-biological analogue of biomacromolecular structure, since the folded geometry of which is determined by its backbone and sidechains. Hence controlling the residue distribution is important fundamental study for foldamer design. In this work, we have changed the sidechain orientation in β-peptide foldamer series by a single atom mutation. A cyclic β-amino acid ATC ((R,R)-4-aminotetrahydrofuran-3-carboxylic acid) was prepared as an oxygen-containing analogue of (S,S)-ACPC. With these two building blocks, a series of hexapeptide foldamer containing one ATC and five ACPC residues was synthesized. While all six foldamers maintain 12-membered helix in both solid and solution state, only four entities that contain their ATC residue at the certain position showed the distinct conformation having triangular sidegroup distribution in the single crystal state. By comparison of the foldamer crystal structures, we could suggest a hypothesis that relates the effect of ATC on foldamer scaffold and the condition to induce such 'helix-releasing' phenomena. That is, an introduction of a single oxygen atom instrad of a carbon increases the dihedral angle θ at the residue, and a foldamer that has θ larger than a certain threshold distorts its backbone. This study can provide a rational guideline to predict a foldamer's exact secondary structure from its sequence information, which will be crucial for utilizing the peptide foldamers.
E-mail august15@kaist.ac.kr